Schwingungs- und Elektronenspektren der Dekahalogenodiosmate(IV), [Os2X10]2−, X  Cl,Br

Vibrational and Electronic Spectra of Decahalogenodiosmates(IV), [Os₂X₁₀]^2?, X ? Cl, Br The IR and Raman spectra of the edge-sharing bioctahedral anions [Os₂X₁₀]^2?, X ? Cl, Br, are assigned according to point group D_2h. The bands are found in three characteristic regions; at high wavenumbers stretching vibrations with terminal ligands v(OsCl_t): 365–280, v(OsBr_t): 235–195; in a middle region with bridging ligands v(OsCl_b): 270–240, v(OsBr_b): 175–165 cm^?1; the deformation bands are observed at distinct lower frequencies. The electronic spectra of the dimers show intraconfigurational transitions near 2000, 1000, and 600 nm which by position and intensity correspond to those of the monomeric complexes. They are therefore discussed separately for both metal centers according to C_2v symmetry. Two additional band systems are presumable pair transitions arising from interactions of the central ions within the dimeric complexes. Due to the different bonding strength of terminal or bridging ligands the intensive charge transfer bands are shifted by 3000–4000 cm^?1 bathochromicly or by 2000–3000 cm^?1 hypsochromicly compared with the hexahaloosmates(IV).     

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 und spektroskopische Charakterisierung der reinen Bindungsisomeren [ReX5(NCS)]2− und [ReX5(SCN)]2−, X = Cl,Br

Preparation and Spectroscopic Characterization of the Pure Bondisomers [ReX₅(NCS)]^2? and [ReX₅(SCN)]^2?, X = Cl, Br The treatment of (TBA)₂[ReBr₆] with NaSCN in acetone or of (TBA)₂[ReCl₅I] with AgSCN in CH₂Cl₂ yields mixtures of the bondisomers [ReBr₅(NCS)]^2?/[ReBr₅(SCN)]^2? or [ReCl₅(NCS)]^2?/[ReCl₅(SCN)]^2?, which are isolated as pure compounds by ion exchange chromatography on DEAE-Cellulose. The i.r. and Raman spectra are assigned according to local symmetry C_4v. The bondisomers are significantly distinguished by the frequencies of inner ligand vibrations: ν_CN(S) > ν_CN(N), ν_CS(N) > ν_CS(S), δ_NCS > δ_SCN. The electronic absorption spectra measured at 10 K exhibit in the region 6000 to 16000 cm^?1 all intraconfigurational transitions (t) splitted into Kramers dubletts by lowered symmetry (C_4v) and spin orbit coupling. The O? O transitions are deduced from vibrational fine structure. The charge transfer spectra of the bondisomers in the UV/VIS region are similar to those of the corresponding hexahalorhenates(IV).     

Darstellung und Charakterisierung von Bindungsisomeren Bromorhodanorhenaten(IV)

Preparation and characterization of bondisomeric bromorhodanorhenates(IV) The new compounds [ReBr₅(SCN)]^2?, [ReBr₅(NCS)]^2?, cis/tr.-[ReBr₄(NCS)(SCN)]^2?, cis-[ReBr₄(NCS)₂]^2?, mer-[ReBr₃(NCS)₃]^2? are prepared from [ReBr₆]^2? by ligand exchange with NaSCN, KSCN, or (SCN)₂ in organic solvents and isolated by ion exchange chromatography on DEAE cellulose. The bondisomers are significantly distinguished by the frequencies of inner ligand vibrations: v_CN(S) > v_CN(N), v_CS(N) > v_CS(S), δ_NCS δ_SCN. The electronic absorption spectra measured at 10 K exhibit in the region 5700 to 15300 cm^?1 all intraconfigurational transitions (t_2g³) splitted into 8 Kramers doublets by lowered symmetry (C_4v, C_2v, C_s) and spin orbit coupling. The O–O-transitions are deduced form vibrational fine structure and confirmed by electronic Raman bands in some cases. The magnetic moments are in the range of 3.0 to 3.9 B.M.     

Ruthenium(II)-Phthalocyaninate(2–): Darstellung und Eigenschaften von Acido(carbonyl)phthalocyaninato(2–)ruthenat(II), [Ru(X)(CO)Pc2−]− (X = Cl,Br, I,NCO, NCS,N3)

Ruthenium(II) Phthalocyaninates(2–): Synthesis and Properties of (Acido)(carbonyl)phthalocyaninato(2–)ruthenate(II), [Ru(X)(CO)Pc^2?]^? (X = Cl, Br, I, NCO, NCS, N₃) (ⁿBu₄N)[Ru(OH)₂Pc^2?] is reduced in acetone with carbonmonoxid to blue-violet [Ru(H₂O)(CO)Pc^2?], which yields in tetrahydrofurane with excess (ⁿBu₄N)X acido(carbonyl)phthalocyaninato(2–)ruthenate(II), [Ru(X)(CO)Pc^2?]^? (X = Cl, Br, I, NCO, NCS, N₃) isolated as red-violet, diamagnetic (ⁿBu₄N) complex salt. The UV-Vis spectra are dominated by the typical π-π* transitions of the Pc^2? ligand at approximately 15100 (B), 28300 (Q₁) und 33500 cm^?1 (Q₂), only fairly dependent of the axial ligands. v(C? O) is observed at 1927 (X = I), 1930 (Cl, Br), 1936 (N₃, NCO) 1948 cm^?1 (NCS), v(C? N) at 2208 cm^?1 (NCO), 2093 cm^?1 (NCS) and v(N? N) at 2030 cm^?1 only in the MIR spectrum. v(Ru? C) coincides in the FIR spectrum with a deformation vibration of the Pc ligand, but is detected in the resonance Raman(RR) spectrum at 516 (X = Cl), 512 (Br), 510 (N₃), 504 (I), 499 (NCO), 498 cm^?1 (NCS). v(Ru? X) is observed in the FIR spectrum at 257 (X = Cl), 191 (Br), 166 (I), 349 (N₃), 336 (NCO) and 224 cm^?1 (NCS). Only v(Ru? I) is RR-enhanced.     

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,Struktur und Thermolyse von NH4[Re3Br10]

Synthesis, Structure and Thermolysis of NH₄[Re₃Br₁₀] NH₄[Re₃Br₁₀] crystallizes as dark brown single crystals upon slow cooling of a hot, saturated hydrobromic-acid solution of [Re₃Br₉(H₂O)₂] after the addition of NH₄Br. The crystal structure (monoclinic, C2/m (Nr. 12); Z = 4; a = 1461.6(7), b = 1 085.6(4), c = 1030.3(7) pm, β = 92.63(4)°, V_m = 245.9(4)cm³/mol; R = 0.097, R_w = 0.043) contains [Re₃Br₁₂]^? units that share two common edges. These chains run along [010] and are held together by NH₄⁺ ions. Each NH₄⁺ is surrounded by eight Br^? from four different chains. The first step of the thermal decomposition at 290°C is the disproportionation to ReBr₃ (ReCl₃ type), rhenium metal and (NH₄)₂[ReBr₆]. Secondly, the internal reduction of (NH₄)₂[ReBr₆] at 390°C to rhenium metal takes place.     

Darstellung der Halogeno-Pyridin-Rhenate(III), [ReX6−n (Py)n](3−n)− (X = Br,Cl; n = 1−3), sowie Kristallstrukturen von trans-[(C4H9)4N][ReBr4(Py)2], mer-[ReCl3(Py)3] und mer-[ReBr3(Py)3]

Preparation of Halogeno Pyridine Rhenates(III), [ReX_6?n(Py)_n]^(3?n)? (X = Br, Cl; n = 1?3) Crystal Structures of trans-[(C₄H₉)₄N][ReBr₄(Py)₂], mer-[ReCl₃(Py)₃], and mer- [ReBr₃(Py)₃] The mixed halogeno-pyridine-rhenates(III), [ReX_6?n(Py)_n]^(3?n)? (X = Br, Cl), n = 1?3, have been prepared for the first time by reaction of the tetrabutylammoniumsalts (TBA)₂[ReX₆] (X = Br, Cl) in pyridine with (TBA)BH₄ and separation by chromatography on Al₂O₃. Apart from the monopyridine complexes only the trans and mer isomers are formed from the bis-and tris-pyridine compounds. The X-ray structure determinations of the isotypic neutral complexes mer- [ReX₃(Py)₃] (monoclinic, space group P 2₁/n, Z = 4; for X = Cl: a = 9,1120(8), b = 12,5156(14), c = 15,6100(13) Å, β = 91,385(7)°; for X = Br: a = 9,152(5), b = 12,852(13), c = 15,669(2) Å, β = 90,43(2)°) reveal, due to the stronger trans influence of pyridine compared with Cl and Br, that the Re? X distances in asymmetric Py? Re? X3 axes with ReCl3 = 2,397 Å and ReBr3 = 2,534 Å are elongated by 1,3 and 1% in comparison with symmetric X1? Re? X2 axes with ReCl1 = ReCl2 = 2,367 Å and ReBr1 = 2,513 and ReBr2 = 2,506 Å, respectively. The Re? N bond lengths are roughly equal with 2,12 Å. Trans-(TBA)[ReBr₄(Py)₂] crystallizes triclinic, space group P1 , a = 9,2048(12), b = 12,0792(11), c = 15,525(2) Å, α = 95,239(10), β = 94,193(11), γ = 106,153(9)°, Z = 2. The unit cell contains two independent but very similar complex anions with approximate D_2h(mmm) point symmetry.     

Synthesis,spectroscopic investigation,structural characterization,and DFT calculations of [ReX2(N2COPh)(CH3PhCN)(PPh3)2] (X=Cl,Br)

Reactions of [ReX₂(η ²-N₂COPh-N′,O)(PPh₃)₂] with 3-methylbenzonitrile give two iso-structural complexes, [ReX₂(N₂COPh)(CH₃PhCN)(PPh₃)₂] (X?=?Cl, Br). The crystal and molecular structures of [ReCl₂(N₂COPh)(CH₃PhCN)(PPh₃)₂] (1) and [ReBr₂(N₂COPh)(CH₃PhCN)(PPh₃)₂]?·?CH₂Cl₂ (2) were determined. The electronic structures were examined with density functional theory (DFT). The spin-allowed electronic transitions were calculated with the time-dependent DFT method, and the UV-Vis spectrum has been discussed.     

Rhenium,part XIV. Studies on the action of hydrogen halides on [ReO2en2]+

Summary The products from the reaction oftrans-dioxobis(ethylenediamine)rhenium(V) halides with hydrogen halides have been investigated. Dilute (2M) and concentrated hydrochloric acid react with (ReO₂en₂)Cl in the cold to give ReO(OH)enCl₂ and IRe(OH)₂enCl₂]Cl respectively, while with hot 6M HCl [ReOCl₅]^2– is formed. Dilute solutions of HX protonate [ReO₂en₂]X (X = Br and I) giving [ReO(OH)en₂]X₂ which are converted slowly into ReO(OH)enBr₂ and [ReO(OH)en2](I₃)₂. Hot and concentrated solutions of HX reduce Re^v in (ReO₂en2 )X (X = Br and I) giving enH₂(ReBr₆) and ReI₄en. The thermal decomposition of (ReO₂en₂)X (X = Cl, Br and I) has been studied by thermogravimetry and a polymeric compound, Re₂O₇en₂, has been isolated by heating (ReO₂en₂)X at 200°. The compounds have been characterised by molecular conductivities, magnetic susceptibility and i.r. spectra.     

Reactions of [ReX5(NO)]2− with triphenylstibine. Spectroscopic investigations of [ReX2(NO)(SbPh3)3], X-ray structures of [ReCl2(NO)(SbPh3)3] and [ReBr2Cl(SbPh3)3] and DFT calculations for [ReCl2(NO)(SbPh3)3]

The reactions of [NBu₄]₂[ReX₅(NO)] (X = Cl, Br) with triphenylstibine have been examined and three new rhenium complexes – [ReCl₂(NO)(SbPh₃)₃] (1), [ReBr₂(NO)(SbPh₃)₃] (2) and [ReBr₂Cl(SbPh₃)₃] (3) – have been obtained. The last one has been isolated in a low yield during slow recrystallization of the complex 2 from a mixture of chloroform and ethanol. The stibine rhenium nitrosyls have been characterized by IR and UV–vis spectroscopy. The X-ray structures of 1 and 3 have been determined. The geometric parameters of 1 have been examined using the density functional theory (DFT) method.     

Darstellung von trans-[Pt(ox)2X2]2− (X = Cl,Br, I,SCN, OH) durch oxydative Addition an [Pt(ox)2]2− in organischen Solventien

Preparation of trans-[Pt(ox)₂X₂]^2? (X = Cl, Br, I, SCN, OH) by Oxidative Addition to [Pt(ox)₂]^2? in Organic Solvents After extraction of [Pt(ox)₂]^2? with long-chain alkyl-ammonium ions into organic solvents the new Pt^IV complexes trans-[Pt(ox)₂X₂]^2?, X = Cl, Br, I, SCN, OH, are formed directly by oxidative addition. In nonpolar solvents the bulky organic cations prevent the formation of compounds with columnar structure which by partial oxidation in aqueous solution are formed immediately. The IR and Ra spectra of the stable anhydrous (TBA) salts are assigned according to point group D_2h. A characteristical dependence of the C?O, C? O, and Pt? O stretching modes in response to the oxidation state of the central ion is observed. There is vibrational fine structure in the absorption spectrum of [Pt(ox)₂]^2? measured at 10 K with long progressions by coupling of d—d transitions with v_s(Pt? O) and v_s(C?O). The characteristical feature in the UV/VIS spectra of the Pt^IV complexes is caused by intensive π(O, X) ← e_g(Pt) CT transitions.     

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 und spektroskopische Charakterisierung der Nona-halogenodiiridate(III), [Ir2X9]3−, X = Cl,Br

Preparation and Spectroscopic Characterization of Nonahalogenodiiridates(III), [Ir₂X₉]^3?, X = Cl, Br The pure nonahalogenodiiridates(III), A₃[Ir₂X₉] (A = K, Cs, tetraalkylammonium; X = Cl, Br) have been prepared. They are formed from the monomer hexahalogenoiridates(III) which are bridged to confacial bioctahedral complexes by ligand abstraction in less polar organic solvents. The IR and Raman spectra exhibit bands in three characteristic regions; at high wavenumbers stretching vibrations with terminal ligands ν(Ir?Cl_t): 360?300, ν(Ir?Br_t): 250?220; in a middle region with bridging ligands ν(Ir?Cl_b): 290?235, ν(Ir?Br_b): 205?190 cm^?1; the deformation bands are observed at distinct lower frequencies. The distance between ν(Ir?X_t) and ν(Ir?X_b) increases with decreasing size of the cations. The electronic spectra measured at thin films of the pure complex salts at 10 K show some intensive charge transfer transitions in the UV and one or two weak d? d bands in the visible region.     

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.     

Novel Copper(I) Clusters with 2‐(Diphenylphosphanyl)anilide Ligands. Synthesis and Crystal Structures of [Cu6X2(NHR)4] (X = Cl,Br, I; R = C6H4‐2‐PPh2)

Treatment of copper(I) halides CuX (X = Cl, Br, I) with lithium 2‐(diphenylphosphanyl)anilide [Li(HL)] in THF led to the formation of hexanuclear copper(I) complexes [Cu₆X₂(HL)₄] [X = Cl ( 1 ), Br ( 2 ), I ( 3 )]. In compounds 1 – 3 , the copper atoms are in a distorted octahedral arrangement and the amide ligands adopt a μ₃‐κP,κ²N bridging mode. Additionally there are two μ₂‐bridging halide ligands. Each of the [Cu₆X₂(HL)₄] clusters comprises two copper atoms, which are surrounded by two amide nitrogen atoms in an almost linear coordination [Cu–N: 186.2(3)–188.0(3) pm] and four copper atoms, which are connected to an amide N atom, a P atom, and a halogen atom in a distorted trigonal planar fashion [Cu–N: 199.6(3)–202.3(3) pm)].     

Darstellung und Schwingungsspektren von trans-[Pt(acac)2X2] (X  Cl,Br, I,SCN, SeCN,N3)

Preparation and Vibrational Spectra of trans-[Pt(acac)₂X₂] (X ? Cl, Br, I, SCN, SeCN, N₃) By electrolytical oxidation of [Pt(acac)₂] in presence of chloride or bromide, dissolved in dichlormethane, trans-[Pt(acac)₂X₂], X ? Cl, Br, are formed. On treatment of trans-[Pt(acac)₂I₂] with silver pseudohalides trans-[Pt(acac)₂X₂], X ? SCN, SeCN, N₃, are obtained. Beside the nearly persistent bands of coordinated acetylacetonate in the Raman spectra the intensive and sharp symmetric, in the IR spectra the corresponding antisymmetric stretching vibration of the X? Pt? X axis is observed. The observance of the rule of mutual exclusion proves the complexes to belong to point group D_2h. From the resonance Raman spectrum of trans-[Pt(acac)₂I₂] for v_s (Pt? I), A_g, the harmonic frequency ω₁ = 142.45 cm^?1 and the inharmonicity constant x₁₁ = 0.48 cm^?1 is calculated. In the Raman spectrum of trans-[Pt(acac)₂Cl₂] v_s (Pt? Cl) is splitted by the isotops ³⁵Cl/³⁷Cl into the triplet 340, 335, 330 cm^?1 giving the force constant f_PtCl = 2.01 N/cm.     

The synthesis,molecular, crystal,and electronic structures of [ReBr2(O)(OCH3)(PPh3)2]

[ReBr₂(O)(OCH₃)(PPh₃)₂] has been obtained in the reaction of [ReBr₃O(PPh₃)₂] or [ReBr₂(η²-N₂COPh-N′,O)(PPh₃)₂] with an excess of methanol. [ReBr₂O(OMe)(PPh₃)₂] crystallizes in the triclinic space group P-1. The complex was characterized by infrared, UV-Vis, and ¹H NMR spectra. The electronic structure of the obtained compound has been calculated using the DFT/TD–DFT method.     

Über Chalkogenidhalogenide des Rheniums: Synthese und Kristallstrukturen der Dreieckscluster Re3E7X7 (E = S,Se; X = Cl,Br)

On Chalcogenide Halogenides of Rhenium: Synthesis and Crystal Structures of the Triangular Clusters Re₃E₇X₇ (E = S, Se; X = Cl, Br) The compounds Re₃E₇X₇ are obtained from rhenium tetrahalides ReX₄, elemental chalcogens and the respective chalcogen halides E₂X₂ or SeX₄ (E = S, Se; X = Cl, Br). Re₃S₇Cl₇, Re₃S₇Br₇ and Re₃Se₇Br₇ are formed in solutions of sulfur or selenium halides or SiBr₄ in form of black crystals and crystallize isotypically in the trigonal space group P31c. Re₃Se₇Cl₇ is formed by solid state reaction of ReCl₄, Se and SeCl₄ or by thermal decomposition of Se₄[ReCl₆], crystallizing as red, in thin layers transparent crystals in the orthorhombic space group Pbcm. The crystal structures consist of discrete positively charged cluster units and halide ions according to the formula [Re₃(μ₃-E)(μ₂-E₂)₃X₆]⁺X^–. In the rhenium triangular clusters the Re–Re distances range from 269,0 to 270,4 pm for the sulfur and from 273,3 to 275,3 pm for the selenium containing compounds. The Re₃ units are capped by chalcogen atoms, three E₂ groups form bridges over the edges of the Re₃ triangles. The trigonal and the orthorhombic structure type show differences in the site symmetry of the clusters (C₃ vs. C_s) and in the stacking sequence of the molecules, which are packed in the motif of a closest packing of spheres.     

Komplexe des Rheniums mit planarer ReN2S2-Fünfringstruktur Synthesen und Kristallstrukturen von AsPh4[ReCl4(N2S2)] und PPh4[ReBr4(N2S2)]

Complexes of Rhenium with Planar ReN₂S₂ Rings. Syntheses and Crystal Structures of AsPh₄[ReCl₄(N₂S₂)] and PPh₄[ReBr₄(N₂S₂)] The complex [ReCl₄(N₂S₂)]^? can be obtained as PPh₄^⊕ or AsPh₄^⊕ salt by the action of S(NSiMe₃)₂ and of diphenylacetylene, respectively, on the chlorothionitrene complex [ReCl₄(NSCl)₂]^?. Another method of synthesis is the reaction of [ReCl₃(NSCl)₂(POCl₃)] with SbPh₃. [ReBr₃(N₂S₂)]₂ is obtained from excess Me₃SiBr and [ReCl₃(NSCl)₂(POCl₃)]. The anionic complex [ReBr₄(N₂S₂)]^? forms from either [ReCl₄(NSCl)₂]^? or [ReCl₄(N₂S₂)]^? with Me₃SiBr. All compounds are black, diamagnetic, and sensitive to moisture; the PPh₄^⊕ and AsPh₄^⊕ salts are soluble in CH₂Cl₂ and CH₂Br₂. The IR spectra are reported. The crystal structures of AsPh,₄[ReCl₄(N₂S₂)] and PPh₄[ReBr₄(N₂S₂)] were determined by X-ray diffraction. AsPh₄[ReCl₄(N₂S₂)]: space group P2/n, Z = 2, a = 1244.5, b = 1429.3, c = 791.1 pm, γ = 96.89° (1715 observed reflexions, R = 0.082). PPh₄[ReBr₄[ReBr₄(N₂S₂)]: space group P2₁/n, Z = 4, a = 961.7, b = 1397.4, c = 2205.7 pm, β = 102.10° (1787 observed reflexions, R = 0.073). In both compounds the [ReX₄(N₂S₂)]? anions have the same type of structure, the Re atoms forming part of planar ReN₂S₂ rings; the bond lengths are ReN 177 pm, NS 152 pm, and SS 259 for the chloro compound and ReN 184 pm, NS 153 pm, and SS 264 pm for the bromo compound. In AsPh₄[ReCl₄(N₂S₂)] the cations are stacked to form columns in the c-direction; in PPh₄[ReBr₄(N₂S₂)], there is considerable distortion form this packing principle.