Reversal of stability on metalation of pentagonal-bipyramidal $(1-MB_6H_7^{2-}$,$1-M-2-CB_5H_7^{1-}$, and $1-M-2,4-C_2B_4H_7)$ and icosahedral $(1-MB_{11}H{12}^{2-}, 1-M-2-CB_{10}H_{12}^{1-}$, and $1-M-2,4-C_2B_9H_{12})$ boranes (M= ) Al, Ga, In, and Tl):Energetics of condensation and relationship to binuclear metallocenes

Pathak, Biswarup and Pandian, Shanthi and Hosmane, Narayan and Jemmis, Eluvathingal D (2006) Reversal of stability on metalation of pentagonal-bipyramidal $(1-MB_6H_7^{2-}$,$1-M-2-CB_5H_7^{1-}$, and $1-M-2,4-C_2B_4H_7)$ and icosahedral $(1-MB_{11}H{12}^{2-}, 1-M-2-CB_{10}H_{12}^{1-}$, and $1-M-2,4-C_2B_9H_{12})$ boranes (M= ) Al, Ga, In, and Tl):Energetics of condensation and relationship to binuclear metallocenes. In: Journal of The American Chemical Society, 128 (33). pp. 10915-10922.

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Abstract

The usual assumption of the extra stability of icosahedral boranes (2) over pentagonal-bipyramidal boranes (1) is reversed by substitution of a vertex by a group 13 metal. This preference is a result of the geometrical requirements for optimum overlap between the five-membered face of the ligand and the metal fragment. Isodesmic equations calculated at the B3LYP/LANL2DZ level indicate that the extra stability of $1-M-2,4-C_2B_4H_7$ varies from 14.44 kcal/mol (M= ) Al) to 15.30 kcal/mol (M= ) Tl). Similarly, $M(2,4-C_2B_4H_6)_2^{1-}$ is more stable than $M(2,4-C_2B_9H_11)_2^{1-}$ by 9.26 kcal/mol (M= Al) and by 6.75 kcal/mol (M= Tl). The preference for $(MC_2B_4H_6)_2$ over $(MC_2B_9H_11)_2$ at the same level is 30.54 kcal/mol (M= Al), 33.16 kcal/ mol (M= Ga) and 37.77 kcal/mol (M= In). The metal-metal bonding here is comparable to those in CpZn-ZnCp and $H_2M-MH_2$ (M= Al, Ga, and In).

Item Type:	Journal Article
Publication:	Journal of The American Chemical Society
Publisher:	American Chemical society
Additional Information:	Copyright of this article belongs to American Chemical Society.
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	08 Dec 2006
Last Modified:	19 Sep 2010 04:31
URI:	http://eprints.iisc.ac.in/id/eprint/8616

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