Stereochemical nomenclature for octahedral coordination compounds containing polydentate ligands: a comprehensive proposal.

A universal nomenclature for the stereoisomers of octahedral coordination compounds containing polydentate ligands is hitherto lacking. A proposal for naming such compounds in a systematic and unequivocal way is described. Two skew chelate rings are selected following simple rules, and their helicity is assigned to the complex.

Copper(II) hexaaza macrocyclic binuclear complexes obtained from the reaction of their copper(I) derivates and molecular dioxygen.

Density functional theory (DFT) calculations have been carried out for a series of Cu(I) complexes bearing N-hexadentate macrocyclic dinucleating ligands and for their corresponding peroxo species (1c-8c) generated by their interaction with molecular O2. For complexes 1c-7c, it has been found that the side-on peroxodicopper(II) is the favored structure with regard to the bis(mu-oxo)dicopper(III). For those complexes, the singlet state has also been shown to be more stable than the triplet state.

Reactions of {[Pd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd](&mgr;-SC(6)F(5))}(4).2O(C(2)H(5))(2). Crystal Structures of the Complexes [(Ph(3)P)Pd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd(SC(6)F(5))].1.4CH(2)Cl(2) and [(Ph(3)P)Pd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd(PPh(3))]SO(3)CF(3).2CH(2)Cl(2) and ab Initio MO Calculations on the Model Systems [(H(3)P)Pd(&mgr;-H(2)PCH(2)PH(2))(&mgr;-SH)Pd(PH(3))](+) and [(H(3)P)Pd(&mgr;-H(2)PCH(2)PH(2))Pd(PH(3))](2+).

{[Pd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd](&mgr;-SC(6)F(5))}(4) reacts 1:4 with neutral ligands L to give [LPd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd(SC(6)F(5))] or 1:8 to form [LPd(&mgr;-SC(6)F(5))(&mgr;-dppm)PdL](+) (dppm = bis(diphenylphosphino)methane). These binuclear complexes retain the palladium-palladium bond and the two dissimilar bridging ligands, as demonstrated by the X-ray structural determinations carried out on [(Ph(3)P)Pd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd(SC(6)F(5))].1.