The structure of Na_2H_2[H_2V_2W_(18)O_(62)]12H_2O has been determined by x-ray analysis.The crystals are trigonal,space group R3m,with cell parameters a=37.613(11),c=12.972(7)A,V=15901(13)A^3,and Z=9.The structure mo...The structure of Na_2H_2[H_2V_2W_(18)O_(62)]12H_2O has been determined by x-ray analysis.The crystals are trigonal,space group R3m,with cell parameters a=37.613(11),c=12.972(7)A,V=15901(13)A^3,and Z=9.The structure model was refined by full-matrix least square to R=0.065 for 1702 reflections with F>4σ(F). The existence of the[H_2V_2W_(18)O_(62)]^(4-)heteropolyanion in the crystals has been confirmed.It is composed of two VO_4 tetrahedra and eighteen WO_6 octahedra linked to gve the Dawson-type structure.展开更多
文摘The structure of Na_2H_2[H_2V_2W_(18)O_(62)]12H_2O has been determined by x-ray analysis.The crystals are trigonal,space group R3m,with cell parameters a=37.613(11),c=12.972(7)A,V=15901(13)A^3,and Z=9.The structure model was refined by full-matrix least square to R=0.065 for 1702 reflections with F>4σ(F). The existence of the[H_2V_2W_(18)O_(62)]^(4-)heteropolyanion in the crystals has been confirmed.It is composed of two VO_4 tetrahedra and eighteen WO_6 octahedra linked to gve the Dawson-type structure.