Search results for "Physics::Chemical Physics"
showing 10 items of 517 documents
Naphthalene-2,6-diyl bis(4-methylbenzenesulfonate)
2018
The complete molecule of the title compound, C24H20O6S2, is generated by a crystallographic inversion centre at the middle of the naphthalene ring system. The dihedral angle between the naphthalene ring system and the pendant benzene ring is 10.23 (6)° and the C—S—O—C torsion angle is −172.05 (10)°. In the crystal, weak C—H...O interactions link the molecules into (10-1) sheets.
4-Chloronaphthalen-1-yl 4-methylbenzenesulfonate
2018
In the title compound, C17H13ClO3S, the naphthalene ring system and the benzene ring of the tosylate substituent are inclined to one another by 55.32 (5)°. The crystal structure features weak intermolecular C—H...O hydrogen bonds, one of which forms inversion dimers. Additional C—H...O hydrogen bonds and weak Cl...Cl halogen bonds stack the molecules along the b-axis direction.
Crystal structure of 2-{[1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-yloxy]carbonyl}benzoic acid
2014
In the title compound, C15H15N3O6, the dihedral angle between the planes of the benzene and imidazole rings is 34.93 (10)°. An intramolecular C—H...O hydrogen bond is observed. In the crystal, O—H...N hydrogen bonds link the molecules into chains parallel to thecaxis.
Crystal structure of 3-mesityl-1-[(pyridin-2-yl)methyl]-3,4,5,6-tetrahydropyrimidin-1-ium bromide monohydrate
2015
In the title hydrated salt, C19H24N3+·Br−·H2O, the values of the N—C bond lengths within the tetrahydropyrimidinium ring indicate delocalization of the N=C double bond. In the cation, the dihedral angle formed by the pyridine and benzene rings is 14.97 (12)°. In the crystal, ions and water molecules are linked by O—H...Br, O—H...N, C—H...Br and C—H...O hydrogen bonds into chains running parallel to thebaxis.
Crystal structure and computational study of 3,4-dihydroxy-3-hydroxymethyl-9-methyl-6-methylidene-3a, 4,5,6,6a, 9,9a, 9b-octahydroazuleno[4,5-b]furan…
2015
WOS: 000370762300147
Bis{4-[(2-hydroxy-5-methoxy-3-nitrobenzylidene)amino]phenyl} ether
2020
The molecule of the title oxybis compound lies on a twofold rotational axis. The conformation of the title compound is discussed and compared to those of related structures. In the crystal, molecules of the title compound are assembled into layers parallel to the ab plane through C—H⋯O hydrogen bonds.
Squeezing of Quantum Noise of Motion in a Micromechanical Resonator
2015
A pair of conjugate observables, such as the quadrature amplitudes of harmonic motion, have fundamental fluctuations which are bound by the Heisenberg uncertainty relation. However, in a squeezed quantum state, fluctuations of a quantity can be reduced below the standard quantum limit, at the cost of increased fluctuations of the conjugate variable. Here we prepare a nearly macroscopic moving body, realized as a micromechanical resonator, in a squeezed quantum state. We obtain squeezing of one quadrature amplitude $1.1 \pm 0.4$ dB below the standard quantum limit, thus achieving a long-standing goal of obtaining motional squeezing in a macroscopic object.
Quinoidal oligothiophenes: towards biradical ground-state species.
2009
A family of quinoidal oligothiophenes, from the dimer to the hexamer, with fused bis(butoxymethyl)cyclopentane groups has been extensively investigated by means of electronic and vibrational spectroscopy, electrochemical measurements, and density functional calculations. The latter predict that the electronic ground state always corresponds to a singlet state and that, for the longest oligomers, this state has biradical character that increases with increasing oligomer length. The shortest oligomers display closed-shell quinoidal structures. Calculations also predict the existence of very low energy excited triplet states that can be populated at room temperature. Aromatization of the conju…
Vibrational population of H 2 + after electroionization of thermal H2
1993
In an ion trap experiment we have determined the vibrational population of the lowest 9 vibrational levels of H2+. We used photodissociation of the trapped molecules by 248 nm light from an excimer laser and the dependence of the photodissociation cross section from the vibrational state. Our results are in good agreement to calculations, which are based on the Franck-Condon principle, but include a variation of the internuclear distance in the transition matrix element.
Hartree-Fock calculations and photoelectron spectra of SSO and NSF
1974
Results from ab initio Hartree-Fock calculations on the ground states of SSO and NSF are reported. The calculations employ large basis sets of Gaussian functions of essentially double zeta quality. The photoelectron spectra of the bent triatomic molecules with 18 valence electrons, i.e. SSO, NSF, O3, SO2, NSCl are compared. Further experimental details of the photoelectron spectrum of SSO are presented and an assignment of the observed ionic states of SSO⊕ is attempted. The calculated dissociation energies, dipole moments and the population analyses are given. The correlation effect is qualitatively discussed in connection with the applicability of Koopmans' theorem for the bent tri-atomic …