p-tert-Butylthiacalix[4]arene-supported high-nuclearity {Co24M8} (M = Mo or W) nanospheres and the hybrids with Keggin polyoxometalates

Two hybrid assembies (3 and 4) with two kind of nanoscaled cluster units, the spherical [Co-24(TC4A)(6)(MO4)(8)Cl-6](2+) cation (1 and 2) and Keggin-type [PM12O40](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(b)utylthiacalix[4]arene (Co-4-TC4A) SBUs linked by eight MO4 tetrahedrons and present the highest nuclearity bimetallic clusters capped by cailxarenes.