sigma-->sigma* Transitions in Mn2(CO)8L2 complexes (L = P-donor ligands): pi-acidity and oxygen pendant group effects in phosphite ligands.

Comparison of the energies assigned to the sigma-->sigma* transitions in bis-axial Mn2(CO)8L2 complexes when L = phosphites and phosphinites with those when L = alkyl and aryl phosphines shows that the oxygen-containing ligands do show effects associated with their pi-acidity. However, the data also strongly suggest that the energies are affected by the presence of the oxygen atoms themselves to an extent that increases linearly with the number of oxygen atoms connected to the P-donor atoms. This "oxygen effect" is analogous to, but distinct from, the aryl effect that is also simply proportional to the number of aryl groups attached to the P-donor atoms.

Electronic and steric effects in fragmentation reactions of Os3(CO)9(mu-C4Ph4).

P-Donor nucleophiles of cone angle >or=145 degrees are known to react with Os3(CO)9(mu-C4Ph4) quite differently from those with cone angles View Article and Find Full Text PDF

(R)-(+)-2,2'-Bis(diphenylphosphinoyl)-1,1'-binaphthyl.

The title compound, BINAP oxide, C(44)H(32)O(2)P(2), (I), was synthesized by direct oxidation of (R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP) with tert-butyl hydroperoxide in toluene solution. The angle between the naphthyl planes of the binaphthyl group is 94.17 (3) degrees.