A large heteropolytungstotetracerate(III) based on a new divacant lacunary derivative of the Wells-Dawson tungstophosphate anion

摘要

The heteropolyanion [Ce_4(OH)_2(H_2O)_9(P-2W_(16)O_(59))_2]~(14-) (1) has been isolated as a potassium salt, in approx = 40% yield, from a neutral solution formed by reaction of a suspension of K_(12)H_2P_2W_(12)O_(48)24H_20 IN 1 M Licl with Na_2WO_4 and Ce(NO_3)_3 Single crystal X-ray analysis of K_(12)H_2[Ce_4(OH_2)_9(OH)_2(P_2W_(16)O_(59))_2] 48 H_2O(monoclinic, space group C_2, a = 18.198 0(2) A, b = 12.205 80(10) A, c = 23.238 00(10) A #alpha# = 114,879 0(10) deg; 17 164 independent reflections; R_1 = 0.057 6) reveals an anion of C_(2v) virtual symmetry in which four Ce~(3+) cations are sandwiched between teo novel divacant lacunary derivatives of the wells-Dawson anion, #alpha#-[P_2W_(18)O_(62)]~(6-). The lacunary anions (of C_s symmetry )have adjacent metal atom vacancies on both sides of the equator of the Wells-Dawon structure. The four cerium(III)centers (two 9-and two 10-coordinate) are linked by two #mu#_3-OH(Ce_3), one #mu#_2-H_2O(Ce_2) and four #mu#_3-O(W,Ce_2). The heteropolyanion is aqueous solution and yieleds well resolved ~(31)p (#delta# = + 4.0 ppm) and ~(183)W NMR spectra (8 lines of equal intensity, #delta# = + 296 to -188 ppm) that are consistent with the solid state structure.