Metalloporphyrins. The nature of ligand bonding and the mechanism of replacements

Ostalo - Ostalo

• Autor: Smiljko Ašperger
• Autor: Biserka Cetina-Čižmek
• Autorova ustanova: Sveučilište u Zagrebu; Farmaceutsko-biokemijski fakultet; (Zavod za fizikalnu kemiju)
• Znanstveno / umjetničko područje, polje i grana: PRIRODNE ZNANOSTI; Kemija; Fizikalna kemija

Sažetak (engleski)

The imidazole ring is an essential component of many biological systems (hemoglobin and myoglobin, nucleic acids, vitamin B^, cytochromes, metalloenzymes, etc.). The nature of the bond between imidazole-nitrogen and the metal is therefore of biological interest. Imidazole is an electron-donating ligand in both a and n sense, much more electron donating than the majority of nitrogen heterocycles. As ligands, most imidazoles are good a donors and moderate n donors. They can also function as n acceptors if the imidazole ring has one or more electron-withdrawing substituents. Our recent study of bonding modes of pyridine and imidazole type ligands in the transition state of a Conl(protoporphyrin IX) model complex enabled us to conclude that stabilization of the reaction transition state is more sensitive to the change in the strength of n bonding than in that of a bonding. This observation is important for some metallo-enzymatic reactions. Mechanisms of replacements in porphyrin and in corrin rings are discussed.

• Jezik: engleski
• Vrsta publikacije: Ostalo - Ostalo
• Status objave: Objavljen
• Vrsta recenzije: Recenziran
• Verzija publikacije: Objavljena verzija rada (izdavačev PDF)
• Naslov časopisa: Croatica Chemica Acta
• Brojčani podaci: vol. 69, br. 4, str. 1305-1328
• p-ISSN: 0011-1643
• e-ISSN: 1334-417X
• URN:NBN: urn:nbn:hr:163:315859
• Datum objave publikacije: 1996
• URL dokumenta: https://hrcak.srce.hr/135971
• Vrsta resursa: Tekst
• Prava pristupa: Otvoreni pristup
• Datum i vrijeme pohrane: 2020-04-29 14:35:08