Premium
Trigonal Bipyramidal {Fe(NO)} 7 Complex [(NO)Fe(SC 9 H 6 N) 2 ] Containing an Equatorial Nitrosyl Ligand: The Critical Role of Chelating Ligands in Regulating the Geometry and Transformation of Mononitrosyl Iron Complex (MNIC)
Author(s) -
Lu TsaiTe,
Yang LiBo,
Liaw WenFeng
Publication year - 2010
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.201000126
Subject(s) - chemistry , trigonal bipyramidal molecular geometry , ligand (biochemistry) , crystallography , electron paramagnetic resonance , nitrosylation , stereochemistry , chelation , crystal structure , inorganic chemistry , nuclear magnetic resonance , nitric oxide , biochemistry , physics , receptor , organic chemistry
Trigonal bipyramidal {Fe(NO)} 7 complex [(NO)Fe(SC 9 H 6 N) 2 ] (2) with NO ligand occupying equatorial position, obtained from nitrosylation of complex [(Cl)Fe(SC 9 H 6 N) 2 ] − (1) accompanied by elimination of [Cl] − , was characterized by IR, UV‐Vis, EPR, SQUID and single‐crystal X‐ray diffraction. Compared to the S = 3/2 ground state displayed by the trigonal bipyramidal complex [Et 4 N][(ON)Fe(N‐(CH 2 CH 2 S) 3 )], the chelating ligands ([SC 9 H 6 N] − ) play a key role in modulating the position of exogenous NO ligand and controlling the spin state of complex 2 ( S = 1/2). In contrast to nitrosylation of [Fe(NO)(SPh) 3 ] − MNIC yielding [Fe(NO) 2 (SPh) 2 ] − DNIC, the inertness of complex 2 toward NO (g) was observed. Reaction of [NO][BF 4 ] and complex 2 in a 1:1 stoichiometry led to the formation of homodinuclear {Fe(NO)} 7 ‐{Fe(NO)} 9 complex [(ON)Fe(‐SC 9 H 6 N) 2 Fe(NO) 2 ][BF4] (3) characterized by IR, UV‐vis, 1 H NMR and single‐crystal X‐ray diffraction. Antiferromagnetic coupling between the S = 1/2 {Fe(NO)} 7 [S 2 Fe(NO) 2 ] core and the S = 1/2 {Fe(NO)} 7 [(NO)FeS 2 N 2 ] core may account for the diamagnetism and the EPR silence of complex 3 . This study provides the evidence that the geometric and electronic structures of {Fe(NO)} 7 MNICs modulated by the coordination environment of iron center determines the nitrosylation products.