Synthesis, characterisation and polymerisation of vinylbenzene-substituted triazacyclododecanes and their transition metal complexes

Abstract

The synthesis of a range of methylated and non-methylated triazacyclododecane derivatives featuring the unsymmetrical incorporation of a 4-vinylbenzene side-arm is reported, along with the X-ray crystal structure of an amidinium salt precursor, and NMR characterisation of these ligands. The free amine, 1-(4-vinylbenzyl)-1,5,9-triazacyclododecane (5), has been reacted with a series of transition metal centres and the coordination chemistry is discussed, with structural analysis of an unusual triply-bridged (via one aqua and two chloride ligands) Ni(II) dimer and a mononuclear W(CO)₅ complex. Co-polymerisation studies on 5 and its metal complexes with varying percentages of styrene show the formation of low and high (via cross-linking) molecular weight polymers.