Bond order-bond length correlations for SN bonds in organic molecules

1973 ◽  
Vol 3 (6) ◽  
pp. 331-336 ◽  
Author(s):  
S. C. Nyburg
1993 ◽  
Vol 90 (23) ◽  
pp. 11297-11301 ◽  
Author(s):  
C B Gorman ◽  
S R Marder

A computational method was devised to explore the relationship of charge separation, geometry, molecular dipole moment (mu), polarizability (alpha), and hyperpolariz-abilities (beta, gamma) in conjugated organic molecules. We show that bond-length alternation (the average difference in length between single and double bonds in the molecule) is a key structurally observable parameter that can be correlated with hyperpolarizabilities and is thus relevant to the optimization of molecules and materials. By using this method, the relationship of bond-length alternation, mu, alpha, beta, and gamma for linear conjugated molecules is illustrated, and those molecules with maximized alpha, beta, and gamma are described.


1957 ◽  
Vol 30 (6) ◽  
pp. 638-647 ◽  
Author(s):  
Tosinobu Anno ◽  
Mitsuo Ito ◽  
Ryoichi Shimada ◽  
Akira Sado ◽  
Wataru Mizushima

1983 ◽  
Vol 36 (4) ◽  
pp. 639 ◽  
Author(s):  
RD Brown ◽  
PD Godfry ◽  
BT Hart ◽  
AL Ottrey ◽  
M Onda ◽  
...  

The microwave spectrum of the benzene isomer 3,4-dimethylenecyclobutene including spectra of all possible single 13C-substituted and sufficient singly and doubly D-substituted species to give a complete r5 geometry, have been measured and analysed. An estimate of the re geometry has also been derived. The additional precise CC bond lengths obtained for an unsubstituted, conjugated hydrocarbon enable us to examine bond order-bond length relationships more thoroughly than has previously been possible. The CC bond lengths exhibit a noticeably better correlation with SCFMO bond orders than with simple H�ckel bond orders. Further confirmatory measurements of the dipole moment of dimethylenecyclobutene have been made. Ab initio molecular orbital calculations using a 6-31G basis set give an optimized geometry with CC bond lengths within 2 pm of the r5 values. The computed dipole moment agrees almost exactly with experiment but a corresponding calculation on fulvene is discrepant with experiment by 0.16 D, which is probably a more typical error.


1996 ◽  
Vol 65 (6) ◽  
pp. 1641-1647 ◽  
Author(s):  
Kei Odai ◽  
Hideki Ono ◽  
Hideo Suzuki
Keyword(s):  

2003 ◽  
Vol 68 (2) ◽  
pp. 307-330 ◽  
Author(s):  
Antonio Laganà ◽  
Stefano Crocchianti ◽  
Noelia Faginas Lago ◽  
Leonardo Pacifici ◽  
Gianni Ferraro

Computational approaches to the evaluation of the reactive scattering properties of atom- diatom reactions are revisited. The aim is to exploit both the use of nonorthogonal coordinates in reactive scattering and the restructuring of related computer codes for concurrent computing. To this end, bond length, bond-order and hyperspherical bond order coordinate formalisms are examined for the collinear case. At the same time, the evolution of parallel models from coarse to fine granularity and the development of parallelization supports from directive libraries to programming environments are discussed. The scalability of related codes is tested by measuring the performances of restructured codes. The suitability of the use of nonorthogonal coordinates for scattering purposes is tested by performing collinear calculations for the H + H2 reaction.


1987 ◽  
Vol 42 (6) ◽  
pp. 674-678 ◽  
Author(s):  
Norbert Kuhn ◽  
Hans Schumann ◽  
Gotthelf Wolmershäuser
Keyword(s):  

AbstractThe P - Te bond length in (tert-C4H9)3PTe of 2.368 Å corresponds to a bond order near 1.5. The distance may be influenced by the tert-C4H9 groups, but the 125Te NMR shift is well within the common R3PTe range, while 1J(125Te-31P) is about 140 Hz smaller than in other tellurophosphoranes.


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