Uber die Reaktionen der Hexacarbonyle der VI. Nebengruppe mit Zinn (II)- und Germanium (II)-halogeniden

On Reactions of Subgroup. VI. Hexacarbonyls with Tin(II) and Germanium (II) Halides The neutral complexes M(CO)₅SnX₂ and M(CO)₅GeCl₂ (M = Cr, Mo, W; X = Cl, Br, J) have been prepared by a photochemical reaction between M(CO)₆ and SnX₂, or CsGeCl₃ in THF. The reaction of these compounds with [N(CH₃)₄]X (X = Cl, Br, J) in THF was found to lead to a series of anions [M(CO)₅SnX₃]^? or [M(CO)₅GeCl₃]^? (M = Cr, Mo, W; X = Cl, Br, J), some of which have previously been prepared. The physical properties and IR-spectra of the above compounds are discussed.     

Synthesis and reactivity of ω-haloalkyltin compounds

ω-Haloalkyltin trihalides, X(CH₂)_nSnX₃ (n ≧ 3; X = halogen) can readily be prepared in high yields by the direct reaction of stannous halides with α,ω-dihaloalkanes, catalysed by trialkylantimony compounds. The compounds are versatile starting materials for the synthesis of a variety of ω-functionallysubstituted organotin compounds R_3-mX_mSn(CH₂)_n Y (R = alkyl, phenyl; m = 0-3; X = Cl, Br, O; Y = Br, NMe₂, NEt₂, COOH, CHOHR, R₃Sn). ¹H-NMR spectral data for a series of such compounds are presented. The trends observed in the chemical shifts and the ¹¹⁹Sn—methyl proton coupling constants of Me_3-m Br_mSn(CH₂)_nBr (m = 0-3; n = 3-5) are discussed in terms of inductive effects. Intramolecular coordination between the ω-bromine atom and tin could not be demonstrated.     

Umsetzung von N-Trimethylmetall(IVb)-trialkylphosphiniminen mit Halogenwasserstoffen

Reaction of N-Trimethylmetal(IVb) Trialkylphosphine Imines with Hydrogen Halides Investigations of the reaction of N-trimethylmetal(IVb)-substituted phosphine imines with hydrogen have been carried out. With one mole of HX phosphonium halides of the general formula [R₃P? NH? MMe₃]^⊕X^? (R = CH₃, C₂H₅; M = Si, Ge, Sn; X = Cl, Br, J) are obtained. A second mole of HX causes M? N bond cleavage, yielding aminophosphonium halides, [R₃P? NH₂]^⊕X^?.     

Density functional theory study on the reactions of X− with CH3SY (X,Y = F,Cl, Br,I)

Gas‐phase anionic reactions X^? + CH₃SY (X, Y = F, Cl, Br, I) have been investigated at the level of B3LYP/6‐311+G (2df,p). Results show that the potential energy surface (PES) of gas‐phase reactions X^? + CH₃SY (X, Y = Cl, Br, I) has a quadruple‐well structure, indicating an addition–elimination (A–E) pathway. The fluorine behaves differently in many respects from the other halogens and the reactions F^? + CH₃SY (Y = F, Cl, Br, I) correspond to deprotonation instead of substitution. The gas‐phase reactions X^? + CH₃SF (X = Cl, Br, I), however, follow an A–E pathway other than the last two out going steps (COM2 and PR) that proceeds via a deprotonation. The polarizable continuum model (PCM) has been used to evaluate the solvent effects on the energetics of the reactions X^? + CH₃SY (X, Y = Cl, Br, I). The PES is predicted to be unimodal in the solvents of high polarity. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007     

Polarographie de quelques halogénures organostanniques dans le diméthylformamide

The polarographic behavior of compounds R_nSnX_4?n with R=CH₃, C₂H₅, C₆H₅; X=Cl,Br and n=0–3, on a dropping Hg electrode, in dimethylformamide, has been examined and for all cases, reduction pathways have been proposed; the most important features being: the disappearance of the second one-electron step for chlorotrimethyl(ethyl)tin, the observation of two one-electron steps for R₂SnBr₂ dibromides, the easy complexation of R₂SnCl₂ and RSnCl₃ compounds by chloride ions, and the discrete steps involving 2 and 1 electrons for tribromo(ethyl)tin.     

Structures and Properties of Spherical 90‐Vertex Fullerene‐Like Nanoballs

By applying the proper stoichiometry of 1:2 to [Cp^RFe(η⁵‐P₅)] and CuX (X=Cl, Br) and dilution conditions in mixtures of CH₃CN and solvents like CH₂Cl₂, 1,2‐Cl₂C₆H₄, toluene, and THF, nine spherical giant molecules having the simplified general formula [Cp^RFe(η⁵‐P₅)]@[{Cp^RFe(η⁵‐P₅)}₁₂{CuX}₂₅(CH₃CN)₁₀] (Cp^R=η⁵‐C₅Me₅ (Cp*); η⁵‐C₅Me₄Et (Cp^Et); X=Cl, Br) have been synthesized and structurally characterized. The products consist of 90‐vertex frameworks consisting of non‐carbon atoms and forming fullerene‐like structural motifs. Besides the mostly neutral products, some charged derivatives have been isolated. These spherical giant molecules show an outer diameter of 2.24 (X=Cl) to 2.26 nm (X=Br) and have inner cavities of 1.28 (X=Cl) and 1.20 nm (X=Br) in size. In most instances the inner voids of these nanoballs encapsulate one molecule of [Cp*Fe(η⁵‐P₅)], which reveals preferred orientations of π–π stacking between the cyclo‐P₅ rings of the guest and those of the host molecules. Moreover, π–π and σ–π interactions are also found in the packing motifs of the balls in the crystal lattice. Electrochemical investigations of these soluble molecules reveal one irreversible multi‐electron oxidation at E_p=0.615 V and two reduction steps (?1.10 and ?2.0 V), the first of which corresponds to about 12 electrons. Density functional calculations reveal that during oxidation and reduction the electrons are withdrawn or added to the surface of the spherical nanomolecules, and no Cu²⁺ species are involved.     

Selenoquinones Stabilized by Ruthenium(II) Arene Complexes: Synthesis,Structure, and Cytotoxicity

A new series of monoselenoquinone and diselenoquinone π complexes, [(η⁶‐p‐cymene)Ru(η⁴‐C₆R₄SeE)] (R=H, E=Se ( 6 ); R=CH₃, E=Se ( 7 ); R=H, E=O ( 8 )), as well as selenolate π complexes [(η⁶‐p‐cymene)Ru(η⁵‐C₆H₃R₂Se)][SbF₆] (R=H ( 9 ); R=CH₃ ( 10 )), stabilized by arene ruthenium moieties were prepared in good yields through nucleophilic substitution reactions from dichlorinated‐arene and hydroxymonochlorinated‐arene ruthenium complexes [(η⁶‐p‐cymene)Ru(C₆R₄XCl)][SbF₆]₂ (R=H, X=Cl ( 1 ); R=CH₃, X=Cl ( 2 ); R=H, X=OH ( 3 )) as well as the monochlorinated π complexes [(η⁶‐p‐cymene)Ru(η⁵‐C₆H₃R₂Cl)][SbF₆]₂ (R=H ( 4 ); R=CH₃ ( 5 )). The X‐ray crystallographic structures of two of the compounds, [(η⁶‐p‐cymene)Ru(η⁴‐C₆Me₄Se₂)] ( 7 ) and [(η⁶‐p‐cymene)Ru(η⁴‐C₆H₄SeO)] ( 8 ), were determined. The structures confirm the identity of the target compounds and ascertain the coordination mode of these unprecedented ruthenium π complexes of selenoquinones. Furthermore, these new compounds display relevant cytotoxic properties towards human ovarian cancer cells.     

Electronic effects in octahedral π-allyliron complexes: 13C NMR spectra

¹³C NMR spectra have been studied for the three series of allyliron derivatives: (i) C₃HP₅Fe(CO)₃X (X = I, Br, Cl, ONO₂, OCOCH₃, OCOCF₃); (ii) 2-RC₃H₄Fe(CO)₃X (R = CH₃, Br; X = I, Br, Cl, ONO₂, OCOCF₃), and (iii) 1-RC₃H₄Fe(CO)₃X (R = CH₃, C₆H₅; X = Br, Cl, OCOCF₃). The spectra reveal the effect of the nature of the ligand X and substituent R on the chemical shifts of the allyl and carbonyl carbon atoms.     

Structure and Stability of Quaternary Ammonium Interhalides: Experimental and Quantum-Chemical Study

The electronic structure of a series of ammonium interhalides [R¹R²R³R⁴N]XI₂, where R¹ = CH₃, C₂H₅, C₃H₇, F, H; R² = R³ = R⁴ = CH₃, H; X = Cl, Br, I, was studied by ab initio calculations (RHF/3-21G, RHF/HW, MP2/HW). The thermodynamic stability of these compounds correlates with the strength of the hydrogen bond N-H···X and three-center interhalide bond X-I-I. Calculations confirmed that, in polar solvents, these compounds preferably decompose to [R¹R²R³R⁴N]⁺ and XI₂ ^- (with subsequent decomposition of the anion), and in nonpolar solvents, to the neutral species [R¹R²R³R⁴N]X and I2. The calculation results were compared to the experimental data obtained by single crystal X-ray diffraction, ¹H NMR spectroscopy, and spectrophotometry.     

FTIR spectroscopic study of the Cl- and Br-atom initiated oxidation of ethene

The reaction mechanism of the halogen (Cl and Br)-atom initiated oxidation of C₂H₄ was studied using the long path FTIR spectroscopic method in 700 torr of air at 296 ± 2 K. Among the major halogen-containing products were X? CH₂CHO, X? CH₂CH₂OH, and X? CH₂CH₂OOH (X = Cl or Br) which were shown to be formed via the self-reaction of the X? CH₂CH₂OO radicals, i.e., 2X? CH₂CH₂OO → 2X? CH₂CH₂O + O₂; (a) 2X? CH₂CH₂OO → X? CH₂CHO + X? CH₂CH₂OH + O₂ and (b) followed by X? CH₂CH₂O + O₂ → X? CH₂CHO + HO₂ and X? CH₂CH₂OO + HO₂ → X? CH₂CH₂OOH + O₂. From the observed yields of X? CH₂CHO and X? CH₂CH₂OH the branching ratios for reactions (a) and (b) were determined to be k_a/k_b = 1.35 ± 0.07(2σ) for both X = Cl and Br. In addition, the O₂-dependence of the rate constant for the Br + C₂H₄ reaction was determined by the relative rate technique as a function of O₂ partial pressure from 140 to 700 torr at 700 torr total pressure of N₂/O₂ diluent. Rate constants for the reactions of Cl-atoms with Cl-CH₂CHO and Br-atoms with Br-CH₂CHO were also determined to be [4.3 ± 0.2(2sigma;)] × 10^?11 and less than or equal to [1.83 ± 0.11(2σ)] × 10^?13 cm³ molecule^?1 s^?1, respectively.     

Neue Synthesewege für Organohalogenstibane

New Methods for Synthesis of Organohalogenostibanes Organohalogenostibanes RSbX₂ (R = CH₃, C₆H₅; X = Cl, Br) and R₂SbX (R = C₆H₅; X = Cl) are received in good yields by alkylation or arylation of the corresponding antimony halides with Pb(CH₃)₄, Sn(CH₃)₄, Sb(CH₃)₃, or Sb(C₆H₅)₃. These methods are better than those, described in the literature for preparation of the compounds.     

PMR of complexes of organohalostannanes with N-vinyl-N-ethylimidazole

The chemical shifts and spin-spin coupling constants of the protons of the vinyl and ethyl groups and of the imidazole ring in the PMR spectra of complexes R_4–n·SnX_n · mB, where R=C₂H₅, C₄H₉;X=Cl, Br, I; B is N-vinylimidazole or N-ethylimidazole; and n=1 (m=1) and 2 (m=2), are compared. The electronic and geometrical structures of these complexes are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 391–394, March, 1973.     

Phosphoniumsalze mit Hydrogendihalogenidanionen HCl2−, HBr2− Hl2− oder HBrCl−

Phosphonium Salts with Hydrogen Dihalide Anions HCl₂^?, HBr₂^?, HI₂^?, or HBrCl^? Phosphonium hydrogen dihalides [R₃PR′][XHY] (X = Y = Cl, Br, I; X = Br, Y = Cl) resp. [R₃PH]HBr₂ are obtained as extremely hydrolyzable crystals by reaction of phosphonium halides or tertiary phosphanes with hydrogen halide. According to IR spectroscopic results the solid compounds mostly contain anions [XHX]^? with symmetric hydrogen bonds. In solution ¹H NMR measurements show a slight (X = Cl, Br) or considerable (X = I) dissociation according to HX₂^? ? X^? + HX. On heating the solid compounds decompose with formation of hydrogen halide and [R₃PR′]X or [R₃PH]X. In this process the hydrogen bromidechlorides [R₃PR′][BrHCl] exclusively eliminate HCl. NMR studies (¹H und ³¹P) with solutions containing [R₃PH]HBr₂ (R = phenyl, 1-naphtyl) or HBr and Ph₃P in varying molar ratios show that a fast proton exchange between the competing Lewis bases R₃P and Br^? exists.     

Ionic Transformations in Extremely Nonpolar Fluorous Media: Easily Recoverable Phase‐Transfer Catalysts for Halide‐Substitution Reactions

Solutions of the fluorous alkyl halides R_f8(CH₂)_mX (R_fn=(CF₂)_n?1CF₃; m=2, 3; X=Cl, Br, I) in perfluoromethylcyclohexane or perfluoromethyldecalin are inert towards solid or aqueous NaCl, NaBr, KI, KCN, and NaOAc. However, halide substitution occurs in the presence of fluorous phosphonium salts (R_f8(CH₂)₂)(R_f6(CH₂)₂)₃P⁺X^? (X=I ( 1 ), Br ( 3 )) and (R_f8(CH₂)₂)₄P⁺I^? (10 mol %), which are soluble in the fluorous solvents under the reaction conditions (76–100 °C). Stoichiometric reactions of a) 1 with R_f8(CH₂)₂Br and b) 3 with R_f8(CH₂)₂I were conducted under homogenous conditions in perfluoromethyldecalin at 100 °C and yielded the same R_f8(CH₂)₂I/R_f8(CH₂)₂Br equilibrium ratio (≈60:40). This shows that ionic displacements can take place in extremely nonpolar fluorous phases and suggests a classical phase‐transfer mechanism for the catalyzed reactions. Interestingly, the nonfluorous salt (CH₃(CH₂)₁₁)(CH₃(CH₂)₇)₃P⁺I^? ( 4 ) also catalyzes halide substitutions, but under triphasic conditions with 4 suspended between the lower fluorous and upper aqueous layers. NMR experiments established very low solubilities in both phases, which suggests interfacial catalysis. Catalyst 1 is easily recycled, optimally by simple precipitation onto teflon tape.     

Trialkylgallium-halogeno-komplexe [R3GaX]− und [(R3Ga)2X]− mit X = F,Cl, Br

The preparation and vibrational spectra of the following complexes are reported: K[R₃GaF] (R = CH₃, C₂H₅), NMe₄[(R₃Ga)₂X] (R = CH₃, C₂H₅; X = F, Cl), NMe₄[Me₃GaBr], NMe₄[(Et₃Ga)₂Br].     

Carbon-13 NMR spectra of some o-carbonyl benzeneselenenyl derivatives

The ¹³C NMR signals have been assigned for some ortho-carbonyl benzene-selenenyl derivatives, COR.C₆H₄. Sex, where R = H, CH₃, OCH₃ and OC₂H₅ and X = Cl, Br, CN, SCN, SeCN and CH₃. The effects of the nature of R and X have been discussed.     

1-Haloethane-2,2-dithiols

Optimal conditions were found for the synthesis of 1-bromopropane-2,2-dithiol and 1-halo-2-aryl- ethane-2,2-dithiols by low-temperature acid-catalyzed hydrosulfurization of the corresponding 1-haloketones RCOCH₂X (R = CH₃, X = Br; R = C₆H₅, X = Cl; R = 4-CH₃C₆H₄, X = Cl; R = 4-CH₃C₆H₄, X = Br; R = 1-C_{1 0}H₇, X = Cl). Reaction paths and solvent effect are discussed.     

Dihalomethanes as Bent Bifunctional XB/XB‐Donating Building Blocks for Construction of Metal‐involving Halogen Bonded Hexagons

The dihalomethanes CH₂X₂ (X=Cl, Br, I) were co‐crystallized with the isocyanide complexes trans‐[MX^M₂(CNC₆H₄‐4‐X^C)₂] (M=Pd, Pt; X^M=Br, I; X^C=F, Cl, Br) to give an extended series comprising 15 X‐ray structures of isostructural adducts featuring 1D metal‐involving hexagon‐like arrays. In these structures, CH₂X₂ behave as bent bifunctional XB/XB‐donating building blocks, whereas trans‐[MX^M₂(CNC₆H₄‐4‐X^C)₂] act as a linear XB/XB acceptors. Results of DFT calculations indicate that all XCH₂–X???X^M–M contacts are typical noncovalent interactions with estimated strengths in the range of 1.3–3.2 kcal mol^?1. A CCDC search reveals that hexagon‐like arrays are rather common but previously overlooked structural motives for adducts of trans‐bis(halide) complexes and halomethanes.     

Coordination d'anions organophosphores: 1Ère partie. Complexes du zinc(II)

Twelve compounds of the type [ZnXL], where L^?1 is the anion {(C₂H₅O)₂POCHCOCH₂NR₂}^? with R = CH₃ or C₂H₅ and X = Cl, Br, I, NCO, NCS, NCSe, have been synthesized. For eleven, the unit-cell dimensions have been reported. Chemical bonding with the central zinc atom is discussed.     

Darstellung und schwingungsspektroskopische Untersuchungen von Alkyl- und Arylborhalogeniden

Preparation and Vibrational Spectra of Alkyl- and Arylboronhalides Organohaloboranes R_mBX_3?m (R = CH₃, C₂H₅; X = Cl, Br; m = 1–3) can be prepared from BX₃ and tetraalkyllead as alkylating agent Data of the vibrational spectra (i.r. and Raman) of R_nBY_3?n (Y = F, Cl and Br; n = 1–3) and C₆H₅BY₂ are tabulated and assigned. Mixed halides i. e. RBXY compounds are spectroscopically characterized.