The dipole moment of photochromic diarylethenes is determined in solution for both the coloured and uncoloured forms by measuring the capacitance of a capacitor filled with a photochromic solution as a dielectric material. Diarylethenes with different substituents are investigated and the modulation of the dipole moment is related to their chemical structures. We determine a modulation of the dipole moment up to 4 Debye. We discuss the model used to obtain the dipole moment from the capacitance measurements and we compare the experimental results with the outcomes from DFT calculations. The results highlight the importance of conformational effects in the description of the dipole moment of diarylethenes.
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http://dx.doi.org/10.1039/c6cp05609a | DOI Listing |
Science
January 2025
Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA.
Highly concentrated solutions of asymmetric semiconductor magic-sized clusters (MSCs) of cadmium sulfide, cadmium selenide, and cadmium telluride were directed through a controlled drying meniscus front, resulting in the formation of chiral MSC assemblies. This process aligned their transition dipole moments and produced chiroptic films with exceptionally strong circular dichroism. -factors reached magnitudes as high as 1.
View Article and Find Full Text PDFIn this paper the finite-difference time-domain general vector auxiliary differential equation method [Opt. Express14, 8305 (2006)10.1364/OE.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6243, USA.
The detection of HC(S)CN in TMC-1 suggests that HC(S)NC may also exist. To aid in its possible detection, HC(S)NC and its deuterated isotopologue DC(S)NC were investigated via high-level ab initio methods, specifically CCSD(T) and CCSD(T)-F12. By utilizing multidimensional potential energy surfaces derived from explicitly correlated coupled-cluster calculations, we analyzed their geometrical parameters, vibrational frequencies, rotational constants, and a comprehensive set of spectroscopic constants generated via the vibrational second-order perturbation theory, vibrational self-consistent field, and vibrational configuration interaction theory(VCI) approaches.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Department of Chemistry, University of Washington, Seattle, Washington 98185, USA.
We derive a new expression for the strength of a hydrogen bond (VHB) in terms of the elongation of the covalent bond of the donor fragment participating in the hydrogen bond (ΔrHB) and the intermolecular coordinates R (separation between the heavy atoms) and θ (deviation of the hydrogen bond from linearity). The expression includes components describing the covalent D-H bond of the hydrogen bond donor via a Morse potential, the Pauli repulsion, and electrostatic interactions between the constituent fragments using a linear expansion of their dipole moment and a quadratic expansion of their polarizability tensor. We fitted the parameters of the model using ab initio electronic structure results for six hydrogen bonded dimers, namely, NH3-NH3, H2O-H2O, HF-HF, H2O-NH3, HF-H2O, and HF-NH3, and validated its performance for extended parts of their potential energy surfaces, resulting in a mean absolute error ranging from 0.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Ural Federal University, Ekaterinburg, Russia.
This work is devoted to the study of the static magnetization of immobilized multi-core particles (MCPs) and their ensembles. These objects model aggregates of superparamagnetic nanoparticles that are taken up by biological cells and subsequently used, for example, as magnetoactive agents for cell imaging. In this study, we derive an analytical formula that allows us to predict the static magnetization of MCPs consisting of immobilized granules, in which the magnetic moment rotates freely the Néel mechanism.
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