Structural diversity of cadmium(II) complexes of tetraorganodichalcogenoimidodiphosphinato ligands: Monomeric Cd[(SPMe 2) 2N] 2, dinuclear [Cd{(OPMe 2)(SPPh 2)N} 2] 2 and [Cd 2{(OPPh 2) 2N} 4(H 2O)], and trinuclear K[Cd 2{(OPPh 2) 2N} 5

Abstract

Cadmium complexes of the type Cd [ ( XPR 2 ) ( YPR 2 ′ ) N ] 2 ( X , Y = O , S ; R , R ′ = Me , Ph ) were obtained by reacting CdCl 2 and K [ ( XPR 2 ) ( YPR 2 ′ ) N ] in a 1:2 molar ratio. The compounds were characterized by IR, multinuclear NMR ( 1H, 13C, 31P) spectroscopy and mass spectrometry. The molecular structures of Cd[(SPMe 2) 2N] 2 ( 1), Cd[(OPMe 2)(SPPh 2)N] 2 ( 4), [Cd 2{(OPPh 2) 2N} 4(H 2O)] ( 7 · H 2O) and K[Cd 2{(OPPh 2) 2N} 5] ( 8) were established by single-crystal X-ray diffraction. Colourless crystals of 8 were isolated, along with those of 7 · H 2O, during recrystallization of crude Cd[(OPPh 2) 2N] 2 ( 7). A monomeric structure with a tetrahedral CdS 4 core is found for 1, whereas 4 contains discrete dimers formed through two O, O′, S-bimetallictriconnective ligand units resulting in distorted trigonal bipyramidal CdO 3S 2 cores. In the dinuclear compound 7 · H 2O the Cd atoms are also bridged by two O, O′, O′-bimetallic triconnective ligands, but the coordination of the metal centres is completed by a bridging water molecule to givedistorted octahedral CdO 6 cores. In the trimetallic unit of 8 the K atom is accommodated in the cavity described by the oxygen atoms of three ligand units which bridge the Cd atoms. The remaining two ligands are each one chelating a Cd atom, thus resulting in distorted square pyramidal CdO 5 cores.