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A Stacking Interaction between a Bridging Hydrogen Atom and Aromatic π Density in the n ‐B 18 H 22 –Benzene System
Author(s) -
Hamilton Ewan J. M.,
Kultyshev Roman G.,
Du Bin,
Meyers Edward A.,
Liu Shengming,
Hadad Christopher M.,
Shore Sheldon G.
Publication year - 2006
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200501043
Subject(s) - benzene , cyclohexane , crystallography , chemistry , hydrogen atom , stacking , atom (system on chip) , density functional theory , crystal structure , hydrogen , hydrogen bond , chlorine atom , molecule , computational chemistry , medicinal chemistry , group (periodic table) , organic chemistry , computer science , embedded system
The structures of n ‐B 18 H 22 and of n ‐B 18 H 22 ⋅C 6 H 6 were determined by single‐crystal X‐ray analysis at −60 °C. The geometry of the boron cluster itself does not seem to be appreciably affected by solvation. There does, however, appear to be an unusual interaction of a polyborane bridging hydrogen atom with the benzene π system, giving rise to an extended stacked structure. The 1 H{ 11 B} spectrum of n ‐B 18 H 22 in [D 6 ]benzene differs from that in [D 12 ]cyclohexane most noticeably in the bridging proton region. Upon moving from the aliphatic to the aromatic solvent, the greatest increase in shielding was for the signal corresponding to the bridge hydrogen atom that interacts with the π system of benzene; the signal was shifted upfield by 0.49 ppm. Density functional theory calculations were performed on 1:1 and 2:1 complexes of the n ‐B 18 H 22 unit with benzene.