Role of Electron-Donating and Electron-Withdrawing Groups in Tuning the Optoelectronic Properties of Difluoroboron–Napthyridine Analogues

Abstract

Five napthyridine-based fluorine-boron (BF-napthyridine) conjugated compounds have been theoretically designed, and subsequently, their photophysical properties are investigated. The influence of electron-donating and electron-withdrawing groups attached with the NCO moiety of BF-napthyridine molecule has been interpreted. The optoelectronic properties, including absorption spectra and emission spectra of the BF-napthyridine derivatives are studied using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) based methods. Different characteristics, such as HOMO-LUMO gap, molecular orbital density, ionization potential, electron affinity, and reorganization energy for hole and electron, are calculated. All these molecules show excellent π-electron delocalization. TD-DFT results illustrate that the amine-substituted BF-napthyridine derivative has the highest absorption and emission maxima; it also shows a maximum Stoke shift. These results are well-correlated with the structural parameters and calculated HOMO-LUMO gap. Moreover, it is found that introduction of an electron-donating group into the BF-napthyridine complex improves the hole transport properties and provides useful clues in designing new materials for organic light emitting diodes (OLED). As a whole, this work demonstrates that electron-donating and electron-withdrawing groups in BF derivatives can extend their effectiveness toward designing of OLED materials, vitro cellular studies, ex vivo assays, and in vivo imaging agents.

Enhancement of air-stability, π-stacking ability, and charge transport properties of fluoroalkyl side chain engineered n-type naphthalene tetracarboxylic diimide compounds

“…The increment of the electron affinity values with the increase of EWGs in the compounds indicates the enhancement electron transfer nature. 52 High EA (adiabatic) (>2.80 eV) and low LUMO energy level (<À4.00 eV) are the important parameters for ambient airstability and n-type behaviour of organic semiconductors. 53,54 In our study, it is found that purely alkyl substituted NDIs (1a, 1b, 1c, 1d) have EA value less than 2.8 eV and LUMO levels higher than À4.00 eV.…”

Synthesis and Morphological Control of Biocompatible Fluorescent/Magnetic Janus Nanoparticles Based on the Self-Assembly of Fluorescent Polyurethane and Fe3O4 Nanoparticles

“…Using quinine sulfate as reference, the fluorescence quantum yields of MHHNA and PU-MHNNA were measured to be 0.71. Meanwhile, λ ex (421 nm) and λ em (522 nm) of PU-DHHNA were also the same as that of DHHNA, thus generating a larger Stokes shift (101 nm), because the diethylamino group possessed stronger electron donating ability than the methoxy group, causing a higher intramolecular charge transfer rate and a smaller energy gap between HOMO and LUMO [32,33]. Furthermore, it is worth noting that at the same fluorophore concentration (3 × 10 –2 mM), PU-DHHNA displayed enhanced fluorescence intensity in emission and excitation spectra, and its quantum yield (0.15) was considerably increased compared with DHHNA (0.08) (Figure 2C,D).…”

Synthesis of Fluorinated Aminoalkylboronic Acids from Amphoteric α‐Boryl Aldehydes

“…Increasing the electrophilicity around the boron center is expected to result in enhanced nucleophilic binding to boron. [8,50,51] pK a determination studies of deprotected 3 f (5 a) showed two inflection points of 3.4 and 8.1 (Figure 3 a).…”