Darstellung und Eigenschaften von N,N-Dialkyl-allylaminoboran-Addukten und N,N-Dimethyl-aminopropylboran

Synthesis and Properties of N,N-Dialkyl-allylaminoboranes and N,N-Dimethylaminopropylborane Complexes of the type H₃B ← NR₂(CH₂CH?CH₂) (R?CH₃ I , C₂H₅ II ) are formed by reaction of Li[BH₄] with dialkylallylammonium salts. By addition of AlCl₃ I can be transformed into the chelate-stabilized N,N-dimethyl-aminopropylborane III . The i.r.-, ¹H, ¹³C-n.m.r. and mass-spectra of I – III are reported and discussed.     

Fluoridolyse von N-Phosphorylphosphazenen

Fluoridolysis of N-Phosphoryl Phosphazenes In the reaction of the N-phosphoryl phosphazenes X₃P?N? P(Y)X₂ (X = Cl, PhO, Et₂N, CF₃CH₂O, PrS, Ph; Y = O, S) ( 1 – 18 ) with Et₃N · nHF (n ≈? 3 or 0.6) fluoro derivatives of N-phosphoryl phosphazenes (see table 2) as well as N-phosphorylated imiddotetrafluorophosphates, [F₄P?N? P(Y)Cl₂]^? (Y = O, S), and imidopentafluorophosphates, [F₅P? N? P(Y)X₂]^2? or [F₅P? NH? P(O)X₂]^? (see table 3), are formed. t-BuNHPCl₂?N? POCl₂ reacts in acetonitrile with Et₃N or i-Pr₂EtN to form a product, representing probably the diazadiphosphetine ( 5 b ).     

Nitrosyl-tetrachloro-dichlorphosphato-molybdat(+II); Darstellung,IR-Spektrum und Kristallstruktur von (AsPh4)2[Mo(NO)Cl4(O2PCl2)]

Nitrosyl-tetrachloro-dichlorophosphate-molybdate(+II); Preparation, I.R. Spectrum and Crystal Structure of (AsPh₄)₂[Mo(NO)Cl₄(O₂PCl₂)] The title compound is prepared by the reaction of AsPh₄[Mo(NO)Cl₄] with AsPh₄? [PO₂Cl₂] in dichloromethane solution. It forms orange crystals which are only little sensitive to moisture. The complex crystallizes triclinic in the space group P1 with two formula units in the unit cell. The structure was solved by X-ray diffraction methods (2498 observed, independent reflexions, R = 5.4%). The compound consists of AsPh₄^⊕ cations and [Mo(NO)Cl₄(PO₂Cl₂)]^2? anions. The NO ligand is coordinated in linear array \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {{\rm MO}}\limits^ \ominus = \mathop {\rm N}\limits^ \oplus = {\rm O}(177^{\circ}) $\end{document}. The dichlorophosphate group is coordinated in trans position to the NO ligand with one of its oxygen atoms. The Mo?N bonding of the NO ligand causes the bond angle NMoCl of 93.2° in average. The IR spectrum is recorded and assigned.     

Trägerfixierte Organometallkomplexe. VI. Charakterisierung und Reaktivität Polysiloxan-gebundener (Ether-phosphan)ruthenium(II)-Komplexe

Supported Organometallic Complexes. VI. Characterization und Reactivity of Polysiloxane-Bound (Ether-phosphane)ruthenium(II) Complexes The ligands PhP(R)CH₂D [R = (CH₃O)₃Si(CH₂)₃; D = CH₂OCH₃ ( 1b ); D = tetrahydrofuryl ( 1c ); D = 1,4-dioxanyl ( 1d )] have been used to synthesize (ether-phosphane)ruthenium(II) complexes, which have been copolymerized with Si(OEt)₄ to yield polysiloxane-bound complexes. The monomers cis,cis,trans-Cl₂Ru(CO)₂(P ～ O)₂ ( 3b ) and HRuCl(CO)(P ～ O)₃ ( 5b ) were treated with NaBH₄ to form cis,cis,trans-H₂Ru(CO)₂(P ～ O)₂ ( 4b ) and H₂Ru(CO)(P ～ O)₃ ( 6b ), respectively (P ～ O = η¹-P coordinated; = η²- coordinated). Addition of Si(OEt)₄ and water leads to a base catalyzed hydrolysis of the silicon alkoxy-functions and a precipitation of the immobilized counterparts 4b ′, 6b ′. The polysiloxane matrix resulting by this new sol gel route has been described under quantitative aspects by ²⁹Si CP-MAS NMR spectroscopy. 4b ′ reacts with carbon monoxide to form Ru(CO)₃(P ～ O)₂ ( 7b ′). Chelated polysiloxane-bound complexes Cl₂Ru( )₂ ( 9c ′, d ′) and Cl₂Ru( )(P ～ O)₂ ( 10b ′, c ′) have been synthesized by the reaction of 1b–c with Cl₂Ru(PPh₃)₃ ( 8 ) followed by a copolymerization with Si(OEt)₄. The polysiloxane-bound complexes 9c ′, d ′ and 10b ′, c ′ react with one equivalent of CO to give Cl₂Ru(CO)( )(P ～ O) ( 12b ′– d ′). Excess CO leads to the all-trans-complexes Cl₂Ru(CO)₂(P ～ O)₂ ( 14b ′– d ′), which are thermally isomerized to cis,cis,trans- 3b ′– d ′. The chemical shift anisotropy of ³¹P in crystalline Cl₂Ru( )₂ ( 9a , R = Ph, D = CH₂OCH₃) has been compared with polysiloxane-bound 9d ′ indicating a non-rigid behavior of the complexes in the matrix.     

Synthese und Kristallstruktur von Alkalimetalldiamidodioxosilicaten M2SiO2(NH2)2 mit M ≙ K,Rb und Cs

Synthesis and Crystal Structure of Alkali Metal Diamido Dioxosilicates M₂SiO₂(NH₂)₂ with M ? K, Rb and Cs SiO₂ – α-quartz – reacts with alkali metal amides MNH₂ (M ? K, Rb, and Cs) in molar ratios from 1:2 to 1:10 at 450°C ≤ T ≤ 600°C and P(NH₃) = 6 kbar in autoclaves to diamidodioxosilicates M[SiO₂(NH₂)₂]. Crystals of the colourless compounds which hydrolyze rapidly were investigated by x-ray methods. Following data characterize the structure determination on the isotypic compounds: The structures of the diamidodioxosilicates are closely related to the β? K₂SO₄ type. They contain isolated [SiO₂(NH₂)₂]^2? ions. K⁺ ions and hydrogen bridge bonds N? H…?O (with 2.68 Å ≤ d(N…?O) ≤ 2.78 Å for the K compound) connect the tetrahedral anions.     

Mechanism of pyrolysis of C2Cl6

Using published data on the kinetics of pyrolysis of C₂Cl₆ and estimated rate parameters for all the involved radical reactions, a mechanism is proposed which accounts quantitatively for all the observations: The steady-state rate law valid for after about 0.1% reaction is and the reaction is verified to proceed through the two parallel stages suggested earlier whose net reaction is A reported induction period obtained from pressure measurements used to follow the rate is shown to be compatible with the endothermicity of reaction A, giving rise to a self-cooling of the gaseous mixture and thus an overall pressure decrease. From the analysis, the bond dissociation energy DH⁰(C₂Cl₅? Cl) is found to be 70.3 ± 1 kcal/mol and ΔH_f300⁰(·C₂Cl₅) = 7.7 ± 1 kcal/mol. The resulting π? bond energy in C₂Cl₄ is 52.5 ± 1 kcal/mol.     

Zwei neue Alkylimido-methylgallane mit Käfigstruktur

Two New Alkylimido-Methylgallanes with Cage Structure The tetrameric alkylimido-methylgallanes (MeGa? NR)₄ (R = CH(CH₃)₂ ( ⁱPr), C(CH₃)₃ ( ^tBu) and Me = CH₃) have been prepared by pyrolyses of the dimeric amido compounds (Me₂Ga? N(H)R)₂ at 250–260°C. The mass, NMR and vibrational spectra are discussed, they prove almost identical structures of the skeletons. The X-Ray structure determination of (MeGa? N^tBu)₄ shows four heterocubane molecules in the trigonal unit cell (space group P3 c1, a = b = 1061.7(1), c = 3191.8(5) pm) and two disordered benzene solvate molecules. The Ga? N bonds range between 198.4 to 199.9 pm, the Ga? N? Ga and N? Ga? N bond angles lie between 90.6 to 91.4 and 88.6 to 89.2°, respectively. The structure was refined to an R₁(R₂)-value of 0.049 (0.057).     

The reaction of 2,5-dimethylpyrrole with O2(a1Δg) in the gas phase

The chemical reaction of 2,5-dimethylpyrrole (C₆H₉N) with O₂(¹Δ_g) was studied in the gas phase in an isothermal flow reactor at room temperature and low pressures. The C₆H₉N concentration profiles were studied under pseudo-first order conditions [C₆H₉N]_° ? [O₂(¹Δ_g)] with mass-spectrometric detection of C₆H₉N. O₂(¹Δ_g) was produced either in a microwave discharge or in a chemical reaction. The value for the rate constant: was measured. The rate constant is compared to the value obtained for the quenching process. The primary product C₆H₉NO₂ was detected by mass spectrometry and the reaction mechanism is proposed. The possibility of using this reaction as a gas phase titration reaction for O₂(¹Δ_g) is discussed.     

Die Gasmolekeln Pd2Al2Cl10 und PdAlCl5 als Begleiter von PdAl2Cl8

Gas Molecules Pd₂Al₂Cl₁₀ and PdAlCl₅ as Accompanists of PdAl₂Cl₈ Mass spectrometric observations using a double cell showed that the reaction of gaseous Al₂Cl₆ with solid PdCl₂ besides the known gaseous complex PdAl₂Cl₈ gives PdAlCl₅ and the unexpected complex Pd₂Al₂Cl₁₀. For the equilibrium (with ΔCp? ?1 cal/K) ΔH°(298) = 7.5 kcal/Mol and ΔS°(298) = 5.3 ± 2 cl have been obtained.     

Mutual combination of ClO radicals

The mutual combination reaction is proposed as the rate-limiting step in the removal of ClO radicals at moderate pressures. The third--order rate constants measured at room temperature were k₁(Ar) = 3.51 ± 0.14 × 10⁹ l²/mol²·ec; k₁(He) ≈ 2.8 × 10⁹ l²/mol²·sec, and k₁(O₂) ≈ 7.9 × 10⁹ l²/mol²·sec. There is also an independent second-order reaction for which k₃ ≈ 8 × 10⁶ l/mol·sec. A new absorption spectrum has been observed in the ultraviolet and attributed to Cl₂O₂. The extinction coefficient for Cl₂O₂ has been measured at six wavelengths, and, between 292 and 232 nm, it increases from 0.4 × 10³ to 2.9 × 10³ l/mol·cm. In the presence of the chlorine atom scavengers OClO or Cl₂O, Cl₂O₂ exists in equilibrium with ClO. The equilibrium constant Ke₁ = 3.1 ± 0.1 × 10⁶ l/mol at 298 K, and, with ΔS₁⁰ estimated to be ?133 ± 11 J/K·mol, ΔH₁⁰ = ?69 ± 3 kJ/mol and ΔH_f⁰(Cl₂O₂) = 136 ± 3 kJ/mol.     

Transferts Protoniques de Sels d'Ammonium Substitues—VIII: Sels de Pyridinium 4-Substitues

The deprotonation rate 1/τ of the title compounds, [4 – R – Py H]⁺, where R = NH₂, t-Bu, Me, Cl, Br or CN, is measured using the coalescence of the pyridinic α-protons, in a mixture CF₃COOH/H₂O/HClO₄ of variable acidity Ho, at 38°C. 1/τ is a linear function k/ho of the acidity 1/ho. k is approximately proportional to the water content and independent of the salt concentration, which seems to be evidence for an exchange with an intermediate pyridine hydrate, according to: . After a preliminary ionisation step: k values, like K_A, fit a Hammett relationship (ρ = 5,05), except for R ? NH₂, and are very sensitive to the nature of R (k = 3,44 × 10² for R = NH₂ and k = 3,14 × 10⁸ M^?1 s^?1 for R ? CN), while k_H values (10¹⁰ s^?1) are not.     

Cl-atom transfer from CFCl3 to the c-C6H11 radical. An indirect estimation of the CFCl2?Cl bond dissociation energy

The Cl-transfer reaction between CFCl₃ and c-C₆H₁₁ radicals (R) was studied in liquid cyclohexane (RH). The Arrhenius parameters for Cl abstraction were determined in the RH-CFCl₃ system versus the termination reaction between cyclohexyl radicals and competitively versus addition to C₂Cl₄ in the RH-CFCl₃-C₂Cl₄ system. The two sets of results are in very good agreement and give the following Arrhenius expression for the reaction R + CFCL₃ → RCl + CFCl₂ (2): where θ = 2.303RT in kcal/mol. Comparison with Cl-transfer data of other chloromethanes and chloroethanes shows that an increase in the C? Cl bond dissociation energy is the main cause of the reduced reactivity of CFCl₃. Based on a previously developed correlation, D(CFCl₂ ? Cl) is estimated to be equal to 74.4 kcal/mol.     

Über Chalkogenolate. 126. Untersuchungen über N-Cyanformamidinodithiocarbimidsäure 2. Thermisches Verhalten von Kalium-N-cyanformamidinodithiocarbimat in Lösung

On Chalcogenolates. 126. Studies on N-Cyanformamidino Dithiocarbimic Acid. 2. Thermal Behaviour of Potassium N-Cyanformamidino Dithiocarbimate in Solution The thermal treatment of K₂[S₂C?N? C(NH₂)?N? CN] in methanolic solution yields . The semi-hydrate has been isolated. It reacts with acid to form The reaction with H₃CI gives The compounds have been characterized by means of electron absorption, ¹H- and ¹³C-N.M.R., infrared, and mass spectra.     

Alkylidinphosphane und -arsane. II. Über die Oxydation des Lithoxy-methylidinphosphans PC?O?Li mit Schwefeldioxid und Iod

Alkylidynephosphanes and -arsanes. II. Oxydation of Lithoxy-methylidynephosphane P?C? O? Li with Sulphur Dioxide and Iodine At ?50°C bis(1,2-dimethoxyethane-O,O′)lithoxymethylidynephosphane P?C? O? Li(dme)₂^1,2) ( 1 a ) [2] reacts almost quantitatively with sulphur dioxide or iodine in 1,2-dimethoxyethane solution to give bis(1,2-dimethoxyethane-O,O′)bis(tetrahydrofuran-O)(μ-1,2,4-triphospholo[1,2-a]-1,2,4-triphosphol-1,3,5,7-tetraonato(2?)-O¹,O⁷:O³,O⁵)dilithium ( 2 a ) and lithium dithionite or iodide respectively. From the reaction with sulphur dioxide the crystalline, pale yellow compound is obtained in 40% yield. The formation of the unusual anionic heterocycle, built up of four PCO units, may be explained by an oxydation of two [P?C? O]^? species first, followed by a nucleophilic attack of two other [P?C? O]^? anions and coupled ?intramolecular”? cycloaddition reactions. In the ³¹P{¹H} nmr spectrum two phosphorus atoms each of coordination number two and three give rise to two triplets with chemical shift values of 81.4 and 36.9 ppm and a ²J(PP) coupling constant of 31.7 Hz; the ¹³C{¹H} resonances of the [(PCO)₄]^2? anion come from an ABMM′X spin system, the X part being discussed in detail. An X-ray structure determination {Cmcm; a = 1 277.14(11); b = 1 487.7(2); c = 1 556.94(11) pm at ?100 ± 3°C; Z = 4 molecules; R₁ = 0.061; wR₂ = 0.150} shows compound 2 a to crystallize as a neutral complex of symmetry mm2. The anionic part of the molecule consists of two anellated 1,2-dihydro-5-oxo-1,2,4-triphosphol-3-olate rings which share the central P? P unit (P1? P1′ 215.3; P1–C1 189.1; C1 P2 178.4; C1 O1 123.9pm; C1? P1? P1′ 98.4; Cl? P1? C1″ 91.2; C1 P2 C1′ 98.7°). Thus compound 2a may be assigned to the group of P? P heterocycles with a butterfly structure [71–75] as well as to the well-known diacylphosphanides taking into account, however, the unusual E,E configuration of both O?C? P?C? O^? units. The lithium cations are square pyramidally coordinate (Li? O 193.5 to 209.1 pm), each additionally binding an 1,2-dimethoxyethane and a tetrahydrofuran molecule.     

Organic Phosphorus Compounds 59. A new method for the synthesis of phosphonic dichlorides

Heating of thiophosphonic dichlorides, RP(S)Cl₂, R ? CH₃, C₂H₃, C₂H₅, with a molar equivalent of SOCl₂ under pressure at 150° for 5 to 8 h yields phosphonic dichlorides in quantitative yield. In addition sulfur and sulfur dichloride is formed according to the equation: This method is particularly useful for the preparation of CH₃P(O)Cl₂ since it was observed that chlorination of CH₃P(O)(OCH₃)₂ with PCl₅ yields CH₃OP(O)Cl₂ as a by-product which is difficult to separate from CH₃P(O)Cl₂. On the other hand chlorination of methylphosphonic acid with PCl₅ also gives pure CH₃P(O)Cl₂ .     

Convenient Synthesis of N-Trimethylsilylaminotitanium Trichlorides

Bis(N-trimethylsilylamino)plumbylenes 1 {[Me₃Si(R)N]₂Pb with R = ^tBu ( a ), Me₃Si ( b ), 9-(9-borabicyclo[3.3.1]nonyl) ( c )} react smoothly with an excess of TiCl₄ to give PbCl₂ and N-trimethylsilylaminotitanium trichlorides 3 a – c . In contrast, the analoguous reaction of the corresponding stannylenes 2 a – c leads to mixtures containing unidentified Ti^III compounds, the amides 3 a or 3 b , bis[bis(trimethylsilyl)amino]titanium dichloride 4 b and bis(amino)tin dichlorides 5 a – c . The crystal structure of 3 a was determined by X-ray structural analysis. Compound 3 a is a dimer in the solid state with distorted trigonal pyramidal surroundings of the titanium atoms. Each titanium atom bears two μ²-Cl ligands which are in axial (d_Ti–Cl = 250.7(1) pm) and equatorial positions (d_Ti–Cl = 247.0(1) pm) and two terminal chloro ligands, one in axial (d_Ti–Cl = 228.0(1) pm) and one in equatorial position (d_Ti–Cl = 221.1(1) pm). The equatorial Ti–N bonds are short (183.8(2) pm).     

Bildung und NMR-spektroskopische Charakterisierung von Alk-(ar-)oxyderivaten von Trichlorphosphazen-N-phosphoryldichlorid,Cl3PN?P(O)Cl2, Imido- und N-Methylimidodiphosphoryltetrachlord,Cl2P(O)NHP(O)Cl2 bzw. Cl2P(O)N(CH3)P(O)Cl2

Formation and N.M.R.-Spectroscopic Characterization of Alk-(ar-)oxy Derivatives of Trichlorophosphazene-N-phosphoryldichloride, Cl₃P?N? P(O)Cl₂, Imido- and N-Methylimidodiphosphoryltetrachloride, Cl₂P(O)NHP(O)Cl₂ and Cl₂P(O)N(CH₃)P(O)Cl₂ The ester chlorides and esters P₂NOCl_5?x(OR)_x (x = 1?5), P₂(NH)O₂Cl_4?x(OR)_x (x = 1–4) and P₂(NCH₃)O₂Cl_4–x(OR)_x (x = 1–4) derived from the title compounds by substitution of chlorine atoms by alk- or aroxy groups are characterized by their ³¹P-n.m.r. data. The possibilities for forming these compounds by alcoholysis, chloridolysis, dealkylation and P? N-bond formation are discussed.     

Kinetic and mechanistic study of the reactions of palladium(II) chlorocomplexes with ethylenediamine in aqueous acid medium

The complexes PdCl₄^2?, PdCl₃(H₂O)^?, and PdCl₃(Ac)^2?, in rapid equilibrium with each other under the adopted experimental conditions, react with ethylenediamine according to the experimental rate law A reaction scheme is proposed involving the reaction of enH⁺ with each of the above species, and the specific rate constants are computed. The activation parameters are given.     

Darstellung,Kristall- und Molekülstruktur von Triphenylphosphinoxidhydrochlorid (C6H5)3PO · HCl

On Phosphazo Compounds from Nitriles. IV. The Reaction of Tri, Di, and Monochloroacetonitrile with [Cl₃P?N? PCl₃]Cl. Improved Preparation of [Cl₃P?N? PCl₃]Cl Trichloroacetonitrile reacts with P₂NCl₇ to give Cl₃C? CCl₂? N?PCl₂? N?PCl₃ I , dichloroacetonitrile to give Cl₂C?CCl? N?PCl₂? N?PCl₃ II , and chloroacetonitrile to give the ring compound III . Preparation, n.m.r. and mass spectra of the new compounds are described. The mechanism of formation is discussed. An improved procedure for the preparation of P₂NCl₇ is given.     

Carbon–nitrogen bond dissociation energy values in C-nitrosocompounds

Measurements of the D(R? NO) bond strength in some C-nitrosocompounds have been made using an electron impact method. The appearance potential of the radical ion (R⁺) has been determined, the D(R? NO) bond energy being obtained from the relation The values obtained are: D(C₆H₅? NO) = 41 kcal/mole, D(t-C₄H₉? NO) = 34 kcal/mole, D(t-C₅H₁₁? NO) = 36 kcal/mole and D(i-C₃H₇? NO) = 36.5 kcal/mole. These values are in good agreement with the numerous estimations of Benson and coworkers and confirm that the C? N bond strength in C-nitrosocompounds is very much less than in nitrocompounds or in amines.