Über Chalkogenolate. 155. Reaktion von N-Methylformamid mit Kohlenstoffdisulfid 2. N-Methyl-N-formyldithiocarbamidsäure und Oxydation von N-Methyl-N-formyldithiocarbamaten

On Chalcogenolates. 155. Reaction of N-Methyl Formamide with Carbon Disulfide. 2. N-Methyl N-Formyl Dithiocarbamic Acid and Oxidation of N-Methyl N-Formyl Dithiocarbamates The reaction of a solution of K[S₂C? NCH₃? CO? H] in acetone-d₆ with gaseous HCl at ?78°C forms unstable H? CO? NCH₃? CS? SH. The existence of this acid in solution has been demonstrated by nuclear magnetic resonance spectra. The oxidation of N-methyl N-formyl dithiocarbamates with iodine yields N,N′-dimethyl N,N′-diformyl thiuram disulfide (H? CO? NCH₃? CS? S? )₂, which has been characterized by means of diverse spectroscopic methods.     

Über Chalkogenolate. 158. Reaktion von N-Methylthioformamid mit Kohlenstoffdisulfid 2. Oxydation von N-Methyl-N-thioformyldithiocarbamaten und S-Methylester der N-Methyl-N-thioformyldithiocarbamidsäure

On Chalcogenolates. 158. Reaction of N-Methyl Thioformamide with Carbon Disulfide. 2. Oxidation of N-Methyl N-Thioformyl Dithiocarbamates and S-Methyl Ester of N-Methyl N-Thioformyl Dithiocarbamic Acid The oxidation of N-methyl N-thioformyl dithiocarbamates with iodine forms the hitherto unknown N-methyl-1,2,4-dithiazole-3,5-dithione . The S-methyl ester of N-methyl N-thioformyl dithiocarbamic acid H? CS? NCH₃? CS? SCH₃ has been prepared by reaction of potassium N-methyl N-thioformyl dithiocarbamate with methyl iodide as well as by reaction of the S-methyl ester of N-methyl N-formyl dithiocarbamic acid with Lawesson reagent. Both compounds have been characterized by means of chemical and diverse spectroscopic methods.     

Über Chalkogenolate. 157. Reaktion von N-Methylthioformamid mit Kohlenstoffdisulfid 1. Darstellung und Eigenschaften von N-Methyl-N-thioformyldithiocarbamaten

On Chalcogenolates. 157. Reaction of N-Methyl Thioformamide with Carbon Disulfide. 1. Synthesis and Properties of N-Methyl N-Thioformyl Dithiocarbamates N-Methyl thioformamide has been prepared by reaction of N-methyl formamide with P₄S₁₀. It reacts with carbon disulfide in the presence of hydroxides to yield the corresponding N-methyl N-thioformyl dithiocarbamate. The prepared compounds have been characterized with chemical and thermoanalytical methods as well as by means of electron absorption, infrared, nuclear magnetic resonance (¹H and ¹³C), and mass spectra. Attempts to synthesize N-methyl N-thioformyl dithiocarbamic acid were not successful.     

Übergangsmetall-substituierte Diphosphene. 25. Spaltung der PP-Bindung eines Diphosphens mit N-Methylmaleinsäureimid. Synthese und Struktur eines Bicyclo[3.1.0]-1-aza-4-phosphahexa-2, 6-dions

Transition Metal Substituted Diphosphenes. 25. Cleavage of the P?P-Bond of a Diphosphene by the Reaction with N-Methyl Maleimide. Synthesis and Structure of Bicyclo-[3.1.0.]-aza-4-phosphahexa-2, 6-dione The reaction of (η?⁵?C₅Me₅)(CO)₂FeP = P-Aryl (Aryl = 2,4,6tBu₃C₆H₂) ( 1 ) with a fivefold excess of the N-methyl maleimide leads to the cleavage of the P = P bond. The phosphidoiron complex 3 is formed, which features a phosphorus atom with a succinimidyl and a bicyclo-[3.1.0.]-1-aza-4-phosphahexa-2,6-dion-3-yl substituent. Two diastereiosomers, 3a and 3b , could be distinguished by means of NMR-spectroscopy. Constitution and configuration of 3a in the crystal were elucidated by x-ray analysis.     

Über Chalkogenolate. 128. Untersuchungen über Ester der N-Cyancarbamidsäure. 1. Darstellung und Eigenschaften der Ammoniumsalze von N-Cyancarbamidsäureestern und vom N-Methyl-N-cyancarbamidsäureethylester

On Chalcogenolates. 128. Studies on Esters of N-Cyancarbamic Acid. 1. Synthesis and Properties of Ammonium Salts of N-Cyancarbamic Acid Esters and of the Ethyl Ester of N-Methyl N-Cyancarbamic Acid The reaction of NC? N(CO? OR)₂ with NH₃(g) yields NH₄[NC? N? CO? OR], where R = CH₃, C₂H₅, and C₆H₅. NH₄[NC? N? CO? OC₂H₅] reacts with H₃CI to form NC? N(CH₃)? CO? OC₂H₅. The called compounds have been studied with chemical and spectroscopic methods.     

Über Chalkogenolate. 81. Untersuchungen über N-Hydroxydithiocarbamidsäure 3. Ester der N-Hydroxydithiocarbimidsäure und -carbamidsäure

On Chalcogenolates. 81. Studies on N-Hydroxy Dithiocarbamic Acid. 3- Esters of N-Hydroxy Dithiocarbimic Acid and Dithiocarbamic Acid The reaction between hydroxylamine, carbon disulfide, and alkyl halide leads to the corresponding ester of N-hydroxy dithiocarbimic acid HO? N?C(SR)₂ with R = CH₃, C₂H₅; R₂ = ? CH₂? CH₂? . The phenyl ester of N-hydroxy dithiocarbamic acid HO? NH? CS(SC₆H₅) has been prepared by reaction of hydroxylammonium chloride with the phenyl ester of chlorodithioformic acid. N-Methyl hydroxylammonium chloride reacts with carbon disulfide and alkyl iodide to form the corresponding ester of the dithiocarbamic acid HO? N(CH₃)? CS(SR) with R = CH₃, C₂H₅. The unstable compounds have been characterized by different methods.     

Über Chalkogenolate. 154. Reaktion von N-Methylformamid mit Kohlenstoffdisulfid 1. Darstellung und Eigenschaften von N-Methyl-N-formyl-dithiocarbamaten

On Chalcogenolates. 154. Reaction of N-Methyl Formamide with Carbon Disulfide. 1. Synthesis and Properties of N-Methyl N-Formyl Dithiocarbamates N-Methyl formamide reacts with carbon disulfide in the presence of sodium hydride, potassium hydroxide, and barium hydroxide to form the corresponding N-methyl N-formyl dithiocarbamate. The prepared compounds have been characterized with chemical and thermal methods as well as by means of electron absorption, infrared, nuclear magnetic resonance (¹H and ¹³C), and mass spectra.     

Über Chalkogenolate. 151. Untersuchungen über Derivate der N-Thioformyldithiocarbamidsäure. 1. Darstellung und Eigenschaften von N-Thioformyldithiocarbamaten

On Chalcogenolates. 151. Studies on Derivatives of N-Thioformyl Dithiocarbamic Acid. 1. Synthesis and Properties of N-Thioformyl Dithiocarbamates The N-thioformyl dithiocarbamates M[S₂C? NH? CS? H], where M = K, Rb, Cs, Tl, NH₄, [N(ⁿC₄H₉)₄], Na[S₂C? NH? CS? H] · 0.5 H₂O, and Ba[S₂C? NH? CS? H]₂ · 3 HO? CH₂? CH₂? OCH₃ have been prepared by use of partial different procedures. The compounds were characterized with chemical and thermal methods as well as by means of electron absorption, infrared, nuclear magnetic resonance (¹H and ¹³C), and mass spectra. Attempts to synthesize N-thioformyl dithiocarbamic acid were not successful.     

Über Chalkogenolate. 152. Untersuchungen über Derivate der N-Thioformyldithiocarbamidsäure. 2. Kristallstruktur von Tetra-n-butylammonium-N-thioformyldithiocarbamat

On Chalcogenolates. 152. Studies on Derivatives of N-Thioformyl Dithiocarbamic Acid. 2. Crystal Structure of Tetra-n-butylammonium N-Thioformyl Dithiocarbamate The title compound [N(ⁿC₄H₉)₄][S₂C? NH? CS? H] crystallizes with Z = 2 in the triclinic space group P1 with cell dimensions a = 9.694(2) Å, b = 11.478(3) Å, c = 12.551(6) Å, α = 63.03(3)°, β = 66.42(2)°, γ = 85.60(2)°. The crystal structure has been determined from single crystal X-ray data measured at 20°C and refined to a conventional R of 0.061 for 2249 independent reflections (R_w = 0.042). The structure is built up of dimeric aggregates consisting of 2[N(ⁿC₄H₉)₄]⁺ cations and 2[S₂C? NH? CS? H]^? anions. The two anions are linked together by ? CS? S…?H? N bridges. To make possible a space saving stacking of the dimeric aggregates in the crystal, one methyl group in terminal position of one n-butyl chain in the cation has gauche conformation.     

Über Chalkogenolate. 142. Untersuchungen über Trimethylsilylxanthogensäure. 2. S-Methyl- und S-Ethyltrimethylsilylxanthat

On Chalcogenolates. 142. Studies on Trimethylsilyl Xanthic Acid. 2. S-Methyl and S-Ethyl Trimethylsilyl Xanthates The hitherto unknown S-alkyl trimethylsilyl xanthates (CH₃)₃SiO? CS? SR, where R = CH₃ and C₂H₅, have been characterized with electron absorption, infrared, nuclear magnetic resonance (¹H, ¹³C, and ²⁹Si), and mass spectra.     

Über Chalkogenolate. 94. Untersuchungen über Trithioallophansäure 3. Ester der Trithioallophansäure [1]

On Chalcogenolates. 94. Studies on Trithioallophanic Acid. 3. Esters of Trithioallophanic Acid. The esters of trithioallophanic acid H₂N? CS? NH? CS(SR) with R = CH₃, CH₂C₆H₅ have been characterized by means of electron absorption spectra, infrared spectra, ¹H NMR spectra, and mass spectra.     

A quasi‐diamondoid hydrogen‐bonded framework in an­hydro­us sulfanilic acid

The title compound (C₆H₇NO₃S) exists as a zwitterion (4‐ammonio­benzene­sulfonate), ⁺H₃NC₆H₄SO₃^?, and these units are linked into a three‐dimensional framework by two distinct two‐centre N—H?O hydrogen bonds [H?O 1.84 and 1.87 Å; N?O 2.767 (2) and 2.746 (2) Å; N—H?O 166 and 172°] and a planar three‐centre N—H?(O)₂ hydrogen bond [H?O 2.03 and 2.37 Å; N?O 2.816 (2) and 2.877 (2) Å; N—H?O 162 and 111°; O?H?O 86°].     

The C—H⃛O hydrogen bond in (di­cyano­methyl)­ammonium p‐toluene­sulfonate

In the title compound, C₃H₄N₃⁺·C₇H₇O₃S^?, the activated C—H group of the cation forms a short but bent C—H?O hydrogen bond with a sulfonate O atom of the anion; C?O = 3.075 (5) Å and C—H?O = 130°.     

Über Chalkogenolate. 129. Untersuchungen über Ester der N-Cyancarbamidsäure. 2. Darstellung,spektroskopische Charakterisierung und Zersetzung von O-Methyl- und O-Ethyl-N-cyancarbamat

On Chalcogenolates. 129. Studies on Esters of N-Cyancarbamic Acid. 2. Synthesis, Spectroscopic Characterization, and Decomposition of O-Methyl and O-Ethyl N-Cyancarbamate NH₄[NC? N? CO? OR], where R = CH₃ and C₂H₅, reacts with acids to yield unstable NC? NH? CO? OR. The esters decompose to form NC? N?C(NH₂)? NH? CO? OR. The compounds have been characterized by means of electron absorption, ¹H and ¹³C NMR, infrared, and mass spectra.     

1‐Silacyclopent‐2‐enes and 1‐silacyclohex‐2‐enes bearing functionally substituted silyl groups in 2‐positions. Novel electron‐deficient Si?H?B bridges

The reactions of alkyn‐1‐yl(vinyl)silanes R₂Si[C?C‐Si(H)Me₂]CH?CH₂ [R = Me (1a), Ph (1b)], Me₂Si[C?C‐Si(Br)Me₂]CH?CH₂ (2a), and of alkyn‐1‐yl(allyl)silanes R₂Si[C?C‐Si(H)Me₂]CH₂CH?CH₂ (R = Me (3a), R = Ph (3b)] with 9‐borabicyclo[3.3.1]nonane in a 1:1 ratio afford in high yield the 1‐silacyclopent‐2‐ene derivatives 4a, b and 5a, and the 1‐silacyclohex‐2‐ene derivatives 6a, b, respectively, all of which bear a functionally substituted silyl group in 2‐position and the boryl group in 3‐position. This is the result of selective intermolecular 1,2‐hydroboration of the vinyl or allyl group, followed by intramolecular 1,1‐organoboration of the alkynyl group. In the cases of 4a, b, potential electron‐deficient Si? H? B bridges are absent or extremely weak, whereas in 6a,b the existence of Si? H? B bridges is evident from the NMR spectroscopic data (¹H, ¹¹B, ¹³C and ²⁹Si NMR). The molecular structure of 4b was determined by X‐ray analysis. Copyright © 2005 John Wiley & Sons, Ltd.     

Über Chalkogenolate. 134. Untersuchungen über Ester von Halogenoameisensäuren 2. Darstellung und Eigenschaften von Se-Alkylestern der Chloromonothiomonoselenoameisensäure [1]

On Chalcogenolates. 134. Studies on Esters of Haloformic Acids 2. Synthesis and Properties of Se-Alkyl Esters of Chloromonothiomonoselenoformic Acid The hitherto unknown esters RSe? CS? Cl with R ? C₂H₅ and ⁿC₃H₇ have been prepared by reaction of thiophosgene with the corresponding alkane selenol. The compounds have been characterized with electron absorption, nuclear magnetic resonance (¹H, ¹³C, and ⁷⁷Se), infrared, and mass spectra.     

Über Chalkogenolate. 140. Untersuchungen über Dialkylester von Chalkogenokohlensäuren. 3. S,Se-Dialkyldithiomonoselenocarbonate Existenzbeweis von Alkylselenoxanthaten [S2C?SeR]−

On Chalcogenolates. 140. Studies on Dialkyl Esters of Chalcogenocarbonic Acids. 3. S,Se-Dialkyl Dithiomonoselenocarbonates. Evidence for the Existence of Alkyl Selenoxanthates [S₂C? SeR]^? The esters RSe? CS? SR′ with R = R′ = C₂H₅, ⁿC₃H₇ as well as with R = ⁿC₃H₇ and R′ = C₂H₅ have been produced by three different methods. The compounds have been characterized by means of electron absorption, infrared, nuclear magnetic resonance (¹H, ¹³C, and ⁷⁷Se), and mass spectra. The unstable alkyl selenoxanthates M[S₂C? SeR], where M = Na, K and R = C₂H₅, ⁿC₃H₇, are formed by reaction of carbon disulfide with the corresponding alkane selenolate. Freshly prepared they react with alkyl iodides R′I to yield RSe? CS? SR′.     

The Effect of C4H and C5H on the Microstructure of Aqueous Solutions of 1‐Alkyl‐3‐methylimidazolium Tetrafluoroborate Ionic Liquids

As is well‐known, the C2?H proton of 1‐ethyl‐3‐methylimidazolium tetrafluoroborate ([Emim]BF₄) and 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([Bmim]BF₄) has a strong ability to form hydrogen bonds. The purpose of this work is to evaluate the effect of the interactions of the C4?H and C5?H protons on the microstructure of [Emim]BF₄ and [Bmim]BF₄ with water by using ¹H NMR spectroscopy. The differences between the relative ¹H NMR chemical shifts of C2?H, C4?H, and C5?H and between the interaction‐energy parameters obtained from these chemical shifts are minor, thus suggesting that the interactions of C4?H and C5?H may have a considerable effect on the microstructure. To confirm this, the viscosities of the systems are estimated by using the interaction‐energy parameters obtained from the ¹H NMR chemical shifts of the three studied aromatic protons and water, showing that the interactions of C4?H and C5?H also play an important role in the microstructure.     

Zum Aufbau schlecht geordneter Calciumhydrogensilicate. VI. Chemische,ESR- und Mößbauer-spektroskopische Untersuchungen zum Einbau von Fe3+-Ionen in C?S?H(Di,Poly)

On the Structure of Ill-crystallized Calcium Hydrogen Silicates. VI. Chemical, ESR, and Mössbauer-Spectroscopic Investigations on the Incorporation of Fe³⁺ into C? S? H(Di, Poly) C? S? H(Di, Poly), prepared by precipitation reactions from sodium silicate solutions in presence of Fe³⁺ ions, incorporates at least up to 0.09 Fe₂O₃/SiO₂. Thereby the anion composition of the C? S? H(Di, Poly) ist not affected. The results of ESR and Mössbauer spectroscopic measurements show, that Fe is incorporated as Fe³⁺ at octahedral sites. Only less than 1% of the total amount of Fe³⁺ is situated at tetrahedral sites. In good accordance with that is the change of thermal stability of the silicate anions concerning condensation and degradation reactions.     

Palladium(0)/PAr3‐Catalyzed Intermolecular Amination of C(sp3)H Bonds: Synthesis of β‐Amino Acids

An intermolecular C(sp³)? H amination using a Pd⁰/PAr₃ catalyst was developed. The reaction begins with oxidative addition of R₂N? OBz to a Pd⁰/PAr₃ catalyst and subsequent cleavage of a C(sp³)? H bond by the generated Pd? NR₂ intermediate. The catalytic cycle proceeds without the need for external oxidants in a similar manner to the extensively studied palladium(0)‐catalyzed C? H arylation reactions. The electron‐deficient triarylphosphine ligand is crucial for this C(sp³)? H amination reaction to occur.