A manganese(II) coordination polymer with mixed pyrimidine-2-carboxylate and oxalate bridges: synthesis, structure, and magnetism

作者：Zhang, Man-Yong; Ma, Yu; Cheng, Ai-Ling; Yue, Qi; Sun, Qian; Gao, En-Qing^*

来源：Dalton Transactions, 2008, (15): 2061-2066.

DOI：10.1039/b717837a

• CRYSTAL-STRUCTURE
• HYDROTHERMAL SYNTHESIS
• WEAK FERROMAGNETISM
• II COMPLEXES
• CO-II
• FE-II
• NETWORKS
• LIGAND
• NI
• BEHAVIOR

A new two-dimensional (213) coordination polymer with mixed pyrimidine-2-carboxylate (pymca) and oxalate (ox) bridges, [Mn-2(pymca)(2)(ox)(H2O)(2)](n) (1), was synthesized by a hydrothermal reaction involving the in situ formation of the pymca and ox ligands from 2-cyanopyrimidine (pymCN), and its structure and magnetic properties were characterized. The dianionic ox and monoanionic pymca ligands are both potentially bis(chelating) and have been used to construct anionic and cationic 2D honeycomb networks [(6,3) net], respectively. In the present compound, ox assumes the usual bis(chelating) bridging mode, but pymca serves as a tridentate bridge with one of the pyrimidyl nitrogens uncoordinated. The two different bridges collaborate to generate a highly undulated 2D layer with the (6,3) net topology, and the layers are closely packed in parallel through pi-pi interactions between pyrimidyl rings and hydrogen bonds involving coordinated water molecules, oxalate oxygens, and uncoordinated pyrimidyl nitrogens. Magnetic measurements reveal that the compound is a spin-canted antiferromagnet with weak ferromagnetic transition below T-c = 2.4 K.

• 出版日期2008-4-21
• 单位中国科学院福建物质结构研究所; 华东师范大学; 结构化学国家重点实验室