Cadmium tri-tert-butoxysilanethiolates: Structural and spectroscopic models of metal sites in proteins

Self-assembly of zinc and cobalt complexes mimicking active site of alcohol dehydrogenase

“…Several zinc, cobalt, cadmium and manganese tri-tert-butoxysilanethiolates were described exhibiting resemblance to the ADH active center [19][20][21][22][23][24][25]. In this paper we report syntheses and structures of first zinc and cobalt tri-tert-butoxysilanethiolates with ZnNOS 2 kernel and water as an additional ligand [26][27][28][29].…”

“…All of the forms were enzymatically active with cobalt being the most effective metal [13]. This efficiency of cobalt is connected both with the order of Lewis acidities -cobalt is a stronger Lewis acid than zinc -and similarity of the ionic radii of cobalt and zinc [18].Several zinc, cobalt, cadmium and manganese tri-tert-butoxysilanethiolates were described exhibiting resemblance to the ADH active center [19][20][21][22][23][24][25]. In this paper we report syntheses and structures of first zinc and cobalt tri-tert-butoxysilanethiolates with ZnNOS 2 kernel and water as an additional ligand [26][27][28][29].…”

Modeling of the Alcohol Dehydrogenase Active Site: Two Different Modes of Alcohol Binding in Crystals of Zinc and Cadmium Tri‐tert‐butoxysilanethiolates Evidenced by X‐ray Diffraction and Solid‐State Vibrational Spectroscopy

“…For a discussion on the features of the S ligand see the literature 7. In our previous work, we demonstrated the equilibrium character of the reaction of cadmium tri‐ tert ‐butoxysilanethiolate with 3,5‐dimethylpyridine and 1‐methylimidazole 7k,9 in [D 8 ]toluene and CDCl 3 . As we will show later in this paper, we have been able to prove the presence of similar equilibria for the reactions of cadmium tri‐ tert ‐butoxysilanethiolate with imidazole and 2‐methylimidazole in methanol.…”

“…By means of quantum chemical and molecular mechanical geometry optimisations he showed that such a coordination can be accomplished with small changes in the geometry of the zinc coordination sphere and is kinetically favourable 12b. Oscillation of the apical O ligands at the zinc ion may also explain the spectroscopic properties of the Co‐ and Cd‐substituted enzyme, which indicate the presence of five‐coordinate metal centres in ADH 4d,4f,7j,7k. Figure 8 summarises variations in the zinc coordination spheres in different ADHs represented by HLADH,1b sorbitol dehydrogenase,14 Aeropyrum pernix alcohol dehydrogenase complexed with octanoic acid 15 and formaldehyde dehydrogenase 13…”

“…The existence of relatively simple syntheses of tri‐ tert ‐butoxysilanethiolates with MS 2 NO 2 (M = Zn, Cd, Co, Mn) cores encouraged us to model the enzymatic centre of alcohol dehydrogenase 7. In our previous studies, we proved that heteroleptic cadmium tri‐ tert ‐butoxysilanethiolates with CdS 2 NO 2 kernels exhibit very similar 113 Cd NMR chemical shifts to that of LADH‐NAD + 7k. Furthermore, it has recently been shown that methanol binds to manganese in an environment resembling the LADH catalytic centre 7j.…”