The solid state structure of [b(10)h(11)](-) and its dynamic NMR spectra in solution.

The structure of [PPh(3)(benzyl)][B(10)H(11)] was determined at -123 degrees C and 24 degrees C by single-crystal X-ray analyses. The B(10) core of [B(10)H(11)](-) is similar in shape to that of [B(10)H(10)](2)(-). The 11th H atom asymmetrically caps a polar face of the cluster and shows no tendency for disorder in the solid state.

Computational Studies of Nido-8-Vertex Boranes, Carboranes, Heteroboranes, and the Lewis Base Adduct nido-B(8)H(10)L.

An extensive investigation of boranes, carboranes, and heteroboranes falling into the nido-8-vertex electron-count class has been carried out using ab initio methods. The results of this study indicate a nido six-membered open face geometry, ni-8, is usually the preferred configuration over a nido five-membered open face geometry, ni-8. In only two systems, B(8)H(9)(3)(-) and OB(7)H(7)(2)(-), is a ni-8 geometry calculated to be of lowest energy.

Ab Initio/IGLO/NMR Investigation of nido-C(4)B(7)H(11) Configurations: Structural Assignment of the Three Known Isomers and Reconfirmation of Empirical Carbon Placement Patterns.

The ab initio/IGLO/NMR method has been successfully applied to establish the structures of the three known isomers of nido-C(4)B(7)H(11). The method confirms the previously proposed structure, nido-7,8,9,10-C(4)B(7)H(11), 1a, as one of the three known isomers. Of four candidates considered for the second isomer, one of the previously proposed structures, nido-1,7,8,10-C(4)B(7)H(11), 2b, is selected.