In situ oxidation of a copper (I) complex to produce a hydroxy-bridged dinuclear copper (II) complex. Structural, magnetic and electrochemical properties

Abstract

Abstract The green hydroxo-bridged dicopper (II) complex [Cu2(PTP)(OH)Cl3]∗d2CH3CN (1) was obtained by aerial oxidation of an acetonitrile solution of a red copper (I)/PTP complex (PTP = 3,6-bis(2-pyridylthio)pyridazine). 1 crystallizes in the monoclinic system, space group P21/n, with a = 12.104(1), b = 11.014(4), c = 18.697(2) A , β = 106.372(9) 0 , and four formula units per unit cell. 1 has a triple bridged, distorted five-coordinate structure with a CuCu separation of 3.0514(8) A, and a CuOHCu angle of 106.2(1)0. Variable temperature magnetic studies indicate moderate anti-ferromagnetic coupling between the copper centers (−2J = 296 cm−1). The salt [H2PTPH]2+[CuBr4]2− (2) is also reported from an unusual reaction between CuBr2 and PTPH (PTPH = 1,4-bis(2-pyridylthio)phthalazine) in CH3CN/CHCl3 mixture. 2 crystallizes in the orthorhombic system, space group Pnma, with a = 11.540(5), b = 15.177(6), c = 13.156(4) A , and four formula units per unit cell. The ligand is protonated at both pyridine nitrogens, leading to an essentially flat cation due to internal hydrogen bonding.