Neue Cyclophosphazene mit Metallen der III. Hauptgruppe als Ringbausteine / New Cyclophosphazenes with Metals of Main Group III as Building Blocks

Abstract

Acylic silylated phosphazenes of the type HN(PR2NSiMe3)2 (1) react quantitatively with molecules MMe3 (M = Al, Ga, In) under ring formation and CH4 evolution. The ring com pounds N(PPh2NSiMe3)2AlMe2 (2 a) and N(PPh2NSiMe3)2InMe2 (4 a) have been investiga ted by X-ray structure determination. 2a and 4a crystallize in the space groups P 1 and P 3 15 respectively; they show different conformations regarding the cyclohexane framework. NMR spectroscopy of the nuclei in the chelating phosphazene ligand indicates decreasing Lewis acidity of the metal containing fragments in the series AlMe2 > GaMe2 > InMe2.

Rare-Earth-Metal Complexes Bearing Phosphazene Ancillary Ligands: Structures and Catalysis toward Highly Trans-1,4-Selective (Co)Polymerizations of Conjugated Dienes

“…On the other hand, rare-earth-metal bis(alkyl)s supported by monoanionic non-Cp ancillary ligands have been demonstrated as highly active single-component catalysts or excellent precursors for the polymerizations of conjugated dienes and olefins under the activation of borates or/and aluminum alkyls. , Our group has designed a series of non-Cp-ligated rare-earth-metal bis(alkyl)s , and found that the ligands containing N, O, and P heteroatoms play distinctive roles in governing the catalytic performance of the attached central metal ions. For instance, the cationic NCN-tridentate pincer type bis(aryliminomethylene)-2,6-phenyl-1-yl and bis(N-cyclocarbenemethylene)-2,6-phenyl-1-yl, bis(phospheno)carbazolyl rare-earth-metal complexes show high cis-1,4-selectivity for diene monomers, ,, rare-earth-metal bis(alkyl) complexes bearing an iminophosphonamido ligand (NPN type) have been employed as catalyst precursors to provide extremely high activity for 3,4-selectivity polymerization of isoprene, and the thiophene-NPN ligands and quinolinyl anilido ligands supported rare-earth-metal complexes, under the activation of organoborates and aluminum alkyls, exhibited distinguished catalytic activity and trans-1,4-selectivity for both butadiene and isoprene homo- and copolymerizations. , Meanwhile, the bis(silylated phosphazene) [HN(PPh 2 NSiMe 3 ) 2 ] originately explored by Oakley and Roesky as early as the 1990s has been developed into versatile NPNPN-type ligands consisting of a five-atom scaffold, and their supported complexes based on various metals such as Na, K, Ca, Al, Ga, In, V, Zn, Cd, Hg, Ti, Zr, As, and U have been synthesized and their chemistry has been investigated. Comparatively, the rare-earth-metal complexes supported by such NPNPN-type ligands still have been untapped to date, although their bis(phosphinimino)methanide ligand (PNCPN) supported analogues have been reported .…”

Uranyl bis-iminophosphorane complexes with in- and out-of-plane equatorial coordinationElectronic supplementary information (ESI) available: Variable temperature 1H NMR spectra; Raman spectra; solid state diffuse reflectance electronic absorption spectra; luminescence spectra; interatomic distances of the optimised structures of 1* and 2* from molecular modelling calculations. See http://www.rsc.org/suppdata/dt/b3/b304602h/

“…Sodium bis-trimethylsilylamide (BDH) was used as received. The ligand precursors CH 2 (Ph 2 PNSiMe 3 ) 2 33 and NH(Ph 2 -PNSiMe 3 ) 2 21 were synthesised according to the literature. Sodium salts of I and II were prepared by a slightly modified literature procedure using sodium bis-trimethylsilylamide as a base instead of NaH.…”