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)N-3](n) and phenoxo bridged [Mn(5-Clsalpn)N-3](2)

作者：Bhargavi G; Rajasekharan M V^*; Costes J P; Tuchagues J P

来源：Dalton Transactions, 2013, 42(22): 8113-8123.

DOI：10.1039/c3dt31966k

An end-on azido bridged Mn-III coordination chain polymer [Mn(5-Clsalpn)N-3](n) (complex 1) and its dimeric polymorph, [Mn(5-Clsalpn)N-3](2) (complex 2), where 5-Clsalpn is N,N%26apos;-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 mu-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 center dot center dot center dot Cl and Cl center dot center dot center dot H-phenyl interactions which are also ferromagnetic.

• 出版日期2013