ABSTRACT
Nine complexes of adenosine and related compounds (adenosine-5'-monophosphate, adenosine-5'-triphosphate, 1-methyl-adenosine, pyridoxal-5-phosphate and beta-nicotinamide-adenine-dinucleotide-phosphoric acid) with di-n-butyltin(IV) oxide and/or di-n-butytin(IV) dichloride were prepared in the solid state. The compositions of the complexes were determined by standard analytical methods. It was found that the complexes contain organotin(IV) moiety and the ligand in a ratio of 1:1 or 2:1. The FTIR spectra demonstrated that di-n-butyltin(IV) oxide reacts with the D-ribose moiety of the ligands, while di-n-butyltin(IV) dichloride is co-ordinated to the deprotonated phosphate group. The basic part of the ligands does not participate directly in complex formation. Comparison of the experimental Mössbauer delta E values with those calculated on the basis of the PQS concept revealed that the organotin(IV) moiety has trigonal-bipyramidal, octahedral and in some cases tetrahedral geometry also. Some of the complexes contain the organotin(IV) cation in two different surroundings.
Subject(s)
Adenosine/analogs & derivatives , Adenosine/chemistry , Organotin Compounds/chemistry , Adenosine Monophosphate/chemistry , Adenosine Triphosphate/chemistry , Ligands , Molecular Structure , NADP/chemistry , Organotin Compounds/chemical synthesis , Pyridoxal Phosphate/chemistry , Spectroscopy, MossbauerABSTRACT
To study the effect of the conformation of sugar hydroxy groups on metal complexation processes, complex formation of eight saccharides (D-fructose, L-sorbose, L-arabinose, D-arabinose, D-glucose, D-sorbitol, 2-deoxy-D-glucose and D-saccharose) with dimethyltin(IV)2+ cations was investigated in aqueous solution by potentiometric equilibrium measurements, 13C NMR, polarimetric and Mössbauer spectroscopic methods. The experimental results proved that deprotonation of D-fructose and L-sorbose is caused by the coordination of dimethyltin(IV)2+ in the unusual low pH interval 4-6 in contrast to the other saccharides deprotonated in analogous way at pH > 8. Increasing the pH of the solution resulted in the formation of further complexes. Stability and composition of the species was determined by potentiometric studies. 13C NMR measurements led to the assignment of the sugar OH groups participating in the processes. Mössbauer investigations in the quick-frozen solutions permitted the determination of the stereochemistry of tin(IV) in the complexes.
