10.1021/jp405228f.s001
Dorian
S. N. Parker
Dorian
S. N.
Parker
Nadia Balucani
Nadia
Balucani
Domenico Stranges
Domenico
Stranges
Ralf I. Kaiser
Ralf I.
Kaiser
Alexander Mebel
Alexander
Mebel
A Crossed Beam and ab Initio Investigation on the
Formation of Boronyldiacetylene (HCCCC<sup>11</sup>BO; <i>X</i><sup>1</sup>Σ<sup>+</sup>) via the Reaction of the Boron Monoxide
Radical (<sup>11</sup>BO; <i>X</i><sup>2</sup>Σ<sup>+</sup>) with Diacetylene (C<sub>4</sub>H<sub>2</sub>; <i>X</i><sup>1</sup>Σ<sub>g</sub><sup>+</sup>)
American Chemical Society
2013
BO
C 1 carbon atom
gas phase reaction
boron monoxide
hydrogen atom emission
exit transition state
HCCCC
terminal carbon atoms
ab Initio Investigation
CN
boronyldiacetylene molecule
RRKM
C 4H X 1Σg
kJ
C 4H X 1Σg reaction dynamics
11BO
2013-08-29 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/A_Crossed_Beam_and_ab_Initio_Investigation_on_the_Formation_of_Boronyldiacetylene_HCCCC_sup_11_sup_BO_i_X_i_sup_1_sup_sup_sup_via_the_Reaction_of_the_Boron_Monoxide_Radical_sup_11_sup_BO_i_X_i_sup_2_sup_sup_sup_with_Diacetylene_C_sub_4_sub_H_sub_2_sub_i_X/2559355
The reaction dynamics of the boron
monoxide radical (<sup>11</sup>BO; <i>X</i><sup>2</sup>Σ<sup>+</sup>) with diacetylene
(C<sub>4</sub>H<sub>2</sub>; <i>X</i><sup>1</sup>Σ<sub>g</sub><sup>+</sup>) were investigated at a nominal collision energy
of 17.5 kJ mol<sup>–1</sup> employing the crossed molecular
beam technique and supported by <i>ab initio</i> and statistical
(RRKM) calculations. The reaction is governed by indirect (complex
forming) scattering dynamics with the boron monoxide radical adding
with its boron atom to the carbon–carbon triple bond of the
diacetylene molecule at one of the terminal carbon atoms without entrance
barrier. This leads to a doublet radical intermediate (C<sub>4</sub>H<sub>2</sub><sup>11</sup>BO), which undergoes unimolecular decomposition
through hydrogen atom emission from the C1 carbon atom via a tight
exit transition state located about 18 kJ mol<sup>–1</sup> above
the separated products. This process forms the hitherto elusive boronyldiacetylene
molecule (HCCCC<sup>11</sup>BO; <i>X</i><sup>1</sup>Σ<sup>+</sup>) in a bimolecular gas phase reaction under single collision
conditions. The overall reaction was determined to be exoergic by
62 kJ mol<sup>–1</sup>. The reaction dynamics are compared
to the isoelectronic diacetylene (C<sub>4</sub>H<sub>2</sub>; <i>X</i><sup>1</sup>Σ<sub>g</sub><sup>+</sup>)–cyano
radical (CN; <i>X</i><sup>2</sup>Σ<sup>+</sup>) system
studied previously in our group. The characteristics of boronyl-diacetylene
and the boronyldiacetylene molecule (HCCCC<sup>11</sup>BO; <i>X</i><sup>1</sup>Σ<sup>+</sup>) as well as numerous intermediates
are reported for the first time.