Reactions of α,ω-dithiolate ligands with bis(cyclopentadienyl)molybdenum dichloride; crystal structures of Mo(η-C5H5)2{S(CH2)nS)} (n = 2, 3) and a layered hydrate, Mo(η-C5H5)2(SCH2CH2O) · 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(η-C5H5)2(SCH2CH2 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(η-C5H5)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(η-C5H5)2(SCH2 CH2O) · 4.5H2O comprises stacks of double layers of hydrated organometallic molecules of overall composition [{Mo(η-C5H5)2(SCH2CH2O)}2 · H2O]n separated by layers of hydrogen-bonded water molecules, interconnected by H-bonds between H2O molecules and O-atoms of the 2-thioethoxy ligand.