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Alkali metal derivatives of sulfinimidamides. Preparation and crystal structures
No full textA 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
No full textLi(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
1,3-Bis[tert-butyl(di-tert-butylfluorosilyl)amino]trisulfane - a Compound with FSiNSSSNSiF Helix
No full textThe lithium derivative of tert-butyl(di-tert-butylfluorosilyl)-amine (1) reacts with sulfur or selenium to give the bis[(fluorosilyl)-amino]di- and -trisulfanes 2, 3 and -selane 4, respectively. The trisulfane 3 crystallizes from n-hexane and exhibits a helical structure (X-ray analysis)
(Perfluoralkyl)(dimethylamino)sulfonium-hexafluoroarsenate
No full textMeN = S(CF3)2 (5) is alkylated by Me3O AsF6 to Me2N-S(CF3)2 AsF6 (4). From 5 and MeOp. AsF6 (6) MeOS(O)-N(Me)S(CF3)2 AsF6 (7) is formed as a relatively stable primary product. Decomposition of 7 gives the expected 4 only in poor yield. Nucleophilic substitution of the sulfur-bonded fluorine in CF3SF2 AsF6 (8) by Me3SiNMe2 yields CF3S(NMe2)2 AsF6 (9). Similarly, (CF3)2CFSF2 AsF6 (10) reacts with dimethyl(trimethylsilyl)amine to give (CF3)2CFS(NMe2)2 AsF6 (11). The structures of 4 and 9 are elucidated by X-ray analyses, and the influence of the substituents on the bonding is discussed
Preparation and structural characterization of dioxane-coordinated alkali metal bis(trimethylsilyl)amides
No full textUnsolvated RbN(SiMe3)z (1) and CsN(SiMe3)z (2) have been prepared from rubidium and cesium metal respectively and excess hexamethyldisilazane. The molecular structures of the polymeric dioxane adducts NaN(SiMes) .C4HsO2 (3) and [MN(S~M~~)~~.~C~H~(4O, M~ ]=. ROb; .5, ~MC =~ CHs)~ haOveZ been determined by low-temperature single-crystal X-ray diffraction
IMINOAMINOSULFINATES - SYNTHESIS, CRYSTAL-STRUCTURES, AND REARRANGEMENT MONITORED BY LI-7 SOLID-STATE NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY
No full textAlkali- and alkaline-earth-metal iminoaminosulfinates have been synthesised and characterized by X-ray diffraction and solid-state NMR investigations. The viability of metal-exchange reactions has been demonstrated resulting in a magnesium and a copper(I) derivative. The structural investigations reveal the presence of different structures, which can be classified into four types. Phase transitions between different structural types involving the loss of donor solvent have been observed by solid-state magic angle spinning experiments
Synthesis and crystal structures of three four-membered ring compounds containing PN2Ti skeletons
No full textDepending 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
Isocyanatosulfonium Salts
No full textRR'SF2 reacts with Me3SiNCO to give the corresponding N-(fluoroformyl)sulfur imides FC(O)NSRR' [R = NMe2, R' = F (7); R' = CF3 (9)]. From these AsF5 abstracts F- with formation of isocyanatosulfonium salts ONC - SRR' + AsF-6 [R = F, R' = CF3 (6); R = NMe2, R' = F (8); R = NMe2, R' = CF3 (10)]. The spectroscopic properties of the fluoroformyl derivatives and of the isocyanato salts are discussed. The structures of 8 and 10 are determined by X-ray analyses
Fluorsilyl- und Fluorboryl-substituierte Cyclotetrasilazane - Synthese und Kristallstrukturen
No full textMono- und dilithiiertes Octamethylcyclotetrasilazan (1, 6) reagieren mit Fluorsilanen bzw. F2BN(SiMe3)2 unter Erhalt des Cyclotetrasilazangerüstes zu den mono- und disubstituierten Verbindungen 2-5 und 7-13. Bei der Umsetzung des Dilithiumsalzes (6) mit einem Fluorsilan im Molverhältnis von 1:1 werden die Bicyclen 14 und 15 erhalten. Kristallographische Untersuchungen von 2, 3, 8 und 9 zeigen, daß der monosilylierte Achtring in einer Wannen-, der disilylierte Achtring in einer Sesselkonformation vorliegt. In der Kristallstruktur des Bicyclus 14 zeigen die Stickstoffatome der Si3N-Einheiten eine pyramidale Umgebung. Translated Abstract: Fluorosilyl and Fluoroboryl Substituted Cyclotetrasilazanes. Synthesis and Crystal Structures Mono- and dilithiated octamethylcyclotetrasilazanes (1, 6) react with fluorosilanes and F2BN(SiMe3)2, respectively, under retention of the cyclotetrasilazane structure yielding the mono- and disubstituted compounds 2-5 and 7-13. In the reaction of the dilithium compound 6 with a fluorsilane in equivalent amounts, the bicyclic compounds 14 and 15 are obtained. Crystallographic investigations of the compounds 2, 3, 8, and 9 indicate that the monosilylated eight-membered ring has a cradle conformation while the disilylated ring has a chair conformation. The X-ray structure of the bicyclic system 14 indicates that the nitrogen atoms of the Si3N-units have a pyramidal environment
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