Polyhedral Borane Analogues of the Benzynes and Beyond: Bonding in Variously Charged B₁₂H₁₀ Isomers

Abstract

The effect of removing two protons, hydrogen atoms, or hydrides from the stable icosahedral B(12)H(12)(2-) is investigated theoretically. The resulting B(12)H(10)(q) (q = 4-, 2-, 0) isomers show interesting and understandable bond distance and stability variations, as well as special deformations associated with the apex-ring configuration typical of the underlying polyhedron. The dianions are analogous to o-, m-, and p-benzyne and have the special feature of distinct singlet and triplet states not far removed from each other in energy.

Density functional studies on (NCH)n azagraphane: activated surface for organocatalysis

“…Compared to the ideal C-H (1.10 Å) and C-N (1.47 Å) single bond distances, C-H bonds are elongated by B0.05 Å while C-N bonds are shortened by 0.015 Å since the C-H bonds are aptly oriented for anomeric delocalization of the N: lone pair. The pyramidalization angle 22 of nitrogen, computed as the deviation of the sum of all the The computed band structure shows a large band-gap (Fig. 3), the conduction band minimum is at G while the valence band maximum lies in between G and K special k-points.…”

Carboranes as model hypercarbon systems; structural and bonding patterns in selected isoelectronic closo-borane and carborane systems; [BnHn]2−, [1-CBn−1Hn]− and 1,n-C2Bn−2Hn (n = 5, 6, 7, 10 or 12)

“…[17][18][19][20][21][22][23][24][25][26][27] We carried out MP2/6-31G* calculations on the fifteen systems [B n H n ] 2-, [1-CB n-1 H n ] -and 1,n-C 2 B n-2 H n (n = 5, 6, 7, 10, and 12) with the Gaussian09 computational package. [28] Our bond orders/indices were calculated by the Wiberg Bond Index method and the atomic and group charges by Natural Population Analysis (NPA) using the NBO 3.1 program within Gaussian09.…”

Boron, aluminium, gallium, indium and thallium

“…65,66 Theoretical studies into B 12 H 10 q (q = 0, À2 or À4) were performed which indicated that [o-B 12 H 10 ] 2À has a singlet ground state with a short B naked -B naked distance making it an o-carboryne analogue. 67 A method to C-alkylate [1-H-CB 11 Cl 11 ] À using KOtBu and RI was reported, 68 whilst [1-H-CB 11 Cl 11 ] À partnered with the tBu cation enabled hyperconjugation and anion-cation hydrogen bonding to be probed in the solid state. 69 Cluster opening reactions have been reported on addition of a NHC to o-carborane and on addition of nucleophiles (e.g., HOR and HNR 2 ) to the 13-vertex carborane, m-1,2-(CH 2 ) 3 -1,2-C 2 B 11 H 11 .…”