Einkernige und zweikernige Kupfer(I)‐Komplexe vom Typ LCuCl,LCu2Cl2 und LCu2ClX [L = P(C6H4CH2NMe2)3; X = Br,I]

The title compounds 3‐5 are accessible by treatment of P(C₆H₄CH₂NMe2)₃( 1 ) with CuX ( 2a : X = Cl, 2b : X = Br, 2c : X = I) in the ratio of 1:1 or 1:2 in very good yields. Reaction of 1 with equimolar amounts of 2a affords the copper(I) chloride [P(C₆H₄CH₂NMe2)₃]CuCl ( 3 ). With a further equivalent of 2a homobimetallic [P(C₆H₄CH₂NMe2)₃]Cu₂Cl₂ ( 4 ) is formed, which also can be synthesized by the reaction of 1 with two equivalents of 2a. Complex 3 reacts with CuX (X = Br, I)to afford [P(C₆H₄CH₂NMe2)₃]Cu₂ClX ( 5a : X = Br; 5b : X = I) in which mixed halides are present. The newly synthesized complexes 3‐5 were characterized by elemental analyses, by their IR‐, ¹H‐, ¹³C{¹H}‐ and ³¹P{¹H}‐NMR spectra as well as by mass spectrometrical studies. The solid‐state structures of complexes 3 and 4 are reported. Mononuclear 3 crystallizes in the monoclinic space group P2₁/c with the cell parameters a = 14.285(2), b = 10.853(2), c = 17.425(2) Å , β = 103.310(10)?, V = 2628.9(7) Å ³ and Z = 4 with 4053 observed unique reflections; R₁ = 0.0314. The crystal structure of 3 consists of monomeric molecules with planar coordinated copper(I) centres (CuClNP). Homobimetallic 4 crystallizes in the monoclinic space group P2₁/n with a = 23.905(4), b = 10.874(3), c = 25.314(5), β = 99.130(10)?, V = 6497(2) /Aring; ³ and Z = 4 with 9021 observed unique reflections; R₁ = 0.0480. In 4 one of two copper(I) centres possesses a distorted trigonal‐pyramidal environment, while the other one is almost square‐pyramidal coordinated. The Cu₂Cl₂ segment resembles to a building block which is set up by a contact ion pair consisting of Cu⁺ and [CuCl₂]^‐ , respectively.     

Thermodynamic Studies on the Complexation Reactions of copper(II) Macrocyclic Tetramine Complexes with Monodentate Ligands: I. RAC-5, 7, 7, 12, 14, 14-Hexamethyl-l, 4, 8, 11-Tetraazacyclotetradecane-Copper(II) (Blue) with-Halide Ions

The possibility of a trigonal bipyramidal structure for [Cu(tet b)X]⁺ (blue) (where X=Cl, Br, I) is supported by the observation of two distinct d-d bands, which are assigned as and d, d_xy→d and d_xz, d_yz→d transitions respectively. The stability constants for the formation of [Cu(tet b)X]⁺ (blue) from [Cu(tet b)]^z+ (blue) and X^? were determined by spectrophotometric method at 25°, 35° and 45°C. The corresponding δH° and δS° values were obtained from the variations of the stability constants between 25° and 45°C     

Schwingungsspektren und Normalkoordinatenanalysen der 92Mo-, 100Mo-, 35Cl- und 37Cl-Isotopomeren der Clusteranionen [(Mo6X)Y]2−; Xi = Cl,Br; Ya = F,Cl, Br,I

Vibrational Spectra and Normal Coordinate Analysis of ⁹²Mo, ¹⁰⁰Mo, ³⁵Cl, and ³⁷Cl Isotopomers of the Cluster Anions [(Mo₆X )Y ]^2?; Xⁱ = Cl, Br; Y^a = F, Cl, Br, I The tetrabutylammonium (TBA) salts of the octa-μ₃-halogeno-hexahalogeno-octahedro-hexamolybdate(2 –) anions [(Mo₆X)Y]^2?; Xⁱ = Cl, Br; Y^a = F, Cl, Br, I; have been synthesized using ⁹²Mo, ¹⁰⁰Mo, ³⁵Cl, and ³⁷Cl. The 10 K IR and Raman spectra reveal significant frequency shifts due to the isotopic labelling of the Mo₆ cage, the inner sphere halides X₈ⁱ or the outer sphere ligands Y, respectively. The normal coordinate analysis yields (Mo? Mo) valence force constants of about 1.3 to 1.5 mdyn/Å. For the μ₃-bonded halogenes Clⁱ and Brⁱ valence force constants of 1.1 resp. 1.0 mdyn/Å are calculated. The values for (Mo? Y^a) bonds are found in the usual halide range. The observed isotopic shifts are verified very well by the calculations, allowing detailed assignment of the IR and Raman spectra of these compounds for the first time.     

Transition-Metal Complexes with Bidentate Ligands Spanning trans-Positions. III. Preparation and solution studies of complexes [MX(1)] (M = Cu,Ag and Au; X = anionic ligand; 1 = 2, 11-bis(diphenylphosphinomethyl)benzo[c]phenanthrene)

The preparation of monomeric complexes [MX( 1 )] is reported where M = Cu, Ag, Au; X = I, Cl, NO₃, BF₄ and 1 = 2,11-bis(diphenylphosphinomethyl)benzo[c]phenanthrene. The solution structure of the complexes is discussed on the basis of molecular weight, conductivity and NMR. measurements. In acetonitrile and nitromethane, the nitrate and fluoroborate complexes exist as ionic species [M( 1 )]⁺X^? whereas the halo-complexes are present as equilibrium mixtures of ‘covalent’ and ‘ionic’ forms. All the complexes are associated in CH₂Cl₂-solutions. The values of ¹J show that this association in [Ag(NO₃) ( 1 )] and [Ag(BF₄) ( 1 )] is best described in terms of ion-pairing while that for species [AgX( 1 )] (X = Cl, Br and I) is mainly ‘covalent’ in nature. Evidence is presented for the formation of the complex ion [Ag(CH₃CN)_n( 1 )]⁺ in acetonitrile solution.     

Effect of fullerene on radical polymerization of vinyl acetate

The effect of fullerene (C₆₀) on the radical polymerization of vinyl acetate (VAc) with dimethyl 2,2′‐azobisisobutyrate (MAIB) in benzene was investigated kinetically and by means of ESR. C₆₀ was found to act as an effective inhibitor in the present polymerization. All C₆₀ molecules used were incorporated into poly(VAc) during polymerization. The relationship of induction period and initiation rate reveals that a C₆₀ molecule can trap 15 radicals formed in the polymerization system. The polymerization rate (R_p) after the induction period is given by R_p = k [MAIB]^0.6 [VAc]^2.0 (60 °C), which is similar to that observed in the absence of C₆₀. Stable fullerene radical (C) was observed in the polymerization system by ESR. The C concentration increased with time and was then saturated. The saturation time well corresponds to the induction period observed in the polymerization. About 20% of C₆₀ molecules added could survive as stable C. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2572–2578, 2000     

Solubility and hydrolysis of HCFC‐22 (CHF2Cl): Upward revision of rate constants for aqueous reactions of CHF2Cl with OH− at elevated temperature

Henry's law constants of CHF₂Cl in water at temperature T in K, K_H(T) in M atm^?1, were determined to be ln(K_H(T))=?(11.1±1.5)+((2290±500)/T) at 313–363 K by means of a phase ratio variation headspace method. The temperature‐dependent rate constants for aqueous reactions of CHF₂Cl with OH^?, k(T) in M^?1 s^?1, were also determined to be 3.7×10¹³exp(?(11, 200/T)) at 313–353 K, by considering the gas–water equilibrium, the aqueous reaction at room temperature, and liquid‐phase diffusion control. The liquid‐phase diffusion control was approximated with a one‐dimensional diffusion first‐order irreversible chemical reaction model. The k(T) value we determined is 10 times (at 353 K) or 3 times (at 313 K) as large as the value reported (R. C. Downing, Fluorocarbon Refrigerants Handbook, Prentice Hall: Englewood Cliffs, NJ, 1988). This upward revision of k(T) indicates that the removal efficiency of CHF₂Cl directly through the hydrolysis (CHF₂Cl + OH^?) is higher than previously expected at temperatures, such as 353 K, relevant to wet flue gas cleaning systems for ozone‐destruction substance‐destruction facilities. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 639–647, 2011     

Structural Comparison of Oligoribonucleotides and Their 2′-Deoxy-2′-fluoro Analogs by heteronuclear NMR spectroscopy

1-(2′-Deoxy-2′-fluororibofuranosyl)pyrimidines were synthesized and incorporated into an RNA oligonucleotide to give 5′-r[C_fGC_f(U_fU_fC_fG)GC_fG]-3′ (C_f: short form of C = 2′-deoxy-2′-fluorocytidine; U_f: short form of U = 2′-deoxy-2′-fluorouridine). The oligomer was investigated by means of UV, CD, and NMR spectroscopy to address the question of how F-labels can substitute ¹³C-labels in the ribose ring. Through-space (NOE) and through-bond (scalar couplings) experiments were performed that make use of the ameliorated chemical-shift dispersion induced by ¹⁹F as an alternative heteronucleus. A comparison of the structures of fluorinated vs. unmodified oligomer is given. It turns out that the fluorinated oligonucleotide exists in a 14:3 equilibrium between a hairpin and a duplex conformation, in contrast to the unmodified oligonucleotide which predominantly adopts the hairpin conformation. Furthermore, the fluorinated hairpin structure adopts two distinct conformations that differ in the sugar conformation of the U and C nucleoside units, as detected by the ¹⁹F-NMR chemical shifts. The role of the 2′-OH group as stabilizing element in RNA secondary structure is discussed.     

Barriers to internal rotation in neopentylbenzenes substituted on the benzyl group. A 13C NMR band shape study

Two series of neopentylbenzenes with one or two substituents on the benzyl group have been synthesized. In one series the substituents were H, F, Cl, Br, I, OCH₃, OCOCH₃, OSi(CH₃)₃ CH₃ and CH₂CH₃, and in the other OH and R [R ? H, CH₃, CH₂CH₃, (CH₂)₃CH₃, CH(CH₃)₂ and C(CH₃)₃]. Barriers to internal C? C and C? C rotation have been estimated by ¹³C NMR band shape methods. Estimated barriers were found to increase as the size of the substituent increases. The results are discussed in terms of possible initial and transition states, based on summations of results from molecular mechanics (MM) calculations, using the Allinger MMP1 program. Barriers estimated experimentally are compared with results from other systems found in the literature.     

Darstellung,Kristallstruktur und spektroskopische Eigenschaften der Clusteranionen [(Mo6Br)X]2− mit Xa = F,Cl, Br,I

Synthesis, Crystal Structure and Spectroscopic Properties of the Cluster Anions [(Mo₆Br )X ]^2? with X^a = F, Cl, Br, I The tetrabutylammonium (TBA), tetraphenylphosphonium (TPP) and tetraphenylarsonium (TPAs) salts of the octa-μ₃-bromo-hexahalogeno-octahedro-hexamolybdate(2?) anions [(Mo₆Br)X]^2? (X^a = F, Cl, Br, I) are synthesized from solutions of the free acids H₂[(Mo₆Br)X] · 8 H₂O with X^a = Cl, Br, I. The crystal structures show systematic stretchings in the Mo? Mo bond length and a slight compression of the Brⁱ₈ cube in the F^a to I^a series. The cations do not change much. The i.r. and Raman spectra show at 10 K almost constant frequencies of the (Mo₆Brⁱ₈) cluster vibrations, whereas all modes with X^a ligand contribution are characteristically shifted. The most important bands are assigned by polarization measurements and the force constants are derived from normal coordinate analysis. The ⁹⁵Mo nmr signals are shifted to lower field with increasing electronegativity of the X^a ligands. The fluorine compound shows a sharp ¹⁹F nmr singlet at ?184.5 ppm.     

Three‐Coordinate Nickel(I) Complexes Stabilised by Six‐, Seven‐ and Eight‐Membered Ring N‐Heterocyclic Carbenes: Synthesis,EPR/DFT Studies and Catalytic Activity

Comproportionation of [Ni(cod)₂] (cod=cyclooctadiene) and [Ni(PPh₃)₂X₂] (X=Br, Cl) in the presence of six‐, seven‐ and eight‐membered ring N‐aryl‐substituted heterocyclic carbenes (NHCs) provides a route to a series of isostructural three‐coordinate Ni^I complexes [Ni(NHC)(PPh₃)X] (X=Br, Cl; NHC=6‐Mes 1 , 6‐Anis 2 , 6‐AnisMes 3 , 7‐o‐Tol 4 , 8‐Mes 5 , 8‐o‐Tol 6 , O‐8‐o‐Tol 7 ). Continuous wave (CW) and pulsed EPR measurements on 1 , 4 , 5 , 6 and 7 reveal that the spin Hamiltonian parameters are particularly sensitive to changes in NHC ring size, N substituents and halide. In combination with DFT calculations, a mixed SOMO of ∣3d〉 and ∣3d〉 character, which was found to be dependent on the complex geometry, was observed and this was compared to the experimental g values obtained from the EPR spectra. A pronounced ³¹P superhyperfine coupling to the PPh₃ group was also identified, consistent with the large spin density on the phosphorus, along with partially resolved bromine couplings. The use of 1 , 4 , 5 and 6 as pre‐catalysts for the Kumada coupling of aryl chlorides and fluorides with ArMgY (Ar=Ph, Mes) showed the highest activity for the smaller ring systems and/or smaller substituents (i.e., 1 > 4 ≈ 6 ? 5 ).     

Kinetics and mechanisms of substitution reactions with sulfur-containing nucleophiles in aqueous acid solutions. I—rates of reactions of some tetrahalopalladate (II) anions with thiourea and selenourea

The activation energy parameters for the reaction of PdX (X=Cl^?, Br^?) in aqueous halide acid solution with thiourea (tu) and selenourea (seu) have been determined. High rates of reaction parallel low enthalpies and appreciable negative entropy of activation. The rate law in each case simplifies to k_obs=k[L] where L=tu or seu, and only ligand-dependent rate constants are observed at 25°C. The ligand-dependent rate constants for the first identifiable step in the PdCl + X system is (9.1±0.1) × 10³ M^?1 sec^?1 and (4.5±0.1) × 10⁴ M^?1 sec^?1 for X=tu and seu, respectively, while for the PdBr + X system it is (2.0±0.1) × 10⁴ M^?1 sec^?1 and (9.0±0.1) × 10⁴ M^?1 sec^?1 for X=tu and seu, respectively.     

Gas‐phase reaction of Cl with dimethyl sulfide: Temperature and oxygen partial pressure dependence of the rate coefficient

The kinetics of the reaction of Cl atoms with dimethyl sulfide has been investigated using a relative rate technique. Experiments were performed with oxygen partial pressures of 0, 200, and 500 mbar at a total pressure of 1000 mbar (N₂ + O₂) over the temperature range 283–308 K in a 1080 L reactor using long path in situ Fourier transform infrared absorption spectroscopy to monitor the reactants. The 254 nm photolysis of trichloroacetyl chloride was used as the Cl atom source. Three reference hydrocarbons, cyclohexane, n‐butane, and propene were employed. Good agreement was found between the rate coefficients determined using the different reference compounds. The rate coefficients were found to decrease with increasing temperature at constant O₂ pressure and increase moderately with increasing O₂ partial pressure at constant temperature. The temperature dependences of the Cl atom reaction with dimethyl sulfide for the three O₂ partial pressure investigated can be expressed by the simple Arrhenius expressions: k = (4.22 ± 1.78) × 10^?13 exp((1968 ± 379)/T), k = (5.42 ± 1.85) × 10^?13 exp((1946 ± 381)/T), and k = (6.90 ± 2.04) × 10^?13 exp((1912 ± 381)/T). The errors are a combination of the 2σ statistical errors from the kinetic data analysis plus an estimated systematic error that includes the error in the reference hydrocarbon. The mechanistic implications of the results are discussed. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 37: 66–73, 2005     

Über die Reaktion von Schwefel mit Aminen und Formaldehyd. Eine neue Methode zur Herstellung von Thioformamiden und Dithiocarbamaten

The reaction of sulfur with primary or secondary amines and formaldehyde has been studied. A simple one step process for the preparation of thioformamides (RR′NCHS; R ? H, R′ ? CH₃, C₂H₅; R ? R′ ? CH₃, C₂H₅; R+R′ ? ? (CH₂), ? (CH₂), ? C₂H₄OC₂H) and the amine salts of N, N-dialkyl-dithiocarbamic acids (R₂NCS₂ · H₂NR₂, R ? CH₃, C₂H₅, C₄H₉; R₂ ? ? (CH₂), ? (CH₂), ? C₂H₄OC₂H) is reported. In addition, the isolation of diethylamidosulfoxylic acid, (C₂H₅)₂NSOH · 1/2 H₂O, the first derivative of a new class of compounds, is described. The physical properties and the ¹H-NMR. spectra of the above mentioned compounds are given.     

Complexes of 3,3′-Oxybis[(diphenylphosphino)methylbenzene] with Ni(II), Pd(II), Pt(II), Rh(I), and Ag(I). How Important is Backbone Rigidity in the Formation of trans-Spanning Bidenatate Chelates??

The bidentate diphosphine ligand, 3,3′-oxybis[(dipenylphosphino)methylbenzene] ( 1 ) forms monomeric, trans-square-planar complexes MX₂( 1 ) (M = Ni, Pd, Pt; X = Cl^?, Br^? I^?, and, in part, N, NCS^?, CN^?, NO) as well as Pt(H)Cl( 1 ), Pt(H)Br( 1 ), and RhCl(CO)( 1 ). Polymeric species have been observed with substitutionally inert metal centres: trans-[PtCl₂( 1 )]₂ and cis-[PtCl₂( 1 )]_n (mean value of n ≈ 4–5) ³¹P-NMR, and selected IR and UV/VIS parameters are reported. Ligand 1 shows a marked preference for trans-spanning and monomeric chelate formation, despite its various degrees of freedom of internal rotation in the lignad backbone. The readily available ligand 1 as well as analogues with other donor atoms, therefore, appear useful in most potential applications of trans-spanning chelate ligands. The crystal structure of AgCl( 1 )·0.5 (CH₃)₂C?O·0.39 C₆H₁₂ (space group C2/c,a = 21.02 Å, b = 14.57 Å, c = 24.79 Å, β = 99.77°, V = 7531.4 ų, Z = 8) confirms the presence of three-coordinate Ag( I ), with a coordination intermediate between a trigonal-planar and a T-shaped geometry (P-Ag-P = 145.61(8)°).     

Zum thermischen Verhalten der Hydrogensulfate des Magnesiums,Calciums, Strontiums und Bariums

On the Thermal Behaviour of the Hydrogen Sulfates of Magnesium, Calcium, Strontium and Barium The thermal behaviour of the solvent-free crystals of alkaline earth hydrogen sulfates has been investigated. The DTA and TG curves of M^II(HSO₄)₂ indicate a decomposition following the equation Thermal treatment of Mg(HSO₄)₂ in static gas atmosphere yields α-MgSO₄ which is transformed to α-MgSO₄ at higher temperature. Contrary to that in dynamic gas atmosphere direct decomposition to α-MgSO₄ can be observed. T = 356°C, T = 204°C, T = 175°C, T = 156°C. The strong difference between the peak temperatures of Mg(HSO₄)₂ and the other alkaline earth hydrogen sulfates may be explained not only through the higher covalency of the bondings in the Mg compound but, especially, through differences of their structures. Whereas the hydrogen sulfates of Ca, Sr, and Ba contain chains of edge-linked M^IIO₈ polyhedra, in Mg(HSO₄)₂ exist isolated MgO₆ octahedra.     

Cs[Er10(C2)2]I18 und [Er10(C2)2]Br18: zwei neue Beispiele für „reduzierte”︁ Halogenide der Lanthanide mit isolierten [M10(C2)2]-Clustern

Cs[Er₁₀(C₂)₂]I₁₈ and [Er₁₀(C₂)₂]Br₁₈: Two New Examples for Reduced Halides of the Lanthanides with Isolated [M₁₀(C₂)₂] Clusters Cs[Er₁₀(C₂)₂]I₁₈ is obtained from the reaction of ErI₃ with caesium and carbon in sealed tantalum containers at 700°C and [Er₁₀(C₂)₂]Br₁₈ through the metallothermic reduction of ErBr₃ with rubidium in the presence of carbon at 750°C in sealed niobium containers. The crystal structures {Cs[Er₁₀(C₂)₂]I₁₈: triclinic, P1 ; a = 1 105.2(8) pm, b = 1 112.0(7) pm; c = 1 122.9(8) pm; α = 66.91(3)°, β = 87.14(3)°; γ = 60.80(3)°; Z = 1; R = 0.049, R_w = 0.043; [Er₁₀(C₂)₂]Br₁₈: monoclinic, P2₁/n, a = 971.8(6) pm, b = 1 623.4(9) pm, c = 1 163.8(6) pm, β = 104.00(6)°; Z = 2; R = 0.077, R_w = 0.057} contain isolated dimeric [Er₁₀(C₂)₂] clusters. Due to the inclusion of C₂ units, the octahedra are elongated in the direction of the pseudo C₄ axis. The connecting edges of the two octahedra are exceptionally short (316.7 pm and 314.8 pm respectively). The dimeric units are connected via X^i?a and X^a?i (X = Br, I) bridges according to [Er₁₀(C₂)₂XX]X. Cs⁺ is surrounded by a cuboctahedron of iodide ions in Cs[Er₁₀(C₂)₂]I₁₈.     

Die Gadoliniumcarbidhalogenide Gd4C2X3 (X = Cl,Br)

The Gadolinium Carbide Halides, Gd₄C₂X₃ (X = Cl, Br) The compounds Gd₄C₂X₃ (X = Cl, Br) and Tb₄C₂Br₃ have been prepared by reaction of the metals (RE), REX₃, and C in sealed Ta capsules at 1 100° and 1 300°C, respectively. Monophasic samples of Gd₄C₂Br₃ and Tb₄C₂Br₃ were obtained by reacting stoichiometric mixtures of the starting materials for five days. The needle shaped crystals are bronze-coloured and sensitive to air and moisture. Gd₄C₂X₃ crystallizes in the space group Pnma (No. 62) with lattice constants a = 1 059.6(4), b = 368.4(1), c = 1 962.7(8) pm (Gd₄C₂Cl₃), a = 1 084.4(1), b = 373.0(1), c = 2 036.1(1) pm (Gd₄C₂Br₃). According to Guinier photographs, Tb₄C₂Br₃ is isotypic (a = 1 074.3(2), b = 370.6(1), c = 2 019.4(1) pm). In the crystal structure C is octahedrally coordinated by Gd. The Gd₆ octahedra are linked via common edges to form corrugated layers. The X-anions coordinate all free edges and corners of these layers and connect them via Xⁱ? Xⁱ contacts parallel [001]. Gd₄C₂Br₃ shows metallic conductivity. The magnetic susceptibility follows at high temperatures a Curie Weiss law with an effective moment of 7.95 μ_B. At temperatures below 50 K antiferromagnetic order is observed.     

Schwingungsspektren der Clusterverbindungen (M6X)X · 8 H2O,M = Nb,Ta; Xi = CI,Br; Xa = CI,Br, I

Vibrational Spectra of the Cluster Compounds (M₆X₁₂ⁱ) · 8H₂O, M = Nb, Ta; Xⁱ = Cl, Br; X^a = Cl, Br, I IR and, for the first time, Raman spectra at 80 K of the cluster compounds (M₆X)X · 8H₂O; M = Nb, Ta; Xⁱ = Cl, Br; X^a = Cl, Br, I, have been recorded, characterized by typical frequencies of the (M₆X) unit, which are only slightly influenced by the terminal X^a ligands. The most intense line with the depolarisation ≈? 0.2 in all Raman spectra is caused by inphase movement of all atoms and assigned to the symmetric metal-metal vibration v₁, observed for the clusters (Nb₆Cl) at 233–234, for (Nb₆Br) at 186–187, for (Ta₆Cl) at 199–203, and for (Ta₆Br) at 176–179 cm^?1. The IR spectra exhibit in the same series intense bands at 233, 204, 207, and 179 cm^?1, assigned to the antisymmetric metal-metal vibration. The metal-metal frequencies are significantly higher than discussed before. The tantalum clusters show on excitation with the krypton line 647.1 nm in the region of a d–d transition at 645 nm a resonance Raman effect with series of overtones and combination bands. In case of (Ta₆Br) another polarisized band is observed at 229 cm^?1 and assigned to the Ta? Brⁱ vibration v₂. From the progressions of v₁ and v₂ anharmonicity constants of about ?3 cm^?1 are calculated indicating a strong distortion of the potential curves.     

Photoelektronen-Spektren und Moleküleigenschaften. 132 [1, 2]. Trifluormethylsulfan und Derivate F3CSX (X  CF3, Cl,Br, I)

Photoelectron Spectra and Molecular Properties. 132. Trifluoromethylsulfane and Derivatives F₃CSX (X ? CF₃, Cl, Br, I) The He(I) photoelectron spectra of trifluoromethylsulfane F₃CSH and its derivatives F₃CSX (X ? CF₃, Cl, Br, I) are assigned by Koopmans' correlations, IE = ?ε, with MNDO eigenvalues, by radical cation state comparison and based on resolved vibrational fine structures, which can' be discussed by MNDO FORCE calculations. The spin/orbit splitting in F₃CSI can be approximated by additional ITEREX-85 calculations. Gasphase thermolysis of the trifluoromethylhalogensulfanes F₃CSX at 10^?4 mbar yields decomposition temperatures, which decrease from X ? Cl to I, and as fragmentation products of presumably radical intermediates, in addition to the respective halogens X₂ and F₂C?S, also F₃CX as well as S₂ and CS₂ (X ?Cl, Br) are PE spectroscopically detected.     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von [(Mo6Br)Y]2−; Ya  CN,NCS

Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of [(Mo₆Br )Y ]^2?; Y^a ? CN, NCS By treatment of [(Mo₆Br)Br^a₆]^2? with AgNO₃ in acetone and addition of KCN or KNCS the hexacyano and hexaisothiocyanato derivates [(Mo₆Br)Y]^2?, Y^a ? CN, NCS are formed. X-ray structure determinations of (Ph₄P)₂ [(Mo₆Br)(CN)^a₆]·4H₂ O ( 1 ) (triclinic, spacegroup P1, a = 11.63(3), b = 11.85(1), c = 14.23(5) Å, α = 71.8(1)°, β = 67.6(3)°, γ = 62.8(1)°, Z= 1) and (n-Bu₄N)₂[(Mo₆Br ⁱ₈)(NCS)^a₆] · 2Et₂O ( 2 ) (monoclinic, spacegroup P2₁/n, a = 11.483(3), b = 16.348(5), c = 20.059(6) Å, β= 95.44(3)°, Z = 2) have been performed. The via C coordinated cyano ligands of ( 1 ) reveal facial groups with (MoCN) angles of 168.0–171,5° and 174.1°–175.7°. In ( 2 ) the via N coordinated isothiocyanato groups at the apical positions show MoNC-angles of 164.4°, the equatorial angles are 172.7–173.5°. Using the molecular parameters of the X-ray determinations the 10 K IR and Raman spectra of the (n-Bu₄N) cluster salts are assigned by normal coordinate analyses based on a modified valence force field. The valence force constants are f_d(MoMo) = 1.41 (CN^a), 1.43 (NCS^a), f_d (MoBrⁱ) = 0.97 (CN^a), 0.96 (NCS^a), f_d(MoC) = 1.62, f_d(Mo-N) = 2.09 mdyne/Å.