Relationship between oxygen-17 nuclear magnetic resonance chemical shifts and Π-bonding to oxygen in the dichromate ion

Abstract

A linear relationship between 170 chemical shift and degree of T-bonding from oxygen to chromium in a number of chromium(V1) compounds is reported. The basis for this relationship is presented in terms of chemical shift theory. The 170 chemical shift values for the two types of oxygen in the Cr2072-ion are shown to be consistent with an angular rather than a linear Cr-0-Cr arrangement.

New soluble monomeric polyselenide anions, [MQ(Se4)2]2- (M = Mo, W; Q = O, S, Se)

“…25 In general, there is a correlation between increasing M-0 bond order and decreasing field. 26 Owing to the similar size of Mo and Se atoms, there may be a greater orbital overlap in the selenomolybdates than in the selenotungstates. This would cause a greater withdrawal of electron density by Mo as compared with W from adjacent selenide ligands.…”

Oxygen-17 nuclear magnetic resonance spectra of certain oxomolybdenum(VI) complexes and the influence of the multiplicity of the molybdenum-oxygen bond

“…Similar dependencies have been noted for the C-0 bonds in organic compounds21 and the Cr-0 bonds in oxochromium(VI) complexes. 22 Cotton and Wing3 have shown that the -bond orders for each Mo-O bond within the ds-Mo03 and tis-Mo02 fragments are 1 and 1.5, providing possible bonding by other donor atoms is ignored. Although Cotton and Wing have estimated the -bond order of each Mo-O bond in Mo042" to be close to unity,3 a better estimate would appear to be 0.75.23 The expected -bond orders have been noted in Table II.…”

Solid-State 17O NMR and Computational Studies of C-Nitrosoarene Compounds

“…As a result, δ iso ( 17 O) also increases with the π bond order, as first noted by Kidd more than 40 years ago. 93 Recently, we reported a quite general correlation between 17 O CS tensor components and C Q for carbonyl compounds.…”