title: Diverse manganese(II) coordination polymers derived from achiral/chiral imidazolium-carboxylate zwitterions and azide: structure and magnetic properties.
abstract: Five Mn(II) coordination polymers containing azide and carboxylate as simultaneous bridges have been derived from different imidazolium-carboxylate zwitterionic ligands: 1-methyl-3-(carboxylatomethyl)imidazolium (L(1)), 1,3-bis(carboxylatomethyl)imidazolium (L(2)), (S,S)-, (R,R)-, and (R,S)-1,3-bis(1-carboxylatoethyl)imidazolium (S,S-L(3), R,R-L(3) and R,S-L(3)). The compounds are formulated as [Mn(L(1))(N3)2] (1), [Mn(L(2))(N3)] (2), [Mn(R,R-L(3))(N3)]·0.5CH3OH (3-R), [Mn(S,S-L(3))(N3)]·0.5CH3OH (3-S), [Mn(R,S-L(3))(N3)] (4). In compound 1, the neutral monocarboxylate zwitterion ligand (L(1)) leads to uniform chains with bis(azide)(carboxylate) bridges. For compounds 2-4, the anionic dicarboxylate zwitterions L(2) and L(3) lead to (azide)bis(carboxylate) bridges, but the overall coordination networks are different. In 2 and 3-S (or 3-R), chains with the (azide)bis(carboxylate) bridges are connected by L(2) and S,S-L(3) (or R,R-L(3)), respectively, to give achiral and chiral 2D coordination networks with different connecting topologies. In compounds 4, which is derived from the mesomeric ligand R,S-L(3), linear trinuclear units with the (azide)bis(carboxylate) bridges are linked by μ-1,3 azides to give 2D layers, and the layers are pillared into a 3D framework by the 1,3-dimethyleneimidazolium tethers. Magnetic analyses suggested that compounds 1-3 behave as 1D antiferromagnetic systems, while 4 shows canted antiferromagnetism with weak ferromagnetic ordering below T(C) = 12.4 K.
authors.affiliation: Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, Shanghai 200062, PR China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Wang
authors.forename: Xiu-Bing
authors.initials: XB
authors.lastname: Li
authors.forename: Ren-He
authors.initials: RH
authors.lastname: Yan
authors.forename: Yan-Qin
authors.initials: YQ
authors.lastname: Wang
authors.forename: En-Qing
authors.initials: EQ
authors.lastname: Gao
mesh_terms: D001386:Azides / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D060526:Magnetic Fields; D008345:Manganese / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*
chemical_list: D001386:Azides; D002264:Carboxylic Acids; D007093:Imidazoles; D009942:Organometallic Compounds; D011108:Polymers; D008345:Manganese