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Intramolecular Interactions Through Triple Bonds. Internal Rotation in Aminoborylpolyynes, NH 2 (C≡C) n BH 2
Author(s) -
Radom Leo,
Vincent Mark A.
Publication year - 1980
Publication title -
israel journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.908
H-Index - 54
eISSN - 1869-5868
pISSN - 0021-2148
DOI - 10.1002/ijch.198000037
Subject(s) - chemistry , intramolecular force , triple bond , crystallography , ab initio , ab initio quantum chemistry methods , stereochemistry , molecule , double bond , organic chemistry , polymer chemistry
Ab initio molecular orbital theory has been used to examine interactions through triple bonds in polyynes [H‐(C≡C) n ‐H], aminopolyynes [NH 2 ‐(C≡C) n ‐H], borylpolyynes [H‐(C≡C) n ‐BH 2 ], and aminoborylpolyynes [NH 2 ‐(C≡C) n ‐BH 2 ], with n = 1,2,3 and 4. The rotational barrier in aminoborylpolyynes is a particularly effective probe of interactions transmitted through the triple bond network. The barrier for NH 2 ‐C≡C‐BH 2 is substantial (25.1 kJ mol −1 ) but is reduced by a factor of approximately 3 by the interposition of each additional C≡C linkage. There is a residual barrier (of 1.0 kJ mol −1 ) in NH 2 ‐C≡C‐C≡C‐C≡C‐BH 2 despite the fact that the interacting groups are separated by a distance of greater than 11 Å.