Reaction of bis[bis(tri‐tert‐butoxysilanethiolato) cadmium(II)] with 3,5‐dimethylpyridine ‐ ¹¹³Cd NMR solution study

Abstract

NMR studies on the reaction of bis[bis(tri-tert-butoxysilanethiolato)cadmium(II)] with 3,5-dimethylpyridine in benzene-d(6) and toluene-d(8) solutions provide clear evidence for the equilibrium character of formation of mixed S,N-ligand cadmium complex.

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

“…The addition of an increasing amount of imidazole or 2‐methylimidazole to [D 4 ]MeOH solutions of 1 and 2a induced a continuous change in 113 Cd chemical shift (Table 7). As in previously published studies,7k,9 these results confirm the presence of an equilibrium between a mixture of a (probably dimeric9) cadmium thiolate and imidazole and the corresponding heteroleptic adduct in solution; the formation of the latter occurs with increasing imidazole or 2‐methylimidazole concentration.…”

“…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.…”

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].…”

Two isomorphous ZnII/CoIIcomplexes with tri-tert-butoxysilanethiol and histamine, and (4-hydroxymethyl-1H-imidazole-κN)bis(tri-tert-butoxysilanethiolato-κ2O,S)zinc(II)

“…Structural and spectroscopic studies on heteroleptic transition-metal tri-tert-butoxysilanethiolates have been undertaken to provide a source of reference data for cysteine-ligated metal centers in proteins (Becker, Zalewska et al, 2001;Becker et al, 2002;Dołęga et al, 2004Dołęga et al, , 2007Dołęga et al, , 2008Kropidłowska et al, 2007). Unfortunately, 113 Cd NMR and UV-vis solution studies revealed low stability of these complexes; in solution, N-containing ligands are discarded and homoleptic metal thiolates restored (Becker, Zalewska et al, 2001;Dołęga et al, 2007;Dołę ga & Walewski, 2007). We have not noticed any correlation between ligand-metal bond lengths in solids and the stability of the obtained complexes in solution.…”