Abstract: The title compound was synthesized and its molecular structure was determined by X-ray diffraction analysis with Cu Ka radiation. The crystal belongs to space group P₂₁ and the crystal cell parameters are:α=0. 7566(1) nm, b=0. 7708(2) nm, c=1. 0255(1) nm,β=98. 60(1)°, V=0. 5913 nm³, Z=2. The molecular skeleton is composed of three rings, the sev-en-membered ring containing phosphorous and nitrogen atoms in boat conformation, in which the bond P-Sis in equatorial and P-Oin axial position; the six-membered ring and five-mem-bered ring are in chair form and envelop form, respectively. The absolute configuration was established by using the approciable anomalous scattering effect of Pand Satoms.

Key words: Diazaphosphabicyclo[3,2,1]octane, Synthesis, Crystal structure, Absolute configu-ration