Structure of 8-[1,2-dicarba-closo-dodecaboran(12)-3-yl]-5,6-dicarba-nido-decaborane(12)

Dicarbaheteroborane Chemistry. Representatives of Two Eleven-Vertex Dicarbaazaundecaborane Families: nido-10,7,8-NC2B8H11, Its N-Substituted Derivatives, andarachno-1,8,11-NC2B8H13

“…As seen in Figure and as previously predicted in our preliminary communication, the basic cluster geometry of the arachno compound 3 is based on that of the ten-vertex dicarbaborane nido -5,6-C 2 B 8 H 12 in which the 8,9-bridging hydrogen atom has been replaced by a bridging {NH 2 } group. The dicarbaborane nido -5,6-C 2 B 8 H 12 itself is not structurally characterized by X-ray work, but interatomic distances may be compared to the equivalent distances in the { nido -5,6-C 2 B 8 H 11 } subcluster of the structurally characterized C 4 B 18 H 22 isomer 8-(3‘- closo -1,2-C 2 B 10 H 11 )- nido -5,6-C 2 B 8 H 11 . Here it is immediately apparent that there are significant variations in otherwise equivalent interatomic distances when the two clusters are compared in detail.…”

Structural characterization and cage-condensation reactions of the coupled-cage borane 1:2'-[B5H8]2: new routes to higher single-cage boranes and carboranes

“…Single crystals were grown by sublimation in vacuo in a sealed Pyrex tube over ~1 week at 5 °C. Since 1:2'-[B5H8]2 melts at 18.4 °C and is also air-sensitive, it was necessary to open the Pyrex tube in a N2 gas filled glovebag in a cold room (5 °C) in order to select a crystal. A crystal of suitable size was mounted inside a capillary tube and then transferred quickly to the diffractometer.…”

A Return to the Plesek Reaction and Some Useful Variations. Carbon-Substituted Methyl and Phenyl Derivatives of 5,6-Dicarba-nido-decaborane(12), nido-5,6-C2B8H12

“…In particular, the results of mass spectrometry ( Table I) and the observed NMR data for the previously unreported derivatives of type 2, specifically 2b, 2c and 2f (Table II), are in excellent agreement with their formulation as the specified C-substituted compounds of the nido ten-vertex 5,6-dicarbadecaborane constitution 2. This general type-2 constitution was of course previously established unambiguously by single-crystal X-ray crystallography 33 and NMR studies 32 . Intercorrelation of the 11 B and 1 H chemical shifts for all the C-substituted derivatives of 2a thus far isolated is 6-Me-nido-5,6-C2B8H11 (2b) 11 In conclusion, therefore, it is now established that C-substituted derivatives of 2a can also be conveniently prepared by the Plesek reaction.…”

“…1 Stick representation and comparison of the 11 B chemical shifts and relative intensities for the unsubstituted 5,6-nido-C 2 B 8 H 12 (2a) (data from ref. 33 ) and its 5-Me (2c), 6-Me (2b), 5,6-Me 2 (2d) (data from ref. 8 ), 5-Ph (2f), 6-Ph (2e) (data from ref.…”