Issue 13, 2003

Synthesis and reactivity of 1,8-bis(imino)carbazolide complexes of iron, cobalt and manganese

Abstract

The synthesis and characterisation of a new family of monoanionic, tridentate bis(imino)carbazolide ligands (L) and their cobalt, iron and manganese complexes are described. The solid state structure of the five coordinate FeIII complex LFeCl2 (9c) reveals a trigonal bipyramidal geometry with a short Fe–N(carbazolide) bond (1.959(3) Å), indicative of π-donation from the carbazole nitrogen to the metal centre. The cationic derivatives LFeCl(MeCN)+ (11), LFe(acac)+ (12) and LCo(MeCN)+ (14) have been prepared by chloride abstraction from the neutral precursors using AgSbF6 or Ag(acac). Treatment of LMCln (M = Fe, Co) complexes with MeLi affords metal–methyl species, tentatively formulated as LFeMe2 (13), LFeMe (16a) and LCoMe (16b). All of the Mn, Fe and Co compounds are paramagnetic and generally exhibit magnetic moments consistent with high spin configurations. In certain cases, however, low spin as well as intermediate spin configurations are found, depending on the nature of the co-ligands around the metal centre. The LFeCl29c complex exhibits a room temperature magnetic moment of 4.8 µB and is a rare example of a trigonal bipyramidal FeIII complex in which a spin admixture between a high spin and an intermediate spin state is present. None of the divalent or trivalent bis(imino)carbazolide metal complexes, using a variety of activators, showed activity for ethylene oligomerisation or polymerisation.

Graphical abstract: Synthesis and reactivity of 1,8-bis(imino)carbazolide complexes of iron, cobalt and manganese

Supplementary files

Article information

Article type
Paper
Submitted
18 Feb 2003
Accepted
01 May 2003
First published
30 May 2003

Dalton Trans., 2003, 2718-2727

Synthesis and reactivity of 1,8-bis(imino)carbazolide complexes of iron, cobalt and manganese

V. C. Gibson, S. K. Spitzmesser, A. J. P. White and D. J. Williams, Dalton Trans., 2003, 2718 DOI: 10.1039/B301902K

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