Ground-state vibrational assignments of cis- and trans-1,3,5-hexatriene

1987 ◽  
Vol 91 (2) ◽  
pp. 276-282 ◽  
Author(s):  
R. McDiarmid ◽  
A. Sabljic
Keyword(s):  
Ground State ◽  
Vibrational Assignments ◽  
Cis And Trans

Vibrational assignments and thermodynamic functions for cis- and trans-1,2-difluoro-1-chlorethylenes

1970 ◽  
Vol 74 (26) ◽  
pp. 4520-4527 ◽  
Author(s):  
Norman C. Craig ◽  
David Albert Evans ◽  
Lawrence G. Piper ◽  
Vicki L. Wheeler
Keyword(s):  
Thermodynamic Functions ◽  
Vibrational Assignments ◽  
Cis And Trans

scholarly journals A Post-HF Approach to the Sunscreen Octyl Methoxycinnamate

2021 ◽  
Author(s):  
Ettore Fois ◽  
Mario Oriani ◽  
gloria tabacchi
Keyword(s):  
Gas Phase ◽  
Ground State ◽  
Stable Isomer ◽  
Dispersion Interactions ◽  
Trans Form ◽  
Compact Structure ◽  
Hartree Fock ◽  
Molecular Dispersion ◽  
Cis And Trans ◽  
Effect Of Light

Octyl methoxycinnamate (OMC) is a commercial sunscreen with excellent UVB filter properties. However, it is known to undergo a series of photodegradation processes that decrease its effectiveness as UVB filter. In particular, the trans (E) form - which is considered so far the most stable isomer - converts to the cis (Z) form under the effect of light. In this work, by using post-Hartree-Fock approaches (CCSD, CCSD(t) and CCSD+T(CCSD)) on ground state OMC geometries optimized at the MP2 level we show that the cis and trans form of the gas-phase OMC molecule have comparable stability. Our results suggest that the cis form is stabilized by intra-molecular dispersion interactions, leading to a folded, more compact structure than the trans isomer.<br>

Vibrational assignments and potential constants for cis- and trans-1-chloro-2-fluoroethylenes and their deuterated modifications

1970 ◽  
Vol 74 (8) ◽  
pp. 1712-1727 ◽  
Author(s):  
Norman C. Craig ◽  
Y. S. Lo ◽  
Lawrence G. Piper ◽  
John C. Wheeler
Keyword(s):  
Vibrational Assignments ◽  
Cis And Trans

Probing the Ground-State δ Effect of Group 14 Metal Substituents. X-Ray Structures of cis- and trans-4-Trimethylmetal-Substituted Cyclohexyl p-Nitrobenzenesulfonates

1998 ◽  
Vol 51 (7) ◽  
pp. 555 ◽  
Author(s):  
Alison J. Green ◽  
Victor Van ◽  
Jonathan M. White
Keyword(s):  
Low Temperature ◽  
Ground State ◽  
Structural Studies ◽  
Structural Effects ◽  
Group 14 ◽  
X Ray ◽  
Bond Interaction ◽  
Cis And Trans

Accurate low-temperature X-ray structural studies on trans-4-trimethylsilylcyclohexyl p-nitrobenzene- sulfonate (31) and cis- and trans-4-trimethylstannylcyclohexyl p-nitrobenzenesulfonates (32) and (33) failed to demonstrate the presence of any significant structural effects due to a σM-C-σC-C-σ*C-O through-bond interaction between the C–M σ donor orbital and the σ*C-ONs acceptor orbital.

Effect of protonation on the ground state properties of retinal analogs: an ab-initio study

1987 ◽  
Vol 65 (4) ◽  
pp. 892-897 ◽  
Author(s):  
Raymond A. Poirier ◽  
Arpita Yadav ◽  
Péter R. Surján
Keyword(s):  
Schiff Base ◽  
Ground State ◽  
Atomic Charge ◽  
Bond Orders ◽  
Bond Lengths ◽  
Ground State Properties ◽  
Cis And Trans Isomers ◽  
Base Analog ◽  
Retinal Analogs ◽  
Cis And Trans

The ground state properties (bond lengths, bond orders, net atomic charge distribution) of various cis and trans isomers of retinal analogs have been studied at abinitio SCF and correlated levels. The effect of protonation on the properties of the retinal Schiff base analogs has also been studied. Convergence in various properties has been observed with increasing chain length justifying the use of smaller analogs mimicking retinal. Convergence is, however, slower for the protonated retinal Schiff base analogs. The protonated retinal Schiff base analogs show an increased conjugation reflected in the bond orders, bond lengths, and in the decrease in the HOMO–LUMO gap. The nodal characteristics of the HOMO of the protonated retinal Schiff base analog also indicate a strong conjugation in the vicinity of the protonated nitrogen. Based on the results of calculations at the correlated level, the sudden polarization charge transfer mechanism is shown to be an artifact of HF-based methods used in the calculations.

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