Issue 18, 2008

A computational study of the electronic structure, bonding, and spectral properties of tripodal tetraamine Co(iii) carbonate complexes

Abstract

Density functional calculations have been carried out on the experimentally characterized Co(III) [Co(N4)(O2CO)]+ carbonate complexes containing a tripodal tetraamine ligand (N4 = tpa, Metpa, Me2tpa, Me3tpa, pmea, pmap, tepa) and also the model [Co(NH3)4(O2CO)]+ system. Calculations on the model species, performed using both gas-phase and solvent-corrected procedures, have revealed that the inclusion of a condensed-phase environment is necessary to obtain generally satisfactory results for the structural and bonding properties in these systems. Using the solvent-corrected approach, the observed trends in structural parameters for the metal–ligand bonds, 59Co chemical shifts, and changes in visible absorption wavelengths have been satisfactorily reproduced for the [Co(N4)(O2CO)]+ complexes. A time-dependent density functional analysis of the electronic excitations indicates that the overall composition and character of the relevant (d–d) transitions remain similar throughout the series, indicating that the changes in the Co–N interactions, associated with the structural variations occurring as the N-donor ligand identity and size change, appear most likely responsible for the particular spectroscopic features displayed by these species. These observations are further supported by molecular orbital and energy decomposition analyses. The results from the present calculations confirm recent findings that the inclusion of a treatment for solvent effects plays a critical role in the computational modelling of coordination complexes involving mixed (anionic and neutral) ligands.

Graphical abstract: A computational study of the electronic structure, bonding, and spectral properties of tripodal tetraamine Co(iii) carbonate complexes

Article information

Article type
Paper
Submitted
14 Nov 2007
Accepted
04 Jan 2008
First published
12 Mar 2008

Dalton Trans., 2008, 2433-2441

A computational study of the electronic structure, bonding, and spectral properties of tripodal tetraamine Co(III) carbonate complexes

G. Cavigliasso, R. Stranger, L. F. McClintock, S. E. Cheyne, P. M. Jaffray, K. E. Baxter and A. G. Blackman, Dalton Trans., 2008, 2433 DOI: 10.1039/B717619H

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