Verbindungen mit dem 2,4‐Dimethyl‐2,4‐diaza‐1,5‐diphosphapentan‐3‐on‐Grundgerüst; Synthese, Struktur und Eigenschaften von 1,5‐Di‐<i>tert</i>‐butyl‐2,4‐dimethyl‐1,5‐diphenyl‐2,4‐diaza‐l,5‐diphosphapentan‐3‐on und Derivaten

Abstract

Compounds with the 2,4‐Dimethyl‐2,4‐diaza‐1,5‐diphosphapentan‐3‐one Skeleton; Synthesis, Structure, and Properties of 1,5‐Di‐ tert ‐butyl‐2,4‐dimethyl‐1,5‐diphenyl‐2,4‐diaza‐1,5‐diphosphapentan‐3‐one and Its Derivatives N,N ′‐Dimethyl‐ N‐N ′‐bis(trimethylsilyl)urea ( 1 ) reacts with tert ‐butylchlorophenylphosphane ( 2 ) to form the monophosphino/ trimethylsilyl‐substituted urea 3 . Under more vigorous conditions the bisphosphino‐substituted derivative 4 was also obtained. The reaction of 4 with the tetracarbonyl norbornadiene derivatives of Cr, Mo, and W furnished the unusual chelate complexes 5 – 7 , in which the ligand 4 is coordinated to the metal through one of the two phosphorus atoms and the oxygen atom of the carbonyl group. The free ligand 4 and the isostructural complexes 5 and 6 were subjected to X‐ray structure analyses. The approximate twofold symmetry of 4 is lost as a result of a major conformational change on complex formation. In contrast, 4 reacts with Fe 2 (CO) 9 and with (COD)‐PtCl 2 (COD=1,5‐cyclooctadiene) to give the complexes 8 and 9 . In both 8 and 9 the ligand 4 is coordinated by both phosphorus atoms. Reaction of 4 with sulfur and selenium led to the disulfide 10 and diselenide 11 , whereas with tellurium no reaction was observed.