Synthesis, characterization and crystal structures of some tungsten and triosmium carbonyl complexes with monopyridyl and dipyridyl azo ligands

Wai Yeung Wong, Suk Ha Cheung, Siu Ming Lee, Sze Yin Leung

Research output: Journal article publicationJournal articleAcademic researchpeer-review

64 Citations (Scopus)

Abstract

Substitution reactions of [W(CO)5(THF)] with the azo-functionalized monopyridyl and dipyridyl ligands, namely, 4-phenylazopyridine L1and 4,4′-azopyridine L2, readily afford two tungsten carbonyl complexes [W(CO)5(NC5H4-N=N-C6H5)] (1) and [(CO)5W(μ-NC5H4-N=N-C5H4N)W(CO)5] (2) in good yields. Ligation of L1and L2with the activated triosmium carbonyl cluster [Os3(CO)10(NCMe)2] by ortho-metallation reaction provides [Os3(μ-H)(CO)10(μ-NC5H3-N=N-C6H5)] (3) and the linking cluster [Os3(μ-H)(CO)10(μ-NC5H3-N=N-C5H3N)Os3(μ-H)(CO)10] (4) in satisfactory yields. All of the complexes have been fully characterized by IR,1H-NMR, UV-vis spectroscopies, fast atom bombardment (FAB) mass spectrometry and electrochemical measurements. The solid-state molecular structures of 1-4 have been ascertained by single-crystal X-ray diffraction methods. The structures of 1 and 3 involve the coordination of L1to one {W(CO)5} and {Os3(CO)10} moieties, respectively. In the case of 2 and 4, two identical metal cores are linked together by the bridging ligand L2. Spectroscopic investigations revealed that the metal-to-ligand charge transfer (MLCT) transitions of 1 and 2 demonstrate strong solvent dependency, displaying a large negative solvatochromism in a wide range of organic solvents.
Original languageEnglish
Pages (from-to)36-45
Number of pages10
JournalJournal of Organometallic Chemistry
Volume596
Issue number1-2
DOIs
Publication statusPublished - 29 Feb 2000
Externally publishedYes

Keywords

  • Clusters
  • Crystal structure
  • Osmium
  • Solvatochromism
  • Tungsten

ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

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