THE SULPHUR–OXYGEN BOND IN SULPHURYL AND THIONYL COMPOUNDS: CORRELATION OF STRETCHING FREQUENCIES AND FORCE CONSTANTS WITH BOND LENGTHS, BOND ANGLES, AND BOND ORDERS

1963 ◽  
Vol 41 (8) ◽  
pp. 2074-2085 ◽  
Author(s):  
R. J. Gillespie ◽  
E. A. Robinson

It is shown that the bond length of an SO bond and the bond angle of an SO2 group may be very satisfactorily correlated with the SO stretching frequency. The bond-length – stretching-frequency relationship is used to predict some bond lengths that have not been measured and the OSO angles in some sulphuryl compounds are also calculated. The problem of defining and measuring the bond order of sulphur–oxygen bonds is discussed. It is shown that there is a linear relationship between the force constant and the bond order and a non-linear relationship between the bond length and the bond order.

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.


1963 ◽  
Vol 41 (12) ◽  
pp. 3021-3033 ◽  
Author(s):  
E. A. Robinson

For oxygen compounds of chlorine, phosphorus, and silicon, respectively, correlations are established between stretching frequencies and force constants of Cl—O, P—O, and Si—O bonds, and their bond lengths.By deducing bond orders on the assumption that only [Formula: see text]and [Formula: see text] orbitals on the central chlorine, phosphorus, or silicon atom are utilized in the formation of double bonds with lone pairs of electrons on oxygen, linear correlations between bond orders and force constants are established.The present treatment leads to the conclusion that the presence of a maximum of 12 electrons in the valency shells of chlorine, phosphorus, and silicon is required to best explain the bond length and force constant data, when highly electronegative ligands such as oxygen or fluorine are attached to the central silicon, phosphorus, or chlorine atom.


An extremely careful inquiry is made into the possibility of predicting bond lengths in condensed aromatic hydrocarbon molecules. Agreement with the best experimental values, such as those of Robertson, Abrahams, White, Mathieson and Sinclair, is fairly easily obtained to an accuracy of about 0.02Å. This shows that the concept of fractional bond order may quite properly be used to infer bond lengths. Both the molecular-orbital and resonance methods are equally good for this purpose. Predictions to within less than 0.02Å require the introduction of new factors usually neglected. No less than five such factors are discussed: ( а ) electrostatic forces, arising from possible differences in electronegativity of the various carbon atoms, ( b ) changes of bond orders due to electronegativity differences, ( c ) variation of resonance integrals with bond length, ( d ) obtaining a self-consistent set of resonance integrals, ( e ) inclusion of configuration interaction. Correction terms which result from these improvements lie between 0 and 0.015Å, and are not all of the same sign. It is unlikely therefore that this type of analysis will be able to give confident predictions of bond lengths to less than 0.01Å.


1975 ◽  
Vol 53 (20) ◽  
pp. 3040-3043 ◽  
Author(s):  
Myung-Hwan Whangbo ◽  
Saul Wolfe ◽  
Fernando Bernardi

The C—O and C—S bond lengths of the cations, radicals, and anions CH3O, CH3S, CH2OH, and CH2SH have been found not to correlate with the overlap populations of the C—X bonds. On the other hand, very satisfactory linear relations are observed with the ionic bond orders of the C—X bonds. It is suggested that, in certain molecular systems, it may be more meaningful to associate shortening of a bond A—B with greater coulombic attraction (or smaller coulombic repulsion) between the two point charges represented by the net atomic charges on the atoms A and B than with an increase in the overlap population between these atoms. It is noted that such an interpretation can account for the short C—P bond in a phosphonium ylide without resort to (p → d)π conjugation.


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

2014 ◽  
Vol 2 (14) ◽  
pp. 2475-2481 ◽  
Author(s):  
M. H. Du

Calculated Mn4+ emission energies for various oxides as functions of Mn–O bond length. The experimental values are shown (in red) wherever available. There are three groups of materials: the ones with small O–Mn–O bond angle distortion (black squares), the ones with large O–Mn–O bond angle distortion (blue circles), and phosphates (green triangles). Weak Mn4+-ligand hybridization as a result of long Mn–O bond lengths and/or large O–Mn–O bond angle distortion generally leads to higher emission energies.


IUCrData ◽  
2017 ◽  
Vol 2 (9) ◽  
Author(s):  
Will Lynch ◽  
Clifford Padgett

In the crystal structure of the title solvatedtrans-dioxidoosmium(VI) flavonolate (flav) complex, [Os(C15H9O3)2O2]·2CH2Cl2or [Os(flav)2O2]·2CH2Cl2, the two dichloromethane solvent molecules have nonclassical hydrogen-bonding contacts at or greater than 3.18 Å. The pseudo-octahedrally coordinated central metal cation is observed with all donor atoms being oxygen. The Os=O bond lengths are 1.721 (5) and 1.728 (5) Å, with a 170.4 (2)° bond angle. The O—Os bond lengths arising from the flanvonolate ligand are observed to all be slightly over 2.0 Å. The chelate bond angles arising from the flavonolate O atoms with the osmium cation are constrained by the ligand at 80.72 (18) and 80.92 (17)°.


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