Draw a crystal field energy-level diagram for the 3d orbitals of titanium in [Ti(H₂O)₆]³⁺]. Indicate the crystal field splitting, and explain why is [Ti(H₂O)₆]³⁺] colored.

Video transcript

All right. Hi everyone. So this question says using crystal field theory provide the splitting energy diagram of chromium three positive in cr cl 63 negative and rationalize why cr cl 63 negative is color. So in this case, the ion in question is hex. So chloro chromate three. Now Hexaco chromate has a central metal ion of chromium three positive as well as six chloride ligands. Now recalled chloride is mono dentate, which means that the co ordination number of this complex is going to be equal to six, which if you recall corresponds to octahedral geometry. Now, octahedral complexes require the use of a specific splitting energy diagram in which we have 3d orbitals that are lower energy, meaning they're on the bottom and two higher energy orbitals at the top. Now the lower energy orbitals are DXY DXZ and DYZ, whereas the higher energy orbitals are DX squared and DX squared subtracted by Y squared. So now the question is to identify the number of D electrons in chromium three positive. So first, let's consider the electronic configuration of chromium as a neutral Arab. Now, chromium, chromium has an atomic number of 24 which if you recall corresponds to 24 protons inside of its nucleus. And so when an atom is neutral, the number of protons is equal to the number of electrons. So in this case, when chromium, when chromium is neutral, the electronic configuration is an argon core followed by four S one and 3d 5 recall, it chromium is an exception to standard electronic configuration because ad orbital would prefer to be half filled rather than having a full s orbital. So now in the case of the electronic configuration of chromium three positive recall that electrons must be removed from the highest energy levels. So in this case, we're removing three electrons, one from the four S orbital and the remaining two from 3d, which means that the electronic configuration of chromium three positive is argon followed by 3D 3. So this means that we have 3d electrons. So in filling out our energy diagram recall that each lower energy D orbital must be filled first before their respective electrons are paired. So in this case, each lower energy de orbital is going to receive one electron. And so that completes our splitting or splitting energy diagram. Excuse me. And so what I want to point out here is that the the higher energy de orbitals are empty, meaning that they can accommodate electrons, should they transition from the lower orbitals or lower energy orbitals to the higher energy ones? So that would explain why hex aloro chromate three is colored right hexaco chroma three is colored because an electron can be promoted to the higher energy the orbitals bye absorbing light in the visible spectrum. Because by absorbing light in the visible spectrum, the electron has gained enough energy to transition or jump, so to speak from the lower energy orbitals to the higher energy one. And so with that being said, thank you so very much for watching and I hope you found this helpful.