A. Soliman, M. Khattab, M. Reißner
Nov 1, 2007
Citations
0
Influential Citations
14
Citations
Journal
Inorganica Chimica Acta
Abstract
Abstract For the first time a 1-cyclopropyl substituted tetrazole ( C 3 tz ) has been used as a potential ligand for iron(II) spin-transition complexes. The complexation of 1-cyclopropyltetrazol with iron(II) tetrafluoroborate yielded a fine powdered product of [Fe( C 3 tz ) 6 ](BF 4 ) 2 being poorly soluble in most common solvents. Single crystals of complex were grown in situ from a solution of ligand and iron(II) hexafluorophosphate, which yielded a hexagonal prismatic crystalline product of [Fe( C 3 tz ) 6 ](PF 6 ) 2 . A comparison of XRPD data of the homologues [Fe( C 3 tz ) 6 ](BF 4 ) 2 and [Fe( C 3 tz ) 6 ](PF 6 ) 2 proves them to be homeotypic. The thermally induced spin-crossover phenomenon of [Fe( C 3 tz ) 6 ](BF 4 ) 2 complex shows very abrupt spin transitions, with a spin-crossover temperature T 1/2 ≈ 180 K which is found to be ≈50 K above the T 1/2 of all known iron(II) complexes with n -alkyltetrazoles as ligands. The T 1/2 was determined by temperature-dependent 57 Fe-Mossbauer, far FT-IR and UV–Vis–NIR spectroscopy as well as temperature dependent magnetic susceptibility measurements (SQUID).