title: Structural and magnetic properties of MCl2 (M = Fe, Mn, Co): acetonitrile solvates.
abstract: MIICl2 (M = Mn, Fe, Co) as their acetonitrile solvates were isolated, and their structural, spectroscopic, and magnetic properties were studied. MCl2(NCMe)2 (M = Fe, Mn) form 1-D chains of octahedral MII ions with four bridging chlorides and two axial MeCN's. The presence of an axial distortion for MFe causes a significant magnetic anisotropy that increases significantly below 150 K; however, chiav [=(chi parallel + 2chi perpendicular)/3] almost coincides with the value obtained on a polycrystalline sample. MnCl2(NCMe)2 is a paramagnet with a weak antiferromagnetic coupling. Annealing FeCl2(NCMe)2 at 55 degrees C forms the monosolvate of FeCl2(NCMe) composition in which two chains collapse into a double chain with formation of Fe-Cl bonding such that half of the mu-Cl's becomes mu3-Cl's. This material orders magnetically below Tc = 4.3 K. For M = Co, paramagnetic tetrahedral [CoCl3(NCMe)]- anions are isolated.
authors.affiliation: Department of Chemistry, 315 S. 1400 E. RM 2124, University of Utah, Salt Lake City, Utah 84112-0850, USA.
authors.forename: Konstantin I
authors.initials: KI
authors.lastname: Pokhodnya
authors.forename: Michael
authors.initials: M
authors.lastname: Bonner
authors.forename: Antonio G
authors.initials: AG
authors.lastname: DiPasquale
authors.forename: Arnold L
authors.initials: AL
authors.lastname: Rheingold
authors.forename: Jae-Hyuk
authors.initials: JH
authors.lastname: Her
authors.forename: Peter W
authors.initials: PW
authors.lastname: Stephens
authors.forename: Jong-Won
authors.initials: JW
authors.lastname: Park
authors.forename: Bretni S
authors.initials: BS
authors.lastname: Kennon
authors.forename: Atta M
authors.initials: AM
authors.lastname: Arif
authors.forename: Joel S
authors.initials: JS
authors.lastname: Miller