Issue 22, 2012

Tuning the electronic structure of Mo–Mo quadruple bonds by N for O for S substitution

Abstract

A series of quadruply bonded dimolybdenum compounds of form Mo2(EE′CC[triple bond, length as m-dash]CPh)4 (EE′ = {NPh}2, Mo22NN; {NPh}O, Mo22NO;{NPh}S, Mo22NS; OO, Mo22OO) have been synthesised by ligand exchange reactions of Mo2(O2CCH3)4 with the acid or alkali metal salt of {PhC[triple bond, length as m-dash]CCEE′}. The compounds Mo22NO, Mo22NS and Mo22OO were structurally characterised by single crystal X-ray crystallography. The structures show that Mo22NO adopts a cis-2,2 arrangement of the ligands about the Mo24+ core, whereas Mo22NS adopts the trans-2,2 arrangement. The influence of heteroatom substitution on the electronic structure of the compounds was investigated using cyclic voltammetry and UV-Vis spectroscopy. Simple N for O for S substitution in the bridging ligands significantly alters the electronic structure, lowering the energy of the Mo2-δ HOMO and reducing the Mo24+/5+ oxidation potential by up to 0.9 V. A different trend is found in the optoelectronic properties, with the energy of the Mo2-δ-to-ligand-π* transition following the order Mo22OO > Mo22NO > Mo22NN > Mo22NS. Electronic structure calculations employing density functional theory were used to rationalise these observations.

Graphical abstract: Tuning the electronic structure of Mo–Mo quadruple bonds by N for O for S substitution

Supplementary files

Article information

Article type
Paper
Submitted
01 Feb 2012
Accepted
21 Mar 2012
First published
21 Mar 2012

Dalton Trans., 2012,41, 6641-6650

Tuning the electronic structure of Mo–Mo quadruple bonds by N for O for S substitution

J. Hicks, S. P. Ring and N. J. Patmore, Dalton Trans., 2012, 41, 6641 DOI: 10.1039/C2DT30234A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements