The TpZn-OH/CS2 reaction: theoretical and preparative visualization of an essential bioinorganic reaction path

The reaction between L3Zn-OH complexes (L = N-3 based ligand) and CS2 which is an analogue of the carbonic anhydrase functionality was computed at the B3LYP/6-311 + G* level to proceed via stable four-center intermediates [L3 Zn-SC(S)OH or L3Zn-SC(O)SH] to give L3Zn-SH and COS; in agreement with thes e calculations, the chemical reaction of Tp(Ph,Me)Zn-OH with CS2 resulted i n the quantitative formation of Tp(Ph,Me)Zn-SH and COS; in the presence of 1 equivalent of MeOH the reaction yielded Tp(Ph,Me)Zn-SC(S)OMe, thus also s upporting the existence of the four-center intermediate L3Zn-SC(S)OH.