Ab initio calculations are reported for three of four possible conformers of 1,3-dichloropropane. The fourth conformer, with Cs symmetry, has a predicted enthalpy difference of more than 1500 cm(-1) from the most stable conformer from each calculation regardless of the basis set used, so there is little chance of observing it. Thus, there is no evidence in the infrared or Raman spectrum of the presence of a fourth conformer. The order of stability given by the ab initio calculations is C2(GG)>C1(AG)>C2v(AA)>Cs(GG'), where A indicates the anti form for one of the CH2Cl groups and G indicates the gauche conformation for the other CH2Cl group relative to the plane of the carbon atoms. Almost every band observed can be confidently assigned to one or another of the conformers. Many observed bands proved to be of a composite nature, with several nearly coincident vibrations of different conformers contributing to the band contour. Nonetheless, a complete assignment of fundamentals is possible for the most stable C2 conformer, and 5 of the fundamentals of the C2v conformer and 13 those of the C1 conformer can be confidently assigned.
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Sci Rep
December 2024
Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka, 1205, Bangladesh.
Prediction and discovery of new materials with desired properties are at the forefront of quantum science and technology research. A major bottleneck in this field is the computational resources and time complexity related to finding new materials from ab initio calculations. In this work, an effective and robust deep learning-based model is proposed by incorporating persistent homology with graph neural network which offers an accuracy of and an F1 score of in classifying topological versus non-topological materials, outperforming the other state-of-the-art classifier models.
View Article and Find Full Text PDFJ Phys Chem A
December 2024
Department of Chemistry, Indian Institute of Technology Patna, Bihta 801106, India.
This study probes the vibronic interactions in the photoelectron spectra of CAlGe, exploring its six excited electronic states through an approach that combines the electronic structure calculations and the quantum nuclear dynamics. Central to this investigation is utilizing a model diabatic Hamiltonian, which allows for the exact evaluation of Hamiltonian parameters and fitting potential energy cuts (PECs). Notably, the analysis of these PECs uncovers pronounced nonadiabatic effects within the photoelectron spectra, emphasized by the presence of multiple conical intersections.
View Article and Find Full Text PDFJ Phys Chem A
December 2024
Department of Chemistry, Lomonosov Moscow State University, Moscow 119991 Russia.
The recent detection of benzonitrile (CHCN) in the interstellar medium is one of the most fascinating discoveries in astrochemistry and molecular astrophysics. However, the mechanism of its formation in interstellar ices remains unclear. Here, we report the first evidence for the direct synthesis of benzonitrile through the radiation-induced transformations of an isolated CH···HCN complex in inert rigid media at cryogenic temperature (4.
View Article and Find Full Text PDFChem Sci
December 2024
Frontier Institute of Science and Technology, State Key Laboratory of Electrical Insulation and Power Equipment, MOE Key Laboratory for Nonequilibrium Synthesis of Condensed Matter, Xi'an Key Laboratory of Electronic Devices and Materials Chemistry and School of Chemistry, Xi'an Jiaotong University 99 Yanxiang Road Xi'an Shaanxi 710054 P. R. China
The benzene tetraanion-bridged rare earth inverse arene amidinate complexes [{Ln(κ:η-Piso)}(μ-η:η-CH)] (2-Ln, Ln = Gd, Tb, Dy, Y; Piso = {(NDipp)C Bu}, Dipp = CH Pr-2,6) were prepared by the reduction of parent Ln(iii) bis-amidinate halide precursors [Ln(Piso)X] (Ln = Tb, Dy; X = Cl, I) or [Ln(Piso)I] (Ln = Gd, Y) with 3 eq. KC in benzene, or by the reaction of the homoleptic Ln(ii) complexes [Ln(Piso)] (Ln = Tb, Dy) with 2 eq. KC in benzene.
View Article and Find Full Text PDFJ Chem Theory Comput
December 2024
Changping Laboratory, No. 28 Life Science Park Rd., Beijing 102206, China.
Accurate modeling of host-guest systems is challenging in modern computational chemistry. It requires intermolecular interaction patterns to be correctly described and, more importantly, the dynamic behaviors of macrocyclic hosts to be accurately modeled. Pillar[]arenes as a crucial family of macrocycles play a critical role in host-guest chemistry and biomedical applications.
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