ABSTRACT: The title salt, triphenyl(P,P,P-triphenylphosphineimidato-kN)-phosphorus(1+) 1,3,5,7-tetrathia(1,5-SIV)-2,4,6,8,9-pentaazabicyclo[3.3.1]nona-1,4,6,7-tetraene(1-), CAS [48236-06-2], prepared by the literature method, is found by crystallography to be a 1:1 CH3CN solvate. Disorder exists for the N atoms of the anion. A VT crystal structure study was conducted at 100 K, 120 K, 140 K, 172 K, 200 K, 240 K and 280 K. The 100 K structure is superior, with only 10% of a second anion position oppositely-oriented w.r.t the diad axis of point group 2mm. At 120 K, an adjacent two-site disorder is encountered, but at higher temperatures three-site disorder with both opposite and adjacent placements of S4N5- ions is required w.r.t. the primary component. At 240 and especially 280 K, the anion nitrogen a
