Naslov
Estimation fo stability of coordination compounds by overlapping spheres method

Autori
Raos, Nenad

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Program and Book of Abstract / Graovac, Ante ; Pokrić, Biserka, Smrečki, Vilko - Dubrovnik : Interuniverzitetski centar Dubrovnik (IUC), 2004

Skup
The 19th Dubrovnik International Course & Conference on the Interfaces among Mathematics, Chemistsry and Computer Sciences

Mjesto i datum
Dubrovnik, Hrvatska, 21.06.2004. - 26.06.2004

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
conformational analysis; overlapping spheres; coordination compounds; N-alkylated amino acids

Sažetak
The method of overlapping spheres was applied for the estimation of stability constants of copper(II) chelates with N-alkylated glycines. The central sphere with radius 0.2 and 0.4 nm was situated at the center, vertices or faces of the coordination octahedron. The stability constants for mono- (log beta110) and bis-complexes (log beta120) of glycine and its methyl, dimethyl, ethyl, diethyl, propyl, butyl, iso-propyl and tert-butyl derivateives were correlated on the overlappling volume of the central sphere and the van der Waals volumes of the neighbouring atoms. The calculations were performed with the two idenpendent sets of stability constants (N=6, 8 and 5, 6 for mono- and bis-complexes, respectively. The better correlations were obtainde for mono- (r=0.768-0.968) than for bis-complexes (r=0.737-0.922). The exclusion of complexes with N-iso-propylglycine and N-tert-butylglycine yielded substantially better results (r=0.741-0.997 for mono-complexes, r = 0.877-0.984 for bis-complexes). the best positions of the central sphere proved to be the faces of the coordination octahedron (r=0.909-0.985 for mono-complexes, r=0.843-0.984 for bis-complexes), and the worst positions appeared to be that of the ligated atoms (r=0.741-0.979 and 0.737 - 0.953 for mon- and bis compllexes, respectively). The best regression lines reproduce stability constants iwth the orror o.oo - 0.2 log beta units, except the constants of N-iso-propylglycine and N-tert-tutylglycije chelates, which were estimated with a typical error around 0.5 log beta units.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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