Adams, RD; Chen, LF; Yamamoto, JH
The reactions of 1,4-dithiacyclohexane (1,4-DTCH) with Os3(CO)10(NCMe)2, Os3(CO)11(NCMe) and Os3(CO)12 have been investigated. The reaction of 1,4-DTCH with Os3(CO)11(NCMe) at 25 °C yielded Os3(CO)11(SCH2CH2SCH2CH2) (1 in 46% yield. The reaction of 1,4-DTCH with Os3(CO)10(NCMe)2 at 25 °C yielded Os3(CO)10SCH2CH2SCH2CH2) (2) in 75% yield. Compound 2 was characterized by a single crystal X-ray diffraction analysis. The molecule consists of a triangular triosmium cluster with ten linear terminal carbonyl ligands, and a 1,4-DTCH ligand coordinated as a chelate to only one of the metal atoms. When compound 2 was heated to reflux in cyclohexane solvent four compounds were obtained: Os3(CO)9(μ3-ν2-CCH2(μ-H)2 (3), Os2(CO)6(μ-SCH2CH2S)(4), Os3(CO)10 (μ-SCH2CH2S)(5), Os3(CO)8(μ30-ν2-CCH2)(SCH2CH2SCH2CH2)(μ-H)2 (6). The formation of ethylene as a coproduct was observed spectroscopically when the reaction was performed in toluene-d8 solvent in an NMR tube at 100 °C. The same cluster complexes were obtained from the pyrolysis of 1, and from the direct reaction of 1,4-DTCH with Os3(CO)12 at 125 °C. Compounds 4 and 5 were characterized by single crystal X-ray diffraction analysis. Both compounds contain a bridging, chelating ethanedithiolato, SCH2CH2S, ligand. Compound 4 can be obtained from 5 in good yield by heating to 125 °C in octane solvent. Compound 3 has been reported previously. Compound 6 is a simple 1,4-DTCH derivative of 3. Crystallographic data for 2: Os3S2O10C14H8, space group, P21/n, a=8.641(2), b=25.108(4), c=10.533(1) A ̊, β=113.35(1)°, Z=4,2064 reflections, R=0.037. For 4: Os2S2O6C8H4, space group P21/n, a=8.612(2), b=16.062(8), c=9.988(4) A ̊, β=98.37(1)°, Z=4, 1295 reflections, R=0.044. For 5 Os3S2O10C12H4, space group P21/c, a=14.079(2), b=9.383(1), c=15.153(2) A ̊, β=108.20(8)°, Z=4, 1893 reflections, R=0.030. 1995.