Thomas Henkel

Four- and eight-membered cyclic phosphazene derivatives of zirconium, titanium and vanadium. Crystal structures of the complexes [ZrCl3(Me3SiNPPh2NSiMe3)]·MeCN and [{TiCl2(OPPh2N)}2]·4MeCN

The reaction of ZrCl4 with (Me3Si)2NPPh2NSiMe31 yields the four-membered heterocycle [[graphic omitted]SiMe3)]. An improved synthesis of the aminoiminophosphorane 1 is described. The compound TiCl4 reacts with Me3SiOPPh2NSiMe3 unexpectedly with elimination of all Me3Si groups to yield the eight-membered heterocycle [{TiCl2(OPPh2N)}2]. A vanadium-containing dimetallacyclophosphazene [{VCl2(NPPh2N)}2] has been synthesised from [VCl3(NSiMe3)] and CiPPh2NSiMe3. The X-ray structures of [[graphic omitted]SiMe3)]·MeCN and [{TiCl2(OPPh2N)}2]·4MeCN have been determined. While the cyclic Zr–N distances in the former have to be considered as single bonds, the short Ti–N of the latter (almost planar) suggest double-bond character.

Synthesis and crystal structures of three four-membered ring compounds containing PN2Ti skeletons

Depending on the reaction conditions, Ph2P(NSiMe3)[N(SiMe3)2]reacts with TiCl4 to form the titanadiazaphosphetidines Ph2P[µ-N(SiMe3)]2TiCl3MeCN (1) and Ph2P[µ-N(SiMe3)]2TiCl2,[NPPh2N(SiMe3)2](2). Compound (1) dimerises slowly in solution with elimination of Me3SiCl to yield a tricyclic system containing a central Ti2N2 ring (3). X-Ray analyses of these compounds show (1) and (3) to be monoclinic, space group P21/n, while (2) is triclinic, space group P. Compound (2) has a Ti–N–P angle of 170.3(7)° and a short exocyclic Ti–N bond of 179.2(9) pm.

Inorganic Heterocycles Containing Two or Three Transition Metal Atoms

Abstract Syntheses and structures of novel inorganic heterocycles containing two or three transition metal atoms are reported. Examples include the first triazatrimetallabenzene derivative, [Cp∗Ta(Cl)N]3, as well as eight-membered phosphazene rings containing two vanadium atoms.

A volatile cyclic metallaphosphazene; preparation and X-ray structure of [(CF3)2PN]2NVCl2

The reaction of (CF3)2P(Cl)NSiMe3 and Me3SiNVCl3 in CH2Cl2 leads to volatile [(CF3)2PN]2NVCl2; the X-ray structure analysis shows a planar six-membered NVNPNP-ring with C2v molecular symmetry.

Syntheses of Novel Four Membered Rings Containing Oxygen and Sulphur as Heteroatoms

Abstract The cyclisation of an alkylidenesulphurtetrafluoride is shown. The addition of SO3 to SF5-substituted olefins yields in an unexpected ring formation. The new oxadithietanes are presented a...