Эффективный способ нахождения матричных элементов оператора дипольного момента и поправок к энергии многоатомной молекулы с помощью теории возмущений в рамках формализма полиномов квантовых чисел

In the framework of quantum numbers polynomials, energy corrections and matrix elements of a dipolar-moment for polyatomic molecules are obtained up to the second order, and a detailed calculation algorithm is presented. The results obtained for the fundamental transition matrix elements are in good agreement with the literature data.

Light-responsive self-assembly of semi-conducting nanoplatelets

CdSe nanoplatelets are a recently discovered class of colloidal semiconducting nanocrystals. Atomic control over their thickness allows achieving control over quantum size effects, and in particular, these platelets exhibit monochromatic light emission because of the confinement of photo-generated excitons only in their thickness. These nanoplatelets can self-organize into supra-particular polymers, depending on their environment, which means that their shape anisotropy can be expressed at the microscale. Here, the self-assembly of semiconducting nanoplatelets is controlled remotely by light, in a dynamic nanoparticulate system that integrates light-responsive molecular switches covalently. Azobenzene ligands were thus designed to (i) be grafted on the nanoplatelets (ii) ensure their colloidal stability in chloroform when confined on their surface in the E-configuration. Upon irradiation, the ligands isomerize into their Z-configuration, leading to a modification of the dipolar moment of the particles and to the formation of one-dimensional stacks. The self-assembly is reversible, as thermal relaxation of the ligands yields the initial dispersion back. This reversible hybrid system can be used in the design of responsive optical systems, as illustrated by photo-patterning experiments leading to controlled spatial resolution of the luminescence intensity in thin films.

Пьезоэлектрические свойства 2D наноаллотропов нитрида бора

Independent components of the piezomoduli tensor for various boron nitride 2D nanoallotropes are calculated. The essence of the offered approximate method of calculation consisted that the effective dipolar moment of an elementary cell of 2D structure brought to unit of area was expressed through a tensor of elastic rigitities and relative deformations of a cell. It is shown that, besides well-known graphene-like boron nitride h-BN, both the other its hexagonal and tetragonal nanoallotropes possessing higher, in comparison with h-BN, piezoelectric properties can be of practical interest.

Synthesis of Pyridazine Derivatives by Suzuki-Miyaura Cross-Coupling Reaction and Evaluation of Their Optical and Electronic Properties through Experimental and Theoretical Studies

A series of π-conjugated molecules, based on pyridazine and thiophene heterocycles 3a–e, were synthesized using commercially, or readily available, coupling components, through a palladium catalyzed Suzuki-Miyaura cross-coupling reaction. The electron-deficient pyridazine heterocycle was functionalized by a thiophene electron-rich heterocycle at position six, and different (hetero)aromatic moieties (phenyl, thienyl, furanyl) were functionalized with electron acceptor groups at position three. Density Functional Theory (DFT) calculations were carried out to obtain information on the conformation, electronic structure, electron distribution, dipolar moment, and molecular nonlinear response of the synthesized push-pull pyridazine derivatives. Hyper-Rayleigh scattering in 1,4-dioxane solutions, using a fundamental wavelength of 1064 nm, was used to evaluate their second-order nonlinear optical properties. The thienylpyridazine functionalized with the cyano-phenyl moiety exhibited the largest first hyperpolarizability (β = 175 × 10−30 esu, using the T convention) indicating its potential as a second harmonic generation (SHG) chromophore.

6,6′-Diaryl-substituted biazulene diimides for solution-processable high-performance n-type organic semiconductors

High electron mobility derived from dense molecular packing induced by the dipolar moment of azulene units.

Dinitroxide biradical crystals with polar order

A dinitroxide biradical (dCdO) has the peculiar tendency to crystallize in non-centrosymmetric polar space groups either as a stable dichloromethane solvate or as a pure phase. The molecules arrange with no compensation of their dipolar moment resulting in net macroscopic polar order.

Application of Bässler′s Energy and Position Disorder Model and Hoping Model in Hole Transport Material

The Bässler’s energy and position disorder model is used to study the relationship between molecular structure of hole-transport materials and performance of the photoreceptor. The result shows that dipolar moments of hole-transport materials (HTM) are inverse proportion to the half decay exposures (E1/2) of the Organic photoreceptors (OPC) which closely related with the hole-mobility of hole-transport layer. In this article Marcus hopping theory and DFT method are also used to calculate the hole-mobility of four hole-transport materials (HTM). The compare of the half decay exposures of OPCs used these material as hole-transport layer and hole mobility, dipolar moments of these molecules show that the E1/2 increases with decrease of hole mobility and dipolar moment.

ATOMIC DIPOLE MOMENT CORRECTED HIRSHFELD POPULATION METHOD

Charge preservation is a necessary condition in population analysis. However, one such constraint is not enough to solve the arbitrariness involved in the population analysis such as Hirshfeld population. This arbitrariness results in too small Hirshfeld charges and poor reproducibility of molecular dipolar moments. In this article, the preservation of the molecular dipole moment is imposed upon the Hirshfeld population analysis as another constraint to improve the original Hirshfeld charges. In the scheme each atomic dipolar moment defined by the deformation density is expanded as contributions from all atoms in the molecule. The corresponding correction charges are then accumulated for each atom together with the original Hirshfeld charge as the predicted charge. All computed charges are generally larger than Hirshfeld charges, independent of basis set, and have very good electrostatic potential reproducibility and high correlation with the charges derived from the electrostatic potential fitting.