title: A new end-on azido bridged Mn(III) single-chain magnet and its dimeric single molecule magnet polymorph. Synthesis, structure and magnetic properties of [Mn(5-Clsalpn)N3]n and phenoxo bridged [Mn(5-Clsalpn)N3]2.
abstract: An end-on azido bridged Mn(III) coordination chain polymer [Mn(5-Clsalpn)N3]n (complex 1) and its dimeric polymorph, [Mn(5-Clsalpn)N3]2 (complex 2), where 5-Clsalpn is N,N'-bis(5-chlorosalicylidene)-1,3-diaminopropane, were prepared. Complex 1, which is obtained as two concomitant polymorphs (1a and 1b) with nearly identical molecular structures but different crystal packing, has μ-1,1(end-on) azido bridges. This single atom bridge is unsymmetrical and leads to a -1 cm(-1) antiferromagnetic interaction among Mn(III) centers of the one-dimensional coordination polymer. Mn(III) anisotropy is manifested through Jahn-Teller elongation along the N(azido)-Mn-N(azido) axis, and results in single-chain magnet behavior. The phenoxo-bridged dimer (complex 2) has terminal azido ligands and a ferromagnetic interaction is mediated by the unsymmetrical bis-phenoxo bridge. Mn(III) anisotropy is manifested through Jahn-Teller elongation along an N-Mn-O axis, and results in single molecule magnet behavior. The dimers are organized into a two-dimensional network structure via Cl···Cl and Cl···H-phenyl interactions which are also ferromagnetic.
authors.affiliation: School of Chemistry, University of Hyderabad, Hyderabad 500 046, AP, India.
authors.forename: G
authors.initials: G
authors.lastname: Bhargavi
authors.forename: M V
authors.initials: MV
authors.lastname: Rajasekharan
authors.forename: J-P
authors.initials: JP
authors.lastname: Costes
authors.forename: J-P
authors.initials: JP
authors.lastname: Tuchagues