Rhodium complexes with diacetyl monoxime ligands; crystal structure of [Rh cis- (C 4H 6NO) 2cis-(PPh 3) 2]ClO 4·CHCl 3

Abstract

The reaction of RhCl 3·3H 2O with Hdamo and PPh 3 (Hdamo = diacetyl monoxime = C 4H 7NO), both in the absence ( 1) and in the presence of HClO 4 ( 2) afforded the complex Rh(damo)(PPh 3) 2Cl 2. The reaction of the acidic water/ethanolic solution of [Rh(H 2O) 6] 3+ with Hdamo and PPh 3 ( 3) gave the mixture of the isomers of the compound [Rh(damo) 2(PPh 3) 2]ClO 4 ( 3A and 3B). A similar mixture of isomers was formed when [Rh(H 2O) 6] 3+ reacted with H 2dopn (H 2dopn = 3,9-dimethyl-4,8-diazaundeca-3,8-diene-2,10-dione dioxime) and PPh 3 ( 4). Two isomers ( 4A = 3B) and [Rh cis-(damo) 2 cis-(PPh 3) 2]ClO 4·CHCl 3 ( 4B) have been isolated. All the compounds were characterized by elemental analysis NMR and IR spectroscopy. Single-crystal X-ray diffraction studies were carried out on the complex 4B. In this compound the coordination environment around rhodium(III) is pseudooctahedral composed of two cis-oxime nitrogen atoms [av. RhN = 2.031(3) Å], two trans-oxime oxygen atoms [av. RhO = 2.026(2) Å] and two cis-phosphine phosphorus atoms [av. RhP = 2.403(1) Å].