CRYSTAL AND MOLECULAR STRUCTURE OF 4-tert-BUTYLPHOSPHORINANE 1-SULFIDE DERIVATIVES. PART II. Cis/trans-4-tert-BUTYL-1-CHLOROPHOSPHORINANE 1-SULFIDE

Abstract Cis- and trans-4-tert-butyl-1-chlorophosphorinane 1-sulfides were prepared and investigated by single crystal X-ray diffraction. Cis-4-tert-butyl-1-chlorophosphorinane 1-sulfide (2a): space group Pbam (No. 55) with a = 21.152(7) A, b = 11.428(1) A, c = 9.884(3) A, V = 2389(2) A3, and Dcalc = 1.250 g cm−3 for Z = 8 (two independent molecules per asymmetric unit), R = 0.057; for trans isomer (2b): space group Pbca (No. 61) with a = 11.750(1) A, b = 10.550(2) A, c = 20.032(3) A, V = 2483.3(9) A3, and Dcalc = 1.202 g cm−3 for Z = 8, R = 0.058. In both structures the phosphorinane ring adopts a chair conformation with the tert-butyl group in an equatorial position. The relative spatial arrangement of the latter and the chlorine atom defines the cis/trans designation. The equilibration of the title compounds under acidic conditions was studied by 31P NMR spectroscopy and discussed in the context of the results of semiempirical calculations.