Hello everyone, I welcome you all to the amazing platform of Physicswala. So today we are here to discuss a new chapter in our inorganic chemistry that is the coordination compounds. Now we have completed the chapter of D and F block. There is nothing that we have left in the chapter. And I expect from you all that you have also completed the chapter.
complete meresaat kar liya hai humne 8 lecture liye hai usme se kuch lectures chote bhi hai kuch lectures bade bhi hai cheezo ko maine bohot araam se samjhaya hai koi jalt bazi nahi kari hai issi huja se kuch kuch lectures lambe bhi huye hai to beta aapko ek baar pura ka pura lecture dekhna hai saath mein notes banane hai hai na hamesha lecture ko aise hi aapko attempt karna hai aap sirf lecture dekhenge usse lecture nahi complete hota hai hai you have to watch the lecture completely you have to make notes of all the lectures you have to do this till 7th lecture in 8th lecture we had studied about Actinoids and then we discussed our PYQs I had left some PYQs in DPP notes if you feel you have to attempt those questions then you can do it you must have got those questions I can guarantee you that PYQ is present in our notes and you know it too. Correct? So my lovely students, I am going to start the coordination compounds chapter today.
And that is a very good chapter, very wonderful chapter, one of my favourite chapter. Where you don't have to remember anything. I mean you have to remember but there will be a logic behind that.
There will be a concept behind that. So it will be very easy for you to remember. Okay dear?
But... I would like to say one thing here The child who has not read the D and F block chapter will face problems in this chapter You have to read D block If you have not read the F block then I will accept it But if you have not read D block then you will not be able to read it You should know D block completely before coming here And you do not have time You should sit for one day finish 8 lectures in a day there are lectures of 1 hour you have to study only 8 hours if not 8 then 10 hours once you will get all the notes then you just have to read them again and again there are some things to understand like oxidation state paramagnetism I have also explained you the reactions of K-minofor, K2, CR2 that how to balance ok son so let's start today's lecture so son Today we will discuss about the introduction to the chapter What is the introduction of your chapter? You have to learn the basics of this chapter After that we will discuss that to understand this chapter We have some important terms We have some important terminologies We have to learn that one by one So let's start our chapter Now see son First of all I want to talk to you about what? We have some compounds which we call addition compounds.
What do you call them? You have a type of compounds which you call addition compounds. What do you call them? You call them addition compounds.
Now what does addition compounds mean? What do you understand by this word addition compounds? Now let me tell you that.
Addition compounds means that if you have two salts that are connected in some proportion then the thing that is made is called addition compounds now these addition compounds are of two types how many types are there? you have two types one of which is Eko beta aap bolte ho, double salt. What do you call it? You call one as double salt. What do you call it as?
You call it as double salt and you call one as complex salt. Double salt and a complex salt. Now you have to learn what are double salt and complex salt.
Okay, I have moved aside. You will write this much. We have two types of addition compounds.
Addition compounds have a type of salt but now it has some different types one is double salt, one is complex compound and the basic meaning of addition compounds when you have two salts fused in some respective definite proportion means, now we individually talk about them that here we write our double salt here we write our Double salt, here we are writing as double salt and here we will write about our complex salt. About whom dear? About complex salt. Double salt, complex salt. Now, one by one we will discuss about both the things.
So, first of all, what does double salt mean? What do you understand by the simple word double salt? If this happens If this happens When two souls When two souls fuse together When two souls fuse together in a in a Now don't write definite in equal ratio right son if you have two salts see he was saying in definite proportion now you want to fuse two salts but the amount of both salts should be equal if both salts are mixing in equal amount right now what is the meaning of equal amount if you are mixing in equal ratio then what do you call it son it is called double salt right now Let's learn about this first. When two sols fuse together, if you have two sols fusing together in unequal ratio, so what do you call it?
you call it double salt first of all this is the basic definition of these two one says that if you are fused in equal amount and the other one says that you are not in equal amount but in unequal amount means in unequal molar ratio so you call it complex salt now let's come to the next point next point comes to the next point comes to you You are told that these kids get dissociated. These kids get dissociated completely. What happens, son?
These kids get completely dissociated. But these kids cannot do complete dissociation. These kids cannot do complete dissociation.
Now I will show you how to do it and how not to do it. It will be shown to you. Right son? Here always the ratio of ketones and anions that you have it is something like this that you have two ketones, one anion or you have two anions 1 ket Ion will be there.
In this way, what is their ratio? What does this mean? I will explain you now. We will discuss everything point by point.
First of all, you make your table. Because, any question can be asked from here. We will even write here, that every Ion gives its individual test give the Its individual test.
Every ion gives its individual test. test. But here beta does not happen like this. Every ion do not give, every ion do not give beta, do not give individual test, do not give individual test.
First of all, I have written many differences between these two. Now I am going to explain all of these one by one First of all, let's see I have moved aside, you can pause and write Now see, what is the meaning of double salt? Suppose I mix KCL and with that, MGCL2 and if I make a solution of it and make this salt then the salt that comes after making it, its name is KCL dot MgCl2 dot 6H2O this salt most of the kids in their life you must have met this salt once this salt is called carnalite this salt is called carnalite now if you pay attention here I have taken the equimolar ratio of these two what have I taken?
I have taken the equimolar ratio of these two if I and the equimolar ratio of these two so this means that the thing I have is double salt so the compound that you have is called as double salt now what happens now if I dissociate this respective compound if I dissociate it then what all do I get I get potassium, magnesium plus 2 and plus I get Cl negative means I am getting three types of ions here What am I getting here? I am getting 3 types of ions You are getting 2 ket ions and 1 anion So you must have understood what I had written in front of you Right dear children? So you will always see dissociation in 2 ket ions and 1 anion And it will be dissociated in this way that 1 anion which is a part of salt will be completely dissolved like pearls every single ion see that is water of crystallization that is water we are talking about the respective salt constituent ions so every respective salt ion will dissolve in water every ion will be present now how do we know this? because if you believe that you are If you put a reagent in it that wants to react with potassium, it will do it.
If you put a reagent that wants to react with magnesium, it will do it. If you put a reagent that wants to react with Cl-it will do it. Why does this happen?
If I put AgNO3 in it, what is the property of AgNO3? AgNO3 reacts with Cl-and makes you AgCl and what is AgCl? Every child knows that it is white colour PPT Why was AgNO3 able to react with Cl-? Why? Because it broke and you got Cl-ion If they were connected, you wouldn't have got Cl-So, AgNO3 is- it does not give you any ppt so the ppt you got is because every ion is able to give its individual test because you are able to get individual ion every ion gives its individual test every ion gives its individual test this is going fast but no problem, you should understand so first of all I have written this in front of you this is a double salt, all important things whatever reagent you want to add, you add for potassium you will add reagent, you will get test for magnesium you will add, you will get test for silver, you will add nitrate for chloride test, you will get test so what does it mean that all the points which we have written for double solve we have covered all of them here now we will talk about the other respective part now we will talk about the other respective part now what happens?
now we are going to make complex salt now assume that I have taken copper sulphate and I have made its reaction with ammonia so let's make this reaction what will happen? we didn't know, neither scientists know we were not even born at that time now if they mix it, then what will happen? let's see So, as soon as beta is obtained, we get something like this. Copper, ammonia, 4 and then we have SO4.
Here we will write 4. That means now we don't have an equimolar ratio. Now what do we have? No equimolar ratio. Did you write here?
that we have unequal amounts and unequal molar ratio. So, the compound you have is beautiful. From today, whatever you will read in this chapter, you will read for this personality, you will read for this face. This is what you have to read from today.
What is this? This is a complex salt you are going to get. What is this?
This is a complex salt. What is it, son? Complex solve, which you have made. Okay.
So, ma'am, now what is it that when we are going to dissociate it, then what will happen? Have you written anything, ma'am, that it is having an incomplete dissociation? Ma'am, here complete dissociation does not happen.
Incomplete dissociation happens. What does this mean, ma'am? So, let's learn.
Let's learn, son. Come on, copper. Ammonia with four and breaking This is just breaking like this This is not breaking more than this This is not breaking more than this This is just breaking This is not breaking more than this First of all, keep this in your mind very well This is just breaking Now You Next point is there is no complete dissociation.
I had written one more point. What was written here? Every ion does not give individual test. I think that I should put a reagent here.
I think that I should put a reagent here. I put a reagent here. That it reacts with copper. I will put a reagent here. which reacts with copper, then nothing is going to happen.
I think that I should add such a reagent I should add such a reagent which will react with ammonia, nothing is going to happen. And if I think that I should add BACL2 in it then the reaction is going to be with great love. Isn't it? The reaction is going to be with great love. BSO4 is becoming, what is BSO4?
White PPT, what is this? So, now understand, nothing comes out of this respective square bracket, whatever ions are present in it, they remain intact in it. When this respective complex breaks, then it will break in the same way, the one outside the square bracket, that just gets separated, if you have an individual test it if you put any such reagent in this respective solution which wants to react with the respective ion outside then it will do it but if you think that in this square bracket with any thing you want to put any reagent and to get any one of them to react that cannot happen because they are not existing independently so they cannot give any individual test you have to react with copper and you have to do the action it will not happen if you want to react with ammonia it will not happen if you want to react with sulphate it will happen because it is not in the square bracket so remember every iron does not give its individual test this is your next point in the differences between the complex salt and the double salt now first you all will write this much all of you will write this much This is your next point. All the children will write this much.
So, now we will... Now we have to study in this respective chapter. Now we have to study in this respective chapter.
We have to study for this complex compound. We have to study for this complex salt. Isn't it?
We have to study for this complex salt. And from today you are giving a name to this complex salt. You are giving a name to this complex salt.
What name are you giving? Coordination compound. What name are you giving? Coordination compound with which there is a lot of confusion there are many things which we have discussed just now correct, coordination compound first of all we start from here what is coordination compound how it was made, what happened so that is the case now what is it first of all we know what is the theory of making a coordination compound means what is happening inside What is this? There is a present in the middle, there are four ammonia present.
I mean, you all don't understand. Now you see, I just saw this complex. You just saw the copper ammonia complex. Do you remember?
Now see the definition. If I define it, if we define it, we define it like this, when Electron deficient PC which is the metal atom or iron is getting complexated. with electron rich PC which is ligand by forming coordinate bond.
By forming beta coordinate bond. If you have any electron rich PC which is ligand by forming coordinate bond. electron rich species means your metal atom and iron get attached to an electron deficient species then the complex you are going to have you will call it coordination complex what will you call it?
coordination complex and when these are made you will see coordinate bond there how will it look like? only ma'am will explain you right? I am a little bit tired, can you write? Now see what happens, you have a metal, right?
What is this metal? Electron deficient. First of all, this is its basic, you have to keep in your mind what is going on in the coordination compound.
It is attached to whom? Who comes to him? He comes to him with a thing called L, which we call ligand, right?
and this ligand is very electron rich whenever an electron rich species connects with electron deficient species it always has electron pair present it goes and donate this electron pair to metal what is happening here? donation is happening here as a result The complex that you have, it becomes something like this. Coordinate bond always becomes from donor to acceptor. Where does it always come from? It becomes from donor to acceptor.
And this complex that you have, it is basic. Always between electron rich and electron deficient species, the formation of coordinate bond occurs. if it is happening then as a result the thing that will be made we will call it coordination compound what will we call it as a result coordination compounds now you can write this thing this is the basic of what is happening inside what is happening inside like when a mixer is running what happens inside the mixer its blades rotate you have a coordination complex but what is happening inside How it is made, what is its basic?
Now who is metal, who is ligand, we will study all this in future But now we have seen only basic Ok son now come to some important terms first of all it says coordination compounds first of all it has told you the definition of coordination compounds so it says coordination compounds a central atom contain a central atom which is coordinated to a suitable number of anions or neutral molecules this is you have anions and neutral molecules we call them with love we call them with love we call them as legans and if they say central atom or cation we call them with love metal atom and ion called legans are usually the one which retain their identity in the solution as well as in the solid state What does this mean? Here you can add one more thing They retain their identity retain their identity in solid as well as in solid as well as beta solution state. What does this mean? You just learnt that when you made it into salt, when you made it into salt, then also its identity is retained. You put it in solution, tried to break it still its identity is retained you saw that copper and ammonia are not separated we have understood this point so keep this point in mind that they retain their identity whether you talk about their solid state whether you put them in water talk about their solution state they will retain their identity what is the meaning of this word retain their identity this word means this word means that this present you have present hai yeh jo beta aapke paas present hai aapka yeh compound yeh dono ek jusre se alag nahi hongi jaise theh waise hi rahenge yeh baat aap bilkul achche se apne dimaak me bithayenge beta to yeh cheez bhi aapar likhi hai yeh cheez bhi aapar aapke paas likhi hui hai so they retain their identity in the solution state as well as beta in the solid state ap kyahta hai beta ki yeh jo aapke paas complexes hote hai yeh aapke can be negatively charged, positively charged and you can also have neutral see this complex you have what is this?
positively charged what is this? positively charged this complex is positively charged positively charged and this complex you have What is this? This is the negative charge. And this is your complex. It does not have any charge on it.
So, what will you have? Neutral. So, negatively charged, positively charged and the neutral complex. So, you may have any type of complex. Keep this in mind.
First, we have learnt this much. Will we write it? Now, the next thing we need to discuss is now see son, now I will explain you the meaning of everything about every respective important term now you have made this complex copper NH3 4 bracket close and outside what you have is SO4 this is your complex so son First of all, this respective complete part What do we call this respective complete part?
First of all, we call it complex salt What do we call it? We call it complex salt Along with salt, we can also call it an entity Complex entity Inside which you have all the species connected Okay, son? Now what is this thing you have?
The first part of the song is called Central metal, either it can be an atom or an iron. When, how, what will happen, I will explain it to you myself. What can you have?
Central metal atom and iron. Anything can happen from these. The first thing that always present is always, no exception, either it will be a central metal atom or a central metal iron. Keep this in mind. Okay?
then you have these four things these are called as Legans Legans are those which are electron rich species which donate their electron density metal atom now i am just writing electron rich species we have to read a lot about this maybe next lecture will be on legans only so for now legans means electron rich species which donate its electron density to metal atom as i told you earlier ok son, be careful these square brackets these square brackets these square brackets this way your square brackets are called coordination sphere what is called by them? they are called coordination sphere what is called coordination sphere? coordination sphere is the part in which your complex salt's main body is present we will talk about the things inside the square bracket in the whole chapter ok son This is your coordination sphere and this thing present here in these brackets This is called ionization sphere First of all, naming of all things This is called ionization sphere I will tell you about everything in detail Which thing is representing what?
You should know that very well. Okay? Sulfate is written, so what is that part called?
Square bracket is written, so what is that part called? What is written in the square bracket first? What is it called after that? What is it called? Right?
What is called this entire entity? Everything is written in front of you. This is a number.
What is this number called? This number is called Coordination Number This number is called Coordination Number First of all, I have written everything here Now see the definition of everything one by one I have moved aside, you will make it Now first of all coordination entity subse pehle beta coordination entity what do you understand by this word coordination entity kya tha coordination entity ye poori ki poori jo cheez hai complex salt ya fir entity ke baare mein woh baat kar raha hai kaita hai a coordination entity constitutes a central metal atom it constitutes a central metal atom or ion bonded to a fixed number of ions bonded to a fixed number of ions or molecules that are called as ligand that are called as ligands beta like in front of you as an example we will tell you any complex of yours can be like we just wrote copper NH3 4 and this sulphate is a complex entity for you ok then comes central metal atom and ion Then comes, what is central metal atom or what is central metal ion? What is central metal atom or what is beta ion? In a coordination entity, the atom ion to which a fixed number of ions groups are bound in a definite geometrical arrangement around it is called the central atom or ion.
Right? Now, just focus on the central atom. So, what we have to do is that he is telling you that in coordination entity, the atom ion with which the fixed number of ions are attached, ammonia is attached to it.
What will be called? This will be called beta of yours. Central atom or ion. What will be called? Central atom or ion.
Okay. Like you have in your complex, the copper ammonia, four you write, along with sulphate, so he is talking to you about this. Now what comes next?
I have moved aside, you can write. Next thing comes, you have coordination sphere next thing is coordination sphere I have told you coordination sphere what was coordination sphere when we make square brackets these square brackets are called coordination sphere these parts are called coordination sphere these square brackets So we will write the central atom ion and the ligands are attached to it enclosed in square brackets and are collectively termed as the coordination sphere. The part of square bracket we will call it enclosed in square bracket.
So what do we call it? We call it coordination sphere. Everything is written in front of you. Then we write what are counter ions?
Now we write what are counter ions? What do you call as counter ions? Counter ions are the ions present outside the coordination sphere are called as counter ions. Now you have copper, ammonia, and porous.
You had made a complex with SO4. Now if I break this complex, then what do I get? 2 positive plus beta, SO4 2 negative. So whatever beta you see breaking out, what do you call it?
You call it counter ion. You call it counter ion or you can call it ionization sphere. Like I had written in front of you, beta.
like I have written in front of you this is called ionization sphere or you can also call it counter ion you can also call it counter ion this is present outside the coordination sphere you have to make your mind sit in a good way whatever I am saying should go crystal clear in your mind crystal clear so whatever is present outside the square brackets we can also call it counter ion we can also call it ionization sphere we can call both things ok son, be careful to every child ok be careful be careful to every child son you will write this is the part of another example we are following the same example we are following the same example now let's come to the next thing next thing is what do you have? ligands next thing you have is your legions now let's talk about legions what do we call legions they are called a molecule, ion or group that is bonded to the central atom or ion in a complex or coordination compound by a coordinate bond is called a legion each and every word of this respective definition is very important for you such that such definition you can use in your in respective exam Legand is that thing which donate metal to electron by making coordinate bond we call it as Legand is an electron rich species right son we will write it may be neutral, negatively or positively charged so what I told you you have metals right what you have son Legand Ligand donates metal to its electron pair and the compound that you have is made in this way and in this respective coordination compound this L thing we are calling it Ligand what we are calling it? Ligand now see this is neutral negatively charged positively charged we will discuss about this but first we will understand the basic meaning of Ligand right son, first of all we will understand the basic meaning of Ligand ok, now what happens son after knowing this thing after knowing about Ligand now you have to understand about donor atom now you have to know about donor atom an atom of the ligand attached directly to the metal is called the donor atom now understand things very carefully you have M a metal and you say that it is donated by the ligand to the electron pair the electron pair of the ligand is fine but with your metal which atom of the ligand is donating the electron pair he is talking about that he is saying that the oxygen here the oxygen here what is donor atom now ligand is of many types different types of atoms you will see now which atom is there in the ligand which is doing the respective donation hydrogen is not doing any donation here so that is not your donor atom it is a part of the ligand but that is not the donor atom donor atom is that which is directly attached to the metal which itself donates the present electron density that is a donor atom take care son ok every child should be careful they should be directly attached directly attached this should not come out of any child's mind ok yes ma'am next comes coordination number now what is this coordination number now you see you have made complex copper ammonia for and what is next? Sulfate Now, the number you see this number what do we call this number?
this number is called coordination number Coordination number CN of a metal ion in a complex can be defined as the number of ligand donor atoms to which the metal is directly bonded How many donor atoms are there in the ligand? metal ke saath attached hai, mai bol rahi hu, mai phir se bol rahi hu ki number of kitne donor atom ligand ke metal ke saath attached hai, hai naa, kya matlab ma'am, what do you mean by this respective statement, dekho beta, yaha par jo copper hai naa, ek ammonia yaha hai, ek beta, ammonia yaha hai, ek beta, ammonia yaha hai, ek beta, ammonia yaha hai, Ammonia is here, so 1 beta ammonia is here. Now what is happening?
You can see 1 donation here. You can see 1 donation here. You can see 1 donation here.
So you can see 1 donation here. You can see 4 donations like this. How many donations are you seeing? 4 donations. Legand, how many are directly attached?
4 with your central atom just by saying this we cannot end the definition of coordination number in the next chapter we will come across many definitions of coordination number which are tricks I will remind you but for now how many respective ligands are attached either remember this or how many donor atoms are visible in the ligand which are attached to the metal remember that as you like take that definition how much coordination number is there? 4 how much coordination number is there? 4 now we will talk about many things we will talk about coordination number in the next chapter for now we are talking about basic now you have another terminology which is called coordination polyhedron coordination polyhedron now see it is attached to the ligand metal but it is like this It does not attach in any way.
It is present with metal according to a definite geometrical arrangement. Isn't it? It is not that it will be present anywhere. For example, you just saw your complex.
You just saw your complex. Which complex did you see? You saw that it was copper.
What was with it? It was ammonia. How many were there? Four were there.
Two positive. Right? Now, do you know, son, the structure that will be made, right? The structure that is made, it is made like this.
Right? The structure that is made, son, it is made like this. Right?
This thing is fixed. This thing, son, is fixed. And this thing that you have fixed, according to this, its geometrical arrangement, its shape, or suppose its geometry is not decided by me it is decided by itself that it will be present in square planar form I will teach you how to remove it, it will come in the next chapter but for now it will be present like this I cannot make it in any other way they have a definite geometrical arrangement a ligand surrounds metal in a definite geometrical arrangement keep this in mind like you have many types of geometrical arrangement many types of geometrical arrangement like you have first we have seen square planer it is possible that your ligands are arranged in tetrahedral manner with metal in that case ligands will be attached like this how will they be attached? like this attached to it.
Or it can be that it is not tetrahedral but it is trigonal triangular bipyramidal. Or it can be that it is attached in this form. In which form?
Triangular bipyramidal attached to it. M will be in the middle. L will be up. L will be down.
1L here. And 2L here. like this this can be your form which one? triangular by pyramidal triangular by pyramidal like this and around metal it can be present in definite geometry and what else can be there and what you have mainly then one is octahedral right Main beta, what you will see in your syllabus will be these only.
So we will talk about these only. We don't need the rest. By the way, when you study chemical bonding, you study many types of arrangements. But in our chapter, we need only this much.
So different different are your arrangements. Different different are your arrangements that how to make ligand and metal. bonding beta banasakte hai how can we make bonding between metal and ligand will you write son?
all the children will write all will make these are your three geometrical arrangements you have to keep this in mind and all these arrangements you have made these are called coordination polyhedron what do you call it? coordination polyhedron octahedral, square planar triangular bipyramidal, octahedral all of these keep in mind let's move forward so now as you have prepared dnf block very well you have got it i hope so keep in mind that you have to make good command on your coordination it is very easy chapter and scoring too you don't have to give any deal in this chapter of any way this is done now let's move forward Now, let's talk about charge on the complex ion. What is charge on the complex ion? It says, The charge on the complex ion is equal to the algebraic sum of the charges on all the ligands coordinated to the central metal atom.
See, the simple thing is that the complexes that you have, like this is your complex, right? Now you have broken this complex. As soon as you broke this complex, what do you have?
Copper NH3 4 2 positive. Plus, what do you have? SO4. 2 negative this is your complex which charge is there on this complex?
2 positive charge so this is positively charged complex so charge on the complex ion what charge is present on the ion of the complex? 2 positive now let us take one more example as I am telling you you have a complex present K4 Fe Tn6 beta you have a complex of this type now you break it if you break it then how will it break it will break in 4k positive and in which it will break feCn6 4 negative so what is the charge on it negative charge means this is your negatively charged complex ion by the way i have already told you about this although but still Now next what you get is, it can be that you have a complex which has no charge on it that it is neutral. So this can be positively charged, positively charged, negatively charged and even neutral.
Now this thing which is written in the definition, it means you will understand when you will learn to remove the amount of charge on the ligand so I have explained the meaning to you when you will learn then you will be able to understand this definition better now let's come to homoleptic and heteroleptic complexes what does this mean? see it may be that you have inside a complex it may be that you have inside a complex same type of ligands same type of ligands if there is only one type of ligands present then we call it homoleptic complex like this now you have four ammonia present and all four are same all four are ammonia so what will be called homoleptic When you talk about heteroleptic, heteroleptic means a complex in which different types of ligands present. For example, we may have cobalt ammonia for Cl2 positive this is written in front of you so now in this you have four ammonia and you have two Cl negative present that means you can say that you have different type of ligands present okay son this is homo leptin and heteroleptic example. Okay dear, this thing will be taken care of.
homoleptic and heteroleptic. Now let's come again dear. Now you have learned all the basic terminologies of all of them and dear you have learned them very well.
Now you know all these things. Where are the ligands? What are the ligands?
Where are they present? what is coordination sphere and where it is present what is ionization sphere and where it is present what is its meaning what is coordination number what is central metal atom what is complex salt puri ki puri entity so you should know everything very well ok son, now let us move ahead now, what is in this chapter it is said that like the foundation of the house Who takes care of our house? Our mother takes care of our house So, mother is the most important part of our house The most important part of this chapter is Ligands The child who does not know ligands The child who does not know ligands The child who is not understanding That child will have a lot of problems in this chapter In attempting the questions of this chapter So, you have to learn the meaning of ligands very well very well, okay son, so first of all let's discuss every point, a ligand is an ion or a molecule which donates a pair of electrons to the central metal atom or ion to form a coordination complex, you know this definition I have explained to you many times in today's class, so you know this, now next comes son, ligand can be anions, cations and the neutral molecule, ligands can be of any type, anion, cation, neutral, anything Legans are the Lewis bases Lewis bases are those things Lewis bases are those things which are the second name of Lewis bases Electron rich Lewis bases means electron rich who can donate to electron who is electron rich you are rich so you can donate money we are also rich so we are also If you are thirsty, how will you donate to someone else?
So, Lewis bases, i.e. electron rich species are ligands. That's why they can donate their electron density metal very easily. Okay, son?
And central metal atom viewed as a Lewis acid. So, now who are Lewis acids, son? Simple thing is, those who have lack of electrons.
I.e. whatever is electron deficient. Right? Electron pair.
Right? these two things this thing is not here I want it here it should come here ok now what is it the nature of bonding is always changing from the covalent bond to ionic bond in chapter you will understand about this coordinate bond is also called covalent bond coordinate bond is also called as covalent bond so remember in this chapter after covalent bond after long time you will understand about this you will see some changes in bonding so I have written that thing down from now what is the meaning of denticity? I will explain it now I am not telling you now, I will explain it now now see, first of all now learn, ma'am enjoys studying she comes after writing ma'am enjoys studying after writing now see now you say that you are talking about legand we are talking about ligands you have understood the meaning of ligands now we have to classify ligands we have to study different classifications of it what we have to study? different classifications now see how can you classify it? you can classify it on the basis of charge you can classify it first of all On the basis of charge, you can classify it.
Your ligands can be negatively charged, positively charged and neutral. Any of these three types can be classified. you can have any type of type now as I talk to you now as I talk to you first of all let's talk about negatively charged so if your ligand is negatively charged then you can have examples like f negative oh negative right son br negative o2 negative o22 negative o22 negative o22 negative o22 negative o22 negative o22 negative o22 negative o22 negative you have many respective ions present now we are calling all these as legand because you know electron rich species is the way to identify the lowest base either you have negative charge or you have low end base everyone has negative charge everyone is electron rich everyone will be called as legand everyone will be called as legand ok so now you can name it What have you read?
You have read its name. You call it fluoride. You have been reading fluoride since childhood. Hydroxide, what are you reading? Hydroxide, what are you reading?
Bromide, right? Then what are you reading, son? Superoxide, right?
What are you reading, son? Peroxide, we are reading some names like this. But now in this chapter, you will not remember this name. You will remember the name of negatively charged ligand.
the suffix of the letter O in that either you put O or you put IDO now your name will not be written according to your wish or according to what you have read now the naming will be different now the naming will be different either you write it as Floro or you write it as write whatever you like but you can't call it fluoride because we have rules of some ligands we should remember those rules very well if any negatively charged ligand is there then at the end of that write IDO or O otherwise it won't work next one is hydroxide either write hydroxo or write hydroxido or what do you write? hydroxido then what do you write? either write bromo or bromido either write bromo or bromido then what can you write? now you can write super oxido then you write peroxo or peroxido more you will see the name of IDO so now I will tell you according to IDO ok you can write superoxo and paroxo so dear keep all this in mind first of all I have written everything in front of you regarding the negatively charged ligands regarding the negatively charged ligands now the ligand you have what can be that?
they can be positively charged also What can they be? They can be positively charged Like? Like NO2 positive Right? NO positive You can have NH2, NH3 positive Right? Now you have to keep in mind their names Right?
Now this is called Positively charged ligand always has a suffix with the suffix em The suffix always has the letter em You can write it So this is the name of this ligand Nitronium This is called nitrosonium and its name is Hydrazenium whatever name it is, remember it today because it will come in front of you many times it will be repeated many times remember it today ok son positive recharge is done after that now learn which one son? neutral now there is no rule in neutral son that you have to put some suffix but neutral has its own self names right they have their own self names they have their own names like like what you have H2O is water NH3 is ammonia CO is carbon monoxide CS is carbon sulfoxide right now Now you will write these names in some other way You will write this as Aqua You will write this as Amine And with double M Not single M but double M You will call this as Carbonyl And you will call this as Thiocarbonyl This name will be given to you very well. Very well, dear.
So first of all, dear, first of all, the classification I have done in front of you, first of all, the classification I have done in front of you, the first classification is on the basis of Charge. The first classification is on the basis of charge. Now we have, now we have beta.
Now we have the classification on the basis of denticity. Right? On the basis of denticity.
On the basis of denticity beta. On the basis of. Denticity.
Now what is this? Let's learn it. Before learning this, you should know about something which we call Denticity.
I had just given you the definition of Denticity. Right? It was here. What is Denticity? It is defined as the number of ligating atoms present in ligand is called as Denticity.
Ligating, linking. Atoms present in the ligand. Right?
Ligating atoms present in the ligand. How many atoms are there in the ligand which are attached to metal? Right? What should I write?
Density. That was the written definition. Now ma'am will explain in her own way.
Right? What is density? So write it.
Number of, hai na? Number of donor atoms present. Number of donor atoms present.
Present beta in a ligand. Present in a ligand. Number of donor atoms present in a ligand. Which are? Which are?
directly which are directly attached to metal atom. This is the number of donor atoms present in a ligand which are directly attached to the metal atom. Or you can write number of donor sites on ligand if you want to understand in one line then you can understand it like this whatever you like you can take it ok son now what happens now see son the ligands that can be first of all you get unidentate ligand unidentate ligand means monodentate ligand this means that there is only one donor site on the ligand not more than one you will call it monodentate it is written only one donor atom is bonded to the metal or you can say that there is only one donation site on the ligand what is only one donation site like if you read the example F-what is the example F- OH negative Right?
Now you will read the example You read a lot of examples Right? N3 negative Now I will write a lot of examples Now we will just read the classification We will discuss the whole table Right? How much donor site is there? One is negative One is negative One is negative So how much donor site is there? Just one This is called azido Right?
Its structure is this is the structure of the donor site so all have the same donor site so what will be called as mono dentate what is the meaning of denticity how many donor sites are there on the legion one negative charge, two negative charge how many are there now we can see only one so it will be mono dentate it will be like this and nothing else is visible right dear yes mam after mono dentate beta can come di dentate or beta bi dentate he can write anything now what are these? these are those beta in which in one ligand two donor sites are present like I will tell you with an example we have a ligand whose name is ethylene di amine now when I write amine then I write double m Now, if you stick ethylenediamine or any other amine in front of amine, then you will not get double M. double M will not come again double M beta comes only in ammonia double M comes only in NH3 this thing will not come out of any child's mind Ethylene Diamine which we call EN with love every ligand has an abbreviation of Bidentate or Polydentate why we write short form I will tell you that too first you learn the meaning of it Ethylene Diamine see child its structure is like this NH2, PH2, PH2 and NH2 one lone pair and another lone pair now what happens? you have a metal M now you can see first you have this donor site through which you can do bonding with metal see this also see son, ligand means Lewis base you can also get negative charge You may also have a loan pair. How is water a ligand?
Because of loan pair. How is Amine a ligand? Because of loan pair.
Right? How was CO a ligand? It was a loan pair on oxygen. How was CS a ligand? It was a loan pair on sulfur.
We will not say everywhere that only if there is a negative charge, it will be a ligand. The meaning of your electron rich species is either there is a negative charge or a loan pair. So, if there is a negative charge somewhere, then somewhere there can be a loan pair.
Now if you are getting more than one lone pair in any respective ligand then it will be called di-dentate In this case, your Density is 2 because it is saying that you will have two donor atoms present Now you can see that in this respective bonding you can see a ring formation What are you seeing? Whenever you have more than one donor site, you see a ring formation. And whenever there is a ring formation, this phenomenon, this phenomenon, right?
Whenever there is a ring formation, we will call this phenomenon chelation. What will we call it? Say it, we will call it chelation. And this ring form is called chelate ring. What is called a chelate ring?
This is a chelate ring. And how many members are there? How many members are there?
There is one, there are two, there are three, there are four, there are five. How many members are there? This chelate ring you have five members. I am teaching you everything.
You have to listen carefully. Everyone's attention should be on the blackboard. there is ring formation, chelate ring and 5 membered whenever you have bidentate ligand whenever bidentate ligand is present then there will be ring formation because metal is present in between and will connect with donor side So, the ring will be made, the chelation will be done. Right? Now, learn a little about chelation.
About whom, dear? About chelation. What is chelation?
What do you understand by this term chelation? It will come in front of you many times. And it is also a very important term. Chelation means, dear, during. During complex formation.
During beta complex formation. During complex formation between. Right beta? Between.
During complex formation between metal and ligand. If. ring formation occurs if ring formation occurs so it is called chelation okay if ring formation occurs it is called as chelation chelation will be present when dendicity When beta denticity is greater than 1. then only chelation will happen otherwise it can't happen mono dented ligand can never make a ring it will give one arrow to the metal so how can ring formation happen right? keep in mind the size of the ring you have it can be 6 membered it can be 5 membered, 4 membered it can be 3 membered and if we talk about stability if If we talk about stability, then this is the stability order of your ring. This is the stability order of your ring.
This is your stability order of the ring. We don't prefer 3-membered rings. This is the stability order of your ring. I will teach you where it is used.
Okay, the size of the ring is done. And the more in your complex, In complex, the more chelate rings are there, the more stability is there. This thing should be taken into consideration.
Now see this is the meaning of this Now you saw the ring formation, it was a 5 membered ring It is stable, it is considered stable as 4 membered 3 membered ring is considered unstable In the present case, a ring is being formed in front of you You can clearly see the ring is being formed How many members are there? 5 members With ethylene diamine complexation, chelation phenomena you are exhibiting ok ma'am now see we come to the next thing whose name is polydentate ligand what is the name polydentate ligand now the polydentate ligand you have is those who have several donor atoms present many types of donor atoms present not one or two but more than that there are donor atoms present in more numbers so we call it polydentate like you may have tri-dentate, tetra-dentate, penta-dentate now there is no question from tri, tetra, penta so your focus should be on hexa-dentate now your The focus will be like you have Tridentate In which you have three donor sites Three atoms will be there which will be shown to you while donating What can you have? This can be you This can be you Tetraidentate Tridentate can be or you can have tetradentate means what can be on it? four donor sites or you can have pentadentate what can be on pentadentate?
in which you can have five donor sites what can be? you may have 5 donor sites so this way you have all these present but in our boards, these are not the questions that come so you don't have to think about them I will ask you to apply it in which you want to apply don't apply it in this but you should know the meaning I have told you that now what is important for you next that is the hexa dentate now your question will come from here which will come will come from hexadentate. From whom will it come? Now your question will come from hexadentate which will have six donor sites. Now you have a very important example here which we call ethylene which we call EDTA We call it Ethylene Di-Amin See I haven't used double M Remember Ethylene Diamine Tetra Acetate This is your ligand Ethylene Diamine Tetra Acetate So here you have written Nitrogen What is here?
CH2 What is here? CH2 And what is here? Nitrogen Right? This is connected to CH2 C double bond O negative beta this is connected to CH2 C double bond O negative this is connected to beta CH2 C double bond O negative and this is connected to CH2 beta C double bond C double bond O negative now you can see which donor sites are visible here now you will see carefully you will see carefully and you should remember its structure very well see for Ethylene 2 CH2 Ethylene, Di-Amin, 2 Nitrogen Tetra Acetate remember one acetate group 4 acetate groups are formed Ethylene, Di-Amin, Tetra Acetate Ethylene, Di-Amin, Tetra Acetate if you will remember by doing parts like this then it will be easy for you to remember ok my child so one is the donor site on nitrogen so one donor site is done, this is the negative charge this is done one donor site is done, this is the negative charge one is done, you have this now one is the lone pair one is the lone pair so how many donor sites are you seeing here? six okay its structure should be remembered in sleep If I ask you how many donor sites are there in DTA, you will say that there are 6 and then I will say that you should sleep.
Okay, so be careful. Hexadentate means there are 6 donor sites. In one ligand, there are 6 places where you can donate electron density to metal.
Right? Okay, son? Now see, how many chelate rings can it make? Now tell me one thing, how much of this can be made into a chilled drink?
You only have to tell me, right? You will tell me, I will not tell you. You tell me, I am making it, you have to tell me, right son? this is your metal so one arrow is this one arrow is this one arrow is this one arrow is this one arrow is this one arrow is this one arrow is this and one arrow is this these are different types of arrows which are used to electron density donate hotay bhai dikhayi dena hai ek ring, 2 ring, 3 ring, 4 ring, 5 ring kitni chelate rings thi?
puchenge aapse kitni chelate rings thi? EDTA ne metal ke sath bonding kari EDTA ne metal ke sath bonding kari to bhai batao kitni chelate rings thi? Your answer is that ma'am was 5. Right? Be careful.
Yes ma'am. This can be asked from you. Okay? Now if we go to NEET and JEE, then we ask the members of every ring. We don't ask the members in boards, so I am not telling you.
Okay? We don't ask in boards, so I am not telling you the members. Right? Be careful.
now what comes next? now next thing now we will do a question first after that we will move forward now see dear you are given a complex cobalt en whole thrice 3 positive cobalt en whole thrice 3 positive this is a complex now you have to tell how many trilaterings are present in this first of all what is the meaning of en en means ethylenediamine tetra acetate ethylenediamine that's it ethylenediamine now how many present are these? you have 3 present NH2 TH2 TH2 NH2 ethylenediamine you have a complex is made.
Right? Which is written in front of you and this is written in front of you. Now, you have three present. So, the complex which you will make will be made in this way. Right?
That complex will be made in this way. This is how you will make a complex. I will show you one of the parts. you know the bond line structure so this complex is something like this now for the last question of today's class you don't have to worry about this thing where did this ring come from, what is this, what is this name, this EN all this is my work to teach you, you will know all this in the chapter for now I have made a complex in front of you Just tell me how many chelate rings are there in this complex? So your answer should be 3 One is this chelate ring, one is this chelate ring, and one is this chelate ring There are 3 chelate rings Now I am asking you to tell me how many members are there in one ring of these chelate rings Tell me So you are clearly knowing that in one ring how many members are there?
5 members are there how many members are there in one ring? 5 members are present so this question can be asked to you he will give you this structure in front of you and will ask you how many chelate rings are there? how many members are there? so you can tell it very lovingly ok son so now we with this we will end today's lecture and there are many things about ligands that we have to discuss tomorrow which we will discuss tomorrow ok dear so till here whatever introduction I have told you today basic terminology I have told you you have to do them very well if you want then you can also do reading of NCRT as much portion is done till now in respect of that obviously in NCRT many things can be seen less but in NCRT you can see little more you know but if you just want to read definitions then you can read even if you don't read then there is no problem you will write these definitions in your boards but you should know the meaning of everything very well ok son so with this positivity we will end today's lecture thank you so much for attending the lecture