Electronic structure of diatomic boron nitride

Abstract

BN molecules, isoelectronic with C2, are produced by laser vaporization of boron nitride and trapped in solid neon. Through Fourier-transform absorption and laser-induced fluorescence spectra, three new electronic states are observed. Unlike C2, BN has a triplet ground state (X 3Π), but with an exceedingly low-lying singlet (a 1∑+) state with 15 cm−1<Te<182 cm−1.

Molar Binding Energy of Zigzag and Armchair Single-Walled Boron Nitride Nanotubes

“…An explanation may be that BN molecular spectra [64] verify triplet ground state, but at the same time reveal a low-lying singlet state with longer bond.…”

“…However, neglecting the insignificant redistribution of valence electrons arisen from association of atoms into a molecular or crystalline structure, the quasi-classical selfaction energy of the substance is approximated by the sum of self-action energies of constituent atoms: A complete quasi-classical theory of substance including calculation schemes for structural and binding, as well as for electronic spectrum characteristics, one can find in [102,103]. These schemes have been applied successfully for Na molecular and crystalline structures [104], various diatomic molecules [60,61], boron nanotubes [105,106], and mainly for one-, two-and threedimensional structural modifications of boron nitridediatomic molecule, isolated plane sheet, hexagonal h-BN, cubic c-BN, and wurtzite-like w-BN crystals [59,60,64,[73][74][75]107,108].…”

“…Quasi-classically calculated interatomic vibration energy in a B−N diatomic system of 0.178 eV/mole (the corresponding vibration quantum equals to 1435 cm , from the absorption spectra Fourier analysis for laser-induced molecular fluorescence) [64].…”

Electronic spectroscopy of B atoms and B2 molecules isolated in para-H2, normal-D2, Ne, Ar, Kr, and Xe matrices

“…2 In fact, we find only three manuscripts which include ultraviolet (UV) absorption spectra of B and B 2 , and these studies were performed exclusively in Ar matrices.3-5 Technical difficulties in evaporating elemental boron cannot completely explain this situation, as there are several groups actively pursuing electron spin resonance (ESR), 6 " 13 infrared (IR) absorption,14"23 and electronic 24 " 27 spectroscopic studies on matrix isolated molecules containing B atoms. Rather, we believe that complementary experimental and theoretical results, essential to expanding upon the original understanding 3 of the B/Ar and B 2 /Ar matrix spectra, have only recently become available (vide infra).…”

Factors affecting the relation between stretching frequencies and bond lengths. Diatomic and polyatomic species without adjustable fitting parameters

“…This eliminates the possibility of a Lewis structure of the type B:::N: and requires that the species be a diradical. After considerable effort, spectroscopic measurements have now established that the ground state is a diradical ( 3 P state) [22]. Actually BN is not a gas but forms ceramic materials in various allotropic forms.…”