The electrophoretic properties of boron cluster compounds were determined in water, methanol and ACN as solvents of the BGE and discussed based on the principles of ion migration. Two types of boron cluster compounds were investigated. One type consisted of derivatives of the nido-7,8-dicarbaundecaborate cluster, the other types are derivatized cobalt bis(dicarbollide) ions (COSANs) whose central cobalt atom is sandwiched by two 7,8-dicarbaundecaborate clusters. The BGE in all solvents was acetate/acetic acid buffer with pH 4.75 in water, 9.7 in methanol and 22.3 in ACN, respectively, at different ionic strength between 5 and 30 mM. The dependence of the mobility on ionic strength could not be explained by the theory of Debye, Hückel and Onsager, but good agreement was found upon considering an ion size parameter. Limiting mobilities were derived by curve fitting, and by the aid of the solvent viscosities the hydrodynamic radii of the analyte anions were calculated. They are between 0.25 and 0.48 nm, and were nearly independent of the solvent. Electrophoresis of the analytes in a BGE consisting of 6 mM perchloric acid in ACN allows the conclusion that the present boron cluster compounds behave as stronger acids than perchloric acid.
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http://dx.doi.org/10.1002/elps.200700815 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Brown University, Department of Chemistry, UNITED STATES OF AMERICA.
Despite major progress in the investigation of boron cluster anions, direct experimental study of neutral boron clusters remains a significant challenge because of the difficulty in size selection. Here we report a size-specific study of the neutral B9 cluster using threshold photoionization with a tunable vacuum ultraviolet free electron laser. The ionization potential of B9 is measured to be 8.
View Article and Find Full Text PDFJ Chem Theory Comput
January 2025
Department of Chemistry, Birla Institute of Technology Mesra, Ranchi 835215, India.
Planar hexacoordination is an extremely uncommon phenomenon for the atoms that belong to the main group. Within this article, we have analyzed the potential energy surfaces (PES) of ABeCB (A = N, P, As, Sb, and Bi) clusters in neutral, monocationic, monoanionic, dicationic, and dianionic states using density functional theory (DFT). Among which PBeCB, PBeCB, AsBeCB, AsBeCB, SbBeCB, and BiBeCB clusters contain a planar hexacoordinate boron (phB) atom in the global minimum energy structures with symmetry.
View Article and Find Full Text PDFJ Chem Phys
January 2025
MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, China.
By using a tight-binding model, first-principles calculations, and ab initio molecular dynamics simulations, we theoretically demonstrate that the C76-Td-assembled two-dimensional (2D) honeycomb lattice is stable at room temperature and is resistant to mechanical deformation. We disclose that each C76-Td mimics a single carbon atom (geometrically and electronically); hence, it plays the role of one supercarbon. This inspires that the 2D material exhibits an exotic hourglass-like fermion at the Fermi level.
View Article and Find Full Text PDFInorg Chem
January 2025
Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, c/Marcel·lí Domingo 1, 43007 Tarragona, Spain.
Gas-phase synthesis and detection of boron-doped nitride clusterfullerenes and a large variety of monometallofullerenes have been achieved using a pulsed laser vaporization cluster source. Density functional theory (DFT) calculations show that the electronic structures of boron-doped endohedral metallofullerenes differ from those of the pristine all-carbon cages due to the lack of one electron upon boron substitution. For monometallofullerenes, this is likely the main reason for the somewhat different abundance distribution observed for boron-doped with respect to all-carbon cages.
View Article and Find Full Text PDFMolecules
December 2024
Department of Chemical and Materials Engineering, Lyuliang University, Lishi 033001, China.
We studied the boron-based composite cluster BAl doped with Al atoms. The global minimum structure of the BAl cluster is a three-layer structure, consisting of three parts: an Al unit, a B ring and an isolated Al atom. Charge calculations analysis shows that the cluster can be expressed as [Al][B][Al], has 6π/6σ double aromaticity and follows the (4+2) Hückel rule.
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