Darstellung von Nonahalogenodiplatinaten(IV), [Pt2X9]−, X  Cl,Br Spektroskopische Charakterisierung,Normalkoordinatenanalyse und Kristallstruktur von (PPN)[Pt2Br9]

Preparation of the Nonahalogenodiplatinates(IV), [Pt₂X₉]^?, X ? Cl, Br Spectroscopic Characterization, Normal Coordinate Analysis, and Crystal Structure of (PPN)[Pt₂Br₉] On heating the tetrabutylammonium salts (TBA)₂[PtX₆], with trifluoroacetic acid the nonahalogenodiplatinates(IV) (TBA)[Pt₂X₉], with X ? Cl, Br are formed. The X-ray structure determination on (PPN)[Pt₂Br₉] (orthorhombic, space group Pca2, Z = 4) shows for the anions pairs of face-sharing octahedra with nearly D_3h symmetry. The mean terminal and bridging Pt? Br bond lengths are determined to be 2.42 and 2.52 Å, respectively. The electrostatic interaction of the Pt atoms results in the Pt? Pt distance of 3.23 Å and an elongation as it has been forecasted by the MO scheme for d⁶ systems. Using the structural data a normal coordinate analysis based on a general valence force field for [Pt₂Br₉]^? has been performed, revealing a good agreement of the calculated frequencies with the bands observed in the IR and Raman spectra. The stronger bonding of the terminal as compared to the bridging ligands is shown by the valence force constants, f_a(Br₁) = 1,55 > f_d(Br_b) = 0,93 mdyn/ Å.     

Darstellung,Schwingungsspektren und Normalkoordinatenanalyse der Decahalogenoditechnetate(IV), [Tc2X10]2−, X = Cl,Br

Preparation, Vibrational Spectra and Normal Coordinate Analysis of Decahalogenoditechnetates(IV), [Tc₂X₁₀]^2?, X = Cl, Br The reaction of [TcX₆]^2?, X = Cl, Br, with trifluoroacetic acid yield at room temperature the edge-sharing bioctahedral anions [Tc₂X₁₀]^2?, which IR and Raman spectra are assigned according to point group D_2h. Using the crystal data of isostructural osmium complexes a normal coordinate analysis based on a general valence force field has been performed for [Tc₂X₁₀]^2?, revealing a good agreement of the calculated frequencies with the bands observed in the IR and Raman spectra. The stronger bonding of the terminal as compared to the bridging ligands is shown by the valence force constants, f_d(TcX_t) > F_d(TcX_b).     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalysen von trans-(PNP)[TcCl4(Py)2] und trans-(PNP)[TcBr4(Py)2]

Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of trans-(PNP)[TcCl₄(Py)₂] and trans-(PNP)[TcBr₄(Py)₂] By reaction of (PNP)₂[TcX₆] with pyridine in the presence of [BH₄]^? (PNP)[TcX₄(Py)₂], X = Cl, Br, are formed. X-ray structure determinations on single crystals of these isotypic Tc^III complexes (monoclinic, space group P2₁/n, Z = 2, for X = Cl: a = 13.676(4), b = 9.102(3), c = 17.144(2) Å, β = 91.159(1)°; for X = Br: a = 13.972(2), b = 9.146(3), c = 17.285(4) Å, β = 90.789(2)°) result in the averaged bond distances Tc? Cl: 2.386, Tc? Br: 2.519, Tc? N: 2.132(3) (X = Cl) and 2.143(4) Å (X = Br). The two pyridine rings are coplanar and vertical to the X? Tc? X-axes, forming angles of 42.28° (X = Cl) and 43.11° (X = Br). Using the molecular parameters of the X-ray structure determination and assuming D_2h point symmetry, the IR and Raman spectra are assigned by normal coordinate analysis based on a modified valence force field. Good agreement between observed and calculated frequencies is obtained with the valence force constants f_d(TcCl) = 1.45, f_d(TcBr) = 1.035, f_d(TcN) = 1.37 (X = Cl) and 1.45 mdyn/ Å (X = Br), respectively.     

Polynuclear clusters of technetium. I. Synthesis,crystal and molecular structure of bromide octanuclear lrismatic and hexanuclear octahedral clusters of technetium

The synthesis, crystal and molecular structure of the first representatives of polynuclear technetium clusters are described. The composition of these clusters is: [Tc₈Br₄μ? Br₈]Br. 2H₂O; [H(H₂O)₂][Tc₈Br₄μ? Br₈]Br; [H(H₂O)₂]₂[Tc₈Br₄μ? Br₈]Br₂; [H₃O(H₂O)₃]₂[Tc₆Br₆μ₃? Br₅]; [(C₄H₉)₄N]₂[Tc₆Br₆μ₃? Br₅]; [H₃O₃]₂[Tc₆Br₆μ₃? Br₅]. 4 H₂O. It is shown that these clusters strongly differ in their structure from the known clusters of other d-elements. The crystal and molecular structure of hexabromotechetium acid (H₃O)₂TcBr₆ is studied too.     

Darstellung,Schwingungsspektren und Normalkoordinatenanalyse der Halogenonitrosylruthenate [Ru(NO)ClnBr5–n]2–, n = 0–5, sowie die Kristallstruktur von (CH2py2)[Ru(NO)ClBr4]

Syntheses, Vibrational Spectra, and Normal Coordinate Analysis of Halogenonitrosylruthenates [Ru(NO)Cl_nBr_5–n]^2–, n = 0–5, and the Crystal Structure of (CH₂py₂)[Ru(NO)ClBr₄] By treatment of [Ru(NO)Cl₅]^2– with anhydrous HBr in dichloromethane a mixture of [Ru(NO)Cl_nBr_5–n]^2–, n = 0–5, is formed, from which individual complexes can be separated by ion exchange chromatography on diethylaminoethyl cellulose. The X-Ray structure determination on a single crystal of (CH₂py₂)[Ru(NO)ClBr₄] (monoclinic, space group P2₁/c, a = 11.480(2), b = 10.175(4), c = 16.025(6) Å, β = 107.40(1)°, Z = 4) reveals, that the chlorine atom is trans positioned to the nitrosyl group. The low temperature IR and Raman spectra have been recorded of six complexes of the series (n-Bu₄N)₂[Ru(NO)Cl_nBr_5–n], n = 0–5, and are assigned by normal coordinate analysis. A good agreement between observed and calculated frequencies is achieved. The valence force constants are f_d(NO) = 13.86–13.93 und f_d(RuN) = 5.43–5.49 mdyn/Å.     

Darstellung,Schwingungsspektren und Normalkoordinatenanalyse von Hexachlororhenat(V) sowie Kristallstruktur von [P(C6H5)4][ReCl6]

Preparation, Vibrational Spectra, and Normal Coordinate Analysis of Hexachlororhenate(V) and Crystal Structure of [P(C₆H₅)₄][ReCl₆] By oxidation of A₂[ReCl₆], A = [(n-C₄H₉)₄N]⁺, [P(C₆H₅)₄]⁺, with Cl₂ in dichloromethane/trifluoracetic acid A[ReCl₆] is formed. [P(C₆H₅)₄][ReCl₆] crystallizes with tetragonal symmetry, space group P4/n-C, a = 12.967(4), c = 7.6992(8) Å, Z = 2. The octahedral complexion [ReCl₆]^? is compressed (C_4v) with the bond lengths, axial Re? Cl1 = 2.28 and Re? Cl3 = 2.24 Å, equatorial Re? Cl2 = 2.31 Å. The infrared active antisymmetric Re? Cl stretching vibration is split into v′₃ = 346 an v″₃ = 326 cm^?1. The assignment of all IR and Raman modes is confirmed by a normal coordinate analysis. The different valence force constants, f_d(ReCl1) = 2.09, f_d(ReCl3) = 2.10, f_d(ReCl2) = 1.88 mdyn/ Å result from the distortion of the octahedron. On excitation with the Ar laser line 514.5 nm a resonance Raman spectrum is observed, showing 8 overtones of v′(A₁) = 382 cm^?1, from which the harmonic frequency ω₁ = 382.1 cm^?1, the anharmonicity constant X₁₁ = ?0.76 cm^?1, and the maximum bond dissociation energy of the [ReCl₆]^? ion to be 138 kcal/mol, are calculated. The vibrational fine structure of the intraconfigurational transitions in the near infrared has been resolved by measuring the absorption spectrum of [(n-C₄H₉)₄N][ReCl₆] at low temperature (10 K), resulting in the assignment of the following electronic origins: Γ₃(³T_1g) → Γ₄(³T_1g): 7 512, Γ₃(³T_1g) → Γ₁(³T_1g): 7 624 and Γ₃(³T_1g) → Γ₅(¹T_2g), Γ₃(¹E_g): 8 368 cm^?1.     

Electrochemical Investigations Give Some Insights into the Coordination Chemistry of New Stable Iridium(+1), Iridium(0), and Iridium(−1) Complexes

The redox chemistry of the stable tetracoordinated 16 valence electron d⁸‐[Ir^+I(tropp^Ph)₂]⁺(PF₆)^? and pentacoordinated 18 valence d⁸‐[Ir^+I(tropp^Ph)₂Cl] complexes was investigated by cyclic voltammetry (tropp^Ph=dibenzotropylidenyl phosphine). The experiments were performed using a platinum microelectrode varying scan rates (100 mV/s–10 V/s) and temperatures (? 40 to 20 °C) in tetrahydrofuran, THF, or acetonitrile, ACN, as solvents. In THF, the overall two‐electron reduction of the 16 valence electron d⁸‐[Ir^+I(tropp^Ph)₂]⁺(PF₆)^? proceeds in two well separated slow heterogeneous electron transfer steps according to: d⁸‐[Ir^+I (tropp^Ph)₂]⁺+e^?→d⁹‐[Ir⁰(tropp^Ph)₂]+e^?→d¹⁰‐[Ir^?I(tropp^Ph)₂]^?, [k^s₁=2.2×10^?3 cm/s for d⁸‐Ir^+I/d⁹‐Ir⁰ and k^s₂=2.0×10^?3 cm/s for d⁹‐Ir⁰/d¹⁰‐Ir^?I]. In ACN, the two redox waves merge into one “two‐electron” wave [k^s_1,2=7.76×10^?4 cm/s for d⁸‐Ir^+I/d⁹‐Ir⁰ and d⁹‐Ir⁰/d¹⁰‐Ir^?I] most likely because the neutral [Ir⁰(tropp^Ph)₂] complex is destabilized. At low temperatures (ca. ? 40 °C) and at high scan rates (ca. 10 V/s), the two‐electon redox process is kinetically resolved. In equilibrium with the tetracoordianted complex [Ir^+I(tropp^Ph)₂]⁺ are the pentacoordinated 18 valence [Ir^+I(tropp^Ph)₂L]⁺ complexes (L=THF, ACN, Cl^?) and their electrochemical behavior was also investigated. They are irreversibly reduced at rather high negative potentials (? 1.8 to ? 2.4 V) according to an ECE mechanism 1) [Ir^+I(tropp^Ph)₂(L)]+e^?→[Ir⁰(tropp^Ph)₂(L)]; 2) [Ir⁰(tropp^Ph)₂(L)]→[Ir(tropp^Ph)₂]+L, iii) [Ir⁰(tropp^Ph)₂]+e^?→[Ir^?I(tropp^Ph)₂]^?. Since all electroactive species were isolated and structurally characterized, our measurements allow for the first time a detailed insight into some fundamental aspects of the coordination chemistry of iridium complexes in unusually low formal oxidation states.     

Darstellung und spektroskopische Eigenschaften von Di(phthalocyaninato(1−))-lanthanidpolybromid; Kristallstruktur von α-Di(phthalocyaninato)samariumpolybromid, α-[Sm(Pc)2]Br1,45 und α-Di(phthalocyaninato)samariumperchlorat, α-[Sm(Pc)2](ClO4)0,63

Synthesis and Spectroscopical Properties of Di(phthalocyaninato(1?))lanthanidepolybromide; Crystal Structure of α-Di(phthalocyaninato)samariumpolybromide, α-[Sm(Pc)₂]Br_1.45 and α-Di(phthalocyaninato)samariumperchlorate, α-[Sm(Pc)₂](ClO₄)_0.63 Bronze-coloured di(phthalocyaninato)lanthanidepolybromide, [Ln(Pc^?)₂]Br_y (Ln = La…(? Ce, Pm)…Lu; y > 1.5) is prepared by oxidation of (ⁿBu₄N)[Ln(Pc^2?)₂] with bromine in excess. The UV-VIS-NIR spectra show the typical B and Q₁ bands of the Pc^? ligand at ～ 14 kK and ～ 20 kK. For the [Ln(Pc^?)₂]⁺ cation a NIR(D) band between 9,14 kK (La) and 11,50 kK (Lu) is characteristic for dimeric cofacial Pc^? radicals. Within the row La…Lu, there is a linear relationship of the hypsochromic shift of the strong bands and the Ln^III radius. In the case of La? Nd the D band shifts successively with longer time of bromination to ～ 3 kK as a result of increasing electron delocalisation. Characteristic vibrational bands are at ～ 1350/1450 cm^?1 (IR) and ～ 560/1120/1170/1600 cm^?1 (RR). In the FT-Raman spectra the totally symmetric Ln? N stretching vibration between 141 cm^?1 (La) and 172 cm^?1 (Lu) is selectively enhanced. As shown by α-[Sm(Pc)₂]Br_1,45 and α-[Sm(Pc)₂](ClO₄)_0,63 only partially ringoxidized complexes are obtained by the anodic oxidation. Both crystallize in the tetragonal space group P4/nnc. The [Sm(Pc)₂] molecular building block contains two nearly planar staggered (～41°) Pc rings packed in columns parallel along [001] leading to the quasi-one-dimensional structure. There is a statistical disorder of the Sm^III and the ClO₄^? resp. Br^?/Br₃^? ions over two incompletely filled crystallographic positions for the cation resp. anion. This results in a partial oxidation of the Pc ligand, which in the picture of localized valence states for α-[Sm(Pc)₂](ClO₄)_0,63 corresponds to [SmPc^?Pc^2?] · 2[Sm(Pc^?)₂](ClO₄). Accepting the same valence state for [Sm(Pc)₂]Br_1,45 five positive charges are compensated by two Br^? and three Br₃^?. The spectroscopic differences of the partially and fully oxidized complexes are discussed.     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalysen der mer‐Trihalogeno‐tris‐Pyridin‐Osmium(III)Komplexe mer‐[OsX3Py3], X = Cl,Br, I

Synthesis, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analyses of the mer ‐Trihalogeno‐tris‐Pyridine‐Osmium(III) Complexes mer‐[OsX₃Py₃], X = Cl, Br, I By reaction of the hexahalogenoosmates(IV) with pyridine and iso‐amylalcohol mer‐trihalogeno‐tris‐pyridine‐osmium(III) complexes are formed and purified by chromatography. X‐ray structure determinations on single crystals have been performed of mer‐[OsBr₃Py₃] (monoclinic, space group P2₁/n, a = 9.098(5), b = 12.864(5), c = 15.632(5) Å, β = 90.216(5)°, Z = 4) and mer‐[OsI₃Py₃] (monoclinic, space group P2₁/n, a = 9.0952(17), b = 13.461(4), c = 15.891(10), β = 91.569(5)°, Z = 4). The pyridine rings are twisted propeller‐like against the N₃ meridional plane with mean angles of 49° (Cl), 46° (Br), 44° (I). Based on the molecular parameters of the X‐ray structure determinations and assuming C₂ point symmetry, the IR and Raman spectra are assigned by normal coordinate analysis. Due to the stronger trans influence of pyridine as compared with the halide ligands for N'–Os–X ^· axes significantly different valence force constants are observed in comparison with symmetrically coordinated octahedron axes: f_d(OsCl) = 1.74, f_d(OsCl^·) = 1.49, f_d(OsBr) = 1.43, f_d(OsBr ^· ) = 1.18, f_d(OsI) = 0.99, f_d(OsI ^· ) = 0.96, f_d(OsN) between 1.96 and 2.07 and f_d(OsN') between 2.13 and 2.32 mdyn/Å.     

Kristallstrukturen,Normalkoordinatenanalysen und 15N‐NMRund 77Se‐NMR‐Verschiebungen von trans‐[OsO2(NCO)4]2–, trans‐[OsO2(NCS)4]2– und trans‐[OsO2(SeCN)4]2–

Crystal Structures, Normal Coordinate Analyses, and ¹⁵N NMR and ⁷⁷Se NMR Chemical Shifts of trans ‐[OsO₂(NCO)₄]^2–, trans ‐[OsO₂(NCS)₄]^2–, and trans ‐[OsO₂(SeCN)₄]^2– The crystal structures of trans‐(Ph₃PNPPh₃)₂[OsO₂(NCO)₄] ( 1 ) (orthorhombic, space group Pbca, a = 19.278(3), b = 16.674(4), c = 19.982(2) Å, Z = 4), trans(n‐Bu₄N)₂[OsO₂(NCS)₄] ( 2 ) (triclinic, space group P1, a = 12.728(3), b = 12.953(3), c = 16.255(6) Å, α = 97.39(4), β = 105.62(2), γ = 95.25(3)°, Z = 2) and trans‐(n‐Bu₄N)₂[OsO₂(SeCN)₄] ( 3 ) (tetragonal, space group I4/m, a = 13.406(2), c = 12.871(1) Å, Z = 2) have been determined by single‐crystal X‐ray diffraction analysis, showing the bonding of NCO and NCS via the N atom but the coordination of SeCN via the Se atom to osmium. Based on the molecular parameters of the X‐ray determinations the vibrational spectra have been assigned by normal coordinate analyses. The valence force constants are for 1 f_d(OsO) = 6.43, f_d(OsN) = 3.32, f_d(NC) = 14.50, f_d(CO) = 12.80, for 2 f_d(OsO) = 6.56, f_d(OsN) = 1.75, f_d(NC) = 15.00, f_d(CS) = 5.50, and for 3 f_d(OsO) = 6.75, f_d(OsSe) = 0.99, f_d(SeC) = 3.23, f_d(CN) = 15.95 mdyn/Å. The observed NMR shifts are δ(¹⁵N) = –386.6 ( 1 ), δ(¹⁵N) = –294.7 ( 2 ) and δ(⁷⁷Se) = 108.8 ppm ( 3 ).     

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.     

Kristallstruktur,Schwingungsspektren und Normalkoordinatenanalyse von (CH2py2)[Ru(NO)FCl4]

Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of (CH₂py₂)[Ru(NO)FCl₄] By treatment of [Ru(NO)Cl₅]^2– with a BrF₃ saturated frigen solution in dichloromethane the complex [Ru(NO)FCl₄]^2– is formed, which can be separated from hydrolysis products by ion exchange chromatography on diethylaminoethyl cellulose. The X‐Ray structure determination on a single crystal of (CH₂py₂)[Ru(NO)FCl₄] · ¹/₂ (CH₃)₂CO (triclinic, space group P1, a = 9.416(2), b = 14.919(6), c = 15.127(3) Å, α = 61.86(3), β = 80.31(2), γ = 72.49(3)°, Z = 4) reveals, that the fluorine atom is trans positioned to the nitrosyl group. The low temperature IR and Raman spectra have been recorded of (n‐Bu₄N)₂[Ru(NO)FCl₄] and are assigned by normal coordinate analysis. A good agreement between observed and calculated frequencies is achieved. The valence force constants are f_d(NO) = 13.92, f_d(RuN) = 5.16, f_d(RuF) = 3.19 and f_d(RuCl) = 1.45 mdyn/Å. The ¹⁹F NMR spectra exhibits one singlet at –144.6 ppm.     

Darstellung,Kristallstruktur und Schwingungsspektren von cis‐(CH2Py2)[ReBr4Py2]2 · (CH3)2CO

Synthesis, Crystal Structure, and Vibrational Spectra of cis ‐(CH₂Py₂)[ReBr₄Py₂]₂ · (CH₃)₂CO By reaction of (n‐Bu₄N)₂[ReBr₆] with pyridine and (n‐Bu₄N)BH₄ in dichloromethane halogeno‐pyridine‐rhenium(III)complexes are formed and purified by chromatography. X‐ray structure determination on a single crystal has been performed of cis‐(CH₂Py₂)[ReBr₄Py₂]₂ · (CH₃)₂CO (monoclinic, space group P2₁/c, a = 15.0690(9), b = 8.3337(8), c = 35.588(4) Å, β = 96.409(7), Z = 4). Based on the molecular parameters of the X‐ray structure determination and assuming C₂ point symmetry for the anion cis‐[ReBr₄Py₂]^– the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are in the Br–Re–Br axis f_d(ReBr) = 1.49, in the asymmetrically coordinated N′–Re–Br ^· axes f_d(ReBr ^· ) = 1.03 und f_d(ReN′) = 2.52 mdyn/Å.     

Vibrational Spectra of Cluster Anions. 2. Vibrational Spectra of Compounds with the Cluster Anions [E4]4−: M4E4 (M = K,Rb, Cs; E = Ge,Sn) and β‐Na4Sn4

Vibrational spectra of the compounds M₄E₄ (M = K, Rb, Cs; E = Ge, Sn) and of β‐Na₄Sn₄ with the cluster anions [E₄]^4? were analysed based on the point group of isolated tetrahedranide units. The lower individual symmetry of the anions in the real structure being more patterned and complex primarily affects the spectra of the tetrahedro‐tetragermanides. ν₃(F₂) clearly splits both in Raman and IR and in the case of K₄Sn₄ only in IR. Rb₄Sn₄ and Cs₄Sn₄ exhibit very simple spectra with three bands in Raman and one band in IR. The breathing mode ν₁(A₁) for the quasi isolated [E₄]^4? cluster appears only in the Raman spectrum and is hardly influenced by the structural environment and by the nature of the alkali metal cations: ν₁(A₁) = 274 cm^?1 ([Ge₄]^4?) and 183‐187 cm^?1 ([Sn₄]^4?), respectively. The calculated valence force constants f_d(E–E) are: [Ge₄]^4? : f_d = 0.89 Ncm^?1 ( K ), 0.87 Ncm^?1 ( Rb ), 0.86 Ncm^?1 ( Cs ) and [Sn₄]^4? : 0.67 Ncm^?1 ( Na ), 0.66 Ncm^?1 ( K ), 0.67 Ncm^?1 ( Rb ), 0.68 Ncm^?1 ( Cs ). Both, the frequencies and the force constants fit well into the range previously reported.     

Kristallstrukturen,Schwingungsspektren und Normalkoordinatenanalyse von cis-(Et4N)[OsF2Cl4] und trans-(Ph4P)[OsF2Cl4]

Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of cis -(Et₄N)[OsF₂Cl₄] and trans -(Ph₄P)[OsF₂Cl₄] By oxidation of the pure fluorochloroosmates(IV) with KBrF₄ or PbO₂/trifluoracetic acid in dichloromethane the mixed pentavalent complex anions cis-[OsF₂Cl₄]^– and trans-[OsF₂Cl₄]^– are formed. X-ray structure determinations on single crystals have been performed of cis-(Et₄N) · [OsF₂Cl₄] ( 1 ) (monoclinic, space group P2₁/n, a = 7.519(2), b = 17.648(2), c = 11.942(4) Å, β = 105.98(2)°, Z = 4) and trans-(Ph₄P)[OsF₂Cl₄] ( 2 ) (tetragonal, space group P4/n, a = 12.677(2), c = 7.743(1) Å, Z = 2). Based on the molecular parameters of the X-ray determinations and assuming C_2v point symmetry for the anion of 1 and D_4h point symmetry for the anion of 2 the IR and Raman spectra have been assigned by normal coordinate analysis. Due to the stronger trans influence of chlorine as compared with fluorine for F ^· –Os–Cl′ axes significally different valence force constants are observed in comparison with symmetrically coordinated axes: f_d(OsF ^· ) = 3.35, f_d(OsF) = 3.73, f_d(OsCl′) = 2.05 and f_d(OsCl) with 1.98 and 2.00 mdyn/Å.     

Darstellung,Schwingungsspektren, Normalkoordinatenanalyse und Kristallstruktur von fac-(PPN)2[ReClBr2I3]

Preparation, Vibrational Spectra, Normal Coordinate Analysis, and Crystal Structure of fac-(PPN)₂[ReClBr₂I₃] By treatment of cis-[ReBr₂I₄]^2? with HCl fac-[ReClBr₂I₃]^2? is formed beside other mixed complex ions of the Type [ReCl_kBr_lI_m]^2?, k + l + m = 6, which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. The X-ray structure determination on single crystals of (PPN)₂[ReClBr₂I₃] (monoclinic, space group P2₁/c, a = 22.059(3), b = 13.569(2), c = 23.9679(2) Å, β = 106.194(4)°, Z = 4) reveals the complete ordering of the complex anions. Due to the different trans influence the bond lengths ReCl (2.39) and ReBr (2.50) are slightly increased, the average ReI distance (2.66 Å) is a little shortened as compared with corresponding homoleptic octahedral complexes. The well resolved low temperature (80 K) IR and Raman spectra exhibit rheniumhalogen stretching vibrations in characteristic regions. The assignment is confirmed by the normal coordinate analysis based on a general valence force field. Taking into account increments of the trans influence on the valence force constants of the structural groups an adjustment between calculated and observed frequencies within a few cm^?1 is achieved.     

Darstellung,Kristallstruktur, Schwingungsspektren und Normalkoordinatenanalyse von [Co(NH3)6][Os(SCN)6]

Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of [Co(NH₃)₆][Os(SCN)₆] From the mixture of the linkage isomers [Os(NCS)_n(SCN)_6–n]^3–, n = 0–2, pure [Os(SCN)₆]^3– has been isolated by ion exchange chromatography on diethylaminoethyl cellulose. The X‐ray structure determination on a single crystal of [Co(NH₃)₆][Os(SCN)₆] (trigonal, space group R 3, a = 12.368(2), c = 11.830(2) Å, Z = 3) reveals that the thiocyanate ligands are exclusively S‐coordinated with the Os–S distance of 2.388 Å and the Os–S–C angle of 108.8°. The IR and Raman spectra of (n‐Bu₄N)₃[Os(SCN)₆] are assigned by normal coordinate analysis based on the molecular parameters of the X‐ray determination. The valence force constant f_d(OsS) is 1.42 mdyn/Å.     

Darstellung,Kristallstruktur, Schwingungsspektren und Normalkoordinatenanalyse von (Ph4P)2[OsN(N3)5] und 15N‐NMR‐Verschiebungen von Nitridoosmaten(VI,VIII)

Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of (Ph₄P)₂[OsN(N₃)₅] and ¹⁵N NMR Chemical Shifts of Nitridoosmates(VI, VIII) The treatment of (Ph₄P)[OsNCl₄] with NaN₃ yields (Ph₄P)₂[OsN(N₃)₅], which crystal structure has been determined by single crystal X‐ray diffraction analysis (monoclinic, space group P 2₁/a, a = 20.484(6), b = 11.168(1), c = 20.666(4) Å, β = 97.35(3)°, Z = 4). The IR and Raman vibrations were assigned by a normal coordinate analysis based on the molecular parameters of the X‐ray determination. The valence force constants are f_d(Os≡N) = 8.52, f_d(Os–N^α) = 1.99, f_d(N^α–N^β) = 12.42, f_d(N^β–N^γ) = 12.73 and for the azido ligand in trans‐position to the nitrido group f_d(Os–N^{α ·} ) = 1.84, f_d(N^{α ·} –N^{β ·} ) = 11.91, f_d(N^{β ·} –N^{γ ·} ) = 12.18 mdyn/Å. The ¹⁵N NMR spectra of various nitridoosmates reveal the chemical shifts δ(¹⁵N) for K[OsO₃¹⁵N] = 387.6, K₂[Os¹⁵NCl₅] = 446.7, (Ph₄P)[Os¹⁵NCl₄] = 352.9, [(n‐C₆H₁₃)₄N]₂[Os¹⁵N(N₃)₅] = 307.3 and for [(n‐Pr)₄N]₂[Os¹⁵N(¹⁵NCO)₅] = 483,7 (Os≡N), –417,7 (OsNCO_eq) und –392,8 ppm (OsNCO_ax).     

Darstellung und Schwingungsspektren von Chloro-Bromo-Dirhodaten(III), [Rh2ClnBr9−n]3−, n = 0–9

Preparation and Vibrational Spectra of Nonahalogenodirhodates(III), [Rh₂Cl_nBr_9-n]^3?, n = 0–9 The pure nonahalogenodirhodates(III), A₃[Rh₂Cl_nBr_9-n], A = K, Cs, (TBA); n = 0–4, 9, have been prepared. They are formed from the monomer chlorobromorhodates(III), [RhCl_nBr_6-n]^3?, n = 0–6, which are bridged to confacial bioctahedral complexes by ligand abstraction in less polar organic solvents. From the mixtures the complexions are separated by ion exchange chromatography on DEAE-cellulose. The solid, air-stable, air-stable, K-, Cs- and (TBA)-salts of [Rh₂Cl_nBr_9-n]^3?, n = 0–4, are green, of [Rh₂Cl₉]^3? are brown. The IR and Raman spectra of [Rh₂Br₉]^3? and [Rh₂Cl₉]^3? are assigned according to the point group D_3h. The chlorobromodirhodates exist as mixtures of geometrical and structural isomers, which belong to different point groups. The vibrational spectra exhibit bands in characteristic regions; at high wavenumbers stretching vibrations with terminal ligands v(Rh—Cl_t): 360–320, v(Rh—Br_t): 280–250; in a middle region with bridging ligands v(Rh—Cl_b): 300–270, v(Rh—Br_b): 210–170 cm^?1; the deformation bands are observed at distinct lower frequencies. The terminal ligands are fixed very strong, and the distance between v(Rh—X_t) and v(Rh—X_b) increases with decreasing size of the cations.     

Synthese und spektroskopische Charakterisierung von Fluorocarbonylosmaten sowie Normalkoordinatenanalyse und Kristallstruktur von fac-[OsF3Br2(CO)]2–

Synthesis and Spectroscopic Characterization of Fluorocarbonylosmates, Normal Coordinate Analysis and Crystal Structure of fac -[OsF₃Br₂(CO)]^2– By treatment of (n-Bu₄N)₂[OsBr₅(CO)] with TlF in C₆H₅CF₃ fac-(n-Bu₄N)₂[OsF₃Br₂(CO)] is formed, from which salts with the cations (Et₄N)⁺, (py₂CH₂)²⁺, Tl⁺ and Cs⁺ are obtainable. Oxidation of the by-product [OsF₅(CO)]^2– with Cl₂ yields [OsF₅(CO)]^– which ¹⁹F NMR spectrum reveals a quintet (δ_F = 89.9) and a dublet (43.5 ppm) in the ratio 1 : 4 with coupling constants ²J_FF = 94.9 Hz. Simultaneously produced mer-[OsF₃Cl₂(CO)]^– exhibits in the high field region a triplet (δ_F = –70.4) and a dublet (–66.2 ppm) in the ratio 1 : 2 and ²J_FF = 9.5 Hz. The X-ray structure determinations of fac-Tl₂[OsF₃Br₂(CO)] ( 1 ) (monoclinic P2₁/n, a = 11.143(12), b = 11.654(4), c = 13.751(10) Å, β = 91.50(6)°, Z = 8) and fac-(py₂CH₂)[OsF₃Br₂(CO)] · 1/2(CH₃)₂CO ( 2 ) (triclinic, P 1, a = 8.432(1), b = 9.009(1), c = 12.402(2) Å, α = 80.30(1), β = 79.68(2), γ = 68.14(1)°, Z = 2) result in nearly C_s symmetry of the complex anion with bond lengths in the ranges Os–F = 1.98–2.08, Os–Br = 2.45–2.46, Os–C = 1.83–1.84, C–O = 1.10 – 1.17 Å. Using the molecular parameters of the X-ray determinations the IR spectra have been assigned by normal coordinate analysis. The valence force constants are f_d(CO) = 15.4–15.7, f_d(OsC) = 4.4–4.7, f_d(OsF) = 2.4–2.7, f_d(OsF˙) = 1.6–2.0, f_d(OsBr) = 1.7–2.1 mdyn/Å.