School of Chemistry, University of Hyderabad, Hyderabad 500 046, AP, India.
Dalton Trans. 2013 Jun 14;42(22):8113-23. doi: 10.1039/c3dt31966k. Epub 2013 Apr 15.
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.
合成了一个末端桥联叠氮的 Mn(III)配位链聚合物[Mn(5-Clsalpn)N3]n（复合物 1）和它的二聚体多晶型物[Mn(5-Clsalpn)N3]2（复合物 2），其中 5-Clsalpn 是 N,N'-双（5-氯水杨醛）-1,3-二氨基丙烷。复合物 1 以两种几乎相同的分子结构但不同晶体堆积的同时存在的多晶型物（1a 和 1b）获得，具有μ-1,1（末端桥联）叠氮桥。这种单原子桥联是不对称的，导致一维配位聚合物中 Mn(III)中心之间存在-1 cm(-1)的反铁磁相互作用。Mn(III)各向异性通过 Jahn-Teller 沿 N(叠氮)-Mn-N(叠氮)轴的伸长表现出来，并导致单链磁行为。邻苯氧基桥联二聚体（复合物 2）具有末端叠氮配体，通过不对称的双邻苯氧基桥联介导铁磁相互作用。Mn(III)各向异性通过 Jahn-Teller 沿 N-Mn-O 轴的伸长表现出来，并导致单分子磁行为。通过 Cl···Cl 和 Cl···H-苯基相互作用，二聚体被组织成二维网络结构，这些相互作用也是铁磁的。
