N. Hadjiliadis, J. Markopoulos, O. Pneumatikakis
1977
Citations
0
Influential Citations
48
Citations
Journal
Inorganica Chimica Acta
Abstract
Abstract The reactions of Thiamine·HCl (ThH), Thiamine monophosphate·HCl (TMP) and Thiamine pyrophosphate (TPP) have been studied in aqueous solutions (pH ∼3–4) at room temperature. Two types of complexes have been characterized by elemental analyses, conductivity measurements, ir, 1 H nmr and 13 C nmr spectra: ionic 1:2 sults in which thiamine is present as a cation, and 1:1 complexes in which the organic ligand is directly coordinated to the metal ions. The formulae of the ionic salts that were prepared are [MX 4 ] 2− [Th] + 2 and MThX 3 . The salts can easily be converted into 1:1 products by stirring in water at room temperature, while the TPP analogs require excess of ligand. The 1:1 complexes appear to have a zwitterionic structure and the metal is bound through N′ 1 of the pyrimidine ring of thiamine. These solid and stable complexes of thinmine are the first examples reported having a direct metal-to-nitrogen bond.