Issue 17, 2017

Contrasting the group 6 metal–metal bonding in sodium dichromate(ii) and sodium dimolybdate(ii) polymethyl complexes: synthetic, X-ray crystallographic and theoretical studies

Abstract

Extending the class of group 6 metal–metal bonded methylate compounds supported by alkali metal counter-ions, the first sodium octamethylmolybdate(II) complex [(TMEDA)Na]4Mo2Me8 and heptamethylchromate(II) relations [(donor)Na]3Cr2Me7 (donor is TMEDA or TMCDA) are reported. The former was made by treating [(Et2O)Li]4Mo2Me8 with four equivalents of NaOtBu/TMEDA in ether; whereas the latter resulted from introducing TMEDA or TMCDA to ether solutions of octamethyldichromate [(Et2O)Na]4Cr2Me8. X-ray crystallography revealed [(TMEDA)Na]4Mo2Me8 is dimeric with square pyramidal Mo centres [including a short Mo–Mo interaction of 2.1403(3) Å] each with four methyl groups in a mutually eclipsed conformation. In dinuclear [(TMCDA)Na]3Cr2Me7 trigonal bi-pyramidal Cr centres each bond to three terminal methyl groups and one common Me bridge, that produces a strikingly short Cr–Cr contact of 1.9136(4) Å. Broken symmetry density functional theoretical calculations expose the multiconfigurational metal–metal bonding in these compounds with a Mo–Mo bond order of 3 computed for octamethylmolybdate(II). This is contrasted by the single Cr–Cr bond in heptamethylchromate(II) where the singlet ground state is derived by strong antiferromagnetic coupling between adjacent metal ions.

Graphical abstract: Contrasting the group 6 metal–metal bonding in sodium dichromate(ii) and sodium dimolybdate(ii) polymethyl complexes: synthetic, X-ray crystallographic and theoretical studies

Supplementary files

Article information

Article type
Paper
Submitted
08 dez 2016
Accepted
25 jan 2017
First published
26 jan 2017

Dalton Trans., 2017,46, 5650-5659

Author version available

Contrasting the group 6 metal–metal bonding in sodium dichromate(II) and sodium dimolybdate(II) polymethyl complexes: synthetic, X-ray crystallographic and theoretical studies

R. Campbell, A. R. Kennedy, R. McLellan, S. D. Robertson, S. Sproules and R. E. Mulvey, Dalton Trans., 2017, 46, 5650 DOI: 10.1039/C6DT04644D

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