Synthesis and X-ray structural characterization of Cobalt(II), Copper(II), and Silver(I) complexes of triphenylphosphoniopropionate

Four transition-metal carboxylate-like complexes have been synthesized from the reaction of the tertiary phosphine betaine triphenylphosphoniopropionate, Ph(3)P(+)(CH2)(2)CO2-, with Co(ClO4)(2) . 6H(2)O, Cu(ClO4)(2) . 6H(2)O, Cu(BF4)(2) . xH(2)O, and AgClO4, respectively, and fully characterized by single-crystal X-ray analysis. [Co{Ph(3)P(CH2)(2)CO2}(4)(H2O)(2)](ClO4)(2) . 2H(2)O, 1, space group P (1) over bar with a = 9.195(2), b = 13.000(2), c = 18.795(3) Angstrom, alpha = 102.52(1), beta = 90.12(1), gamma = 109.28(2)degrees and Z = 1; [Cu{Ph(3)P(CH2)(2)CO2}(4)][Cu-2{mu-Ph(3)P(CH2)(2)CO2-O,O}(4)(H2O)(2)](ClO4)(6) . 4H(2)O, 2, space group P2(1)/c with a = 14.225(3), b = 24.624(6), c = 24.297(5) Angstrom, beta = 94.18(1)degrees, and Z = 2; [Cu{Ph(3)P(CH2)(2)CO2}{Me(2)N(CH2)(2)NMe(2)}(H2O)(2)](BF4)(2) space group P2(1)/c with a = 17.668(2), b = 13.454(3), c = 15.876(2) Angstrom, beta = 116.45(1)degrees, and Z = 4; [Ag-2{Ph(3)P(CH2)(2)CO2}(2)(ClO4)(2)(ClO4)](2) 4, space group P (1) over bar with a = 10.925(2), b = 13.110(3), c = 18.795(3) Angstrom, alpha = 82.93(3), beta = 87.45(3), gamma = 67.49(3)degrees, and Z = 2. In complex 1, the cobalt(II) atom is located in an inversion center and coordinated by four unidentate betaine ligands and a pair of trans aqua ligands, and strong hydrogen bonds are formed between the aqua ligands and the pendant oxygen atoms of the betaine ligands. In complex 2, mononuclear and dinuclear cations coexist in the asymmetric unit. In the mixed-ligand complex 3 the betaine ligand acts in the unidentate coordination mode and N,N,N',N'-tetramethylethylenediamine (tmen) in the chelate mode. Complex 4 contains a discrete centrosymmetric tetranuclear cations in which one pair of betaine ligands act in the bidentate bridging mode and the other in both bidentate and one-atom bridging modes.