Decaborane structure

Plane projection of the slructure or/ B gH2]. The two decaborane units are fused at the S(7 > and 6(6 ) positions to give a non rTJmetric structure with Cj symmetry... 

Decaborane-14 and Its Derivatives M. Frederick Hawthorne The Structure and Reactivity of Organophosphorus Compounds R. F. Hudson... 

The ruthenium-catalyzed isotope exchange of boron atoms in decaborane is remarkable because several bonds are selectively broken and formed with a nanoscale catalyst without altering the structure of the decaborane. Highly enriched [10B] decaborane can be obtained by repeated treatment (six times) of decaborane with 10B2H6 in presence of Ru(0) NPs in ILs (entry 3, Table 1.5 Scheme 1.5), where the catalyst was recycled three times in batch experiments without significant activity loss [107]. 

Interaction of the Bi0Hi0(2—) anion with excess nitrous acid gives an inner diazo-nium salt (of unknown structure, possibly containing a nitronium ion) which is highly explosive in the dry state. It is readily reduced wet to the non-explosive l,10-bis(diazonio)decaboran(8)ate inner salt. 

The formation of adducts [arachno-9-l -b-S x)ilu was studied with several donors L.107,183 18s The structure of the 1-thia-c/ftro-decaborane [SB9H9] cluster was determined by microwave spectroscopy.186... 

As is to be expected from its structure (see Figure 2.1-25), which has Civ symmetry, the molecule has a significant dipole moment (// = 3.4 Debye). This is one of the reasons why decaborane(14) dissolves in alcohols and water. One of its four bridging protons can readily be removed by a base in aqueous solution (pKa = 2.7) according to Eq. (50). The yellow anion B ()H 3 in not very stable in solution. The deprotonation of B10Hi4 leads to a shortening of the B6-B7-bond. 

The structure of this compound (Figure 2.1-30) shows the decaborane cluster with... 

The carborane 64c was characterized by a consistent set of NMR data, ab initio MO calculations, and by X-ray structure analysis [88]. The synthetic potential of 64c is indicated by its reaction with Fe(CO)3 fragments to give 69 [87]. The di-ferracarborane 69 is isostructural with nido-decaborane(14), because two BH and four BH(H) fragments were replaced by two isolobal Fe(CO)3 and four CH fragments, respectively. 

This disilaborane was an unexpected co-product in the synthesis of decaborane-alkylamine polymers. The Si2Bio cluster core consists of a distorted icosahedron in which the two silicon atoms occupy adjacent positions. The Si-Si interatomic distance is 2.308(2) A, which is slightly less than the Si-Si distance in organodisilanes (2.35 A) and the Si-B distances [2.017(3) to 2.116(3) A] are very close to the sum of the covalent radii of the two atoms (2.07 A). Further derivatives with disilaborane cluster geometry are known for the phenyl substituted compounds l,2-Ph2-doso-l,2-Si2B1oH1o and l-Me-2-Ph-doso-l,2-Si2BioHi0 [6, 7]. In addition to these disila-doso-dodecaborane clusters one example with two different group 14 elements as a part of the cluster core is known. In Scheme 3.3-2 the synthesis of this sila-stanna-doso-dodecaborate is shown. The structure of this heteroborate was determined in the solid state and the Si-Sn distance is 2.608(4) A (Scheme 3.3-2) [8]. 

The material reviewed in this Chapter hitherto has focused on metallacarboranes in which the metal atom is a vertex in an icosahedral cage framework. Until recently, monocarbollide metal compounds with core structures other than 12 vertexes were very rare since suitable carborane precursors were not readily available." However, Brellochs recent development of the reaction of decaborane with aldehydes to give 10-vertex monocarboranes permits a considerable expansion in this area of boron cluster chemistry. As a consequence, several intermediate-sized monocarboranes are now easily accessible and we have recently begun to exploit the opportunities that these present. In particular, we have focused thus far on complexes derived from the C-phenyl-substituted species [6-Ph- zJo-6-CBgHii] It is clear from these initial studies that a wealth of new chemistry remains to be discovered in this area, not only from among the metal derivatives of PhCBg car-boranes such as those discussed in this section, but also in the metal complexes of other newly available carboranes. 

Were this reaction carried out slowly at the lowest possible temperature and in an inert solvent with decaborane in excess rather than with the Lewis base in excess, there might be sufficient time for a Lewis base rearrangement to take place (see rearrangement VII-N6 to VI-N6). The Lewis base could eflFectively migrate to a higher coordination position and the predicted to-be-stable BioHx2 LB isomer (XXI-NlO) should be produced from the intermediate XXII-NIO. Only a 3s violation occasioned by the placement of the surrogate carbon would compromise the XXI-NlO structure for BioHij, LB. 

Decaborane dianion, oxidative coupling, 26 73 Decaboron decahalides, 26 13, 48 hydrogenation of chloride, 26 48 pyrolysis of dianions, 26 48 Decabromotriselenate(lI,IV), 35 290 Decadiene complexes with silver, 12 340 Decaholotellurate(IV), structure, 35 249-251 Decarbonylation, thermal, of trifluoroacetyl derivatives, 27 295-300... 

Dicarbadodecaborane, preparation and structure of, 5 342-343 Dicarbomethoxy acetylene, 45 48, 49 Dicarbon decaboranes, 26 85 base degradation, 26 90 bonding, 26 62 dianions, 26 78-79 reaction with Lewis bases, 26 85 1,2-Dicarbonic acid dichlorides, 33 300 Dicarbon nonaborane anion, oxidative coupling, 26 73... 

Fig. 16.47 Molecular structures of boranes related to (a) decaborane l4) formed...

The structures of some ethylated derivs of penta-borane and decaborane are reported by Williams(Ref 34). Stock Pohland(Ref 2) reported the formation of complexes by the reaction of NH3 with boranes. The structure props of these boron hydride ammo-niates were studied by Agronomov(Ref 7)... 

The structure of decaborane(16) 200> reveals that it should be considered as an apically substituted derivative of pentaborane(9). The bond energy of the unique boron-boron bond which connects the two B5H8 cages has been determined to be 3.2 0.2 e.v. from mass spectrometry 201> the standard heat of formation is 34.8 kcal. per mole 202>. An analysis of the vibrational spectrum of decaborane(16) has been made by Pinson and Lin 203> who note the absence of the strong absorption at 901 cm-1 which was previously reported 204>. 

Fig. 7. Proposed structure of 1-germa-, 1-stanna-, and l-plumba-2,3-dicarba

Boron hydrides could be incorporated successfully into polymeric structures through various routes. Early studies by Thiokol had established the difunctionality of decaborane to Lewis bases (9). 

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