(11)B and (13)C NMR spectra of so-far experimentally unknown carbon-rich cationic closo-carboranes C(3)B(n-3)H(n)(+) (n = 5, 6, 7, 10, 12) have been calculated at the GIAO-MP2 level and subsequently analyzed to reveal the nature of bonding in these potentially weakly coordinating cations. All previous rules derived for understanding (11)B NMR spectra of borane derivatives can be applied to realistically account for the corresponding shieldings. The correlated wavefunction for n = 5 and, to a lesser extent, for n = 10 seems to be decisive when trying to compute realistic shielding tensors, which is in agreement with the corresponding known dicarbaboranes. For other cluster dimensions noncorrelated wavefunctions also work well, in particular in relation to the corresponding dicarbaboranes. All these observations strongly support the fact that experimental availability of these unique clusters is possible.
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http://dx.doi.org/10.1002/jcc.23176 | DOI Listing |
Phys Chem Chem Phys
February 2023
Chemistry Department, Federal University of Santa Catarina, Florianópolis, SC, 88040-970, Brazil.
-Carboranes are structures that have been studied for many decades due to their vast applicability in medicine, catalysis, and energy storage. In order to go deeper into the physics behind the interactions of oppositely charged ions, which have potential applications in electrical energy storage and conversion devices, the present work aims to shed light on the physical nature of the interactions involving (R-CBH, R = H, F, CH, CF) and M = Li, Na, Mg, Zn ions. The bonding situations are evaluated in light of both canonical Kohn-Sham energy decomposition, EDA-NOCV, and local energy decomposition, LED, analyses.
View Article and Find Full Text PDFJ Comput Chem
March 2013
Institute of Inorganic Chemistry of the ASCR, vvi, Husinec-Řež, Czech Republic.
(11)B and (13)C NMR spectra of so-far experimentally unknown carbon-rich cationic closo-carboranes C(3)B(n-3)H(n)(+) (n = 5, 6, 7, 10, 12) have been calculated at the GIAO-MP2 level and subsequently analyzed to reveal the nature of bonding in these potentially weakly coordinating cations. All previous rules derived for understanding (11)B NMR spectra of borane derivatives can be applied to realistically account for the corresponding shieldings. The correlated wavefunction for n = 5 and, to a lesser extent, for n = 10 seems to be decisive when trying to compute realistic shielding tensors, which is in agreement with the corresponding known dicarbaboranes.
View Article and Find Full Text PDFJ Phys Chem A
July 2010
Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany.
The dehydrogenation of semiconducting boron carbide (B(10)C(2)H(x)) films as well as the three closo-carborane isomers of dicarbadodecaborane (C(2)B(10)H(12)) and two isomers of the corresponding closo-phosphacarborane (PCB(10)H(11)) all appear to be very similar. Photoionization mass spectrometry studies at near-threshold gas phase photoionization indicate that the preferred pathway for dissociation of the parent cation species (C(2)B(10)H(10)(+) or PCB(10)H(9)(+)) is, in all cases, the loss of H(2). Ab initio density functional theory (DFT) calculations indicate that energetically preferred sites for exopolyhedral hydrogen (B-H) bond dissociation are in all cases at B atoms opposite the C atoms in the parent cage molecule.
View Article and Find Full Text PDFJ Mol Model
August 2007
State Key Laboratory of Coal Conversion, Institute of Coal chemistry, Chinese Academy of Sciences, Taiyuan, People's Republic of China.
Structures and stabilities of tricarbonyl closo-boranes cation, BnHn-3(CO)3+ (n = 5-12), isolobal with cationic closo-carboranes C3Bn-3Hn+, have been investigated at the B3LYP/6-311+G** level of theory. The most stable positional isomers of individual cluster are in agreement with those of closo-C3Bn-3Hn+ clusters except for n = 8 and 10. Energetic analysis identifies closo-B6H3(CO)3+, closo-B10H7(CO)3+ and closo-B12H9(CO)3+ as the most stable cages.
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