Metallation of the NH-functional amino(imin0)phosphanes Mes*NPNHR (R = CPh3, Ad, tBu) l ac yields the 1,3-diaza-2-phosphaallyllithium compounds 2a -c. The crystal structure shows an ether-stabilized monomer of 2a and a solvent-free dimer with an eight-membered ring in the case of 2b,c. The reaction of 2 b with chlorodiphenylphosphane yields, dependent on the reaction conditions, (phosphany1amino)iminophosphane 3 or bis(imino)phosphanylphosphorane 4. The structural and reactivity is discussed on the basis of ab initio calculations.Der formale Ersatz eines oder mehrerer Stickstoff-Atome im Triazenid I['] durch zweifach koordinierte Phosphor-Atome fuhrt zu entsprechenden Phosphaallyl-Systemen, von denen drei bislang isoliert (IIa, b) bzw. spektroskopisch identifiziert (IIc) werden konnten[*l. Wahrend jedoch die Chemie und Struktur des Stickstoff-Systems I gut dokumentiert ist"], ist uber die Phospha-Analoga IIa-c bislang erst wenig bekannt.

No abstract

Chloro(ary1imino)phosphane (1) reacts with the 1,3-diaza-2-phosphaallylic system 3 to form 1,3,5-triaza-2,4-diphospha-1,4-pentadienes Ar -N = P -N(R) -P = N -Ar (Ar = 2,4,6-tBu3-C6Hz; R = tBu, 2,4,6-iPr3C6Hz, 2,4,6-tBu3C6Hz) (4a-c). The molecular structure of 4a ("exo-endo-S conformation") as well as the dynamic behaviour of the compounds in solution are discussed. The observed temperature dependance of the NMR spectra of 4c was interpreted as a sigmatropic 1,3-rearrangement followed by a P-N rotation.

Key Words: Phosphanes, (2)-amino(imin0)-/ 1,3,5-Triaza-2,4-diphospha-1,4-pentadienes, transition metal complexes of, dynamic behavior of On the Knowledge of the 1,3,5-Triaza-2,4-diphospha-l,4-pentadienes * Nucleophilic substitution reactions of the chloro(ary1imino)-phosphane 1 yield the NH-functional amino(imin0)phosphanes Mes*NPNHR (R = Mes, Ad, CPh3) 2d-f. Upon further reaction with 1 they are converted into the 1,3,5-triaza-2,4-diphospha-1,4-pentadienes Mes*NPN(R)PNMes* (R = Mes, Ad) 4d, e and Mes*NPN(Mes*)PNCPh, 5. According to crystal structure determinations all compounds 4a.d.e, 5 exhibit S conformation in the solid state. In addition to the "exo-endo" arrangement of the substituents (4a, 5) in the case of 4d.e the "endo-endo" conformation is observed for the first time. In solution, 4d,e and 5 are subject to dynamic rearrangements, whose mechanism is proven by NMR studies of partially "N- Die bislang nicht beschriebenen Amino(imino)phosphane 2a,d,e,f sind leuchtend gelbe (2a,e,f) bzw. orangerote (2d), die Triazadiphosphapentadiene (4d -e, 5) tiefrote feste Stoffe, die unter Inertgas bei 25 "C praktisch unbegrenzt lagerbar sind. Strukturanalytische und NMR-spektroskopische UntersuchungenAufgrund von theoretischen Berechnungen liegt das Stammsystem, H2N -P = NH, in der @)-Form vor, wobei Schema 1

No abstract