Acta Chimica Sinica ›› 2013, Vol. 71 ›› Issue (04): 555-559.DOI: 10.6023/A12100839 Previous Articles     Next Articles



蔡中胜, 鲍松松, 郑丽敏   

  1. 南京大学 配位化学国家重点实验室 210093
  • 投稿日期:2012-10-30 发布日期:2013-01-25
  • 通讯作者: 郑丽敏
  • 基金资助:

    项目受科技部重大研究计划(No. 2010CB923402)和江苏省自然科学基金(No. BK2009009)资助.

Layered Cobalt Phosphonate with Metamagnetism

Cai Zhongsheng, Bao Songsong, Zheng Limin   

  1. State Key Laboratory of Coordination Chemistry, Nanjing University 210093
  • Received:2012-10-30 Published:2013-01-25
  • Supported by:

    Project supported by the National Basic Research Program of China (No. 2010CB923402) and the Natural Science Foundation of Jiangsu Province of China (No. BK2009009).

Two layered cobalt phosphonates, namely, Co2(L)(H2O)2·0.3H2O (1) and Co2(L)(H2O) (2) (H4L=C6H5CH2N- (CH2PO3H2)2) have been synthesized under hydrothermal condition. Single-crystal X-ray diffraction determinations reveal that compound 1 crystallizes in triclinic space group P-1, with a=6.320(1) Å, b=9.484(1) Å, c=12.705(1) Å, α = 91.7(1)°, β= 96.2(1)°, γ =103.9(1)°, V=733.8(1) Å3, Z=2 and compound 2 crystallizes in monoclinic space group P21/c, with a=14.165(2) Å, b=9.574(1) Å, c=10.072(1) Å, β=102.5(1)°, V=1333.4(3) Å3, Z=4. Both compounds display layered structures in which the inorganic layers made up of tetranuclear clusters of {Co4O6} and {PO3C} linkages are separated by the methylphenyl groups. However, the tetranuclear clusters are different in the two compounds. In 1, the {Co4O6} cluster is composed of edge-sharing {Co(1)NO5} and {Co(2)O6} octahedra in a zigzag arrangement. While in 2, the equivalent edge-sharing {Co(1)NO5} octahedra are each corner-shared with the {Co(1)O5} triangular bipyramids, forming a butterfly-like tetramer. Magnetic measurements are conducted for compound 1 which shows a dominant antiferromagnetic interactions between the Co(II) centers. Moreover, metamagnetism is observed for 1 at low temperature with a critical field of 26.0 kOe at 2 K. The dehydrated sample, 1-de, was also prepared by heating 1 at 180 ℃ for 20 min. Magnetic measurement reveals that 1-de exhibits field-induced spin-flop transition with HSF of 28.0 kOe at 1.8 K. CCDC: 908112 (1), 908113 (2).

Key words: layer, cobalt, phosphonate, metamagnetism