作者:Tao Zheng、Song-Song Bao、Min Ren、Li-Min Zheng
DOI:10.1039/c3dt52125g
日期:——
The first examples of metal phosphonates based on 4-(ethoxycarbonyl)naphthanen-1-yl)phosphonic acid (4-cnppH2) are reported, namely, Co(4-cnpp) (1), Co2(4-cnpp)2(dptz) (2) and Co2(4-cnpp)2(4,4′-bpy)(H2O) (3) (dptz = 3,6-di(pyridin-3-yl)-1,2,4,5-tetrazine, 4,4′-bpy = 4,4′-bipyridine). The cobalt atoms are four-coordinated with distorted tetrahedral geometries in both 1 and 2, while five-coordinated with a distorted trigonal bipyramidal environment in compound 3. Compound 1 shows a layer structure in which the inorganic layers made up of edge-sharing CoNO3} dimers and PO3C} linkages are separated by the organic groups of the 4-cnpp2− ligands. Compound 2 displays a different type of layer structure, where the ladder-like chains composed of corner-sharing CoNO3} and PO3C} tetrahedra are connected by dptz ligands with the organic groups of the 4-cnpp2− ligands pendent on the two sides of the layer. In 3, similar ladder-like chains of corner-sharing CoNO4} and PO3C} are also found except that the cobalt atoms within the chain are further bridged by a coordinated water molecule. The chains are cross-linked by 4,4′-bpy, leading to a three-dimensional open-framework structure. Magnetic studies reveal that dominant antiferromagnetic interactions are mediated between the Co(II) ions in all three cases.
首次报道基于4-(乙氧基羧基)萘-1-基磷酸(4-cnppH2)的金属磷酸酯示例,即Co(4-cnpp) (1)、Co2(4-cnpp)2(dptz) (2)和Co2(4-cnpp)2(4,4′-bpy)(H2O) (3)(dptz = 3,6-二(吡啶-3-基)-1,2,4,5-四氮唑,4,4′-bpy = 4,4′-联吡啶)。在化合物1和2中,钴原子的配位方式为四配位,并呈现畸变的四面体几何形状,而在化合物3中则为五配位,呈现畸变的三角双锥环境。化合物1显示出一种层状结构,其中由边共享的CoNO3}二聚体和PO3C}链接构成的无机层被4-cnpp2−配体的有机基团分隔开。化合物2则展示出一种不同类型的层状结构,楼梯状链由角共享的CoNO3}和PO3C}四面体组成,并通过dptz配体连接,4-cnpp2−配体的有机基团悬挂在层的两侧。在3中,发现了类似的楼梯状链,由角共享的CoNO4}和PO3C}构成,唯一不同的是链中的钴原子通过一个配位水分子进一步桥连。链之间通过4,4′-bpy交联,形成三维开放框架结构。磁性研究表明,在这三种情况下,Co(II)离子之间主要存在反铁磁相互作用。