1,3,2‐Dioxaborines as potential components in advanced materials—a theoretical study on electron affinity

Abstract

Abstract1,3,2‐Dioxaborines with fluorine and other substituents at boron were calculated by first‐principles methods based on density functional theory (DFT: B3‐LYP) or many‐body perturbation theory at the second order [MBPT(2): MP2]. 1,3,2‐Dioxaborines are derivatives of 1,3‐dicarbonyl compounds also known as 1,3‐diketoborates. According to quantum chemical calculations, 2,2‐difluoro‐1,3,2‐dioxaborines are of puckered structure with a low barrier to inversion. The calculated charge distribution does not reflect well the traditional formula description. The boron atom carries a positive rather than a negative charge. Some compounds have a pronounced zwitterionic character accompanied by relatively high dipole moments. The calculated positive electron affinities (EAs) classify 1,3,2‐dioxaborines as organic electron‐acceptor compounds. Depending on the type of substitution, the EAs vary between about 0.5 and 3.5 eV (DFT calculations). The EAs of various substituted 1,3,2‐dioxaborines are of the same order of magnitude as those of quinones and close to electron affinities of strong organic acceptor compounds such as tetracyanoethylene (TCNE). Numerical predictions are verified by comparison with EAs of a series of well‐known medium‐sized organic compounds studied experimentally and theoretically at the same level of theory. In good agreement with results reported for other series of compounds, the average absolute error between theoretical and experimental EAs was 0.19 eV. Because of the ability of 3,5‐diaryl‐2,2‐difluoro‐1,3,2‐dioxaboranes to fluoresce efficiently and to accept electrons easily, these compounds are potential candidates for future applications. Copyright © 2004 John Wiley & Sons, Ltd.

Boron Difluoride Curcuminoid Fluorophores with Enhanced Two‐Photon Excited Fluorescence Emission and Versatile Living‐Cell Imaging Properties

“…This trend confirms the relaxation toward a solvent‐equilibrated singlet excited state with a charge‐transfer character and shows that the excited‐state dipole moment is larger than the ground‐state one. This behavior is in agreement with what was observed for other curcuminoid boron difluoride compounds and is related to the strong electron‐withdrawing effect of the central difluoro dioxaborine chelate . These data evidence the strong charge transfer character of the curcuminoid dyes …”

Molecular design of near infrared polymethine dyes: A review

“…Hales et al [91], I. Kurdyukova et al [92,93] . Theoretical consideration of the electron structure of dioxaborine anionic dyes was performed by J. Fabian and H. Hartmann [94].…”

Influence of the electron donor groups on the optical and electrochemical properties of borondifluoride complexes of curcuminoid derivatives: a joint theoretical and experimental study

“…Their optical [1][2][3][4][5][6][7][8][9][10][11] and electrochemical [11][12][13][14][15][16] properties have been described in previous studies and it has been shown that they can be used as versatile uorophores, 1-5 electron acceptors 17,18 in one-electron transfer processes 19 or in chargetransport materials in both organic eld effect transistors and organic light emitting diodes. [20][21][22][23][24][25] One-electron reduction proceeds via the formation of a radical anion where the unpaired electron is delocalized on the p-system of the boroncontaining six-membered chelate ring, as demonstrated by electron paramagnetic resonance studies.…”