Campus Units

Chemistry, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

3-7-2011

Journal or Book Title

Inorganic Chemistry

Volume

50

Issue

7

First Page

3010

Last Page

3016

DOI

10.1021/ic102510c

Abstract

rac-Bis[{(diphenylphosphino)ethyl}-phenylphosphino]methane (DPPEPM) reacts with iron(II) and ruthenium(II) halides to generate complexes with folded DPPEPM coordination. The paramagnetic, five-coordinate Fe(DPPEPM)Cl2 (1) in CD2Cl2 features a tridentate binding mode as established by 31P{1H} NMR spectroscopy. Crystal structure analysis of the analogous bromo complex, Fe(DPPEPM)Br2 (2) revealed a pseudo-octahedral, cis-α geometry at iron with DPPEPM coordinated in a tetradentate fashion. However, in CD2Cl2solution, the coordination of DPPEPM in 2 is similar to that of 1 in that one of the external phosphorus atoms is dissociated resulting in a mixture of three tridentate complexes. The chloro ruthenium complex cis-Ru(κ4-DPPEPM)Cl2 (3) is obtained from rac-DPPEPM and either [RuCl2(COD)]2 [COD = 1,5-cyclooctadiene] or RuCl2(PPh3)4. The structure of 3 in both the solid state and in CD2Cl2 solution features a folded κ4-DPPEPM. This binding mode was also observed in cis-[Fe(κ4-DPPEPM)(CH3CN)2](CF3SO3)2 (4). Addition of an excess of CO to a methanolic solution of 1 results in the replacement of one of the chloride ions by CO to yieldcis-[Fe(κ4-DPPEPM)Cl(CO)](Cl) (5). The same reaction in CH2Cl2 produces a mixture of 5and [Fe(κ3-DPPEPM)Cl2(CO)] (6) in which one of the internal phosphines has been substituted by CO. Complexes 2, 3, 4, and 5 appear to be the first structurally characterized monometallic complexes of κ4-DPPEPM.

Comments

Reprinted (adapted) with permission from Inorganic Chemistry 50 (2011): 3010, doi:10.1021/ic102510c . Copyright 2011 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Included in

Chemistry Commons

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