Synthesis and characterization of two hexacopper-capped Keggin-type polyoxoniobates

摘要

Two new capping Nb-Keggin clusters, [{Cu(2,2'-bipy)}(6)(TNb12O40)](3-) (T = P and As), have been hydrothermally synthesized and characterized by IR spectroscopy, single crystal X-ray diffraction, powder X-ray diffraction, elemental analysis and thermal gravimetric analysis. The polyoxoanion [{Cu(2,2'-bipy)}(6)(TNb12O40)](3-) consists of a classical alpha-Keggin-type {TNb12O40} structure capped by six {Cu(2,2'-bipy)} fragments, which represents the first example of copper-capped Keggin-type {TNb12O40} polyoxoanion. Besides, the organo-amines play key roles in the construction of structural diversity under the studied system.