Issue 5, 2016

P–S bond cleavage in reactions of thiophosphinidene-bridged dimolybdenum complexes with [Co2(CO)8] to give phosphinidene-bridged heterometallic derivatives

Abstract

The thiophosphinidene complex [Mo2Cp2(μ–κ216-SPMes*)(CO)2] (Mes* = 2,4,6-C6H2tBu3) reacted with [Co2(CO)8] at room temperature or below to give several of the following phosphinidene-bridged products, depending on reaction conditions: the MoCo complexes [CoMoCp(μ–κ116-PMes*)(CO)3] and [CoMoCp(μ-PMes*)(CO)5] (Co–Mo = 2.972(1) Å), the MoCo3 cluster [Co3MoCp(μ3-PMes*)(CO)9] (Co–Mo = 2.664(1), 2.810(1) Å), and the sulphido-bridged tetranuclear complexes [Co2Mo2Cp2(μ–κ1114-PMes*)(μ3-S)(CO)7] and [Co3MoCp(μ–κ1114-PMes*)(μ3-S)(CO)8]. In contrast, the thiophosphinidene complex [Mo2Cp2(μ–κ214-SPMes*)(CO)3] reacted with the same cobalt reagent selectively to give the above Mo2Co2 complex in very high yield. The latter could be decarbonylated photochemically to give [Co2Mo2Cp2(μ–κ1116-PMes*)(μ3-S)(CO)6] (Co–Co = 2.435(3), Co–Mo = 2.769(2), 2.798(2) Å), after an η4- to η6-haptotropic rearrangement of the aryl ring of the phosphinidene ligand that could be reversed upon reaction with CO. The related complex [Mo2Cp2(μ–κ214-SPMes*)(CO)2(CNtBu)], however, displayed poor selectivity towards the cobalt dimer and yielded a mixture of CoMo complexes [CoMoCp(μ-PMes*)(CO)5] and [CoMoCp(μ-PMes*)(CO)3(CNtBu)2], and the tetranuclear sulphido-bridged ones [Co2Mo2Cp2(μ–κ1114-PMes*)(μ3-S)(CO)6(CNtBu)] (Co–Co = 2.533(1), Co–Mo = 2.7485(9), 2.770(1) Å) and [Co3MoCp(μ–κ1114-PMes*)(μ3-S)(CO)7(CNtBu)] (Co–Co = 2.4120(7) to 2.5817(7) Å). This reduction in selectivity might have an electronic origin rather than a steric origin, since the related but cationic substrate [Mo2Cp2{μ–κ215-SP(C6H3tBu3)}(CO)2(CNtBu)]BAr4 [Ar′ = 3,5-C6H3(CF3)2] reacted with [Co2(CO)8] more selectively to give the sulphido-bridged Co2Mo2 complex [Co2Mo2Cp2{μ–κ1115-P(C6H3tBu3)}(μ3-S)(CO)6(CNtBu)]BAr4, along with small amounts of the Co3Mo complex [Co3MoCp{μ–κ1115-P(C6H3tBu3)}(μ3-S)(CO)7(CNtBu)]BAr4 (Co–Co = 2.414(2) to 2.560(2) Å). The structure of the new complexes was analyzed on the basis of the corresponding X-ray diffraction and spectroscopic data, and likely reaction pathways were discussed on the basis of the above results and some additional experiments.

Graphical abstract: P–S bond cleavage in reactions of thiophosphinidene-bridged dimolybdenum complexes with [Co2(CO)8] to give phosphinidene-bridged heterometallic derivatives

Supplementary files

Article information

Article type
Paper
Submitted
16 avr. 2015
Accepted
18 mai 2015
First published
08 juin 2015

Dalton Trans., 2016,45, 1937-1952

P–S bond cleavage in reactions of thiophosphinidene-bridged dimolybdenum complexes with [Co2(CO)8] to give phosphinidene-bridged heterometallic derivatives

B. Alvarez, M. A. Alvarez, M. E. García and M. A. Ruiz, Dalton Trans., 2016, 45, 1937 DOI: 10.1039/C5DT01450F

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