Probing the structures and chemical bonding of boron-boronyl clusters using photoelectron spectroscopy and computational chemistry: B4(BO)n- (n=1-3)

The electronic and structural properties of a series of boron oxide clusters, B5O-, B6O2-, and B7O3-, are studied using photoelectron spectroscopy and density functional calculations. Vibrationally resolved photoelectron spectra are obtained, yielding electron affinities of 3.45, 3.54, and 4.94 eV for the corresponding neutrals, B5O, B6O2, and B7O3, respectively. Structural optimizations show that these oxide clusters can be formulated as B-4(BO)(n)(-) (n = 1-3), which involve boronyls coordinated to a planar rhombic B-4 cluster. Chemical bonding analyses indicate that the B-4(BO)(n)(-) clusters are all aromatic species with two pi electrons. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4737863]