Reactions of α,ω-dithiolate ligands with bis(cyclopentadienyl) molybdenum dichloride; Crystal structures of Mo(η-C₅H ₅)₂{S(CH₂)_nS)} (n = 2, 3) and a layered hydrate, Mo(η-C₅H₅)₂(SCH ₂CH₂O)·4.5H₂O

Reaction of bis(cyclopentadienyl)molybdenum dichloride 1 in ethanol with 1,3-propanedithiol 2 either in the presence of base or as its thallium derivative produces [Mo(?-C₅H₅)₂(SCH ₂CH₂ CH₂S)] (5) containing a 6-membered ring with a chair conformation, structurally characterized by X-ray diffraction. However, reactions of compound 1 with 2,2'-thiodiethanethiol (3) or 2,2'-oxydiethanethiol (4) under the same conditions do not form complexes with 8-membered chelate rings but lead to thioether or ether bond cleavage, respectively, to yield as major products [Mo(?-C₅H ₅)₂(SCH₂CH₂X)] (6, X = S, or 7, X = O), containing ligands which form 5-membered rings; crystal structures of 6 and 7 are reported and both contain chelating ligands with envelope conformations. Compound 7 readily incorporates water and the unusual crystal structure of the hydrate Mo(?-C₅H₅)₂(SCH₂ CH ₂O)·4.5H₂O comprises stacks of double layers of hydrated organometallic molecules of overall composition [{Mo(?-C ₅H₅)₂(SCH₂CH₂O)} ₂ • H₂O]_n separated by layers of hydrogen-bonded water molecules, interconnected by H-bonds between H ₂O molecules and O-atoms of the 2-thioethoxy ligand. © 2004 Elsevier B.V. All rights reserved.