In the present work, the absorption and fluorescence spectra of newly synthesized aryl boronic acid derivative namely 2-Methylphenyl boronic acid (2MPBA) have been recorded in various solvents of different polarities. The ground state dipole moment of 2MPBA was obtained from quantum chemical calculations. Solvatochromic correlations were used to estimate the ground state (μ g ) and excited state (μ e ) dipole moments. The excited state dipole moments are observed to be greater than the ground state dipole moment and ground and excited state dipole moments are not parallel but subtend by an angle of 88(0). Further, the changes in dipole moment (Δμ) were calculated both from solvatochromic shift method and microscopic solvent polarity parameter (E T (N) ), and the value are compared. The spectral variations were analyzed by Kamlet-Taft parameters.
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http://dx.doi.org/10.1007/s10895-014-1452-6 | DOI Listing |
Chemistry
January 2025
Institute of Chemistry Chinese Academy of Sciences, Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organi, Zhongguancun North First Street 2, 100190, Beijing, CHINA.
The discrete π- stacks of specific lengths and orientation is crucial for understanding the impact of intermolecular interactions on optical or electronic properties of nanographdiynes. We designed and synthesized nanographdiynes modified with bulky rotatable asymmetric substituents. The peripheral substituents with different push-pull electronic properties can induce molecular dipoles perpendicular to nanoGDY π surface with different orientation.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Nanjing University, Department of Physics, 22 Hankou Road, 210093, Nanjing, CHINA.
Amino acid crystals have emerged as promising piezoelectric materials for biodegradable and biocompatible sensors; however, their relatively low piezoelectric coefficients constrain practical applications. Here, we introduce a fluoro-substitution strategy to overcome this limitation and enhance the piezoelectric performance of amino acid crystals. Specifically, we substituted hydrogen atoms on the aromatic rings of L-tryptophan, L-phenylalanine, and N-Cbz-L-phenylalanine with fluorine, resulting in significantly elevated piezoelectric coefficients.
View Article and Find Full Text PDFMolecular junctions (MJs) are celebrated nanoelectronic devices for mimicking conventional electronic functions, including rectifiers, sensors, wires, switches, transistors, negative differential resistance, and memory, following an understanding of charge transport mechanisms. However, capacitive nanoscale molecular junctions are rarely seen. The present work describes electrochemically (E-Chem) grown covalently attached molecular thin films of 10, 14.
View Article and Find Full Text PDFAdv Healthc Mater
January 2025
College of Chemistry and Chemical Engineering and Jiangxi Provincial Key Laboratory of Functional Crystalline Materials Chemistry, Nanchang University, Nanchang, 330031, China.
The stacking mode in aggregate state results from a delicate balance of supramolecular interactions, which closely affects the optoelectronic properties of organic π-conjugated systems. Then, managing these interactions is crucial for advancing phototheranostics, yet remains challenging. A subtle strategy involving peripheral phenyl groups is debuted herein to transform X-aggregated SQ-H into J-aggregated SQ-Ph, reorienting intermolecular dipole interactions while rationally modulating π-π interactions.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Department of Environmental Science and Engineering, Fuzhou University, Minhou, Fujian 350108, China; State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Minhou, Fujian 350108, China. Electronic address:
Covalent triazine frameworks (CTFs) are emerging as promising platform for photocatalysis, yet their highly symmetric structure leads to significant charge recombination. Herein, we employed a facile non-metallic boron (B) modification with precisely controlled doping site to introduce asymmetric local electron distribution in CTFs, achieving a 15-fold activity enhancement for CO-to-CH conversion. Calculations including frontier orbitals, dipole moments and molecular electrostatic potentials firmly demonstrated the formation of localized polarized electron regions in CTF-1 via B doping.
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