User:Benjah-bmm27/degree/2/CAR

Transition metals 1, CAR
"Coordination Chemistry of the Transition Metals, Part 1"
 * Review of d-block chemistry

Structure and bonding in transition metal complexes

 * Revision of crystal field theory, which does not explain the spectrochemical series
 * Ligand field theory (application of molecular orbital theory to bonding in complexes)
 * eg* orbitals are antibonding, so when occupied, metal-ligand bonds weaken and lengthen (and substitution rxns happen faster)
 * Stronger metal-ligand interaction raises eg* (and lowers eg), while t2g is unaffected → greater Δo
 * Pi bonding: by symmetry, t2g can and eg and eg* cannot do π bonding, π backbonding
 * π donor ligands – Δo ↓ (weak field ligands)
 * π acceptor ligands – Δo ↑ (strong field ligands)
 * good σ donors – Δo ↑
 * poor σ donors – Δo ↓
 * Metal ligand multiple bonds, such as imido ligands
 * Structural consequences of particular d electron counts
 * Jahn-Teller effect: J-T theorem
 * "any non-linear molecule in a degenerate electronic ground state will undergo a geometrical distortion that removes that degeneracy"
 * for symmetry reasons, tend to get elongation of bonds along z-axis and shortening of bonds in xy plane, so in Cu2+, d9, get (dz2)2(dx2−y2)1
 * Planar-octahedral and planar-tetrahedral equilibria in d8 complexes
 * Lifschitz salts: [Ni(L-L)2]X2 vs. [Ni(L-L)2X2]
 * [NiBr2PEtPh2] brown, square planar, diamagnetic vs. green, tetrahedral, paramagnetic: Acta Cryst. (1992). C48, 406-408
 * Stability constants of complexes

Thermodynamic stability in transition metal complexes

 * Chelate effect
 * Chelation
 * Chelation therapy
 * Macrocyclic effect
 * Template reaction
 * HSAB theory
 * Effects of CFSE
 * Irving-Williams series
 * Redox in transition metal complexes: Co(II)-Co(III) and Cu(I)-Cu(II)
 * Frost diagrams

Application to group 6 chemistry

 * Group 6 elements: Cr, Mo, W
 * Polyoxometallate
 * Dichromate-3D-balls.png