NITRITE LINKAGE ISOMERISM IN HEMES AND RELATED COMPLEXES - MODULATION BY METAL, OXIDATION STATE, MACROCYCLE, AND MEDIUM POLARITY

作者：Silaghi Dumitrescu Radu^*; Uta Matei Maria; Makarov Sergei V

来源：Romanian Journal of Chemistry, 2010, 55(11-12): 897-+.

• nitrite
• linkage isomerism
• DFT
• phthalocyanine
• heme
• porphyrazine

The nitro/nitrito linkage isomerism in metal-nitrite complexes has been shown to be at work in heme proteins and related inorganic catalytic systems such as phthalocyanines. Here, a systematic examination of the nitro/nitrito isomerism is undertaken with computational methods aiming to identify factors controlling it. The systems addressed include iron and cobalt in formal oxidation states of +1, +2 and +3 and complexed by porphyrin, porphyrazine and phthalocyanine. The oxygen-bound isomer (nitrito) is found to be favored by lower-valence states and by porphyrazine; porphyrin favors the nitrogen-bound isomer (nitro), but these preferences can be modulated by the axial ligand. The dielectric constant of the medium is computed to have minimal effects, of at most 1 kcal/mol; the sign of this effect appears to change depending on the density functional and on the solvation model used.

• 出版日期2010-12