层状钴有机膦酸化合物的合成以及变磁行为  

Layered Cobalt Phosphonate with Metamagnetism

作　　者：蔡中胜[1] 鲍松松[1] 郑丽敏[1] 

机构地区：[1]南京大学配位化学国家重点实验室,210093

出　　处：《化学学报》2013年第4期555-559,共5页Acta Chimica Sinica

基　　金：科技部重大研究计划(No.2010CB923402);江苏省自然科学基金(No.BK2009009)资助~~

摘　　要：从配体C6H5CH2N(CH2PO3H2)2(H4L)出发,在水热条件下得到了两个层状结构化合物Co2(L)(H2O)2 0.3H2O(1)和Co2(L)(H2O)(2).在这两个化合物的层结构中分别存在"之"字型和"蝴蝶"型的{Co4O6}四核簇结构单元,相邻四核通过O-P-O桥连形成二维无机层状结构,有机基团位于层与层之间.磁性测试表明,化合物1中存在反铁磁耦合,并且在低温下表现出场致变磁行为;我们还对化合物1的脱水样品(1-de)进行了磁性测试,测试结果表明化合物1-de存在自旋翻转现象.CCDC:908112(1),908113(2).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),b=9.484(1),c=12.705(1),α = 91.7(1)°,β= 96.2(1)°,γ =103.9(1)°,V=733.8(1) 3,Z=2 and compound 2 crystallizes in monoclinic space group P21/c,with a= 14.165(2),b=9.574(1),c=10.072(1),β=102.5(1)°,V=1333.4(3) 3,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 HSFof 28.0 kOe at 1.8 K.CCDC: 908112(1),908113(2).

关 键 词：层状 钴 有机膦酸 变磁 

分 类 号：O627.8[理学—有机化学]