The conjugation stabilization of 1,3-butadiyne is zero.
[reaction: see text] In contrast to 1,3-butadiene, the textbook example of "conjugation stabilization", G3(MP2) calculations yielding the enthalpy of hydrogenation Delta(hyd)H(298) of 1,3-butadiyne indicate that it is not stabilized by the conjugated configuration of its triple bonds. Differences between ethylenic and acetylenic pi bonds are examined in the light of CAS-MCSCF calculations on 1,3-butadiene and 1,3-butadiyne.
Rogers
Donald W
DW
Department of Chemistry and Biochemistry, Long Island University, Brooklyn, New York 11201, USA. drogers@liu.edu
Matsunaga
Nikita
N
Zavitsas
Andreas A
AA
McLafferty
Frank J
FJ
Liebman
Joel F
JF