A density functional theory （DFT） investigation has been performed in this work on the cage-like boron-rich boron oxide clus-ters Bn（BO）n^2-,CBn-1（BO）n^-,and C2Bn-2（BO）n （n = 5–12） which are boronyl analogu...A density functional theory （DFT） investigation has been performed in this work on the cage-like boron-rich boron oxide clus-ters Bn（BO）n^2-,CBn-1（BO）n^-,and C2Bn-2（BO）n （n = 5–12） which are boronyl analogues of the closo-boranes BnHn2-,monocarbo-ranes CBn-1H-n,and dicarboranes C2Bn-2Hn. These boron oxide clusters possess similar geometrical and electronic structures with the corresponding boranes and carboranes and prove to be three-dimensional （3D） aromatic compounds,consistent with the previously proposed BO/H isolobal analogy. Neutral C2Bn-2（BO）n species possess considerably high ionization potentials in the range 12.0–12.7 eV and CBn-1H-n monoanions have the vertical electron detachment energies in the range 6.6–9.4 eV at the DFT level. BO terminals singly bonded to the skeletal vertexes through a B atom possess the characteristic stretching vi-brational frequencies at about 2000 cm-1,clearly indicating the existence of B-O triple bonds in these clusters. Experimental syntheses and characterizations of these interesting clusters may expand the structural concepts of boron oxides and bring im-portant applications for boron oxide clusters as molecular devices in chemistry and new materials in boron neutron capture therapy.展开更多
基金supported by the National Natural Science Founda-tion of China (20873117)the Shanxi Natural Science Foundation (2010011012-3)
文摘A density functional theory （DFT） investigation has been performed in this work on the cage-like boron-rich boron oxide clus-ters Bn（BO）n^2-,CBn-1（BO）n^-,and C2Bn-2（BO）n （n = 5–12） which are boronyl analogues of the closo-boranes BnHn2-,monocarbo-ranes CBn-1H-n,and dicarboranes C2Bn-2Hn. These boron oxide clusters possess similar geometrical and electronic structures with the corresponding boranes and carboranes and prove to be three-dimensional （3D） aromatic compounds,consistent with the previously proposed BO/H isolobal analogy. Neutral C2Bn-2（BO）n species possess considerably high ionization potentials in the range 12.0–12.7 eV and CBn-1H-n monoanions have the vertical electron detachment energies in the range 6.6–9.4 eV at the DFT level. BO terminals singly bonded to the skeletal vertexes through a B atom possess the characteristic stretching vi-brational frequencies at about 2000 cm-1,clearly indicating the existence of B-O triple bonds in these clusters. Experimental syntheses and characterizations of these interesting clusters may expand the structural concepts of boron oxides and bring im-portant applications for boron oxide clusters as molecular devices in chemistry and new materials in boron neutron capture therapy.
