CO < inf > 2 < /inf > fixation by [W < sup > IV < /sup > O(S < inf > 2 < /inf > C < inf > 2 < /inf > (CN) < inf > 2 < /inf > ) < inf > 2 < /inf > ] < sup > 2- < /sup > : functional model for the tungsten-formate dehydrogenase of Clostridium thermoaceticum

Abstract

(NEt4)2[WIVO(S2C2(CN)2)2] (1), isolated by reaction of Na2 WO4, Na2S2C2(CN)2 (Na2mnt) in acidified (pH5.5) aqueous medium in the presence of excess of sodium dithionite and NEt4Br, reduces CO2/HCO 3 - (pH 7.5) to yield HCOO- and (NEt4)2[WVIO2(S2C2(CN)2)2] (2) mimicking tungsten-formate dehydrogenase (W-FDH) activity. (1) reacts with Na2MoO4 in acidic medium to produce [MoIvO(S2C2(CN)2)2]2- implicating the displacement of tungsten by molybdenum from the cofactor complex in W-FDH. © 1992 Indian Academy of Sciences.