The crystal and molecular structure of 1,12-dibromo-1,2-dicarba-closo-dodecaborane 1,12-Br2-1,2-C2B10H10

Šubrtová, V.; Línek, A.; Novák, Cs.

doi:10.1135/cccc19752005

Cited by 7 publications

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“…The shortest skeletal interatomic distance is attributed to the C−C moiety, which also corresponds to the supramolecular connectivity of one B−Br fragment with two C−H groups building thus the global array (Figure ). In the previously reported but incomplete (hydrogen atoms not determined) crystal structure of 2 , the positions of the skeletal C atoms were based on simple comparison of interatomic distances between all pairs of skeletal atoms (the shortest separation was attributed to the HC−CBr fragment). We have now entirely redetermined the structure of 2 at lower temperature using state‐of‐the‐art methods; the connectivity in the supramolecular architecture of 2 is distinguished on the basis of connectivity between the E−Br (E=C or B atoms) and appropriate E‐H moieties from the neighboring carborane.…”

Section: Figurementioning

confidence: 99%

Competition between Halogen, Hydrogen and Dihydrogen Bonding in Brominated Carboranes

et al. 2016

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Halogen bonds are a subset of noncovalent interactions with rapidly expanding applications in materials and medicinal chemistry. While halogen bonding is well known in organic compounds, it is new in the field of boron cluster chemistry. We have synthesized and crystallized carboranes containing Br atoms in two different positions, namely, bound to C- and B-vertices. The Br atoms bound to the C-vertices have been found to form halogen bonds in the crystal structures. In contrast, Br atoms bound to B-vertices formed hydrogen bonds. Quantum chemical calculations have revealed that halogen bonding in carboranes can be much stronger than in organic architectures. These findings open new possibilities for applications of carboranes, both in materials and medicinal chemistry.

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Section: Figurementioning

confidence: 99%

Competition between Halogen, Hydrogen and Dihydrogen Bonding in Brominated Carboranes

et al. 2016

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“…Three dibromocarboranes have been structurally characterised previously, 9,10-dibromo-metacarborane, 39 9,12-dibromo-ortho-carborane 40 and 1,12-dibromoortho-carborane. 41 The latter molecule is very similar to 30 in shape, but adopts entirely different crystal packing (in chiral space group P4 1 ) due to C-H • • • Br hydrogen bonds. Discussion of molecular structures of C-substituted-paracarboranes.…”

Section: Structural Aspectsmentioning

confidence: 97%

Synthetic and structural studies on C-ethynyl- and C-bromo-carboranes

et al. 2006

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A high-yield preparation of the C-monoethynyl para-carborane, 1-Me(3)SiC[triple bond]C-1,12-C2B10H11, from C-monocopper para-carborane and 1-bromo-2-(trimethylsilyl)ethyne, BrC[triple bond]CSiMe(3) is reported. The low-yield preparation of 1,12-(Me3SiC[triple bond]C)2-1,12-C2B10H10 from the C,C'-dicopper para-carborane derivative with 1-bromo-2-(trimethylsilyl)ethyne, BrC[triple bond]CSiMe3, has been re-investigated and other products were identified including the C-monoethynyl-carborane 1-Me3SiC[triple bond]C-1,12-C2B10H11 and two-cage assemblies generated from cage-cage couplings. The contrast in the yields of the monoethynyl and diethynyl products is due to the highly unfavourable coupling process between 1-RC[triple bond]C-12-Cu-1,12-C2B10H10 and the bromoalkyne. The ethynyl group at the cage carbon C(1) strongly influences the chemical reactivity of the cage carbon at C(12)-the first example of the "antipodal effect" affecting the syntheses of para-carborane derivatives. New two-step preparations of 1-ethynyl- and 1,12-bis(ethynyl)-para-carboranes have been developed using a more readily prepared bromoethyne, 1-bromo-3-methyl-1-butyn-3-ol, BrC[triple bond]CCMe2OH. The molecular structures of the two C-monoethynyl-carboranes, 1-RC[triple bond]C-1,12-C2B10H11 (R = H and Me3Si), were experimentally determined using gas-phase electron diffraction (GED). For R = H (R(G) = 0.053) a model with C(5v) symmetry refined to give a C[triple bond]C bond distance of 1.233(5) A. For R = Me3Si (R(G) = 0.048) a model with C(s) symmetry refined to give a C[triple bond]C bond distance of 1.227(5) A. Molecular structures of 1,12-Br2-1,12-C2B10H10, 1-HC[triple bond]C-12-Br-1,12-C2B10H10 and 1,12-(Me(3)SiC[triple bond]C)2-1,12-C2B10H10 were determined by X-ray crystallography. Substituents at the cage carbon atoms on the C2B10 cage skeleton in 1-X-12-Y-1,12-C2B10H10 derivatives invariably lengthen the cage C-B bonds. However, the subtle substituent effects on the tropical B-B bond lengths in these compounds are more complex. The molecular structures of the ethynyl-ortho-carborane, 1-HC[triple bond]C-1,2-C2B10H11 and the ethene, trans-Me3SiBrC=CSiMe3Br are also reported.

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ChemInform Abstract: THE CRYSTAL AND MOLECULAR STRUCTURE OF 1,12‐DIBROMO‐1,2‐DICARBA‐CLOSODODECABORANE 1,12‐BR2‐1,2‐C2B10H10

Šubrtová¹,

Línek²,

Novák³

1975

Chemischer Informationsdienst

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The crystal and molecular structure of 1,12-dibromo-1,2-dicarba-closo-dodecaborane 1,12-Br2-1,2-C2B10H10

Cited by 7 publications

References 0 publications

Competition between Halogen, Hydrogen and Dihydrogen Bonding in Brominated Carboranes

Competition between Halogen, Hydrogen and Dihydrogen Bonding in Brominated Carboranes

Synthetic and structural studies on C-ethynyl- and C-bromo-carboranes

ChemInform Abstract: THE CRYSTAL AND MOLECULAR STRUCTURE OF 1,12‐DIBROMO‐1,2‐DICARBA‐CLOSODODECABORANE 1,12‐BR2‐1,2‐C2B10H10

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