Abstract
Reaction of amorphous molybdenum dichloride with l,2-bis(dimethylphosphino)ethane (dmpe) affords a convenient route to tronj-[Mo(dmpe)2Cl2], while reaction of [Mo(CO)4Cl2] with dmpe leads to the formation of the seven-coordinate cation [Mo- Populations thiobenzoato complexes (Table V), overlap populations and two-center energy terms of the Ni-S bonds for the dithio complexes of Ni(II) (Table VI), and electronic transitions along with their assignments for the hy- dmpe)2(CO)2Cl]+, isolated as the PF6' salt and shown by a single-crystal X-ray diffraction study to have a capped-trigonai- prismatic geometry (orthorhombic space group Pnma, with a = 13.483 (3) Á, b = 11.065 (2) Á, c = 17.796 (3) A, pcalcd = 1.54 g cm'3, pobsd = 1.54 g cm'3, Z = 4, and = 3.83%). Cyclic voltammetry has established that the neutral dichloride is reversibly oxidized to traps-[Mo(dmpe)2Cl2]+ with (£„ + £c)/2 = -0.510 V vs. SCE. The cation can be obtained as the PF6" salt if AgPF6 is the oxidant, or as the SnCl3" salt if SnCl2 is the oxidant. The d4 and d3 dichlorides have both been characterized by single-crystal X-ray diffraction studies: [Mo(dmpe)2Cl2] crystallizes in the monoclinic space group P2}/c with a = 13.218 (3) k,b= 12.640 (2) A, c = 13.327 (3) A, ß = 93.18 (2)°, Pa¡a¡ = 1.40 g cm'3, pobsd =
1.42 g cm'3, Z = 4, and Rw = 3.22%, while [Mo- 14.756 (4) A, b = 10.808 (2) A, c = 18.572 (5) A, 4.01%. Both have octahedral geometries with trans dichlorides. [Mo(dmpe)2Cl2] can be reduced by 40% sodium amalgam in the presence of N2 or CO to give [Mo(dmpe)2(N2)2]
(dmpe)2Cl2]SnCl3 crystallizes in the monoclinic space group P2¡/n with a = ß = 109.80 (2)°, pealed = 1 -65 g cm"3, pobsd = 1.65 g cm"3, Z = 4, and Rw =
and [Mo(dmpe)2(CO)2], respectively, both of which are formed as a mixture of the cis and trans isomers.