Kristall- und Molekülstrukturen von zwei trans-1.2.4.5-Tetraza-3.6-diphospha-cyclohexan-3.6-disulfiden / Crystal and Molecular Structures of Two trans- 1,2,4,5-Tetraza-3,6-diphospha-cyclohexane-3,6-disulfides

Abstract

<jats:p>The crystal and molecular structures of two trans-1,2,4,5-tetraza-diphospha-3,6-cyclohexane- 3,6-disulfides, 2 and 3, have been determined by X-ray diffraction methods. The 3,6-diphenyl- 1,2,4,5-tetramethyl-derivative 2 crystallizes in the monoclinic system, space group C He. Its P2N 4 heterocycle adopts a twist conformation. In contrast, the hexamethyl derivative 3 is triclinic, space group P1̅, and its ring shows chair conformation. Torsion angles in these two compounds and similar ones reveal less interaction between lone pairs of electrons on adjacent N-atoms in the chair conformation but stronger interaction of those bound to phosphorus. It is suggested that the latter interaction is responsible for the larger N -P -N bond angle (107°) as compared to the smaller one (101°) in the P<jats:sub>2</jats:sub>N<jats:sub>4</jats:sub> rings present in twist conformation.</jats:p>