Über Chalkogenolate. 194 [1]: S-Bis(trimethylsilyl)aminoester von Dithiocarbamidsäuren 3. Kristall- und Molekülstruktur vom Methyl-und i-Propylderivat [1]

Inhaltsübersicht. Die Titelverbindungen R₂N–CS–S–N[Si(CH₃)₃]₂ mit Ii = CH₃ bzw. CH(CH₃)₂ kristallisieren orthorhombisch bzw. monoklin: Gitterkonstanten für R = CH₃ (bei ?165°C) a = 8,397(4) Å, b = 11,917(4) Å, c = 31,966 (11) Å, Pbca (Nr. 61), Z = 8. R = CH(CH₃)₂ (bei ?80°C) a =13,183(3) Å, b = 10,873(11) Å, c = 14,865(2) Å, β = 105,86(2)° P2₁/n (Nr. 14), Z = 4. Die Kristallstrukturen wurden unter Verwendung von 4227 bzw. 3 433 symmetrieunabhängigen Reflexen (gemessen bei ?165 bzw. ?80 °C) bestimmt und bis auf Zuverlässigkeitsfaktoren von R = 0,081 bzw. 0,082 verfeinert (R_w = 0,084 bzw. 0,114). Bei beiden Verbindungen ist der C₂N–CS–S–N-Teil des Moleküls nahezu planar. Zwischen dem Thiocarbonyl-S-Atom und dem N-Atom der silylierten Aminogruppe bestehen Wechselwirkungen. On Chalcogenolates. 194. S-Bis (trimethylsilyl) amino Esters of Dithiocarbamic Acids. 3. Crystal and Molecular Structure of the Methyl and i-Propyl Derivative The title compounds R₂N–CS–S–N[Si(CH₃)₃]₂ with R = CH₃ and CH(CH₃)₂, respectively, crystallize orthorhombic and monoclinic, resp.; cell dimensions and space group see “Inhaltsübersicht”. The structures of both compounds have been determined from single crystal X-ray data measured at ?165°C and ?80°C, resp., and refined to R's of 0.081 and 0.082, resp., (R_w = 0.084 and 0.114, resp.) using 4227 and 3433, resp., independent reflections. In both compounds the C₂N–CS–S–N core of the molecule is nearly plane. Between the thiocarbonyl sulfur atom and the nitrogen atom of the amino group interactions exist. In Fortführung unserer Untersuchungen [1, 2] über N, N-Dialkyldithiocarbamidsäure-S-bis(trimethylsilyl)aminoester R₂N–CS–S–N[Si(CH₃)₃]₂ haben wir die Kristall- und Molekülstrukturen der Verbindungen mit R = CH₃ und CH(CH₃)₂ bestimmt. Dabei sollte untersucht werden, welchen Einfluß sterisch anspruchsvollere Alkylgruppen (R = CH₃ → CH(CH₃)₂) auf die Molekülgeo-metrie haben. Eine strukturchemische Charakterisierung dieser Verbindungs-klasse ist bis jetzt noch nicht erfolgt; vgl. die Literaturzusammenstellung bei [3].     

Alkoxylierung von bis(trimethylsilyl)-aminofluorsilanen,sowie siloxanbildung unter äthereliminierung

The reaction of bis(trimethylsilyl)aminofluorsilanes, (Me₃Si)₂NSiF₂R (R = CH₃ or F), with sodium alcoholates or sodium phenylate yields under elimination of NaF alkoxy- and aryloxy-aminofluorosilanes of the composition (Me₃Si)₂NSiF(R)OR′(R′ = CH₃, C₂H₅, C₃H₇, C₆H₅). A disiloxane is formed by thermal elimination of diethyl ether from bis(trimethylsilyl)aminomethylfluoroethoxysilane. The IR, mass, ¹H and ¹⁹F NMR spectra of the above-mentioned compounds are reported. ab]Die Reaktion von Bis(trimethylsilyl)-aminofluorsilanen des Typs (Me₃Si)₂NSiF₂R (R = F, CH₃) mit Natriumalkoholaten und Natriumphenolat führt unter NaF-Abspaltung zu Alkyl- und Aryloxyaminofluorsilanen der Zusammensetzung: (Me₃Si)₂NSiF(R)OR′ (R′ = CH₃, C₂H₇, C₆H₅, C₆H₅). Ein Disiloxan könnte durch die thermische Eliminierung von Diäthyläther aus Bis(trimethylsilyl)aminomethyl-fluor-äthoxy-silylarnin erhalten werden.Die IR-, Massen-, ¹H- und ¹⁹F-NMR-Spektren der dargestellten Verbindungen werden mitgeteilt.     

Die Schwingungsspektren des Chlortrimethylammonium-chlorids und -hexachloroantimonats(V)

Inhaitsübersicht. Die Schwingungsspektren von (CH₃)₃NCI₂ (I) und (CH₃)₃NCl⁺SbCI₆^– (II) wurden aufgenommen und im Hinblick auf die N—Cl-Bindungsverhältnisse diskutiert. The Vibrational Spectra of Chlorotrimethylammonium Chloride and Hexachloroantimonate(V) Abstract. The vibrational spectra of (CH₃)₃NCl₂ (I) und (CH₃)₃NCl⁺SbCl₆^– (II) are measured and discussed in view of the N-Cl bonds. Die IR-Spektren der nach [9] dargestellten Verbindungen wurden als Verreibungen in Nujol bzw. Hostaflonöl mit einem linear in Wellenzahlen registrierenden IR-Spektrophotometer PE 457 (Perkin Elmer) aufgenommen. Die Raman-Spektren wurden mit einem Coderg-Laser-Gerät PHO vermessen. Zur Anregung wurde die 4880 Å-Linie eines Argon-Gaslasers verwendet.     

Synthese eines hexanuklearen Calcium–Phosphor‐Käfigs über heteroleptische Calcium‐amid‐phosphanid‐Vorstufen

Synthesis of a Hexanuclear Calcium–Phosphorus‐Cage The metalation of tri(tert‐butyl)silylphosphane with calcium bis[bis(trimethylsilyl)amide] yields the dimer {(Me₃Si)₂N–Ca(THF)[μ‐P(H)Si^tBu₃]}₂ ( 1 ). In THF monomerization occurs and dismutation reactions lead to the homoleptic compounds, namely (THF)₂Ca[N(SiMe₃)₂]₂ and (THF)₄Ca[P(H)Si^tBu₃]₂. In toluene, 1 undergoes dismutation reactions, bis(tetrahydrofuran)calcium bis[bis(trimethylsilyl)amide] is regained and [(Me₃Si)₂N–Ca(THF)]₂Ca[P(H)Si^tBu₃]₄ ( 2 ) precipitates. At raised temperatures, 2 undergoes a homometallic metalation with the loss of two equivalents of HN(SiMe₃)₂ and dimerizes. The thus formed cage compound (THF)₂Ca₆[PSi^tBu₃]₄[P(H)Si^tBu₃]₄ ( 3 ) with a central Ca₄P₄ heterocubane moiety crystallizes upon cooling of the toluene solution. The molecular structures of 2 and 3 were determined.     

Tris[bis(trimethysilyl)amido]zinkate von Lithium und Calcium

Tris[bis(trimethylsilyl)amido]zincates of Lithium and Calcium Calcium-bis[bis(trimethylsilyl)amide] and Bis[bis(trimethylsilyl)amido]zinc yield in 1,2-dimethoxyethane quantitatively Calcium-bis{tris[bis(trimethylsilyl)- amido]zincate} · 3DME. When THF is chosen as a solvent, the two reactants and the zincate form a temperature-independent equilibrium, whereas in benzene no reaction occurs. The tris[bis(trimethylsilyl)amido]zincate anion displays characteristic ¹³C{¹H) and ²⁹Si{¹H] chemical shifts of 7 and ?8 ppm, respectively; the nature of the solvent, the cation and the complexating ligands don't influence the IR nor NMR data of the zincate anion and thus verify that [Ca(DME)₃]²⁺ and {Zn[N(SiMe_{3 2}]₃}^? appear as solvent separated ions, which is also confirmed by their insolubility in hydrocarbons.     

Bis(trimethylsilyl)diazene revisited. Density functional theory (DFT) calculations of nitrogen NMR parameters of some azo‐compounds

Calculations of nitrogen NMR parameters [chemical shifts δN and indirect nuclear spin–spin coupling constants J(N,N), J(N,¹³C), J(²⁹Si,N)] of noncyclic azo‐compounds R¹ NN R² (R¹, R² = H, Me, Ph, SiH₃, SiMe₃) and cyclic azo‐compounds [NNCH₂, NN(CH₂)₃ NN(CH₂)₂SiH₂, and NN(SiH₂CH₂SiH₂)] by density functional theory (DFT) methods [B3LYP/6‐311+G(d,p) level of theory] provide data in reasonable agreement with experimental values. The influence of cis‐ and trans‐geometry is reflected by the calculations, and amino‐nitrenes are also included for comparison. The spin–spin coupling constants are analyzed with respect to contact (Fermi contact term, FC) and non‐ contact contributions (paramagnetic and diamagnetic spin‐orbital terms, PSO and DSO, and spin‐dipole term, SD). Bis(trimethylsilyl)diazene 6a can be generated by an alternative method, using the reaction of bis(trimethylsilyl)sulfur diimide with bis‐ (trimethylsilyl)amino‐trimethylsilylimino‐phosphane. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:84–91, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20075     

Bis[bis(trimethylsilyl)amino]sulfan 2. Kristall- und Molekülstruktur

Bis[bis(trimethylsilyl)amino]sulfane. 2. Crystal and Molecular Structure The title compound [(CH₃)₃Si]₂N? S? N[Si(CH₃)₃]₂ crystallizes with Z = 4 in the monoclinic space group A2/a (Nr. 15) with cell dimensions a = 22.436(4) Å, b = 6.434(5) Å, c = 17.089(6) Å, β = 117.66(2)º. For 5091 independent reflections, measured at ?80°C, the structure could be refined to R = 0.079 and R_w = 0.120. The molecules are linked together by van der Waals interactions and form layers in the bc plane, in agreement with the observed cleavage along (100).     

Chemie polyfunktioneller Moleküle. 101 [1]: Synthese eines Diphenylphosphin-substituierten Cyclophosphamide und Röntgenstrukturanalyse seines Oxidations-produkts

Inhaltsübersicht. Diphenylphosphin und rac-Cyclophosphamid (ClCH₂CH₂)₂NP(O)N(H)(CH₂)₃O (1) reagieren in Gegenwart von n-Butyllithium zu einem Zwischenprodukt, das mit Wasser das diphenylphosphinsubstituierte Cyclophosphamid, (Ph₂PCH₂CH₂)₂NP(O)N(H)(CH₂)₃O, (2) bildet. Metallierung von 2 mit n-BuLi am N(3)-Atom und Umsetzung mit D₂O führt zum N(3)-Deuteroderivat 2a. Mit H₂O₂ reagiert 2 zur all-Phosphinoxid Verbindung, [Ph₂P(O)CH₂CH₂]₂NP(O)N(H)(CH₂)₃O, (4), die mit 0,5 Mol Wasser auskristallisiert und von der zur Charakterisierung des H-Bückenbindungssystems eine Röntgenstrukturanalyse angefertigt wurde. Die NMR-Spektren (¹H, ¹³C, ³¹P, ¹⁴N) weisen 2–4 als dynamische Moleküle aus. Chemistry of Polyfunctional Molecules. 101. Synthesis of a Diphenylphosphinesubstituted Cyclophosphamide and the X-ray Diffraction of its Oxidation Product Diphenylphosphine and rac-cyclophosphamide, (ClCH₂CH₂)₂NP(O)N(H)(CH₂)₃O, (1) react in the presence of n-BuLi to an intermediate which hydrolyses to the diphenylphosphine substituted Cyclophosphamide, (Ph₂PCH₃CH₂)₂NP(O)N(H)(CH₂)₃O, (2). Metallation of 2 with n-BuLi at the N(3) atom, followed by treatment with D₂O yields the N(3)-deuterated derivative 2a. With H₂O₂ 2 forms the all-phosphine-oxide compound, [Ph₂P(O)CH₂CH₂]₂NP(O)N(H)(CH₂)₃O, ( 4 ), which crystallizes with 0.5 mole of water. In order to characterize the H-bridge bonding system a X-ray structure analysis of 4 was carried out. The NMR-Spectra (¹H, ¹³C, ³¹P, ¹⁴N) indicate 2–4 as dynamic molecules.     

Reactions of the trimethylsilyl ion with 1,2-cyclopentanediol isomers in the collision region of a triple quadrupole instrument

Ion-molecule reactions with the trimethylsilyl ion were used to distinguish between cis- and trans-1,2-cyclopentanediol isomers. The ion kinetic energy of [Si(CH₃)₃]⁺ was varied from 0 eV to 15 eV (center of mass frame of reference). At low ion kinetic energies (<4 eV), there are significant differences in the relative stabilities and decomposition behavior of the adduct ions [M + Si(CH₃)₃]⁺. The cis-1,2-cyclopentanediol isomer favors decomposition of [M + Si(CH₃)₃]⁺ to yield the hydrated trimethylsilyl ion [Si(CH₃)₃OH₂]⁺ at m/z 91. For the trans isomer, the formation of the hydrated trimethylsilyl ion is an endothermic process with a definite threshold ion kinetic energy.     

SYNTHESIS AND NMR CHARACTERIZATION OF P-VINYL SUBSTITUTED PHOSPHAZENE PRECURSORS1

Abstract

The reactions of either PhPCl₂ or PCl₃ with (Me₃Si)₂NLi followed by H₂C[dbnd]CHMgBr were used to prepare the new P-vinyl substituted [bis(trimethylsilyl)amino]phosphines, (Me₃Si)₂NP(R)CH[dbnd]CH₂ [1: R=Ph, 2: CH[dbnd]CH₂, 3: R=Me, and 4: R=N(SiMe₃)₂]. Oxidative bromination of phosphines 3–1 afforded the P-bromo-P-vinyl-N-(trimethylsilyl)phosphoranimines, Me₃SiN[dbnd]P(CH[dbnd]CH₂)(R)Br [5: R=Ph, 6: R=CH[dbnd]CH₂, 7: R=Me], which, upon treatment with CF₃CH₂OH/Et₃N, were subsequently converted to the P-trifluoroethoxy derivatives, Me₃SiN[dbnd]P(CH[dbnd]CH₂)(R)OCH₂CF₃ [8: R=Ph, 9: R=CH[dbnd]CH₂, 10: R=Me]. Compounds 1–10, which are of interest as potential precursors to P-vinyl substituted poly(phosphazenes), were fully characterized by elemental analyses (except for the thermally unstable P-Br derivatives 5–7) and NMR spectroscopy (¹H, ¹³C, and ³¹P) including complete analysis of the vinylic proton splitting patterns via HOM2DJ experiments.     

VIER- UND FÜNFGLIEDRIGE PHOSPHORHETEROCYCLEN,XVI 1.3.4.2Λ3-OXADIAZAPHOSPHOLINE

Abstract

Die Kondensation von N ¹-substituierten N-Acetyl-und-Benzoyl-hydrazinen mit P[N(CH₃)₂]₃ oder CH₃P[NCH₃)₂]₂ fuhrt stets zu 3-substituierten 1.3.4.2Λ³-Oxadizaphospholinen, auch wenn der jeweilige Substituent die Bildung von anderen isomeren Fünfringen oder von Isomeren mit größerem Ring oder eine weitergehende Kondensation zuließe. Sie können in die 2.2-Dichloro- und 2-Thioxo-1.3.4.2Λ⁵-Oxadiazaphospholine übergeführt werden.

Condensation of N ¹-substituted N-acetyl and N-benzoyl hydrazines with P[N(CH₃)₂]₃ or CH₃P[N(CH₃)₂] 2 always gives 3-substituted 1.3.4.2Λ3-oxadiazaphospholines, even if the substituent would allow other isomeric five membered or larger ring phosphorus heterocycles to be formed, or the condensation to proceed further. The title compounds can be oxidized to 2.2-dichloro and 2-thioxo 1.3.4.2Λ⁵-oxadiazaphospholines.     

Synthesis of hydroxy‐terminated,oligomeric poly(silarylene disiloxane)s via rhodium‐catalyzed dehydrogenative coupling and their use in the aminosilane–disilanol polymerization reaction

A series of oligomeric, hydroxy‐terminated silarylene–siloxane prepolymers of various lengths were prepared via dehydrogenative coupling between 1,4‐bis(dimethylsilyl)benzene [H(CH₃)₂SiC₆H₄Si(CH₃)₂H] and excess 1,4‐bis(hydroxydimethylsilyl)benzene [HO(CH₃)₂SiC₆H₄Si(CH₃)₂OH] in the presence of a catalytic amount of Wilkinson's catalyst [(Ph₃P)₃RhCl]. Attempts to incorporate the diacetylene units via dehydrogenative coupling polymerization between 1,4‐bis(dimethylsilyl)butadiyne [H(CH₃)₂Si? C?C? C?C? Si(CH₃)₂H] and the hydroxy‐terminated prepolymers were unsuccessful. The diacetylene units were incorporated into the polymer main chain via aminosilane–disilanol polycondensation between 1,4‐bis(dimethylaminodimethylsilyl)butadiyne [(CH₃)₂N? Si(CH₃)₂? C?C? C?C? (CH₃)₂SiN(CH₃)₂] and the hydroxy‐terminated prepolymers. Linear polymers were characterized by Fourier transform infrared, ¹H and ¹³C NMR, gel permeation chromatography, differential scanning calorimetry, and thermogravimetric analysis, and they were thermally crosslinked through the diacetylene units, producing networked polymeric systems. The thermooxidative stability of the networked polymers is discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1334–1341, 2002     

Spektroskopische Untersuchungen an Siliciumverbindungen. XXXI. Schwingungsverhalten von p-substituierten N,N-Bistrimethylsilylanilinen

The following p-substituted N,N-bis-trimethlsilyl anilines p-X? C₆H₄? N[Si(CH₃)₃]₂ are prepared by silylation of free amines: X = H, CH₃, C₂H₅, CH₃O, CH₃CO, F, Cl, Br, J, CN, C₆H_S, (CH₃)₃SiO, and [(CH₃)₃Si]₂N, and the isotopic derivatives C₆H₅? ¹⁵N[Si(CH₃)₃]₂ and C₆D₅N[Si(CH₃)₃]₂. The vibrational spectra are reported and assigned. The molecular symmetry of p-[(CH₃)₃Si]₂N? C₆H₄? N[Si(CH₃)₃]₂ is determined. The influence of the mass of the substituents X on the positions of the ν_sSiNSi vibrational frequencies is discussed.     

Synthesis of Mixed Silylene–Carbene Chelate Ligands from N‐Heterocyclic Silylcarbenes Mediated by Nickel

The Ni^II‐mediated tautomerization of the N‐heterocyclic hydrosilylcarbene L²Si(H)(CH₂)NHC 1 , where L²=CH(C?CH₂)(CMe)(NAr)₂, Ar=2,6‐iPr₂C₆H₃; NHC=3,4,5‐trimethylimidazol‐2‐yliden‐6‐yl, leads to the first N‐heterocyclic silylene (NHSi)–carbene (NHC) chelate ligand in the dibromo nickel(II) complex [L¹Si:(CH₂)(NHC)NiBr₂] 2 (L¹=CH(MeC?NAr)₂). Reduction of 2 with KC₈ in the presence of PMe₃ as an auxiliary ligand afforded, depending on the reaction time, the N‐heterocyclic silyl–NHC bromo Ni^II complex [L²Si(CH₂)NHCNiBr(PMe₃)] 3 and the unique Ni⁰ complex [η²(Si‐H){L²Si(H)(CH₂)NHC}Ni(PMe₃)₂] 4 featuring an agostic Si? H→Ni bonding interaction. When 1,2‐bis(dimethylphosphino)ethane (DMPE) was employed as an exogenous ligand, the first NHSi–NHC chelate‐ligand‐stabilized Ni⁰ complex [L¹Si:(CH₂)NHCNi(dmpe)] 5 could be isolated. Moreover, the dicarbonyl Ni⁰ complex 6 , [L¹Si:(CH₂)NHCNi(CO)₂], is easily accessible by the reduction of 2 with K(BHEt₃) under a CO atmosphere. The complexes were spectroscopically and structurally characterized. Furthermore, complex 2 can serve as an efficient precatalyst for Kumada–Corriu‐type cross‐coupling reactions.     

VERBINDUNGEN MIT DEM 1,3-DIMETHYL-1,3- DIAZA-2-PHOSPHETIDIN-4-ON GRUNDGERüST: SYNTHESE VON 1,3-DIMETHYL-2-PHENYLIMINO- 1,3-DIAZA-2λ4-PHOSPHETIDIN-4-ON-DERIVATEN. RÖNTGENSTRUKTURANALYSE VON 4,6- DIMETHOXY -5,10-DIPHENYL-1,3,7,9- TETRAMETHYL-l,3,5,7,9,10-HEXAAZA- 4λ5,6λ55-DIPHOSPHADISPIRO[3.1.3.1]DECAN-2,8-DION

Abstract

Die Umsetzung einer Reihe von λ³P-Diazaphosphetidinonen, MeNC(:O)N(Me)PY (Y [dbnd] NEt₂: 1, N(CH₂)₄; 2, NPh₂; 3, OMe; 4, N(cyc)₂; 5), mit Phenylazid wird beschrieben. Die dabei primär entstandenen 2-Phenylimino-λ⁴P-diazaphosphetidinone, MeNC(:O)N(Me)P(:NPh)Y sind mit Ausnahme des sterisch anspruchsvollen Dicyclohexylderivats, Y [dbnd] N(cyc)₂; 12, unbeständig und dimerisieren rasch zu den entsprechenden Diazadiphosphetidinen, 7 und 9–11. Aus 7 bildet sich in Lösung unter Abspaltung von MeN[dbnd]C[dbnd]NMe das A4P, λ⁴P,λ⁵P-Diazadiphosphetidin 8. Die neuen Verbindungen 8–12 wurden analytisch, ₁H-, ₁₃C- und ³¹P-NMR-spektroskopisch sowie durch ihre Massenspektren charakterisiert. Darüber hinaus wurde von Verbindung 11 eine Röntgenstrukturanalyse durchgeführt. Das Molekül besitzt kristallographische zweizählige Symmetric. Die Geometrie am Phosphor ist verzerrt trigonal bipyramidal, mit P—N-Bindungslängen 173.9. 179.2 pm (axial) sowie 168.3, 168.7 pm (äquatorial).

Compounds involving the 1,3-dimethyl-1,3-diaza-2-phosphetidin-4-one framework: Synthesis of 1,3- dimethyl-2-phenylimino-l,3-diaza-2λ⁴-phosphetidin-4-one derivatives. X-ray crystal structure analysis of 4,6-dimethoxy-5,10-diphenyl-l,3,7,9-tetramethyl- 1,3,5,7,9,10-hexaaza-4λ⁵,6λ⁵-diphosphadispiro- [3.1.3.l]decan-2,8-dione.

The reactions of a series of λ³P-diazaphosphetidinones MeNC(:O)N(Me)PY (Y [dbnd] NEt₂,; ₁, N(CH₂)₄; 2, NPh2,; 3, OMe; 4, N(cyc)₂; 5), with phenyl azide are described. The initially formed 2-phenylimino-λ⁴P-diazaphosphetidinones, MeNC(:O)N(Me)P(:NPh)Y, are. except for the bulky dicyclohexyl derivative 12, unstable and dimerize rapidly to the corresponding diazadiphosphetidines, 7 and 9–11. The λ⁴P,λ⁴P-diazadiphosphetidine 8 is formed from 7 in solution by elimination of MeN[dbnd]C[dbnd]NMe. The novel compounds 8–12 were characterized by analysis, n.m.r. and mass spectroscopy; additionally, an X-ray crystal structure analysis of 11 was carried out. The molecule possesses crystallographic twofold symmetry. The P-N bond lengths are 173.9, 179.2 pm (axial) and 168.3, 168.7 pm (equatorial).     

ÜBER EINIGE REAKTIONEN DER DIALKYLBENZYLPHOSPHINIMIDE

Abstract

Dialkylbenzylphosphine imides C₆H₅CH₂–PRR′[dbnd]N″ (R, R′ = CH₃, C₂H₅; R″ = H, CH₃, Si(CH₃)₃ react with aliphatic and aromatic aldehydes in benzene solution on heating to 80°C directly and in high yields according to a Horner-Wittig-reaction with formation of an olefine whereas ketones like benzophenone and acetophenone only perform an O/NR″ exchange (R″ = H).

Dialkylbenzylphosphinimide C₆H₅CH₂–PRR′[dbnd]N″ mit R, R′ = CH₃, C₂H₅ und R″ = H, CH₃, Si(CH₃)₃ reagieren mit aliphatischen und aromatischen Aldehyden in benzolischer Lösung beim Erwärmen auf 80°C direkt und mit hohen Ausbeuten im Sinne einer Horner-Wittig-Reaktion unter Olefinbildung, während sich mit Ketonen wie Benzophenon oder Acetophenon nur ein O/NR″-Austausch (R″ = H) vollzieht.     

Reactions of 1-(3"-Amino)- and 1-(3"-Acetamido)propylsilatranes with Cobalt(II) Chloride and Dicobalt Octacarbonyl

1-(3"-Amino)propylsilatrane (I) and 1-(3"-acetamido)propylsilatrane (II) react with anhydrous cobalt(II) chloride to give dichlorobis[1-(3"-amino)propylsilatrane]cobalt(II) {Co[NH₂CH₂CH₂CH₂Si(OCH₂CH₂)₃N]₂Cl₂} (III) and dichlorobis[1-(3"-acetamido)propylsilatrane]cobalt(II) {Co[CH₃C(O)NHCH₂CH₂CH₂Si(OCH₂CH₂)₃N]₂Cl₂} (IV). Being unstable, compound IV transforms into an imidic acid derivative. Reactions of silatranes I and II with dicobalt octacarbonyl afford hexakis[1-(3"-aminoamido)propylsilatrane]cobalt(II) bis(tetracarbonylcobaltate) {Co[NH₂CH₂CH₂CH₂Si(OCH₂CH₂)₃N]_4.8[HC(O)NHCH₂CH₂CH₂Si(OCH₂CH₂)₃N]_1.2}[Co(CO)₄]₂ (V) and hexakis[1-(3"-acetamido)propylsilatrane]cobalt(II) bis(tetracarbonylcobaltate) {Co[CH₃C(O)NHCH₂CH₂CH₂Si(OCH₂CH₂)₃N]₆}[Co(CO)₄]₂ (VI), respectively. In acetonitrile, tetracarbonylcobaltate anions of compound VI are oxidized with atmospheric oxygen and moisture to cobalt hydroxocarbonate, giving a carbonate gel (VII).     

Mono-Phosphazenyl Phosphines (R2N)3P=N–P(NR2)2 – Strong P-Bases,P-Donors,and P-Nucleophiles for the Construction of Chelates

We present a convenient three-step synthesis of amino substituted phosphazenyl phosphines of the general formula (R₂N)₃P=N–P(NR₂)₂ [NR₂ = N(CH₂)₄, N(CH₂)₅, N(CH₂)₆]. These easily accessible mixed valent compounds display a surprisingly high proton affinity and basicity in the same range as the corresponding Schwesinger diphosphazene (Me₂N)₃P=N–P=NEt(NMe₂)₂ (Et-P₂) and Verkade's proazaphosphatrane superbases. Within the central [P^III–N=P^V] scaffold, the phosphine P^III and not the phosphazene N^III atom is the center of highest proton affinity, basicity and donor strength. As P-bases, the title compounds display calculated proton affinities between 265.8 (NR₂ = NMe₂) and 274.7 kcal · mol^–1 [NR₂ = N(CH₂)₄] and pK_BH⁺ values between 26.4 (NR₂ = NMe₂) and 31.5 [NR₂ = N(CH₂)₄] on the acetonitrile scale. As P-nucleophiles, they are key intermediates in the synthesis of hyperbasic bis(diphosphazene) proton sponges, chiral bis(diphosphazene) proton pincers, bisphosphazides, and superbasic P₂-bisylides. Their Staudinger reactions as nucleophile towards 1,8-diazidonaphthalene leading to 1,8-naphthalene-bisphosphazides is described in detail. The donor strength of the title compounds towards fragments [Se] and [Ni(CO)₃] is in the same range as that of N-heterocyclic carbenes.     

Synthese und Charakterisierung heterobimetallischer Bis(trimethylsilyl)phosphanide von Barium und Zinn

Synthesis and Characterization of Hetero-bimetallic Bis(trimethylsilyl)phosphanides of Barium and Tin The reaction of barium bis[bis(trimethylsilyl)amide] with one equivalent of bis(trimethylsilyl)phosphane in 1,2-dimethoxyethane (dme) yields the heteroleptic dimeric (dme)barium bis(trimethylsilyl)amide bis(trimethylsilyl)phosphanide. This colorless compound crystallizes in the monoclinic space group P2₁/n with a = 1 259.1(3), b = 1 822.7(4), c = 1 516.1(3) pm, β = 110.54(3)° and Z = 4. The central moiety of the centrosymmetric molecule is the planar Ba₂P₂-cycle with Ba? P-bond lengths of 329 and 334 pm. In the presence of bis[bis(trimethylsilyl)amino]stannylene hetero-bimetallic bis(trimethylsilyl)phosphanides of tin(II) and barium are isolated. If the reaction of Ba[N(SiMe₃)₂]₂ and Sn[N(SiMe₃)₂]₂ in the molar ratio of 1:2 with six equivalents of HP(SiMe₃)₂ is performed in toluene, barium bis{tin(II)-tris[bis(trimethylsilyl)phosphanide]} can be isolated. This compound crystallizes in the orthorhombic space group P2₁2₁2₁ with a = 1 265.1(1), b = 2 290.1(3), c = 2 731.9(3) pm and Z = 4. The anions {Sn[P(SiMe₃)₂]₃}^? bind as two-dentate ligands to the barium atom which shows the extraordinary low coordination number of four. The addition of tetrahydrofuran (thf) to the above mentioned reaction solution leads to the elimination of tris(trimethylsilyl)phosphane and the formation of thf complexes of barium bis{tin(II)-bis(trimethylsilyl)phosphanide-trimethylsilylphosphandiide}. The derivative crystallizes from toluene in the monoclinic space group P2₁/c with a = 1 301.9(2), b = 2 316.3(3), c = 3 968.7(5) pm, β = 99.29(1)° and Z = 8.     

Umsetzungen von Borazinderivaten mit Bis(trimethylsilyl)-acetamid und Lithiumhexamethyldisilazan

Bis-(trimethylsilyl)acetamide (BSA) reacts with borazines [RNBX]₃, R=H,X=F; R=CH₃,X=F; R=C₆H₅,X=F and R=C₆H₅,X=Cl to the corresponding borazines,X=OSi(CH₃)₃. The¹H-NMR signal of the Si(CH)₃-groups of [C₆H₅NBOSi(CH₃)₃]₃ is at abnormally high field. With [CH₃NBCl]₃,BSA forms borazines which contain both Si(CH₃)₃O- and O?C(CH₃)=NSiR₃ groups bonded to the boron atoms. With LiN[Si(CH₃)₃]₂, [CH₃NBCl]₃ forms silylaminoboranes.¹H-NMR, mass spectrometric and analytical data are reported.