Preparation and Stereochemistry of Cobalt(III) Complexes Containing (3S,8S)-3,8-Dimethyl-1,1,10,10-tetraphenyl-4,7-diaza-1,10-diphosphadecane or (4S,9S)-2,4,9,11-Tetramethyl-5,8-diaza-2,11-diphosphadodecane (SS-Me2-mm-PNNP). Molecular Structure of (+)589-Λ-cisβ-[Co(acac)(SS-Me2-mm-PNNP)](ClO4)2·H2O (acac=C5H7O2−)

Two new optically active quadridentate phosphine ligands, (3S,8S)-3,8-dimethyl-1,1,10,10-tetraphenyl-4,7-diaza-1,10-diphosphadecane(SS-Me2-pp-PNNP) and (4S,9S)-2,4,9,11-tetramethyl-5,8-diaza-2,11-diphosphadodecane(SS-Me2-mm-PNNP) and their cobalt(III) complexes, trans-[CoCl2(SS-Me2-pp- or SS-Me2-mm-PNNP)]+, Λ-cisβ-[Co(acac)(SS-Me2-pp-PNNP)]2+ (acac=2,4-pentanedionate ion), Λ-cisβ-[Co(CO3)(SS-Me2-pp-PNNP)]+, and Δ- and Λ-cisβ-[Co(acac)(SS-Me2-mm-PNNP)]2+ were prepared and characterized. The molecular structure and the absolute configuration of (+)589-Λ-cisβ-[Co(acac)(SS-Me2-mm-PNNP)](ClO4)2·H2O were determined by X-ray analysis. Crystal data; monoclinic, C2, a=28.274(4)Å, b=9.266(1)Å, c=11.0901(9)Å, β=92.97(1)°, V=2901.6(5)Å3, and Z=4. Three five-membered chelate rings in the complex form distorted gauche (δλλ) conformations, and the methyl group on carbon of the apically linked chelate ring takes an axial disposition. Stereochemistry of all the complexes was discussed on the basis of the NMR, absorption and CD spectra.