A new 28-Ni-added poly(polyoxometalate)with B atoms:synthesis,structure and catalysis for Knoevenagel condensation  

作　　者：Chen Lian Hai-Lou Li Guo-Yu Yang 

机构地区：[1]Key Laboratory of Cluster Science of Ministry of Educaiton,School of Chemistry and Chemical Engineering,Beijing Institute of Technology,Beijing102488,China

出　　处：《Science China Chemistry》2023年第5期1394-1399,共6页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC,21831001,21571016,91122028);the NSFC for Distinguished Young scholars(20725101)。

摘　　要：The synergistic effect of trivacant B-α-Ge W_(9)O_(34)fragments as structure-directing agents and inorganic B-O segments as intramolecular decoration afforded an unprecedented 28-Ni-added huge cluster K_(2)Na_(14)H_(10)[{Ni_(6)(OH)_(3)(H_(2)O)_(6)(Ge W_(9)O_(34))}{Ni_(8)-(μ_(6)-O)(OH)_(3)(H_(2)O)(BO(OH)_(2))(B_(2)O_(3)(OH)_(2))(Ge W_(9)O_(34))_(2)}]_(2)·46H_(2)O(1)under hydrothermal conditions.The polyoxoanion of 1contains two half-units,[{Ni_(6)(OH)_(3)(H_(2)O)_(6)(Ge W_(9)O_(34))}{Ni_(8)(μ_(6)-O)(OH)_(3)(H_(2)O)(BO(OH)_(2))(B_(2)O_(3)(OH)_(2))(Ge W_(9)O_(34))_(2)}]^(13-),which joined together via Ni-O=W linkages.The most fascinating feature is that each half-unit can be regarded as the fusion of an Ni_(6)(OH)_(3)(H_(2)O)_(6)(B-α-Ge W_(9)O_(34))({Ni_6Ge W_(9)})and a previously unobserved sandwiched Ni_(8)(μ_(6)-O)(OH)_(3)(H_(2)O)(BO(OH)_(2))(B_(2)O_(3)-(OH)_(2))(B-α-Ge W_(9)O_(34))_(2)({(Ni_(8)BB_(2))@(Ge W_(9))_(2)}),in which the{Ni_(8)BB_(2)}cluster contains a Lindqvist-type{Ni_(6)}core capped by two Ni O_(6)octahedra and further decorated by a BO(OH)_(2)({B})group and a binuclear B_(2)O_(3)(OH)_(2)({B_(2)})cluster.Furthermore,1 as a heterogeneous catalyst,has good catalytic activity for Knoevenagel condensation under mild reaction conditions.

关 键 词：POLYOXOMETALATE hydrothermal synthesis high-nuclearity TMAPs knoevenagel condensation 

分 类 号：O643.36[理学—物理化学]