Ab Initio and Electron Propagator Theory Study of Boron Hydrides

Abstract

Boron hydrides (BH3, B2H6, B3H7, B4H10, B5H9, and B5H11) and their cations are studied by the coupled cluster CCSD(T) theory, the second-order Mller-Plesset (MP2) perturbation method, and the electron propagator theory in the partial third-order quasi-particle approximation, using the 6-311G(d,p) basis set. The vertical ionization potential energies are calculated, indicating an excellent agreement with the experimental data from photoelectron spectroscopy. Assignments to the experimental spectra are made on the basis of the present computational analyses. A significant Jahn-Teller effect on BH3+ leads to two states, 2A1 and 2B2, with the split energy of 0.14 eV. The triple and double B-H-B bridges are formed in B2H6+ and b-B3H7+, respectively. A new B-H-B bridge is formed while two B-B bonds are broken in B5H11+. The Jahn-Teller effect lowers the symmetry of B5H9 (C4v) to B5H9+ (C2) but slightly influences the structure of ara-B4H10 (C2v). The calculated properties of geometries, vibrational frequencies, and energies are compared with the experimental data available in the literatures.

11B NMR Chemical Shift Predictions via Density Functional Theory and Gauge-Including Atomic Orbital Approach: Applications to Structural Elucidations of Boron-Containing Molecules

“…The development of various computational methods for chemical shift predictions further improves the capabilities of NMR spectroscopy in structural assignments. ,− With the introduction of density functional theory (DFT) − and gauge-including atomic orbital (GIAO)-based approach, the calculations of boron isotropic shielding constants become accessible. At the same time, the application of linear regression correlating calculated isotropic shielding constants and experimental NMR values has also proved effective to improve the prediction accuracy for 1 H, 13 C, and 15 N chemical shifts at relatively low computational costs. − The linear regression between computed isotropic shielding constants (σ) and experimental chemical shifts (δ) was performed via the following equation …”

A theoretical study of the spectroscopic properties of B2H6 and of a series of BHyz−species (x = 1−12, y = 3−14, z = 0−2): From BH3 to B12H

“…The chemistry of B 3 H − 8 has also been recently discussed in detail [3][4][5][6][7]. Many previous theoretical studies have addressed the structures and relative energies of different boron-hydrogen species [8][9][10][11][12][13][14][15][16][17][18][19]. These species can also behave as complexants.…”

Planar π-aromatic C3h B6H 3 + and π-antiaromatic C2h B8H2: boron hydride analogues of D3h C3H 3 + and D2h C4H4

“…Its compounds, especially boron hydrides B n H m (n02-20, n<m), play an essential role in advancing chemical bonding models [1]. Small boron hydride clusters receive consistent attentions in both chemistry and materials science, with typical examples including the reported B 2 H 4 [2], BH 3 , B 2 H 6 , B 3 H 7 , B 4 H 10 , B 5 H 9 and B 5 H 11 [3], B n H + (n01-13) [4], B 2 H + , B 2 H 2 + , and B 3 H 2 + [5], B 2 H 2n 2+ dications (n 01-4) [6], and the cage-like B n H n neutrals (n05- 13,16,19,22) and their anions B n H n -/2-(n05-13) [7][8][9]. However, little has been known about the nature of the partially hydrogenated B n H m clusters which contain fewer hydrogen atoms than boron atoms (n>m).…”