Synthesis and Characterisation of Tris(1-carboxyl-2-phenyl-1,2-ethyleno dithiolenic-S,S’) Tungsten Complex as Photocatalyst for Photolysis of H2O Molecules (Sintesis dan Pencirian Kompleks Tris[1-karboksil-2-fenil-1,2-etilenoditiolenik-S,S’] Tungsten sebagai Fotomangkin untuk Fotolisis Molekul H2O)

Tris(1-carboxyl-2-phenyl-1,2-ethylenodithiolenic-S,S’) tungsten complex is one of the most promising photocatalyst to be used in photolysis of water to produce hydrogen. The first step of the synthesis involves a metathesis reaction of tetrapropylammonium bromide [{(C3H7)4N}Br] and ammonium tetrathiotungstate [(NH4)2WS4] to form a tetrapropylammonium tetrathiotungstate [{(C3H7)4N}2WS4] (precursor). Then, the precursor was reacted with phenylacetylenecarboxylic acid (C9H6O2) to form tris(1-carboxyl-2-phenyl-1,2-ethylenodithiolenic-S,S’) tungsten complex (C27H18O2S6W). The infra-red, ultra violet/visible (UV/Vis) spectrum, nuclear magnetic resonance (NMR) and elemental micro-analysis of C, H, N and S agreed with the characteristic of the tris(1-carboxyl-2-phenyl-1,2-ethylenodithiolenic-S,S’) tungsten complex. The (W-S), (C-S) and (C=O) stretching frequencies were detected at 511, (1470 and 1035) and 1655 cm-1, respectively. The 1H NMR spectrum showed six protons in the complex. The 13C NMR showed only 7 signals for carbon atom in the benzene ring, ethylene groups and carboxylic acid pendant group due to the symmetry of the molecules. The reaction yield was about 50 percent. Photolysis of acetone spiked H2O showed that the catalyst was able to produced 1.8µmol/h hydrogen