Question

We discussed in class how ligands can affect the A. energy splitting. a. Categorize these complexes by whether their ligands are mainly i acceptors, i donors, or o donors. [Cr(CN)6]4-, [Fe(H20)6]2+, [CO(NH3)6]2+, [Cu(H20).]2+ b. Draw the tag-eg splitting and show the electron count for each complex from part a. Categorize each as high or low spin or write neither if both electron filling methods give the same result. Assume all o and i donors given here are weak-field ligands.

Answer 1

a)-

sigma donors - when coordinated to metal, it forms one single sigma bond.
sigma donor and pi donor - when coordinated it forms one sigma bond and one or more pi bonds. The important thing here is that he pi bond is formed by moving electrons from ligand to orbitals of metal
sigma donor and pi acceptor - the sigma bond is formed as in examples before, but there is donation of electrons from metal to empty pi-anibonding orbital.

so here the ligand is CN ,H₂O , NH₃

CN is a pi-acceptor ligand

H₂O is pi-donor ligand

NH₃ is sigma donor-ligand  

b)-
Answer - ② Tre (HO)] 21 [co CNH J M 2 o-donor I- donor Tor CCN), J4 - acceptor TuCH₂0)], 27 - donar Aegeg splitting for octahedral Complexes 3%A0 dorbitae tra alky dyz dza Cr CCN) cr=[Ar]3ds us! cr2t = [Ar]3d" uso (CN) is strong field ligand per as Quition I arumind it's weak. field ligand. so pairing does not Falak 1 trg

a The CH₂0) Jet 2 fe=[Ar]3d fus? feet - Tar]3d6 고 그 왕 e 11 tag co= Tar] 3 dlus? ③ [Co CNH)] 24 Со 2t Гра) 3d [ ahelth TECH2O)] 27 Cu = BAr]3da us' Cu 2 a Tar] zde AL I eg at a tize low spin (strong field ligands) high spin weak field ligands) TECH₂O)J 27 TUCH₂O) Jet TCONH3) J 25 [cr CCN) J &