Opening of Closed Azadecaboranes RNB9H9 by Amines

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Title:Opening of Closed Azadecaboranes RNB9H9 by Amines
Creators:
Roth, Martin
Meyer, Franc
Paetzold, Peter
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 62, 8, pp. 1299-1309
Uncontrolled Keywords:<i>nido/arachno</i> Hybrids, Cluster opening, Azadecaboranes

Abstract

The aza-<i>closo</i>-decaborane RNB<sub>9</sub>H<sub>9</sub> (<strong>4a</strong>; R = 4-ClC<sub>6</sub>H<sub>4</sub>) is opened to give the <i>nido</i>-cluster RNB<sub>9</sub>H<sub>9</sub>(tmeda) (<strong>7a</strong>) by the addition of Me<sub>2</sub>N(CH<sub>2</sub>)<sub>2</sub>NMe<sub>2</sub> (tmeda). The cluster <strong>7a</strong> contains the same type of asymmetric hydrogen bridge as is present in the isoelectronic <i>nido</i>-anion [RNB<sub>9</sub>H<sub>10</sub>]<sup>-</sup> (<strong>10b</strong>, <strong>10c</strong>; R = Ph, PhCH<sub>2</sub>), obtained by the action of KBHEt<sub>3</sub> on the corresponding <i>arachno</i>-cluster RNB<sub>9</sub>H<sub>11</sub>(NH<sub>2</sub><i>t</i>-Bu) (<strong>9b</strong>, <strong>9c</strong>). Secondary amines HNR<sup>1</sup>R<sup>2</sup> yield the azaboranes RNB<sub>9</sub>H<sub>10</sub>(NR<sup>1</sup>R<sup>2</sup>) (<strong>11a-11c</strong>; R<sup>1</sup>/R<sup>2</sup> = H/<i>t</i>-Bu, Et/Et, <i>i</i>-Pr/<i>i</i>-Pr). From 2D-<sup>1</sup>H/<sup>11</sup>B NMR correlations, concerning the two non-terminal H atoms, and from the <sup>11</sup>B NMR shifts, a <i>nido/arachno</i> hybrid structure is deduced for <strong>11a-11c</strong>, governed by the contribution of pi-bonding between the lone pair of the amino group and the neighbouring B atom. Amines, like nucleophiles generally, attack the <i>closo</i>-boranes RNB<sub>9</sub>H<sub>9</sub> at one of the B atoms adjacent to the N atom, as expected.

Title:Opening of Closed Azadecaboranes RNB9H9 by Amines
Creators:
Roth, Martin
Meyer, Franc
Paetzold, Peter
Uncontrolled Keywords:<i>nido/arachno</i> Hybrids, Cluster opening, Azadecaboranes
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:62
Number:8
Page Range:pp. 1299-1309
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19971299UNSPECIFIED
ID Code:1209
Item Type:Article
Deposited On:06 Feb 2009 17:07
Last Modified:06 Feb 2009 16:07

Citation

Roth, Martin; Meyer, Franc; Paetzold, Peter (1997) Opening of Closed Azadecaboranes RNB9H9 by Amines. Collection of Czechoslovak Chemical Communications, 62 (8). pp. 1299-1309. ISSN 0010-0765

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