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Carbene triel bonds between TrR 3 (Tr = B, Al) and N‐heterocyclic carbenes
Author(s) -
Chi Zongqing,
Dong Wenbo,
Li Qingzhong,
Yang Xin,
Scheiner Steve,
Liu Shufeng
Publication year - 2019
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.25867
Subject(s) - chemistry , lone pair , carbene , intermolecular force , crystallography , covalent bond , bond order , atom (system on chip) , hypervalent molecule , bond length , computational chemistry , binding energy , molecule , catalysis , atomic physics , crystal structure , organic chemistry , physics , computer science , embedded system , reagent
The carbene triel bond is predicted and characterized by theoretical calculations. The C lone pair of N‐heterocyclic carbenes (NHCs) is allowed to interact with the central triel atom of TrR 3 (Tr = B and Al; R = H, F, Cl, and Br). The ensuing bond is very strong, with an interaction energy of nearly 90 kcal/mol. Replacement of the C lone pair by that of either N or Si weakens the binding. The bond is strengthened by electron‐withdrawing substituents on the triel atom, and the reverse occurs with substitution on the NHC. However, these effects do not strictly follow the typical pattern of F > Cl > Br. The TrR 3 molecule suffers a good deal of geometric deformation, requiring on the order of 30 kcal/mol, in forming the complex. The R(C···Tr) bond is quite short, for example, 1.6 Å for Tr = B, and shows other indications of at least a partially covalent bond, such as a high electron density at the bond critical point and a good deal of intermolecular charge transfer.