Spin-dependent binding of dioxygen to heme and charge-transfer mechanism of spin-orbit coupling enhancement

• Дата: 2008
• Автори: Minaev, B.F., Minaeva, V.A.
• Формат: Стаття
• Мова: English
• Опубліковано: Інститут молекулярної біології і генетики НАН України 2008
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/7352
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Spin-dependent binding of dioxygen to heme and charge-transfer mechanism of spin-orbit coupling enhancement / B.F. Minaev, V.A. Minaeva // Ukrainica Bioorganica Acta. — 2008. — Т. 6, № 2. — С. 56-64. — Бібліогр.: 25 назв. — англ.

Spin-orbit coupling (SOC) between the starting triplet ³A''(2) state from the entrance channel of the heme-O2 binding reaction and the final singlet ¹A'(1) open-shell state, which are dominated by the Fe^3+-O2-radical-pair structures, is studied. Simulated potential energy surface cross sections along the reaction coordinate for these and other multiplets, calculated by density functional theory (DFT) agree with the recent DFT studies known from the literature. The heme-model includes Fe(II)-porphyrin complex with imidazol, or ammonia molecule, at the fith coordination position, which simulates the hystidine as an aminoacide residue of myoglobin. The SOC is induced mainly at the oxygen moiety by an orbital angular momentum change in the π8-shell during the triplet-singlet transition. This SOC model explains pretty well the efficient spin inversion during the heme-O2 binding.