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

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65 Citations (Scopus)


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
Issue number1-2
Publication statusPublished - 29 Feb 2000
Externally publishedYes


  • 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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