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Iron(II) Complexes Supported by a Tetradentate Ligand Providing a Strained Equatorial Coordination Environment: Geometric and Electronic‐Structural Implications
Author(s) -
Schmidt Sven Olaf,
Kisslinger Sandra,
Würtele Christian,
Bonnet Sylvestre,
Schindler Siegfried,
Tuczek Felix
Publication year - 2013
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201300425
Subject(s) - spectrochemical series , ligand field theory , ligand (biochemistry) , chemistry , steric effects , crystallography , octahedron , mössbauer spectroscopy , pyridine , imidazole , spin states , stereochemistry , crystal structure , inorganic chemistry , ion , medicinal chemistry , biochemistry , receptor , organic chemistry
Searching for SCO compounds with tetradentate equatorial ligands suitable to surface attachment we decided to synthesize iron(II) complexes with the ligand o ‐bpy [ o ‐bpy = 1,2‐bis(2,2′‐bipyridyl‐6‐yl)ethane]. For coordination in axial position three different ligands with increasing ligand field strength were considered: isothiocyanate, pyridine, and imidazole. The new iron(II) complexes [Fe( o ‐bpy)(NCS) 2 ], [Fe( o ‐bpy)(py) 2 ](BPh 4 ) 2 , and [Fe( o ‐bpy)(im) 2 ](BPh 4 ) 2 were characterized with the help of Mössbauer spectroscopy, magnetic measurements, and X‐ray crystallography. The Mössbauer data and magnetic susceptibility measurements show that all three synthesized compounds are in the high‐spin state between 300 and 2 K. To explain these findings DFT calculations are employed. The experimental and theoretical results indicate the presence of distortions from octahedral symmetry due to steric restrictions imposed by the o ‐bpy ligand, which reduce its ligand‐field strength, leading to the observed S = 2 ground states.