2-Dimethylarsino-ethanol

2-Dimethylarsino-ethanol The reaction of 2-dimethylarsino ethanol Me₂As–CH₂CH₂? OH with various metal carbonyles results in the formation of complexes of the general formula (CO)_n?1Z? L respectively (CO)_n?2ZL₂; the ligands are able to form chelate complexes; the reaction with the halides R? X results in the formation of arsonium salts.     

Über die Umsetzung von Adipinsäurediamid mit Phosphorpentachlorid

Reaction of Adipic Acid Diamide with Phosphorus Pentachloride The reaction of adipamide (I) with phosphorus pentachloride in a solvent leads to (Cl₃P?NCCl₂CCl₂CH₂)₂ (II). The stages of the reaction are: 1. chlorination of the keto and methylen groups 2. formation of the ? N?PCl₃ group. This result is a supplement of the existing conception about the course of the reaction of carboxylic acid amides with phosphorus pentachloride. The reaction of (I) with PCl₅ without any solvent has been reproduced and the course of reaction has also been investigated. This reaction gives mainly NC(CH₂)₄CN. The resulting product of a careful hydrolysis of (II) is (Cl₂OPN?CClCl₂CH₂)₂. A total hydrolysis gives back (I).     

Reactions of the nitrate radical with a series of reduced organic sulphur compounds in air

A 480 L evacuable reaction chamber, equipped with FT-IR spectroscopy on-line and ion chromatography off-line, has been used to study the gas phase reaction between the nitrate radical, NO₃, and the reduced organic sulphur compounds CH₃CH₂SH, (CH₃CH₂)₂S, (CH₃CH₂)₂S₂, and CH₃CH₂SCH₃ in air. The products CH₃CH₂SO₃H, SO₂, H₂SO₄, CH₃CHO, and CH₃CH₂ONO₂ were identified and quantified in the reactions of the first three compounds, CH₃CH₂SH, (CH₃CH₂)₂S, and (CH₃CH₂)₂S₂. The reaction products were CH₃CH₂SO₃H, CH₃SO₃H, SO₂, H₂SO₄, CH₃CHO, and CH₂O in the reaction of CH₃CH₂SCH₃. On the basis of identified reaction products and intermediates observed in the infrared spectra, mechanisms are proposed for the reactions between the NO₃ radical and the four reduced organic sulphur compounds. The results of this study, together with those from previous experiments performed in this laboratory on CH₃SCH₃, CH₃SH, and CH₃SSCH₃ lead to the conclusion that all these species, in the reaction with the NO₃ radical, follow a similar degradation mechanism producing SO₂, H₂SO₄, R? SO₃H, R? CHO, and R? CH₂ONO₂, as the main reaction products. The inital step of the reaction of NO₃ with R? S? R and R? S? H type (R = CH₃, CH₂CH₃) reduced organic sulphur compounds was found to be H-atom abstraction, probably after the formation of an initial adduct. For the reaction between NO₃ and R? S? S? R type compounds, evidence for an addition-decomposition reaction, as the initial steps, was obtained. R? S·, R? S(O)·, and R? S(O)₂· appear to be formed as intermediates in all the reactions. © John Wiley & Sons, Inc.     

Bildung siliciumorganischer Verbindungen. 70 [1]. Reaktionen Si-fluorierter 1,3,5-Trisilapentane mit CH3MgCl und LiCH3

Formation of Organosilicon Compounds. 70. Reactions of Si-fluorinated 1,3,5-Trisilapentanes with CH₃MgCl and LiCH₃ F₃Si? CCl₂? SiF₂? CH₂? SiF₃ 3 reacts with meMgCl. (me = Ch₃ starting with a Si-methylation and not with a C-metallation as in the corresponding Si- and C-chlorinated compounds, e. g. (Cl₃Si? CCl₂)₂SiCl₂ [2]. A CCl-hydrogenation is observed too, which in the case of F₃Si? CCl₂? SiF₂? CHCl? SiF₃ 4 gives meS₃Si? CCl₂? Sime₂? CH₂? Sime₃. (F₃Si? CCl₂)_{2 5} reacts with meMgCl to form preferentially 1,2-Disilapropanes by cleaving a Si? Cbond. The isolation of F₃Si? CCl₂H and meF₂Si? CCl₂? SiF₂me allows to locate the bond where 5 is cleaved at the beginning of the reaction. With meLi 5 reacts to form mainly me₃Si? C?C? Sime₃, showing that in the reaction of meLi, being a stronger reagent than meMgCl, and 5 a C-metallation occurs, following the same mechanism as in the reaction with (Cl₃Si? CCl₂)₂)SiCl₂ [2]. The reaction conditions for the synthesis of Si-fluroinated and C-chlorinated 1,3,5-Trisilapentanes in a 0.1 mol scale are reported. N.m.r. data of all investigated compounds are tabulated.     

Koordinationsverbindungen des Silber(I) mit stickstoffhaltigen Liganden Kristallstruktur des NC?SCF2CF2S?CN

Coordination Compounds of Silver(I) with Nitrogen-Containing Ligands. Crystal Structure of NC? SCF₂CF₂S? CN The reaction of F₂S?NCN and NC? SCF₂CF₂S? CN with AgAsF₆ leads to the coordination compounds (F₂S?NCN)₂AgAsF₆ 2 and (NC? SCF₂CF₂S? CN)₂AgAsF₆ 5 . NC? SCF₂CF₂S? CN 3 is formed by the reaction of ClSCF₂CF₂SCl with HCN as well as with Me₃SiCN. 4 is a by-product of the reaction with HCN. 4 was characterized as a six-membered heterocycle. 3 was investigated by an X-ray single structure analysis. In the solid state the all-trans form was found.     

A new phase in the Ag−O−S system

The investigations of reaction between Ag₂SO₄ and Ag₂S in air atmosphere have been carried. Results of DTA and X-ray phase powder diffraction of a reaction mixture have confirmed that in the Ag?O?S system exists a new phase. A formula of the phase is Ag₂SO₂.     

Some addition reactions of bisgermavinylidene

The reaction of bisgermavinylidene [(Me₃SiN?PPh₂)₂C?Ge→Ge?C(PPh₂?NSiMe₃)₂] ( 1 ) with AdNCO (Ad = Adamantyl) afforded the [2 + 2] cycloadditon product [(Me₃SiN?PPh₂)₂CGeC(O) NAd] ( 2 ). Similar reaction of 1 with Ph₃SiOH in tetrahydrofuran (THF) yielded the base‐stabilized germanium(II) triphenylsiloxide [H₂C(PPh₂?NSiMe₃)₂Ge(OSiPh₃)₂] ( 3 ). The results suggested that reactive germavinylidene may exist in solution and is capable of forming addition reaction products. The X‐ray structures of 2 and 3 were determined. Copyright © 2007 John Wiley & Sons, Ltd.     

Ternary invariant point at 403 and 455?°C in the Al–Sb–Zn system

The temperature and location of the invariant eutectic point at 403?°C in the zinc-rich corner of the Al?CSb?CZn system was determined. However, the experimentally determined temperature was found to be lower than the thermodynamically predicted one. Differential thermal analyses, differential scanning calorimetry, and quantitative microstructural analyses were used to determine this specific reaction. The determined ternary eutectic reaction, L??????-Sb₂Zn₃?+?AlSb?+???-Zn, represents the last solidification path in the phase region of Sb?CAlSb?CZn. Before a ternary eutectic reaction takes place, another reaction is also possible near the Sb?CZn binary system, a quasi-peritectic reaction at 455?°C: L?+???-Sb₂Zn₃????AlSb?+???-Sb₂Zn₃. A scanning electron microscope equipped with an energy-dispersive spectrometer was used for the microstructural analyses. The phase identification was conducted with X-ray diffractometry. The experimental data were compared to the thermodynamic predictions made with the CALPHAD method using the SSOL4 database.     

Nebenreaktionen bei der Umsetzung von Trimethylsilylazid mit Trimethylphosphit und Trisdimethylaminophosphin

Side Reactions upon Interaction of Trimethylsilyl Azide with Trimethylphosphite and Trisdimethylaminophosphine Trisdimethylaminophosphine reacts with trimethylsilyl azide with evolution of nitrogen and formation of N-trimethylsilyl-iminophosphoric acid hexamethyltriamide, (Me₂N)₃ · P ? N? SiMe₃. The diphosphazene (Me₂N)₃P ? N? P(NMe₂)₂ ? N? SiMe₃ is formed in a side reaction with concomitant elimination of dimethylamino trimethylsilane. The reaction of trimethylsilyl azide with trimethylphosphite affords, besides the expected N-trimethylsilyliminophosphorus trimethylester, (MeO)₃P ? N? SiMe₃, the isomeric N-trimethylsilyl-N-methyl-aminophosphoric dimethylester, (MeO₂)P(O)? N(Me)SiMe₃.     

A theoretical study of the ground-state potential surface of guanine and its binding with oxygen and water

A molecular orbital geometry optimization study of the potential surface of guanine, guanine? O₂, and guanine? O₂? water reaction products in the ground state has been carried out. The origin of the asymmetric double-well potential surface of guanine suggested earlier on the basis of experimental observations has been explained. The most stable binding of O₂ with guanine (G) is found to occur at the C4C5 double bond of the latter molecule. In the case of G? O₂? water reaction product (HOO? G? OH), the groups ? OOH and ? OH bind at C4 and C8, respectively. The possiblity of a polymeric reaction product of the type R1? (G? O? O? G)n? R2 (R1, R2 = H, OH) has also been suggested. These results are broadly supported by experimental observations. The mechanism of spectral oscillations observed in UV-irradiated guanine solutions has been discussed.     

Zur Bildung cyclischer Silylphosphane Umsetzung von Li-Phosphiden mit R2SiCl2 (R = Me,Et, t-Bu)

Formation of Cyclic Silylphosphanes. Reaction of Li-Phosphides with R₂SiCl₂ (R? Me, Et, t-Bu) The reaction of Me₂SiCl₂ with Li-phosphides (mixture of LiPH₂, Li₂PH) leads to the formation of Me₂Si(PH₂)Cl 1 , Me₂Si(PH₂)₂ 2 , H₂P? SiMe₂? PH? SiMe₂Cl 3 , (H₂P? SiMe₂)₂PH 4 , (HP? SiMe₂)₃ 6 , 5 , 7 , 8 , 9 , 10 , 40 . Excess of phosphides in Et₂O – as well as excess of LiPH₂ – favourably forms 10 . Li₂PH (virtually free of Li₃P and LiPH₂) is obtained by reaction of LiPH₂ · DME with LiBu; Li₃P by reaction of PH₃ with LiBu in toluene. Isomerization by Li/H migration determines the course of reaction of the PH-bearing compounds with Li-phosphides. With Me₂SiCl₂ Li₃P mainly generates compound 10 . The reaction of the Li-phosphides with Et₂SiCl₂ mainly leads to (HP? SiEt₂)₃ 18 and (HP? SiEt₂)₂ 17 as well as to Et₂Si(PH₂)Cl 11 , Et₂Si(PH₂)₂ 12 , (ClEt₂Si)₂PH 13 , H₂P? SiEt₂? PH? SiEt₂Cl 14 , (H₂P? SiEt₂)₂PH 15 and 16 . In the reaction with LiPH₂ · DME the same compounds are obtained and isomerization by Li/H migration (formation of PH₃) already begins at ?70°C. In toluene ClEt₂Si? P(SiEt₂)₂P? SiEt₂Cl is additionally formed. Derivatives of 9, 10, 40 are not observed. The reaction of (t-Bu)₂SiCl₂ with LiPH₂ leads to HP[Si(t-Bu)₂]₂PH 20 (yield 76%) and formation of PH₃, the reaction with Li₂PH to 20 (54%) besides HP[Si(t-Bu)₂]₂PLi 21 .     

Synthese linearer und verzweigter Phosphazene aus N-silylierten Phosphorylamiden

Synthesis of Lineary and Branched Phosphazenes from N-silylated Phosphoryl Amides The use of N-silylated phosphoryl amides in the reaction with PCl₅ favours the KIRSANOV reaction and reduces undesirable substitution reactions. However, silylated monoamides, X₂P(O)NHSiMe₃ (X = OEt, NEt₂), do not give the expected trichlorophosphazenes but the isomeric N-dichlorophosphoryl phosphazenes, Cl₂P(O)? N?PClX₂, which are also formed in the reaction of (EtO)₂P(O)NCl₂ with PCl₅. As the first phosphoryl-P, P-bis(trichlorophosphazene) (EtO)P(O)(N?PCl₃)₂ could be obtained in the reaction of PCl₅ with the silylated diamide (EtO)P(O)(NHSiMe₃)₂. Tris reactivity of silylated amides to P? Cl compounds decreases in the row PCl₅ > POCl₃ > CIP(O)(OEt)₂ > ClP(O)(NEt₂)₂. In the reaction with phosphoryl chlorides the preferred formation of compounds with P? NH? P bridges could not be observed.     

Reactions of the electrochemically generated dianion of [60]fullerene with bulky secondary alky bromides

Reactions of the electrochemically generated dianion of [60]fullerene (C₆₀^2?) with bulky secondary alkyl bromides exhibit different reaction behaviors. Reaction of C₆₀^2? with diphenylbromomethane gives rise to 1,2-C₆₀HR or 1,4-C₆₀R₂ (R?=?CHPh₂) adducts, while reaction of C₆₀^2? with diethyl 2-bromomalonate unexpectedly affords methanofullerene C₆₀?>?CR₂ (R?=?CO₂Et). Plausible reaction mechanisms have been proposed to explain the formation of the observed products.     

Synthese „anorganischer”︁ Tintenfisch-Moleküle. II

Synthesis of “Inorganic” Pode-type Molecules. II The reaction of the amino compounds Me_yB? NMe₂ (B ? As, y ? 2; B ? Si, y ? 3) with 1, n-dioles results in the formation of the compounds HO(CH₂)_nOBMe_y. These compounds can be used as the arms of pode-type molecules Me_xA[? O(CH₂)_nOBMe_y]_z with A ? Si, As. The influence of A, B, n, and z in the rearrangement of these molecules is examined. A second type of pode molecules can be prepared by the reaction of Me₂As? R? OH (R ? CH₂CH₂, CH₂CH₂(OCH₂CH₂)₂) with the amino compounds Me_x(NMe₂)_z (A ? As, Si). These reactions result in the formation of molecules as Me_xA(ORAsMe₂)_z.     

Mechanism of the reaction of N-p-tosylsulphilimine and related compounds with thiophenolate ion

The reaction of alkyl aryl N-p-tosylsulphilimines with thiophenolate ion was found to afford quantitatively the sulphide that arises by an S_N2 like reaction on the carbon atom adjacent to the tri-valent sulphur atom. This reaction was also found to proceed smoothly with such compounds as sulphoxides and sulphones and sulphoxmanes. The kinetic study on the reaction between aryl methyl N-p-tosylsulphilimine with thiophenolate ion in DMF reveals that the reaction is of second order, namely, first order with respect to each thiophenolate ion and the sulphilimine. The enthalpy and entropy of activation for the reaction are ΔH^≠ = ?17· kcal/mol and ΔS^≠ = ?5·7 eu respectively. The effect of substituents in the reaction, p-XC₆H₄⁺(^?SO₂C₆H₄Y-p)CH₃ + p-ZC₆H₄SK is nicely correl with Hammett σ values giving ?_x = + 2·4, ?_y = + 1·2 and ?_z = ?1·8 respectively. Meanwhile, a marked steric retardation by a bulky alkyl group in alkyl phenyl N-p-tosylsulphilimine is observed. Furthermore, from the stereochemical study of the reaction using an optically active sec-octyl phenyl N-p-tosylsulphilimine with thiophenolate ion it is concluded that the reaction proceeds via a typical S_N2 process on α-carbon atom attached to the tri-valent sulphur atom.     

The polymerization of isobutylene by AlCl3 in CH2Cl2 and the role of CH2Cl2 in the initiation reaction

A solution of AlCl₃ in CH₂Cl₂ prepared in advance was used 18 days after the mixing of the components as an initiation system in the polymerization of isobutylene performed in CH₂Cl₂ in the temperature range between ?10 and ?20°C. The ¹H-NMR analysis of polyisobutylene (PIB) samples synthesized to low and high conversion showed that it is the initiation reaction and not the transfer reaction to dichloromethane that is responsible for the ? CH₂Cl endgroup in the polymer chain. In case of the transfer to monomer formation of PIB with internal terminal unsaturation [PIB? CH?C(CH₃)₂] is preferred to external unsaturation [PIB? CH₂(CH₃)C?CH₂]. The solutions of AlCl₃ in CH₂Cl₂ showed an absorption band at λ_max = 302 nm.     

Über Chalkogenolate. 139. Untersuchungen über Dialkylester von Chalkogenokohlensäuren. 2. O,Se- und S,Se-Dialkylmonothiomonoselenocarbonate

On Chalcogenolates. 139. Studies on Dialkyl Esters of Chalcogenocarbonic Acids. 2. O,Se- and S, Se-Dialkyl Monothiomonoselenocarbonates The hitherto unknown esters RSe? CS? OR′, where R = C₂H₅, ⁿC₃H₇ and R′ = C₂H₅, ⁿC₃H₇, are formed by reaction of NaSeR with Cl? CS? OR′ and of RSe? CS? Cl with HOR′. At the first time, the esters RSe? CO? SR′ with R = R′ = C₂H₅, ⁿC₃H₇ have been prepared by reaction between NaSeR and Cl? CO? SR′. The compounds have been characterized by means of diverse spectroscopic methods.     

New ethylzinc reagents with remarkable properties in palladium-catalyzed zinc-ene reactions

Pd-Catalyzed Zn-ene allylic olefinations with the new ethylzinc reagents Et? Zn? OSO₂CF₃ ( 4 ) and Et? Zn? OC(O)CF(MeO)CF₃ ( 5 ) in CH₂Cl₂ showed an unexpected trans-selectivity in the ring closure to cyclopentane derivatives (see Scheme 2 and Table 1). This strong trans-selectivity is in contrast with the corresponding known Zn-ene reaction using Et₂Zn in Et₂O which shows a high cis-selectivity (Table 1). The probable radical origin of the observed trans-selectivity is discussed. The Zn-ene reaction products of the type R? Zn? OSO₂CF₃ could be derivatized by the known protonation, iodination, and cyanation yielding 8–10 (Scheme 4 and Table 2), these derivatizations could furthermore be extended by allylation and oxidation reaction (→ 13, 15 , and 16 ; see Scheme 5).     

I?N  S  N?I – Darstellung und Struktur

I? N ? S ? N? I, Preparation and Reactivity I? N ? S ? N? I is prepared form IN[Si(CH₃)₃]₂ by reaction with SF₄. It is a shock sensitive yellow powder, that appears in brown crystals after recrystallisation from CH₂Cl₂. The crystal structure reveals a syn-anti conformation for the molecule. Due to I … N contacts a layer lattice is formed.     

Synthese neuer Aminofluorsilane,sowie Alkoxylierung von Bis (trimethylsilyl)-amino-fluorsilanen

The reaction of aminofluorsilanes of the type (R=H,F) (Me ₃Si)₂N?SiF₂R with two moles of ammonia, or of a mono- or dialkylamine, yields the corresponding amino-compounds, e.g. (Me ₃Si)₂N?Si(F)R?NH₂, (Me ₃Si)₂N?Si(F)R?NHR′ and (Me ₃Si)₂N?Si(F)R?NR₂′ (R′=Me, Et). Analogous products are obtained by reaction of the aminofluorosilanes with lithium salts of amines with bulky organic substituents in a 1 : 1 molar ratio. Alkoxy- and aryloxyaminofluorosilanes are prepared by the reaction of sodium alcoholates and sodium phenolate with (Me ₃Si)₂N?Si(F₂)R (R=H, C₂H₃, C₂H₅, C₆H₅). The i.r.-, mass-,¹H- and¹⁹F-NMR spectra of the above compounds are reported.