okay let's get into magnetic properties which are going to be determined by the number of unpaired electrons and the D orbitals of the metal ion and what are magnetic properties we're basically going to be properties based on the magnetic fields that these lians are bringing in as they are attracting to our metal ion so we have our D orbitals here and we know that those D orbitals are going to split based on crystal field Theory to higher level D orbitals which are EG and Lower Level D orbitals which are t2g and that splitting is going to have a crystal fill splitting energy which we symbolize as Delta and we also know that these ligans especially since we're dealing with something that's going to be octahedral these ligans are going to be of course bringing their own electrons to form that coordinate coal Bond and so since they're bringing their own electrons these electrons can be paired um or they can be unpaired so if we see them as paired then we know that that then the electrons are going to be in anti-parallel meaning they're in different orientations so we have one spinning up and one spinning down and of course when they are unpaired then they're going to be in the same parallel orientation and so when it comes to magnetic properties that's going to be very important whether or not the electrons in the split D orbitals are paired or unpaired and if they are that's going to produce attractive or repulsive forces so how do we apply magnetism to complex ions well all going to be based on the number of electrons in the D orbitals so let's just say that we have four electrons in the D orbitals here and then we have our six liens because we usually you're dealing with octahedral they're going to start attacking um these three orbitals or approaching the de orbitals to form these coordinate pent Bond and when they do they split to have the higher D orbitals here and the lower D orbitals here so based on H rule just like we normally do we're always going to start filling up the lower electron or sorry the lower energy orbitals first so let's go ahead and start filling them up we have four electrons to work with so we just go one 2 3 now the question become does the fourth electron go here okay or it's that one does the fourth electron go here and you might be thinking well obviously it goes up to the one at the top because that's what we're used to for um our main group elements but with complex ions we do see that there are actually two different ways that the electrons can actually fill these orbitals so in complex ions as we see we have an example of four electrons here in our D orbitals that are supposed to be filling up these lower and higher G orbitals so in complex ions when filling up our D orbitals they can be filled in two ways they can either be filled where the fourth electron goes to the higher energy level so we go one two three and then four or that fourth electron pairs up in the lower energy LEL so we go 1 2 3 4 and the question always becomes well why well it has to do with the crystal field splitting energy that's number one so it has to do with the crystal field splitting energy which we know is between these orbitals we also see it here as well and we also see it here as well and now it also has to do with the electron um pairing repulsion so we know when we have electrons that are in orbitals they're going to repel one another and there's also going to be energy associated with that repulsion so we call that electron parent energy and our Crystal fi splitting energy that's going to influence whether or not um we are going to either fill up the fourth electron in the higher energy level or fill up the fourth electron in the lower energy level and really the size of the actual um the pairing energy or the Delta is going to really determine if they will be paired or unpaired um in the magnetic Behavior so we'll be basically seeing that next as well but I do want to talk about if we did have our um lower let's say we had our lower energy D orbitals all paired up they will be considered diamagnetic diamagnetic because there's going to be no unpaired electrons and also if we had any type of electrons that are going to be by themselves are unpaired so at least if we have one at least one unpaired electron we are going to be paed L okay and what does this really mean it means that we have electrons that are spinning in opposite directions um when they're paired up and then they're going to be spinning in One Direction when they're unpaired and so when they're spinning in opposite directions they actually are going to be weakly affecting that magnetic field that the lians are bringing on to the D orbitals but when they are unpaired they actually are going to be attracted to the magnetic field and so that's going to cause different repulsive forces and attractions and so therefore that's going to cause different magnetism and so if you are paramagnetic you have the ability to probably be attracted to something to even CA different types of bonding and whether or not we have a complex ion that's going to be paramagnetic or diamagnetic just depends on how the electrons are being filled here okay inside these D orbitals which of course is based on the repulsion pairing and also the crystal fi energy so let's put this all into context okay how do we connect liens oxidation state and magnetism all together well how do we do that we classify them even more so you see how we definitely have um Crystal field energy being involved here well we know ligans are going to help us control that Gap so we actually get to connect liance to how um these electrons are pairing up or not now we want to use our relationship of electron PA repulsion energy and Crystal fill energy to help us understand how weak field and strong fi lians connect to fill and deep orbital electron and therefore help us understand magnetism in octal Geometry so let's go ahead and use our 4D orbital electrons as an example like we did before so we're going to fill our lower energy electrons um in this weak field Li in here and we know what a weak field Li in they have a very small Delta or Crystal field so when you have your fourth electron instead of pairing it up it's going to want to jump to a higher orbital why because it's easier to overcome this Crystal field energy than it is to pair up these two electrons of one another so in this situation the electron pairing energy is going to be greater than the crystal field energy and so we have a situation called high spin High spin simply means complexes that are going to have the maximum number of unpaired electrons and of course if we have unpaired electrons then we are dealing with things that are going to be paired magnetic okay now of course we can have the opposite with strong field liens we know strong fi lians are going to have larger Crystal filled energies okay so when we have our three electrons that we're going to fill in the lower energy one two 3 it's actually easier for us to fill the fourth electron in the and stay in the lower energy orbitals instead of trying to overcome the high large Crystal field energy here so in this situation the electron pairing energy is going to be less than the crystal field energy that's the reason why it's easier with strong field liance to have the ne next electron pretty much fill up the entire lower orbital energies first and we call this low spin low spin because they say in the lower energies they fill them up first and then they go ahead and fill up the high spin or the higher energies okay folks and of course if you have your orbitals here and they're all filled then you're going to have a situation where you're going to be having a diamagnetic compound which is going to be colorless okay so now we can see okay our lians are going to help us control our Crystal field energy the crystal field energy is going to help us understand if we're going to have high spin or low spin meaning if we're going to have high Spin and fill up all of the orbitals first before we pair them or if we're going to have low spin and make sure we pair the lower energy um orbitals first before we go ahead and move up to the higher energy so really we have Lian the oxidation states which is basically going to tell us um how many orbitals to fill up in these D orbital how many electrons to fill up in these G orbitals are all going to come from the oxidation state so lians oxidation state and paramagnetism all influence color which is why christophi theory is so powerful so let's go ahead and get into some examples to make even further connections