title: Control of iron(III) spin-state in the model complexes of azide hemoprotein by porphycene, corrphycene, and hemiporphycene macrocycles.
abstract: Spin states of the iron(III) complexes of porphyrin, porphycene, hemiporphycene, and corrphycene bearing both 1-methylimidazole and azide as axial ligands were analyzed with infrared (IR) spectroscopy at 20 degrees C. The IR stretching band of coordinating azide split into two peaks around 2047 and 2017 cm(-1) reflecting an equilibrium between the high- (S = 5/2) and low- (S = 1/2) spin states. The high-spin fraction changed over a 0-90% range among the macrocycles, demonstrating that the tetrapyrrole array is essential to control the equilibrium.
authors.affiliation: Department of Physical Chemistry, Graduate School of Pharmaceutical Sciences, Chiba University, Inage-Yayoi, Chiba 263-8522, Japan. sneya@p.chiba-u.ac.jp
authors.forename: Saburo
authors.initials: S
authors.lastname: Neya
authors.forename: C K
authors.initials: CK
authors.lastname: Chang
authors.forename: Daichi
authors.initials: D
authors.lastname: Okuno
authors.forename: Tyuji
authors.initials: T
authors.lastname: Hoshino
authors.forename: Masayuki
authors.initials: M
authors.lastname: Hata
authors.forename: Noriaki
authors.initials: N
authors.lastname: Funasaki
mesh_terms: D001386:Azides / Q000737:chemistry*; D006420:Hemeproteins / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D001386:Azides; D006420:Hemeproteins; D011166:Porphyrins; C051407:porphycene; D007501:Iron