scholarly journals On the pd Hybridization of the Sulfur Atom in Thiothiophten. I. The Calculations of the Overlap Integrals Involving d Orbitals

1961 ◽  
Vol 34 (6) ◽  
pp. 785-790 ◽  
Author(s):  
Kôgorô Maeda
1969 ◽  
Vol 47 (2) ◽  
pp. 343-348 ◽  
Author(s):  
A. Queen ◽  
T. A. Nour ◽  
E. Bock

The dipole moments of a series of aryl and alkyl thiochloroformate esters have been determined in benzene solution at 25 °C and compared with the corresponding values for chloroformate and fluoroformate esters. The results have been interpreted in terms of conjugative and hyperconjugative electron release by the hydrocarbon group to the d-orbitals of the sulfur atom in the thio compounds. Vector model, bond moment calculations indicate that, as in the cases of the chloroformate and fluoroformate esters, the preferred conformations of the thiochloroformates are those in which the hydrocarbon group and the halogen atom are cis to each other.


1953 ◽  
Vol 21 (2) ◽  
pp. 258-263 ◽  
Author(s):  
H. H. Jaffé
Keyword(s):  

1966 ◽  
Vol 45 (9) ◽  
pp. 3355-3364 ◽  
Author(s):  
D. P. Craig ◽  
T. Thirunamachandran
Keyword(s):  

1981 ◽  
Vol 59 (5) ◽  
pp. 814-816 ◽  
Author(s):  
N. Colin Baird ◽  
Kathleen F. Taylor

Abinitio molecular orbital calculations are reported for SF4 (both C2v and C4v symmetries), SOF2, and SO2F2. Geometry searches were conducted using the STO-3G* basis set; the energies were recalculated at the predicted equilibrium structures also using STO-3G and 44-31G, and the latter basis set with the addition of five real d Gaussian orbitals on the sulfur atom. The predicted geometries agree well with experiment, although S=O bonds are consistently predicted too long by ∼0.03 Å, and the variation in S—F bond lengths among different environments is underestimated. The energy stabilization associated with the addition of d orbitals is generally consistent with our previous calculations, i.e. it is a constant amount per bond in hypervalent sulfur compounds in extended basis calculations. Replacement of F by OH is predicted to be more exothermic in SO2F2 than in SOF2, and the relevance of this prediction to estimated heats of formation for SOF2 and SO(OH)2 is discussed.


1957 ◽  
Vol 27 (4) ◽  
pp. 883-886 ◽  
Author(s):  
Joe L. Roberts ◽  
H. H. Jaffé
Keyword(s):  

1975 ◽  
Vol 53 (11) ◽  
pp. 1677-1681 ◽  
Author(s):  
Robert Faure ◽  
Jean-Richard Llinas ◽  
Emile-Jean Vincent ◽  
Michel Rajzmann

During a general n.m.r. study of five-membered heterocycles with two hetero-atoms, we measured the 13C chemical shifts, the vicinal couplings [Formula: see text] and the long range couplings for a series of variously substituted isothiazoles. At that time we were able to compare the effects of the various substituents to the effect of the group of hetero-atoms and to demonstrate the pre dominant influence of dissymmetry of the latter on the values of the observed parameters. Moreover, a comparison with theoretical results based on a CNDO model showed deficiencies which justify the search for a representation better adapted, by the introduction of d orbitals, to the sulfur atom. Studies of CNDO parametrization for third row elements are being undertaken by other means. [Journal translation]


2020 ◽  
Author(s):  
María Camarasa-Gómez ◽  
Daniel Hernangómez-Pérez ◽  
Michael S. Inkpen ◽  
Giacomo Lovat ◽  
E-Dean Fung ◽  
...  

Ferrocenes are ubiquitous organometallic building blocks that comprise a Fe atom sandwiched between two cyclopentadienyl (Cp) rings that rotate freely at room temperature. Of widespread interest in fundamental studies and real-world applications, they have also attracted<br>some interest as functional elements of molecular-scale devices. Here we investigate the impact of<br>the configurational degrees of freedom of a ferrocene derivative on its single-molecule junction<br>conductance. Measurements indicate that the conductance of the ferrocene derivative, which is<br>suppressed by two orders of magnitude as compared to a fully conjugated analog, can be modulated<br>by altering the junction configuration. Ab initio transport calculations show that the low conductance is a consequence of destructive quantum interference effects that arise from the hybridization of metal-based d-orbitals and the ligand-based π-system. By rotating the Cp rings, the hybridization, and thus the quantum interference, can be mechanically controlled, resulting in a conductance modulation that is seen experimentally.<br>


1988 ◽  
Vol 53 (9) ◽  
pp. 2023-2054 ◽  
Author(s):  
Milan Randić ◽  
Sonja Nikolić ◽  
Nenad Trinajstić

The conjugated circuits model is applied to heterocycles containing divalent sulfur. A novel parametrization is introduced for 4n + 2 and 4n conjugated circuits containing a single sulfur atom. The relative aromatic stabilities of a number of heterocyclic systems containing divalent sulfur are studied. Comparison is made whenever possible with earlier reported resonance energies of these compounds, obtained by using Huckel MO and SCF π-MO models, and appropriate reference structures. Special attention is given to positional isomers. An explanation of the differences amongst such isomers is given.


2021 ◽  
pp. 129912
Author(s):  
Fuxing Jiao ◽  
Chengming Zhang ◽  
Guang Lu ◽  
Yi Man ◽  
Chunbo Duan ◽  
...  

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