
TY  - JOUR
A1  - Clark, GR 
A1  - Palenik, GJ 
T1  - The crystal and molecular structure of 4-Bromo-1,1,3,3,5,7,7,9,9-nonamethylbicyclo[4,4,0]pentaborophane
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1975
VL  - 28
IS  - 6
SP  - 1187
EP  - 1193
KW  - 
UR  - https://doi.org/10.1071/CH9751187 
N2  - Crystals of 4-bromo-1,1,3,3,5,7,7,9,9- nonamethylbicyclo[4,4,0]pentaborophane, C9H35B5P5Br, are monoclinic, with a = 9.502(3), b = 20.185(15), c = 13.604(4) &#506;, &#946; = 116.49(2)°. The space group is P21/c, with four molecules in the cell. Intensity data were collected by means of an automated diffractometer. The atomic positions have been determined by least-squares refinement of 2859 observed reflections. The final residual, R, is 0.077. The molecule contains a framework of alternat- ing boron and phosphorus atoms constituting a decalin-like ring system. The two cis-fused cyclo- hexane type rings are both in the chair conformation. The bromine atom is equatorially bonded to the boron atom in the 4-position. The Br-B bond length is 2.039(10) &#506;. The average P-B and P-C distances are 1.943 and 1.828 &#506; respectively. Average internal ring angles are 112.2° for P-B-P, and 113.6° for B-P-B. This geometry indicates only very slight charge delocalization in the cyclic system. 
ER  -

