Ebbe Nordlander
Professor
Synthesis, characterisation and natural abundance Os-187 NMR spectroscopy of hydride bridged triosmium clusters with chiral diphosphine ligands
Author
Summary, in English
Treatment of [Os-3(mu-H)(2)(CO)(10)] with the chiral diphosphines BINAP, tolBINAP [(R)-2,2'-bis(di-4-tolylphosphino)-1,1'-binaphthyl], DIOP [(4R,5R)-(-)-O-isopropenylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino) butane] affords [Os-3(mu-H)(2)(CO)(8)(mu-L)] (L = BINAP (1), tolBINAP (2), DIOP (4)) in high yield. The X-ray structures for 1, 2 and 4 are reported, and structural and spectroscopic comparisons are made between these clusters and [Os-3(mu-H)(2)(CO)(8)(mu-L)] (L = dppm (5), dppe (6), dppp (7)) which were synthesised similarly. Compounds 5 to 7 were previously synthesised by hydrogenation of 1,2-[OS3(CO)(10)(mu-L)] but the route from [Os(mu-H)(2)(CO)(10)] is preferable. The H-bridged Os center dot center dot Os distances are similar in 1, 2 and 4 indicating that these species are formally unsaturated 46-electron clusters. The P center dot center dot center dot P distances vary from 4.24 to 4.30 angstrom in 1 and 2, respectively, to 4.53 angstrom in 4 and there are related changes in the angles associated with the ligand set around the H-bridged osmium atoms. Introduction of the diphosphine ligands completely suppresses the ability to add CO, to insert acetylene to form a mu-eta(1), eta(2)-vinyl compound, and to exchange hydride ligands with styrene-d(8), which are reactions characteristic of [Os-3(mu-H)(2)(CO)(10)], Clusters 2 and 5-7 were also used to examine the potential of natural abundance Os-187 NMR spectroscopy through techniques based on inverse detection by HMQC, HSQC and HMBC spectroscopy. (c) 2005 Elsevier B.V. All rights reserved.
Department/s
- Chemical Physics
- Centre for Analysis and Synthesis
Publishing year
2006
Language
English
Pages
926-937
Publication/Series
Inorganica Chimica Acta
Volume
359
Issue
3
Document type
Journal article
Publisher
Elsevier
Topic
- Analytical Chemistry
- Atom and Molecular Physics and Optics
Keywords
- NMR
- chiral phosphine
- osmium
- cluster
Status
Published
ISBN/ISSN/Other
- ISSN: 0020-1693