Frank Pauer

The preparation and crystal structures of sodium and potassium pentamethylcyclopentadienyl pyridine solvates

Abstract The compounds (C5Me5)Na · 2py (2) have been prepared and their crystal structures determined at low temperatures. The crystal structure of 1 exhibits a three-legged stool monomer of composition (C5Me5Na · 3py, whereas 2 has a linear zig-zag chain structure of composition [(C5Me5)K · 2py]oo.

Alkali metal derivatives of sulfinimidamides. Preparation and crystal structures

A series of compounds has been prepared in which the NH proton of the sulfiniminamines Me3SiNS(R)NHR′ (R = Ph (mainly) or tBu, R′ = tBu or SiMe3) is replaced by Li, Na, K, Rb, or Cs. The compounds form a series of reagents of increasing reactivity which could be used, for example, to introduce chelating ligands into transition metal complexes. The structures of the compounds have been determined by X-ray diffraction. When there is a phenyl substituent on the sulfur atom, the metal derivatives are isomorphic dimers, involving three fused four-membered rings in a step-shaped structure. The higher the atomic number of the metal, the stronger is the η-coordination of the phenyl group to the metal. With a t-butyl group on the sulfur atom the structures of the lithium derivatives [(Me3SiNS(tBu)NR′)Li]2 are different for R′ = SiMe3 and tBu. For the former the step-shaped structure is still present, but the latter forms an eight-membered ring. Although these tBu derivatives are synthesized in diethyl ether, their lithium atoms are not coordinated by donor molecules, in contrast to those in the phenyl-substituted species.

Synthesis and crystal structure of bis(12-crown-4)lithium bis[N,N′-bis(trimethylsilyl)benzenesulphinamidino]lithiate(1–-); the first observation of three different lithium-7 environments in high-resolution solid-state NMR spectroscopy

[Li(12-crown-4)2]+[Li({N(SiMe3)}2SPh)2]–1 is the product of the reaction of Me3SiNSNSiMe3 with phenyllithium using 12-crown-4 as a donor and has an ion-separated structure which is unique for alkali metal sulphinamidino derivatives; at room temperature 1 undergoes a phase transformation, and a preliminary examination of this process by high-resolution solid-state 7Li NMR spectroscopy shows, for the first time, the presence of three resolvable resonances.

Solid-state and solution structures of three lithiumsulfinimidamides: Identification of two distinct structural types

Abstract The bidentate sulfinimidamide ligand has almost the same bulk as the cyclopentadienyl ligand. Two distinct structural types of highly reactive lithium

Towards acyclic 1,1-linked polycyclobutanes as potential precursors of polyspiranes with a helical primary structure: Synthesis of tercyclobutanes and attempted synthesis of quinquecyclobutanes

Abstract Acyclic 1,1-linked polycyclobutanes 1 should be potentially prone to rearrange to polyspiranes with a helical primary structure. In an exploratory study, the synthesis of the tercyclobutanes 8 (5-6-7-8) and 15 (9-10-11-12-16-15 or 14-15), and several approaches to quinquecyclobutanes with the β- and δ-ketoesters 35 (15-33-34-35) and 24b (23-24a-24b), respectively, as most promising precursors are described.

Fluorosulfonium Hexafluoroarsenate RSF2+AsF6⁻ / Fluorosulfonium Hexafluoroarsenates, RSF2+AsF6⁻

The crystal structures of Me2NSF2⁺ AsF6⁻ (4) and CF3SF2+AsF6⁻ (6) are reported and the cation structures compared with those of the corresponding isoelectronic neutral phosphanes.

Struktur des 2,2,4,4-Tetrakis(trifluormethyl)-1,3-diselenetans / Structure of 2,2,4,4-Tetrakis(trifluoromethyl)-1,3-diselenetane

The reaction of hexafluoroacetone with triphenylphosphane selenide proceeds with elimination of triphenylphosphane oxide to yield 2,2,4,4-tetrakis(trifluormethyl)-1,3-diselenetane (1). Crystals of 1 that are suitable for X -ray crystal structure analysis have been obtained by recrystallization from hexane.

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.