Two Forgotten Ten-Vertex arachno Triheteroboranes: arachno-5,6,9-C2SB7H11 and arachno-5,6,9-C3B7H13, Their Molecular Structure Determination by ab initio/NMR Approach and Synthesis of the Thiacarbaborane

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Title:Two Forgotten Ten-Vertex arachno Triheteroboranes: arachno-5,6,9-C2SB7H11 and arachno-5,6,9-C3B7H13, Their Molecular Structure Determination by ab initio/NMR Approach and Synthesis of the Thiacarbaborane
Creators:
Hnyk, Drahomír
Holub, Josef
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 67, 6, pp. 813-821
Uncontrolled Keywords:Structure elucidation, <i>Ab initio</i> calculations, Boranes, Thiaboranes, Heteroboranes, Carboranes, Thiacarboranes, NMR spectroscopy

Abstract

A solution of <i>nido</i>-5,6-C<sub>2</sub>B<sub>8</sub>H<sub>12</sub> reacted in the presence of Et<sub>3</sub>N with sulfur to yield the first mixed triheteroborane based on the [<i>arachno</i>-B<sub>10</sub>H<sub>14</sub>]<sup>2-</sup> framework (<i>C</i><sub>2<i>v</sub></i> symmetry), <i>i.e.</i> <i>arachno</i>-5,6,9-C<sub>2</sub>SB<sub>7</sub>H<sub>11</sub>. This compound is isoelectrolobal with known <i>arachno</i>-5,6,9-C<sub>3</sub>B<sub>7</sub>H<sub>13</sub>. The structures of these two ten-vertex <i>arachno</i> triheteroboranes have been established by the <i>ab initio</i>/IGLO (and GIAO-SCF)/NMR method. The presence of three heteroatoms and the absence of the hydrogen atom bridging the 5 and 10 atoms are responsible for a symmetry reduction from <i>C</i><sub>2<i>v</sub></i> to <i>C</i><sub>1</sub> in both compounds. The carbon atoms are compressed toward the center and the sulfur atom is pushed away from the center of the respective cluster relative to the positions they would have in [<i>arachno</i>-B<sub>10</sub>H<sub>14</sub>]<sup>2-</sup>. These distortions from the parent compound are well described by the MP2/6-31* geometrical parameters. A good fit between the computed and measured <sup>11</sup>B chemical shifts revealed that the MP2/6-31G* internal coordinates are good representations of the molecular geometries of these two ten-vertex <i>arachno</i> heteroboranes. <p>

Title:Two Forgotten Ten-Vertex arachno Triheteroboranes: arachno-5,6,9-C2SB7H11 and arachno-5,6,9-C3B7H13, Their Molecular Structure Determination by ab initio/NMR Approach and Synthesis of the Thiacarbaborane
Creators:
Hnyk, Drahomír
Holub, Josef
Uncontrolled Keywords:Structure elucidation, <i>Ab initio</i> calculations, Boranes, Thiaboranes, Heteroboranes, Carboranes, Thiacarboranes, NMR spectroscopy
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:67
Number:6
Page Range:pp. 813-821
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20020813UNSPECIFIED
ID Code:1957
Item Type:Article
Deposited On:06 Feb 2009 17:14
Last Modified:06 Feb 2009 16:14

Citation

Hnyk, Drahomír; Holub, Josef (2002) Two Forgotten Ten-Vertex arachno Triheteroboranes: arachno-5,6,9-C2SB7H11 and arachno-5,6,9-C3B7H13, Their Molecular Structure Determination by ab initio/NMR Approach and Synthesis of the Thiacarbaborane. Collection of Czechoslovak Chemical Communications, 67 (6). pp. 813-821. ISSN 0010-0765

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