Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Polish Journal of Chemistry

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: mercury(II)

Sortuj według:

Ogranicz wyniki do:

Complexes of Cadmium (II) and Mercury(II) with Cytidine 5'-Monophosphate and Diamines in Ternary Systems

Łomozik L., Bregier-Jarzębowska R.

Polish Journal of Chemistry

2004

Vol. 78 / nr 4

529-538

Formation of Cd(II) and Hg(II) complexes in ternary systems with cytidine 5_-monophosphate (CMP) and diamines (en, tn, Put) has been studied. In Hg(II)/CMP/diamine systems the formation of heteroligand compounds is accompanied by the occurrence of non-covalent interactions and the formation of molecular complexes. The presence of polyamine in ternary systems does not change the metal-nucleotide mode of coordination. Similarly as in the binary Hg(II)/CMP system, the metallation involves the donor endocyclic nitrogen N(3) atom and CMP phosphate group. On the other hand, in the Cd(II)/CMP system, the introduction of a polyamine changes the coordination mode of the nucleotide. Phosphate group, inactive in binary systems, takes part in the complexation in ternary systems. In systems of cadmium(II) ions, CMP and diamines, only molecular complexes are formed, in which the polyamine is in the outer coordination sphere. In contrast to Cd(CMP)(H2tn) and Cd(CMP)(H2Put) compounds, in Cd(CMP)(H2en) species the phosphate group of nucleotide does not take part in the metallation, i.e. the metal ion coordinates with CMP, through the atom N(3) of the nucleotide, and the phosphate group is involved in non-covalent interactions with en.

Complexes of cadmium(II) and mercury(II) with polyamines, nucleosides and nucleotides

Łomozik L., Brieger-Jarzębowska R.

Polish Journal of Chemistry

1999

vol. 73 nr 6

927-940

Computer analysis of potentiometric titration data was applied for determination of stability constants of Cd(II) and Hg(II) complexes in binary systems with polyamines (PA), nucleosides (Nuc) and nucleotides (NMP). For the systems of Hg(II) and PA an untypical increase in the complex stability with increasing ring size was observed and interpreted as the mercury preference to formation of linear complexes. Results of the potentiometric and 13CNMR studies for the complexes of both metal indicate the involvement of all donor nitrogen atoms of di- and triamines in the coordination, leading to formation of N2 and N3 type chromophores, respectively. Monodentate complexes of Hg(II) with Cyd are formed already at very low pH (complexes with Cd from pH of about 4). In the systems with AMP apart from nitrogen donor atoms, also the phosphate groups are involved in coordination. In the solid complexes of Cd(II) and Hg(II) with PA all donor atoms from the polyamines were found to be involved in the coordination and the presence of nitrate ions was established both in the inner and in the outer coordination spheres.