화학공학소재연구정보센터
Inorganic Chemistry, Vol.49, No.5, 2032-2034, 2010
Stable Eight-Coordinate Iron(III/II) Complexes
The chemistry of unusual coordination numbers of transition-meta I complexes has been of interest because of their presence in biology and catalytic systems. Herein we describe a systematic and predictable approach toward isolation of stable eight-coordinate (8C) iron(III/II) systems. The 8C (S = 2; high-spin, HS) complex [Fe(L-N4)(2)](BF4)(2) (1) has been synthesized and characterized, displaying a distorted square-antiprism structure. Complex 1 is a unique 8C iron complex that exhibits remarkable stability in solution under various unfavorable conditions. The E-1/2 value of 1 (0.430 V vs Ag/AgCl, MeCN) supports the Fe-II oxidation state; however, the corresponding HS (S=5/2) 8C Fe-III analogue [Fe(L-N4)(2)](NO3)(3) (3) has also been synthesized via the chemical oxidation of 1. The structural, spectroscopic, and theoretical descriptions of these 8C iron complexes are reported in this work.