Representative derivative chemistry of the 1,6- and 1,10-B8C2H10 carborane system

Abstract

results have been reported by Solomon, et a/.,15•35 and attributed to the 02+ ion.As might be expected, the X-ray diffraction pattern of the powder is very similar in both spacings and intensity distribution to that40 of NO+BF4~. We have indexed our pattern on the basis of an orthorhombic unit cell, 8.77 X 5.58 X 7.05 ± 0.01 A. Apart from the labeling of the axes, this is similar to the unit cell assigned to NOBF4 by Evans, et al.40 (8.91 X 5.68 X 6.98 A). The systematic absences are consistent with the space group Pnma which conforms also to the observation of the 02+ vibration in infrared absorption. The unit cell and symmetry are very similar to those previously assigned to NH4BF4, KBF4, and other compounds with the BaSQ4 structure.41 Details will be reported elsewhere.Nomenclature. In this paper we have referred to the compounds 02F2 and 04F2 as oxygen fluorides, in accordance with the recommendations of one of the referees and with the concurrence of the editor of this (40) J.

Ten-vertex dicarbaboranes from nido -5,6-C 2 B 8 H 12

“…The structure of the 8-Br derivative was established by X-ray diffraction. As also demonstrated in Scheme 6, all the halogenated compounds closo-1,6-C 2 B 8 H 9 -8-X (5-1) (X ¼ Cl, Br, I) can be converted by heating under argon at high temperatures (500e600 C) into the isomeric closo-1,10-C 2 B 8 H 9 -2-X (4-1) derivatives in essentially quantitative yield [12], which is an alternation of the 5 / 4 rearrangement (path E of Scheme 5 above) [12,49].…”

Four Decades of Organic Chemistry of closo-Boranes: A Synthetic Toolbox for Constructing Liquid Crystal Materials. A Review

“…Carborane and monocarbaborate-derived anions are highly nucleophilic and react with a wide range of C-electrophiles providing a convenient route to C-C bonds. The C-lithium reagents are particularly useful in the alkylation with primary iodides and bromides and carboxylation reactions described for carboranes including para-carboranes 6 (refs 20,82,83 ) and 10 (refs 58,84,85 ), and also for monocarbaborates 2 (refs 67,86 ) and 8 (ref. 61 ).…”

“…Catalytic reduction of azocarboranes 107 is a recommended method for the preparation of C-amino derivatives and is preferable to the reduction of C-nitroso 104 or C-nitro 85 compounds.…”

“…There are relatively few examples of the formation of C-halogen bonds. The C-halogenation reaction is highly efficient 85,103,117 and occasionally observed as an undesired processes (vide supra). The C-I compounds have limited synthetic utility (vide infra) 118 while the C-F and C-Cl compounds may be used to increase molecular dipole moments 119 and to introduce axial chirality in 2,9-disubstituted meta-carboranes.…”

Unique Stereocontrol in Carborane Chemistry: Skeletal Alkylcarbonation (SAC) versus Exoskeletal Alkylmethylation (EAM) Reactions

“…Owing to the absence of symmetry,i ndividual derivatives 4 show seven BH doublets and one singlet assigned to the substituted B(2) vertex;a ssignments of individual BH positions were made on the basis of [ 11 B-11 B]-COSY measurements. [7] Thes tructure of 2-Mecloso-1,6-C 2 B 8 H 9 (4e)was geometry optimized at the MP2/6- . [7] Thes tructure of 2-Mecloso-1,6-C 2 B 8 H 9 (4e)was geometry optimized at the MP2/6- .…”