Role of a Novel Mixed-Valence-Ligand on the Structures of Supramolecular Polymeric Complexes

Abstract

The design of supramolecular polymer complexes of ruthenium, rhodium and uranium based on the homopolymer N-acryloyl-1-ethyl-2-thiourea (AETH) has been pursued. AETH shows three types of coordination behaviour. It acts as a neutral bidentate ligand coordinating through its thiocarbonyl sulphur and carbonyl oxygen atoms in both the mixed valence paramagnetic trinuclear polymer complexes ( (1) and (2)) and mononuclear polymer complexes ( (3)- (5)). On the other hand, it behaves as a monobasic bidentate ligand coordinating through CS and enolic (C-O) bonds in the mixed ligand poly-chelates (PAETH), which are obtained from the reaction of AETH with RuCl 3 · xH 2 O in the presence of N-heterocyclic base consisting of polymer complexes ( (7) and (8)). The mononuclear compound (6) acts as a monobasic and neutral bidentate ligand coordinating through CO and imino atoms. Monomeric distorted octahedral or trimeric chlorine-bridge pseudo-octahedral structures are proposed for these polymer complexes. The stoichiometries of the poly-chelates are 1:1, 1:2 and 3:2 (metal/homo-polymer) and exhibit six-coordinations. The amine homo-polymer exchange reactions of coordination poly-chelate in symmetrical and unsymmetrical bidentate homo-polymer complexes have been investigated and the ligand field parameters were also calculated. The homo-polymer and its polymer complexes have been characterized using a variety of physiochemical techniques.  Koninklijke Brill NV, Leiden, 2008