Configuration of the S-alkyl thiohydroximates: crystal-structure analysis of the syn-(alkylthio)-isomer of S-cyanoethyl acetothiohydroximate

The syn-(alkylthio)-configuration of the thermodynamically more stable α-isomer of S-cyanoethyl acetothio-hydroximate has been confirmed by crystal-structure determination. The compound crystallizes in the monoclinic space group P21/c, with a= 16·535 ± 0·011, b= 4·654 ± 0·003, c= 19·536 ± 0·012 A, β= 106° 44′± 2′, and Z= 8. The X-ray intensities were measured on a computer-controlled four-circle diffractometer with Mo-Kα radiation. The atomic co-ordinates were determined by Fourier and least-squares methods to give R 0·069 over 903 independent reflections. The CN, CN, N–O, C(sp)–C(sp3), C(sp2)–C(sp3), C(sp3)–C(sp3), S–C(sp2), and S–C(sp3) bonds have lengths of 1·28, 1·13, 1·41, 1·45, 1·50, 1·52, 1·76, and 1·82 A, respectively, with standard deviations of ca. 0·01 A.