CLUSTER-ASSISTED CYCLOOLIGOMERIZATION OF THIETANE - A NEW ROUTE TO POLYTHIOETHER MACROCYCLES

The trirhenium complex Re-3(CO)(10)[mu-SCH2CH2CH2](mu-H)(3) (1) was found to produce an oligomerization of thietane at 25 degrees C over 18 h to yield the new complex Re-3(CO)(10)[mu-SCH2CH2CH2SCH(2)CH(2)CH(2)SCH(2)CH(2)CH(2)SCH(2)CH(2)CH(2)](mu-H)(3) (2), in 47% yield. Details of the structure of compound 2 were obtained from a single crystal X-ray diffraction analysis of its PMe(2)Ph derivative 3. It was found to contain a bridging thiolate group SCH2CH2CH2 that is terminated with a SCH2CH2CH2SCH2CH2CH2SCH2CH2CH2 macrocycle. The macrocycle was cleaved from the cluster by treatment with NaOEt and the free molecule trithiacyclodecane was isolated in 32% yield. Crystal data for 3: space group = P2(1)/n, a = 8.637(2) Angstrom, b = 41.80(1) Angstrom, c = 15.418(2) Angstrom, beta = 111.79(2)degrees; Z = 4, 2836 reflections, R = 0.036.