Parker, Dorian S. N. Balucani, Nadia Stranges, Domenico Kaiser, Ralf I. Mebel, Alexander 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>) 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. 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
    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
10.1021/jp405228f.s001