M. Diaz et al., INTERACTION OF TRIMETHYLAMINE AND CLOSO-1,6-C2B7H9 - EVIDENCE FOR AN OPEN CAGE C2B7H9 AMINE ADDUCT/, Inorganic chemistry, 35(16), 1996, pp. 4536-4540
Strong evidence for the low-temperature formation of an axially positi
oned NR(3) (R = H, CH3) adduct of an ''open'' cage C2B7H9 structure is
Obtained via comparison of the experimentally obtained C-13 and B-11
NMR data (R = CH3) with that obtained from ab initio/IGLO/NMR and ab i
nitio/GIAO/NMR approaches (R = H, CH3). The amine is positioned at a b
oron surrounded by the two carborane carbon atoms along a chair arrang
ement of a six-atom CBCB3 open face belonging to a cluster that can be
formally derived by removing a triangular set of three adjacent verti
ces from a 12-vertex icosahedral unit. Rapid equilibration of the addu
ct NR(3) . C2B7H9 With dissociated NR(3) and closo-C2B7H9 is proposed
to explain the NMR chemical shift observations.