Abstract
Reaction of the cesium antimonide complex [Cs(18C6)(2)][SbH(2)] (1, 18C6 = 18-crown-6 ether) with the triamidoamine actinide separated ion pairs [An(Tren(TIPS))(L)][BPh(4)] (Tren(TIPS) = {N(CH(2)CH(2)NSi(i)Pr(3))(3)}(3-); An/L = Th/DME (2Th); U/THF (2U)) affords the triactinide undeca-antimontriide Zintl clusters [{An(Tren(TIPS))}(3)(μ(3)-Sb(11))] (An = Th (3Th), U (3U)) by dehydrocoupling. Clusters 3Th and 3U provide two new examples of the Sb(11)(3-) Zintl trianion and are unprecedented examples of molecular Sb(11)(3-) being coordinated to anything since all previous reports featured isolated Sb(11)(3-) Zintl trianions in separated ion quadruple formulations with noncoordinating cations. Quantum chemical calculations describe dominant ionic An-Sb interactions in 3Th and 3U, though the data suggest that the latter exhibits slightly more covalent An-Sb linkages than the former. Complexes 3Th and 3U have been characterized by single crystal X-ray diffraction, NMR, IR, and UV/vis/NIR spectroscopies, elemental analysis, and quantum chemical calculations.