J. Cowie et al., STRUCTURES OF [HNET3]-PH2-7,8-NIDO-C2B9H10]-( AND [ME3NCH2C6H5]+ SALTS OF [7,8), Acta crystallographica. Section C, Crystal structure communications, 49, 1993, pp. 710-714
Triethylammonium phenyl-7,8-dicarba-nido-decahydroundecaborate(1-), C6
Hl6N+.C14-H20B9-, M(r) = 387.80, triclinic, P1BAR, a = 11.014 (4), b =
11.030 (7), c = 12.333 (6) angstrom, alpha = 67.83 (5), beta = 80.78
(4), gamma = 60.20 (5)degrees, V = 1203.3 angstrom3, Z = 2, D(x) = 1.0
70 Mg m-3, lambda(Mo Kalpha) = 0.71069 angstrom, mu = 0.052 mm-1, F(00
0) = 416, T = 291 (1) K, R = 0.1074 for 3289 independent observed refl
ections. Benzyltrimethylammonium phenyl-7,8-dicarba-nido-decahydrounde
caborate(1-), C10H16N+.-C14H20B9-, M(r) = 435.85, monoclinic, P2(1)/n,
a = 10.751 (4), b = 21.662 (4), c = 11.9745 (25) angstrom, beta = 106
.592 (23)degrees, V = 2672.5 angstrom3, Z = 4, D(x) = 1.083 Mg m-3, la
mbda(Mo Kalpha) = 0.71069 angstrom, mu = 0.053 mm-1, F(000) = 928, T =
185 (1) K, R = 0.0637 for 3857 independent observed reflections. In b
oth determinations, the phenyl substituents lie very roughly orthogona
l to the open C2B3 face of the anion, pairs of rings being twisted (in
a conrotatory manner) by an average of 7.8-degrees for the [HNEt3] salt, and 19.0-degrees for the [Me3NCH2C6H5]+ salt, from this extreme.
In the latter case, this twist is traced to interion contacts. The C(
cage)-C(cage) distances, 1.590 (5) and 1.602 (3) angstrom, respectivel
y, and the mean facial B-B and facial B-C distances are discussed in r
elation to the equivalent distances in 1,2-Ph2-1,2-closo-C2B10H10.