Prelab : 1. Which of the complexes is most likely to be a low-s pin complex? [M(
ID: 949387 • Letter: P
Question
Prelab : 1. Which of the complexes is most likely to be a low-s pin complex? [M(H 2 O) x ] n+ or [M(CN) x ] n+ ?
2. Will Ti 4+ most likely be colored or colorless? Why?
3. Which of the compounds shown below can function as ligands? CH 4 , CH 3 NH 2 , CH 3 OH, CH 3 CH 3
4. How many d-electrons will Fe 3+ have?
5. Which complex of Mn 2+ will most likely be pale in color? It’s high-spin complex or low-spin complex? (First see how many d-electrons Mn 2+ has. Then, write out what the high-spin and low-spin d-orbital configuration will look like. Then decide the answer based on allowed and forbidden transitions).
Explanation / Answer
Strong field ligand complexes are low spin complexes and weak filed ligand complexes are high spin complexes. From [M(H 2O)x ]n+ and [M(CN)x ]n+ ; [M(CN)x ]n+ is a strong field ligand complex, therefore it is most likely be a low spin complex. Ti4+ is colorless. Because the electronic configuration of Ti4+ is 4s03d0 (d-d transition is not possible, so no color is observed.) The compounds shown below can function as ligands: CH3-NH2 , CH3-OH. Because ligands can act as Lewis bases. Ligands have at least one donor atom with an electron pair used to form covalent bonds with the central atom. Number of d-electrons present in Fe3+ is five. (4s03d5) Number of d-electrons present in Mn2+ is five. (4s03d5). High spin electronic configuration is t2g3 eg2. Low spin electronic configuration is t2g4 eg1. Therefore high spin complex of Mn2+ will most likely be pale in color.