p-tert-Butylthiacalix[4]arene-supported high-nuclearity {Co_24M_8} (M = Mo or W) nanospheres and the hybrids with Keggin polyoxometalates

摘要

Two hybrid assembles (3 and 4) with two kind of nanoscaled cluster units, the spherical [Co_24(TC4A)_6(MO_4)_8Cl_6]~(2+) cation (1 and 2) and Keggin-type [PM_12O_40]~(3-) anion (M = Mo (1/3), W (2/4)), were solvothermally prepared and characterized, in which the spherical units are constructed by six Co_4-p-tert-butylthiacalix[4]arene (Co_4-TC4A) SBUs linked by eight MO_4 tetrahedrons and present the highest nuclearity bimetallic clusters capped by cailxarenes.