full chapter of coordination compounds firstly let me teach you the basic introduction of coordination compounds consider the D Block elements like iron copper zinc Etc these all are metals we know that Metals love to lose electrons but here the case is opposite I mean these metal elements love to accept a pair of electrons this iron loves to accept a pair of electrons this copper loves to accept a pair of electrons and this zinc loves to accept a pair of electrons here if you ask me why these metal love to accept a pair of electrons I would say it is due to two reasons firstly these metals have empty shell secondly they complete their octet rule to get stability that's why they love to accept a pair of electrons so these Metals except a pair of electrons now let me teach you that how Metals except a pair of electrons well consider a metal atom like copper and a neutral molecule like NH3 this metal atom of copper has empty shell I mean copper can easily accommodate to upcoming electrons on the other hand there is one lone pair of electrons present on nitrogen so NH3 will donate this lone pair of electrons to copper and copper will accept this one pair of electrons hence coordinate bond is found between NH3 and copper we call this compound as coordinate compound because there exist coordination bound between them therefore we Define coordination compounds as the complex compound in which metal atom is bonded to a number of ions are a molecule is called coordination compound let me repeat it the complex compound in which metal atom is bonded to a number of ions are a molecule is called coordination compound remember that this NH3 do not appear of electrons to a metal atom we call it ligand so we Define ligand as any ion or molecule attached to a central metal atom by donating a pair of electron is called ligand just remember that any coordination compound is made up of two parts one part is a metal atom like copper and the second part is elegant like NH3 this noted down all these important points now let me teach you some basic terms of coordination compounds let's consider this coordination compound there are three species and this coordination compound chromium NH3 and chlorine now listen carefully this metal atom of chromium is known as Central atom we know that NH3 do not appear of electrons so it is elegant this 6 means six molecules of NH3 one molecule of NH3 donate one pair of electrons six molecules of NH3 donate six pair of electrons we call this 6 as coordination number remember that coordination number shows the number of pair of electrons donated this chromium NH3 and the square bracket is called coordination sphere or coordination entity this chlorine outside the bracket is called counter ion secondly consider this complex compound here Cobalt is a metal atom and we call it central atom this chlorine is ligand these two is the coordination number of chlorine this NH3 is another ligand and this 4 is its coordination number this whole thing and the square bracket is known as coordination sphere or coordination entity this chlorine outside the square bracket are coordination sphere is called counter ion the snot it down all these basic terms of coordination compounds now let me teach you Warners Theory well Warner is the first scientist who successfully studied coordination compounds he took bulk chloride and he reacted with NH3 after reaction he got Cobalt chloride.6 NH3 secondly he added silver nitrate to cobalt.6 NH3 after reaction he got 3 moles of agcl3 or silver chloride in the form of white precipitate are white PPT now listen carefully Warner Baba thought that three chlorine are weakly are indirectly bonded to Cobalt and 6 NH3 is strongly are directly bonded to Cobalt that's why chlorine love to react with silver so he rearranged this compound he writes the central metal atom of cobalt then he takes NH3 and there are six molecules of NH3 he puts square bracket around these two species finally he writes chlorine and there are three of them so Warner Baba therefore said that 6 NH3 are directly bonded to Cobalt and three chlorine are indirectly bonded to Cobalt he called this compound as coordination compound remember that this is the first coordination compound in chemistry now what is the conclusion of Warner's Theory well Warner Baba states that every metal atom of coordination compounds has two types of valencies primary valency and secondary valency primary valency is Satisfied by negative ion for example here in this coordination compound chlorine is a negative ion it satisfy the primary valency of cobalt while secondary valency is Satisfied by positive ion or neutral molecule for example here in this compound the NH3 is a neutral molecule it satisfies the secondary valency of cobalt secondly primary valency represents the oxidation state of a central metal atom while secondary valency represents the coordination number thirdly primary valency is denoted by dots and secondary valency is denoted by line fourthly primary valency is ionizable for example chlorine is ionizable and aqueous solution while secondary valency is not ionizable for example NH3 is directly bonded to Cobalt it is not ionized thus noted down all these important points now how can we calculate primary and secondary valencies of a central metal atom well consider this coordination compounds we have already learned that primary valency is the oxidation number of a central atom and secondary valency is coordination number now in case of this molecule the central atom is Cobalt I am going to find its oxidation state I write Cobalt plus 6 and to NH3 plus 3 chlorine equals zero we know that NH3 is a neutral molecule so its oxidation state is zero and that of chlorine is positive one so I write Cobalt plus 6 into 0 plus 3 into negative 1 equals 0 after calculation I get positive 3 the oxidation state of cobalt is positive 3 so the primary Valencia of cobalt is 3. here we can see that there are 6 ligands of NH3 so the secondary valency of cobalt is 6. secondly in case of this molecule I find the oxidation state of iron I write iron plus 6 and to CN equals negative 4 because the overall charge on this coordination compound is negative 4. we know that the oxidation state of CN is negative 1. I write iron plus 6 into negative 1 equals negative 4 after calculation I get positive 2. the oxidation state of iron is positive 2 so the primary valency of iron is positive 2. here there are 6 ligands of c n the coordination number is 6. so the secondary valency of iron is 6. therefore using this trick we can easily calculate the primary and secondary valencies of a central metal atom now let me teach you the structure of Warner's Theory well consider these four coordination compounds I write Cobalt and hydro 6 lines as the octahedral structure similarly in case of these three compounds I write Cobalt and I draw six lines as the octahedral structure we know that primary valency is denoted by dots and secondary valency is denoted by line now listen carefully these are six molecules of NH3 I draw these six molecules of NH3 around the central atom Cobalt now I take these three ions of chlorine they satisfy the primary valency so I randomly draw three dot lines and I put three chlorine ions around Cobalt remember that you can draw this dotted line in any direction around the central atom secondly and this coordination compound there are five molecules of NH3 I write them around the central atom now one secondary valency is Left Behind so I place one chlorine here remember that this chlorine can fulfill the secondary valency in primary valency of the central metal atom I draw two dotted lines and I place 2 chlorine similarly I write 4 NH3 around the central atom I write here one chlorine and one chlorine here these two chlorine act as a primary valency and secondary valency I draw one dotted line and I write chlorine lastly I write 3 NH3 around the central atom I write chlorine chlorine and chlorine here these three chlorine act as a primary valency and secondary valency now Warner Baba added silver nitrate to each of these coordination compound after chemical reaction he got different amount of products in case of this molecule these three dotted lines mean three chlorine are out of coordination sphere let me repeat it these three dotted lines mean three chlorine are out of coordination sphere this here three moles of silver chloride is formed in this case two chlorine are out of coordination sphere so two moles of silver chloride are formed in this case only one chlorine is out of coordination sphere so one molar silver chloride is formed in case of this coordination compound no chlorine is out of coordination sphere so no silver chloride is formed therefore the structure of this compound is Cobalt nh36 square bracket cl3 the structure of this compound is Cobalt nh35 chlorine square bracket cl2 the structure of this compound is co Cobalt nh34cl2 square bracket CL and the structure of this compound is Cobalt nh33cl3 square bracket so these are the different structures of coordination compounds hence noted down all these structures now we will learn about different types of ligands to learn the types of ligands we must learn intenticity of elegant it is defined as the number of lone pair of electrons donated by elegant is called denticity of elegant for example water can donate one pair of electrons so its denticity is one now there are four types of ligands unidenedate are monodented by dentate impedented and pollutantate unidentate are those ligands which can donate one pair of electrons for example chlorine ion bromine iron cyanide iron carbon monoxide Etc secondly bidentate are those ligands which can donate to pair of electrons for example en remember that en stands for ethane one to diamine we know that E10 is ch2 ch2 dye means to and amines mean nh2 1 2 means at first carbon and at second carbon so this is the structure of e n which we often use in coordination compounds hence noted down the another one is oxalate C double O Negative Bond C double O Negative they can donate two pair of electrons thirdly impedented are those ligands which has two different atoms to donate one pair of electron for example consider scn here sulfur can donate one pair of electrons so it is known as Thai cyanide OS also n has the ability to donate one pair of electrons so it is known as thaisan i2n hence remember that and this molecule both sulfur and nitrogen have the ability to donate one pair of electrons fourthly polidentate are those ligands which can donate many lone pair of electrons like EDTA e d t s stands ethylene diamine Tetra acetate it can donate six pair of electrons so it is a pollutant at the snotted down these four types of ligands now what is homoelectric complex and heteroleptic complex well the complex in which Central metal atom is bonded to only one type of ligand is called homolyptic complex for example consider this complex compound here the central metal atom is iron the ligand is CN and this K is counter ion here there is only one type of ligand c n so it is a homolyptic complex on the other hand the complex in which Central metal atom is bonded to more than one type of ligands is is called heteroleptic complex for example consider this complex compound here the central atom is Cobalt NH3 is one type of ligand and chlorine is another type of ligand there are two types of ligands so it is a hydroelectric complex just note it down this difference between homoelectric complex and heteroleptic complex now let me teach you the nomenclature of complex compounds firstly let me teach you the types of ligands based on charts and their names well on the basis of Charles ligands are neutral anionic and ketanic neutral ligands are NH3 ammonia Nitro cell H2 Aqua Co carbonyl CS dicarbonyl secondly in case of anionic ligands we use the suffix o like CL chloro BR bromo H negative Hydro so negative 2 sulfateo nh2 negative 1 amido nh2 negative 2 Amino n negative 3 isido or negative 2 Oxo Etc thirdly in case of catanic ligands we use the suffix ium like no positive nitrosonium NO2 positive nitronium nh2 Dash NH3 positive hydroxenium here let me teach you one important mcqs remember that nh4 are ammonium ion is not elegant because it has no lone pair of electrons sometime it is asked in mcqs so noted down the names of all these ligands now it is time to learn nomenclature of coordination compounds I use these rules to name any coordination compound I write the name of coordination compound from left to right secondly if there are more than one ligand I follow alphabetic order thirdly if the coordination sphere is negative I put he with Central metal atom now consider this coordination compound firstly I find the oxidation state of central atom I write silver plus 2 NH3 plus c l equals zero the oxidation state of NH3 is 0 and that of chlorine is negative one I write silver plus 2 into 0 plus negative 1 equals 0 I get silver equals positive 1. secondly I find the charge on coordination sphere we know that this chlorine is a negative ion and it carries negative one charge so the charge on coordination sphere is positive one hence the charge on coordination sphere is positive now listen carefully firstly I write the ligand and it is ammonia there are two molecules of ammonia I write di secondly I write the central metal atom it is silver and the oxidation state of silver is one so I write here one thirdly the counter ion is chloride so I get di ammonia silver chloride remember that I capitalize the first letter there is no gap between ligand and Central metal atom but there is a gap between coordination sphere name and counter I name secondly consider this coordination compound as usual firstly I find the oxidation number of the central atom I 8 2K plus nickel plus 4 chlorine equals 0 R 2 and 2 positive 1 plus nickel plus 4 into negative 1 equals zero after calculation I get nickel equals to secondly I find the charge on the coordination sphere we know that potassium is positive 1. hence the charge on the coordination sphere is negative now according to the first rule we go from left to right here I write potassium in case of coordination sphere I write ligand name which is chloro there are four of them I write Tetra secondly the central metal atom is nickel according to the third rule if the charge on coordination sphere is negative we put a t e with Central metal atom so I put at e with nickel the oxidation state of nickel is positive 2 I write here to the Sky gate potassium tetrachloro Nicolette II thirdly consider this coordination compound firstly I calculate the oxidation state of a central metal atom I write iron plus 6 fluorine equals negative 4 because the charge on this coordination compound is negative 4 I write iron plus 6 into negative 1 equals negative 4 I get iron is equal to 2. secondly I find the charge on coordination sphere we can see that the charge on coordination sphere is already given and it is negative 4 now as usual I write the name of ligand fluoro there are six of them I write hexa for iron F E I write Fair the coordination sphere has negative charge I write a t e e the oxidation number of iron is to I write to and lastly I write iron because it has negative 4 charge this is the name of this compound is hexafluoro ferret to iron ion fourthly consider this coordination compound I find the oxidation state of a central metal atom I write chromium plus 4 H2O plus 2 chlorine plus NO3 equals zero we know that H2O is a neutral molecule the oxidation number of chlorine is negative 1 and that of nitrate ion is also negative one I write chromium plus 4 into 0 plus 2 into negative 1 plus negative 1 equals 0 I get chromium equals positive 3. secondly I find the charge on coordination sphere we know that nitrate ion carry negative charge so the charge on coordination sphere is positive now there are two types of ligands water and chlorine I write aqua and chloro and the first position I write Aqua because a comes first NC in alphabetic order now there are four water molecules I write Tetra there are two chlorine ions I write diary the central atom is chromium and its oxidation state is three the counter ion is nitrate that's the name of this coordination compound is Tetra Aqua dichloro chromium III nitrate lastly let me teach you an advanced question name this coordination compound well the oxidation state of cobalt is positive 3 and the charge on coordination sphere is positive now here there are two types of legand chlorine and en I write chloro we have already learned that enas Ethan one to diamine we can see that there are two chlorine ions I write dye secondly there are two en molecule I write here base because tie is already there and die amine I cannot try two times die and the same molecule let me repeat it I cannot try two times die and assay molecule so if there are three molecules of En I will write Trace we can see that Central atom is Cobalt and its oxidation number is 3 e the counter ion is chloride so the name of this compound is dichloro bis Ethan one to diamine Cobalt 3 chloride therefore using this simple trick we can easily name any coordination compound now let me teach you the most difficult topic and the most easy way what is Crystal field Theory well consider a metal atom like iron we know that iron is a d block element I mean Iron has 5 degenerate D orbitals now listen carefully when elegant approach near to the iron the 5 T orbitals of the iron breakdown let me repeat it when elegant approaches near to the iron the 5D orbitals of the iron breaks down now here if I ask you that how these 5D orbitals break down and what happens to them after breaking your answer is simple Crystal field Theory explains the braking or splitting of the 5D orbitals when ligand approach toward them let me repeat it Crystal field Theory explains the breaking or splitting of the 5D orbitals when Legend approached towards them so remember that Crystal field Theory explains the splitting of 5T orbitals after interacting with ligand now let me teach you my personal trick of learning this topic firstly I learned CFT and chips of D orbitals we know that D has 5 degenerate orbitals dxy d y c d x c d x square minus 5 square and DZ Square now try to understand to draw the structure of these five orbitals using this simple trick in case of D X Y I draw x axis and y axis I draw y axis and Z axis then I draw x axis and Z axis then I draw x axis and y axis lastly I draw only Z xa's now we know that the ship of the D orbital is double dumbbell I draw double dumbbell ship between these xays like this now I just draw double dumbbell shape between these xays in case of d x square minus y squared and d z Square this Square always tells me to draw me along the x-axis so I draw one Loop along x axis and another one along Y axis in case of d z squared I draw one Loop along Z axis and I put a ring in the center now we can see that the lobes of the orbitals are between X A's and these three orbitals well the lobes of the orbitals are along xays in these two orbitals here many students do not understand CFT because they do not learn these three points so you must learn these three points in case of octahedral complex ligane approach our attack along xays for example only these two orbitals have lobes along axis so ligand will attack on this side are on this side along xays secondly in case of tetrahedral complex ligand approach are attacked between x-rays for example these three orbitals have lobes between xays so ligand will attack either from this side this side or this side thirdly when ligand attacks on lobes of orbital there is repulsion between them and energy increases let me repeat this important point when we get a take on lobes of orbitals there is repulsion between them and energy increases therefore we conclude that applicants attack along x-axis energy of only d x squared minus y squared and DC squared increases we know that it only happens in octahedral complex secondly if ligand attacks between x axis energy of d x y d y z and dxc increases we know that it only happens in tetrahedral complex summarize this whole concept we say that in case of octahedral complex the energy of these two orbital increases and the energy of these three orbital decreases well in case of tetrahedral the situation is opposite the energy of these three orbital increases and the energy of these two orbitals decreases down all these important points now let me teach you the trick to draw the structures a CFT for octahedral well consider these 5 degenerate D orbitals the average energy of these five orbital increases when ligand approach near the D orbitals a lot of students are confused that y energy of D orbital increases I teach them a very simple example I always say when you are in danger your adrenaline level pumps up and you get ready similarly mainly gain approach toward these orbitals they get excited and their average energy increases remember that I use the term average energy after interaction the 5D orbital split into two sets we have already learned that in case of octahedral complex the ligand approach along xays and the energy of d x square minus y square and DC Square increases while that of d x y d y z and d z d x c decreases and we call these three orbitals as T2 G this is the energy gap between them which we call CFS Crystal field splitting here we can see that the energy of these two orbital increases from the average energy level so I write positive 0.6 Delta secondly the energy of these three orbital decreases so I write negative 0.4 Delta so the value of EG equals positive 0.60 and that of t2g equals negative 0.40 just note it down this diagram of octahedral now let me teach you Crystal field theory for tetrahedral well consider these five degenerate D orbitals the average energy of these orbitals increases when elegant approach nearer them after interaction the 5 T orbital splits into two sets we have already learned that in case of tetrahedral complex ligand approach between x-rays so the energy of d x y d y z d x c increases and that of d x square minus y square and DC squared decreases remember that in case of tetrahedral this is T2 set and this is e set of orbital we do not try G with them secondly this is the energy gap our CFS between these two sets of orbitals thirdly the energy of these three orbital increases from average level it is positive 0.4 Delta and the energy of these two orbital decreases from average level so its value is negative 0.60 Delta thus the value of T2 equals positive 0.40 Delta and that of E equals negative 0.60 Delta therefore using this strike we can easily write CFT for octahedral and tetrahedral complex finally let me teach you my personal trick of vbt and hybridization of coordination compounds which I have already explained in my previous video now consider this coordination compound firstly I find the oxidation state of a central atom I write Cobalt plus 6 NH3 equals positive 3 our Cobalt plus 6 into 0 equals positive 3 I gate Cobalt equals positive 3 so the oxidation state of cobalt is positive 3. secondly I find the number of electrons of cobalt we know that the atomic number of cobalt is 27 now listen carefully I always subtract oxidation state of central atom minus 18 from the atomic number of central atom let me repeat it I always subtract oxidation state of a central atom minus 18 from the atomic number of Central atom here the oxidation state of cobalt is positive 3 so I write Cobalt equals 27 minus 3 minus 18 I get 6 electrons now we can see that here the ligand is NH3 and it is a strong ligand remember that in case of a strong ligand the electrons of the central atom get paired while in case of weak ligand the electrons of the central atom do not get paired no I use the police tray I say DSP doctor we know that D has five orbitals s has one orbital P has three orbitals and D has five orbitals now listen carefully I take the six electrons of central atom and I place it in this D orbital one two three four five six I have paired these electrons because the ligand is strong we can see that there are six ligands of NH3 so I select six completely empty orbitals one two three four five six we know that each ligand can donate one pair of electrons there are six ligands so six ligand will donate six pair of electrons thus I fill D6 orbitals now these two D orbitals this one is orbital and these three p orbitals are hybridized so the hybridization of this compound is D2 sp3 and it is inner orbital complex because inner D orbital is hybridized secondly the geometry of this compound is octahedral thirdly we can see that all the electrons are paired so the magnetic nature of this compound is diamagnetic remember that if electrons are paired it is low spin complex a electrons are unpaired it is a high spin complex fourthly what about magnetic movement well we know that Magnetic Moment mu equals under root n n to n plus 2 here n is the number of unpaired electrons we can see that there is no unpaired electron present so n equals 0 plus I get mu equals 0 bohar Magneton fifthly what about spin multiplicity we know that spin multiplicity is 2s plus one here s is the spin quantum number for every unpaired electron s equals 1 upon 2 here we can see that there is no unpaired electron so s equals 0 I put s equals 0 in this equation after calculation I get 1 so the spin multiplicity of this coordination compound is one if you want to learn more about this stake watch our video and its link is given in the description I hope that you have learned the chapter of coordination compounds