Ten-vertex metallaborane chemistry: facile, thermally induced, nido→isocloso cluster-closure oxidation reactions in iridadecaborane clusters

Abstract

The four nido‐iridadecaborane cluster compounds (I), (IV) and (V) lose hydrogen on heating to give in each case an isocloso‐iridadecaborane cluster.

Metal fragment exchange from a molybdaborane to a tungstaborane

“…However, there have been relatively few studies of the reactivity of metallaboranes. Some metallaboranes have been used as synthons in the stepwise synthesis of heterometallaboranes (or polymetallaboranes) by further reaction with metal complexes: these studies have been limited mainly to reactions of transition-metal halides and the larger, more stable metallaborane anions [5][6][7][8][9][10][11][12][13][14][15]. Some years ago we prepared the molybdaborane arachno-2-[Mo(g-C 5 H 5 )(g 5 :g 1 -C 5 H 4 )B 4 H 7 ] (I) in gram quantities permitting a study of its reactivity [16].…”

Metallacarborane chemistry of the hypho-[6,7-C2B6H13]− anion: the formation of uniquely structured metallacarboranes [5-Cp∗-arachno-5Londesborough1, Janoušek2, Štı́br3 et al. 2004Journal of Organometallic Chemistry120110View full textAdd to dashboardCite

“…This nido geometry is also seen in the carborane, C 2 B 7 H 9 Me 2 [8], and in a single metallaborane example; (CO)(PMe 3 ) 2 IrB 8 H 11 [9]. Scheme 4 shows the polyhedral skeletons of these two examples and also that of compound 3.…”

“…For 2: m.p. 167°C, 11 B NMR (128.3 MHz,25°C): d = À0.7 (d,2B,B7,9) 8 mmol) and l,8-bis-(dimethylamino)-naphthaline (proton-sponge) (0.61 g; 2.8 mmol) and the mixture was allowed to stir at room temperature overnight (10 h). In a similar fashion to the preparation of compound 1, the progress of reaction was monitored by TLC and, once the starting-material had disappeared, the reaction mixture was chromatographed using the same conditions as described above for compound 1.…”

“…, À1.4 (d, 1 J(B,H) = $145 Hz, 2B, B1,2), À25.4 (d, 1 J(B,H) = 174 Hz, 1B, B8), À40.7 (d, d, 1 J(B,H) = 137 Hz, 1B, B3), all theoretical [ 11 B-11 B]-COSY crosspeaks observed, except for B7,9-B8 and B1,2-B8; 1 H{ 11 B} NMR (400 MHz, 25°C): d = 3.03 (s, 2H, H7,9), 2.17 (s, 2H, H1,2), 1.95 (s, 1H, H8), 0.13 (s, 1H, H3), À0.38 (m, 3 J(H,H) = $8 Hz, 1H, exo-H4, 6), À1.86 (m, 1 J(H,H) = $8 Hz, 1H, endo-H4, 6), À2.33 (s, 2H, lH7,9).…”

Metallacarborane chemistry of the hypho-[6,7-C2B6H13]− anion: Reaction with nickelocene and the formation of three multimetallic nickel–boron clusters

“…Nevertheless, both isomers share a cluster structure that may be derived from a tricapped trigonal prism by elongation of the Ni7-B9 polyhedral edge. This is an unusual nido configuration that is, in this case, strangely favoured to that derived from the elongation of two edges (such as Ni7-B3 and Ni7-B4) to generate a five-membered open face: a geometry adopted by the majority of nido nine-vertex species [3,[7][8][9][10]. Confirmation of the isomeric nature of compounds (2) of (3) is also in the ready conversion of (3) into (2) on heating in boiling toluene.…”