Darstellung,Kristallstrukturen und Schwingungsspektren von trans‐[Pt(N3)4X2]2–, X = Cl,Br, I

Synthesis, Crystal Structures, and Vibrational Spectra of trans ‐[Pt(N₃)₄X₂]^2–, X = Cl, Br, I By oxidative addition to (n‐Bu₄N)₂[Pt(N₃)₄] with the elemental halogens in dichloromethane trans‐(n‐Bu₄N)₂[Pt(N₃)₄X₂], X = Cl, Br, I are formed. X‐ray structure determinations on single crystals of trans‐(Ph₄P)₂[Pt(N₃)₄Cl₂] (triclinic, space group P1, a = 10.352(1), b = 10.438(2), c = 11.890(2) Å, α = 91.808(12), β = 100.676(12), γ = 113.980(10)°, Z = 1), trans‐(Ph₄P)₂[Pt(N₃)₄Br₂] (triclinic, space group P1, a = 10.336(1), b = 10.536(1), c = 12.119(2) Å, α = 91.762(12), β = 101.135(12), γ = 112.867(10)°, Z = 1) and trans‐(Ph₄P)₂[Pt(N₃)₄I₂] (triclinic, space group P1, a = 10.186(2), b = 10.506(2), c = 12.219(2) Å, α = 91.847(16), β = 101.385(14), γ = 111.965(18)°, Z = 1) reveal, that the compounds crystallize isotypically with octahedral centrosymmetric complex anions. The bond lengths are Pt–Cl = 2.324, Pt–Br = 2.472, Pt–I = 2.619 and Pt–N = 2.052–2.122 Å. The approximate linear Azidoligands with N^α–N^β–N^γ‐angles = 172.1–176.8° are bonded with Pt–N^α–N^β‐angles = 116.2–121.9°. In the vibrational spectra the platinum halogen stretching vibrations of trans‐(n‐Bu₄N)₂[Pt(N₃)₄X₂] are observed in the range of 327–337 (X = Cl), at 202 (Br) and in the range of 145–165 cm^–1 (I), respectively. The platinum azide stretching modes of the three complex salts are in the range of 401–421 cm^–1. Based on the molecular parameters of the X‐ray determinations the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are f_d(PtCl) = 1.90, f_d(PtBr) = 1.64, f_d(PtI) = 1.22, f_d(PtN^α) = 2.20–2.27 and f_d(N^αN^β, N^βN^γ) = 12.44 mdyn/Å.     

Pb2PdX6 (X = Cl,Br) – Verbindungen mit gestreckten [PdX6]-Oktaedern

Pb₂PdX₆ (X = Cl, Br) – Compounds with Elongated [PdX₆] Octahedra In contradiction to published data new compounds in the systems PbX₂—PdX₂ (X = Cl, Br) with the formula Pb₂PdCl₆ (I) and Pb₂PdBr₆ (II) were found. These were synthesized by thermal treatment of the corresponding mixtures of PbX₂ and PdX₂ (X = Cl, Br). X-ray single crystal structure analysis shows isotypism of I and II, monoclinic, P2₁/c (No. 14), Z = 2, I: a = 9.037(2) Å, b = 6.224(1) Å, c = 8.162(1) Å, β = 90.31(7)β, II: a = 9.512(7) Å, b = 6.584(8) Å, c = 8.383(3) Å, β = 90.07(5)º. Strongly elongated PdX₆ octahedra are found in the crystal structure. Additional characterisation of the compounds was done by DTA, IR/RAMAN spectra and ²⁰⁷Pb MAS NMR investigations. Remarcable low field shifts were found for ²⁰⁷Pb.     

Compounds with Cluster Cations together with Cluster Anions [(M6X12)(EtOH)6]2+ besides [(Mo6Cl8)Cl4X2]2– (M = Nb,Ta; X = Cl,Br) – Synthesis and Crystal Structures

Compounds consisting of both cluster cations and cluster anions of the composition [(M₆X₁₂)(EtOH)₆][(Mo₆Cl₈)Cl₄X₂] · n EtOH · m Et₂O (M = Nb, Ta; X = Cl, Br) have been prepared by the reaction of (M₆X₁₂)X₂ · 6 EtOH with (Mo₆Cl₈)Cl₄. IR data are given for three compounds. The structures of [(Nb₆Cl₁₂)(EtOH)₆][(Mo₆Cl₈)Cl₆] · 3 EtOH · 3 Et₂O 1 and [(Ta₆Cl₁₂)(EtOH)₆][(Mo₆Cl₈)Cl₆] · 6 EtOH 2 have been solved in the triclinic space group P1 (No. 2). Crystal data: 1 , a = 10.641(2) Å, b = 13.947(2) Å, c = 15.460(3) Å, α = 65.71(2)°, β = 73.61(2)°, γ = 85.11(2)°, V = 2005.1(8) ų and Z = 1; 2 , a = 11.218(2) Å, b = 12.723(3) Å, c = 14.134(3) Å, α = 108.06(2)°, β = 101.13(2)°, γ = 91.18(2)°, V = 1874.8(7) ų and Z = 1. Both structures are built of octahedral [(M₆Cl₁₂)(EtOH)₆]²⁺ cluster cations and [(Mo₆Cl₈)Cl₆]^2– cluster anions, forming distorted CsCl structure types. The Nb–Nb and Ta–Ta bond lengths of 2.904 Å and 2.872 Å (mean values), respectively, are rather short, indicating weak M–O bonds. All O atoms of coordinated EtOH molecules are involved in H bridges. The Mo–Mo distances of 2.603 Å and 2.609 Å (on average) are characteristic for the [(Mo₆Cl₈)Cl₆]^2– anion, but there is a clear correlation between the number of hydrogen bridges to the terminal Cl and the corresponding Mo–Cl distances.     

Synthesis and Crystal Structure of a Novel Polymeric Lead(II) Compound: [Pb2(phen)2(N3)3(ClO4)]n

A 2D lead(II) coordination polymer [Pb₂(phen)₂(N₃)₃(ClO₄)]_n,( 1 ) containing 1,10‐phenanthroline (phen) and two different anions, has been synthesized and characterized by elemental analysis, IR and ¹H NMR spectroscopy and X‐ray crystallography. The single‐crystal X‐ray data show two different kinds of Pb²⁺ ions with coordination numbers of eight, Pb1 = PbN₆O₂ and Pb2 = PbN₈, with hemidirected and holodirected structures, respectively. The supramolecular features in 1 is negiotated through the weak but directional C‐H···O and C‐H···N interactions and aromatic π–π stacking interactions.     

Magnesiumphthalocyanine: Darstellung und Eigenschaften von Halogenophthalocyaninatomagnesat, [Mg(X)Pc2−]− (X = F,Cl, Br); Kristallstruktur von Bis(triphenylphosphin)iminiumchloro(phthalocyaninato)magnesat-Aceton-Solvat

Magnesium Phthalocyanines: Synthesis and Properties of Halophthalocyaninatomagnesate, [Mg(X)Pc^2?]^? (X = F, Cl, Br); Crystal Structure of Bis(triphenylphosphine)iminiumchloro-(phthalocyaninato)magnesate Acetone Solvate Magnesium phthalocyanine reacts with excess tetra(n-butyl)ammonium- or bis(triphenylphosphine)iminiumhalide ((ⁿBu₄N)X or (PNP)X; X = F, Cl, Br) yielding halophthalocyaninatomagnesate ([Mg(X)Pc^2?]^?; X = F, Cl, Br), which crystallizes in part as a scarcely soluble (ⁿBu₄N) or (PNP) complex-salt. Single-crystal X-ray diffraction analysis of ^b(PNP)[Mg(Cl)Pc^2?] · CH₃COCH₃ reveals that the Mg atom has a tetragonal pyramidal coordination geometry with the Mg atom displaced out of the center (Ct) of the inner nitrogen atoms (N_iso) of the nonplanar Pc ligand toward the Cl atom (d(Mg? Ct) = 0.572(3) Å; d(Mg? Cl) = 2.367(2) Å). The average Mg? N_iso distance is 2.058 Å. Pairs of partially overlapping anions are present. The cation adopts a bent conformation (^b(PNP)⁺: d(P1? N(K)) = 1.568(3) Å; d(P2? N(K)) = 1.587(3) Å; ?(P1? N(K)? P2) = 141.3(2)°). Electrochemical and spectroscopic properties are discussed.     

Synthesis,Crystal Structure,and Optical Properties of (CH3NH3)2CoX4 (X = Cl,Br, I,Cl0.5Br0.5, Cl0.5I0.5, Br0.5I0.5)

The reaction of methylammonium halides and cobalt halides yielded the organic‐inorganic hybrid compounds of general formula (CH₃NH₃)₂CoX₄. By varying the different halides, we were able to synthesize the whole row from Cl to I as well as some mixed halides compounds and to determinate the crystal structures. (CH₃NH₃)₂CoX₄ (X = Cl, Br, Cl_0.5Br_0.5, Br_0.5I_0.5) crystallize isotypic to (CH₃NH₃)₂HgCl₄ in space group P2₁/c with Z = 4 [X = Cl: a = 7.6483(9), b = 12.6885(18), c = 10.8752(12) Å, β = 96.639(9)°; X = Cl_0.5Br_0.5: a = 7.8271(9), b = 12.9543(9), c = 11.1007(11) Å, β = 96.320(8)°; X = Br: a = 7.9782(2), b = 13.1673(2), c = 11.2602(2) Å, β = 96.3260(10)° and X = Br_0.5I_0.5: a = 8.2435(12), b = 13.645(2), c = 11.5856(18) Å, β = 95.54(2)°]. The mixed halides show a statistic distribution in both cases. In (CH₃NH₃)₂CoCl₂I₂ an ordered variant is realized representing a new structure type [C2/m, Z = 4, a = 18.808(4), b = 7.3604(7), c = 10.4109(17) Å, β = 120.364(13)°]. (CH₃NH₃)₂CoI₄ crystallizes again isotypic to the respective mercury compound [(CH₃NH₃)₂HgCl₄] [Pbca, Z = 8, a = 10.9265(5), b = 12.1552(5), c = 20.9588(9) Å]. All structures are build up by inorganic tetrahedral [CoX₄]^2– anions and organic (CH₃NH₄)⁺ cations. Additionally the Raman spectra as well as the optical reflectance spectra are discussed.     

Synthesis and Crystal Structures of Cs5Nb2S4X9 – Double Salts Containing New Cluster Anions [Nb2(μ-S2)2X8]4– (X = Cl,Br)

Bis(disulfide)bridged Nb(+4) cluster halide complexes [Nb₂S₄X₈]^4– (X = Cl, Br) were prepared by acid hydrolysis of [Nb₂S₄(NCS)₈]^4– in concentrated aqueous HCl or HBr, solution from which they can be isolated as double salts Cs₅[Nb₂S₄X₈]X (X = Cl, 1 ; X = Br, 2 ). The crystal structures of 1 and 2 were determined. The isolation and X-ray structure of oxonium salt (H₃O)₅ [Nb₂S₄Cl₈]Cl ( 3 ) is also reported. 1 – 3 contain new [Nb₂S₄X₈]^4– anions which can also be viewed as excised building blocks of polymeric solids NbS₂X₂. The extra halogen resides in the center of octahedron formed by six Cs⁺ or H₃O⁺ ions. All the three salts are isostructural and crystallize in tetragonal space group Immm with the following parameters: a = 10.269(2), b = 16.343(2), c = 7.220(1) Å for 1 , a = 10.934(1), b = 16.613(2), c = 7.470(1) Å for 2 , a = 9.639(1), b = 16.031(1), c = 7.071(1) Å for 3 . The parameters of the Nb₂S₄ core are only slightly affected by the change from Cl to Br.     

Theoretical investigation on identical anionic halide‐exchange SN2 reaction processes on N‐haloammonium cation NH3X+ (X = F,Cl, Br,and I)

CCSD(T) calculations have been used for identically nucleophilic substitution reactions on N‐haloammonium cation, X^? + NH₃X⁺ (X = F, Cl, Br, and I), with comparison of classic anionic S_N2 reactions, X^? + CH₃X. The described S_N2 reactions are characterized to a double curve potential, and separated charged reactants proceed to form transition state through a stronger complexation and a charge neutralization process. For title reactions X^? + NH₃X⁺, charge distributions, geometries, energy barriers, and their correlations have been investigated. Central barriers ΔE for X^? + NH₃X⁺ are found to be lower and lie within a relatively narrow range, decreasing in the following order: Cl (21.1 kJ/mol) > F (19.7 kJ/mol) > Br (10.9 kJ/mol) > I (9.1 kJ/mol). The overall barriers ΔE relative to the reactants are negative for all halogens: ?626.0 kJ/mol (F), ?494.1 kJ/mol (Cl), ?484.9 kJ/mol (Br), and ?458.5 kJ/mol (I). Stability energies of the ion–ion complexes ΔE_comp decrease in the order F (645.6 kJ/mol) > Cl (515.2 kJ/mol) > Br (495.8 kJ/mol) > I (467.6 kJ/mol), and are found to correlate well with halogen Mulliken electronegativities (R² = 0.972) and proton affinity of halogen anions X^? (R² = 0.996). Based on polarizable continuum model, solvent effects have investigated, which indicates solvents, especially polar and protic solvents lower the complexation energy dramatically, due to dually solvated reactant ions, and even character of double well potential in reactions X^? + CH₃X has disappeared. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Penta‐Ammoniates of Aluminium Halides: The Crystal Structures of AlX3·5NH3 with X = Cl,Br, I

Colourless crystals grow in the colder part of a glass ampoule when AlX₃·5NH₃ with X = Cl, Br, I is heated for 3—6 d to 330 °C (Cl), 350 °C (Br) and 400 °C (I), respectively. The chloride forms hexagonal prisms while the bromide and iodide were obtained as a bunch of lancet‐like crystals. The chloride and bromide crystallize isotypic whereas the iodide has an own structure type. All three are related to the motif of the K₂PtCl₆ type. So the formula of the ammoniates may be written as X₂[Al(NH₃)₅X] ≙ [Al(NH₃)₅X]X₂. The compounds are characterized by the following crystallographic data AlCl₃·5NH₃: Pnma, Z = 4, a = 13.405 (1)Å, b = 10.458 (1)Å, c = 6.740 (2)Å AlBr₃·5NH₃: Pnma, Z = 4, a = 13.808 (2)Å, b = 10.827 (1)Å, c = 6.938 (1)Å AlI₃·5NH₃: Cmcm, Z = 4, a = 9.106 (2)Å, b = 11.370 (2)Å, c = 11.470 (2)Å For the chloride and the bromide the structure determinations were successful including hydrogen positions. All three compounds contain octahedral molecular cations [Al(NH₃)₅X]²⁺ located in distorted cubes formed by the remaining 2X^— ions. The orientation of the octahedra to each other is clearly different for those with X = Cl, Br in comparison to the one with X = I.     

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     

Diversity of Strontium Nitridogermanates(IV): Novel Sr4[GeN4], Sr8Ge2[GeN4], and Sr17Ge2[GeN3]2[GeN4]2

Single crystals of three new strontium nitridogermanates(IV) were grown in sealed niobium ampules from sodium flux. Dark red Sr₄[GeN₄] crystallizes in space group P2₁/c with a = 9.7923(2) Å, b = 6.3990(1) Å, c = 11.6924(3) Å and β = 115.966(1)°. Black Sr₈Ge₂[GeN₄] contains Ge^4– anions coexisting with [Ge^IVN₄]^8– tetrahedra and adopts space group Cc with a = 10.1117(4) Å, b = 17.1073(7) Å, c = 10.0473(4) Å and β = 115.966(1)°. Black Sr₁₇Ge₆N₁₄ features the same anions alongside trigonal planar [Ge^IVN₃]^5– units. It crystallizes in P1 with a = 7.5392(1) Å, b = 9.7502(2) Å, c = 11.6761(2) Å, α = 103.308(1)°, β = 94.651(1)° and γ = 110.248(1)°.     

Synthese und Eigenschaften von Bis(tetra(n-butyl)ammonium)-μ-carbidodi(halogenophthalocyaninato(2–)ferraten(IV)); Kristallstruktur von Bis(tetra(n-butyl)ammonium)-μ-carbidodi(fluorophthalocyaninato(2–)ferrat(IV))-Trihydrat

Synthesis and Properties of Bis(tetra(n-butyl)ammonium)μ-Carbido-di(halophthalocyaninato(2–)ferrates(IV)); Crystal Structure of Bis(tetra(n-butyl)ammonium) μ-Carbido-di(fluorophthalocyaninato(2–)ferrate(IV)) Trihydrate μ-Carbido-di(pyridinephthalocyaninato(2–)iron(IV)) reacts with tetra(n-butyl)ammonium halide (ⁿBu₄N)X) in solution (X = F) or in a melt (X = Cl, Br) to yield bis(tetra(n-butyl)ammonium μ-carbido-di(halophthalo-cyaninato(2–)ferrat(IV)). The fluoro-complex salt crystallizes as a trihydrate monoclinically in the space group P12₁/n1 with the following cell parameters: a = 15.814(1) Å; b = 22.690(5) Å; c = 25.127(3) Å; β = 98.27(1)°, Z = 4. The Fe atoms are almost in the centre (Ct) of the (N_iso)₄ planes (N_iso: isoindoline-N atom) with a Fe–Ct distance of 0.053(1) Å. The average Fe–N_iso distance is 1.939(4) Å, the Fe–(μ-C) distance 1.687(4) Å and the Fe–F distance 2.033(2) Å. The Fe–(μ-C)–Fe core is linear (179.5(3)°). The pc²-ligands are staggered (φ = 42(1)°) with a convex distortion. The asymmetric Fe–(μ-C)–Fe stretch (in cm^–1) is observed in the IR spectra at 917 (X = F), 918 (Cl) and 920 (Br) and the symmetric Fe–(μ-C)–Fe stretch at 476 cm^–1 in the resonance Raman spectra. The IR active asymmetric Fe–X stretch (in cm^–1) absorbs at 336 (X = F), 203 (Cl), 182 (Br), respectively.     

Synthesis,Spectroscopic, and X‐Ray Diffraction Studies of cis‐Dichlorobis(4‐propanoyl‐2,4‐dihydro‐5‐methyl‐2‐phenyl3 H‐pyrazol‐3‐onato) Tin(IV)

Reaction between an aqueous ethanol solution of tin(II) chloride and that of 4‐propanoyl‐2,4‐dihydro‐5‐methyl‐2‐phenyl‐3 H‐pyrazol‐3‐one in the presence of O₂ gave the compound cis‐dichlorobis(4‐propanoyl‐2,4‐dihydro‐5‐methyl‐2‐phenyl‐3 H‐pyrazol‐3‐onato) tin(IV) [(C₂₆H₂₆N₄O₄)SnCl₂]. The compound has a six‐coordinated Sn^IV centre in a distorted octahedral configuration with two chloro ligands in cis position. The tin atom is also at a pseudo two‐fold axis of inversion for both the ligand anions and the two cis‐chloro ligands. The orange compound crystallizes in the triclinic space group P 1 with unit cell dimensions, a = 8.741(3) Å, b = 12.325(7) Å, c = 13.922(7) Å; α = 71.59(4), β = 79.39(3), γ = 75.18(4); Z = 2 and D_x = 1.575 g cm^–3. The important bond distances in the chelate ring are Sn–O [2.041 to 2.103 Å], Sn–Cl [2.347 to 2.351 Å], C–O [1.261 to 1.289 Å] and C–C [1.401 Å] the bond angles are O–Sn–O 82.6 to 87.7° and Cl–Sn–Cl 97.59°. The UV, IR, ¹H NMR and ¹¹⁹Sn Mössbauer spectral data of the compound are reported and discussed.     

Darstellung und Kristallstruktur der ersten Vertreter des neuen Verbindungstyps Pb4[SiO4]X4 mit X = Cl,Br

Inhaltsübersicht. Die beiden silicathaltigen Blei(II)-oxidhalogenide Pb₄[SiO₄]Cl₄ und Pb₄[SiO₄]Br₄ wurden erstmals dargestellt und ihre Kristallstruktur an Einkristallen mit Röntgen-beugungsmethoden ermittelt. Die Verbindungen kristallisieren in der monoklinen Raumgruppe P2₁/c (No. 14) mit den Gitterparametern: Pb₄[SiO₄]Cl₄: A = 8,73(1) Å, b = 15,68(1) Å, c = 8,265(6) Å, β = 92,4(1)°, Z = 4 Pb₄[SiO₄]Br₄: A = 9,00(1) Å, b = 16,217(8) Å, c = 8,404(4) Å, β = 92,4(1)°, Z = 4 Im Gegensatz zu der “nichtstöchiometrischen” Verbindungsgruppe um Pb₈O₇Br₂ · SiO₂ konnten hier alle Atomlagen ermittelt werden. Es liegen einzelne SiO₄-Gruppen vor, die über Pb²⁺ zu leicht gewellten Netzen verbunden sind. Zwischenräume und Löcher der Netze werden von Halogenidionen aufgefüllt. Preparation and Crystal Structures of the First Two Members of a New Type of Lead (II) Oxyhalides, Pb₄[SiO₄]X₄ (X = Cl, Br) Both silicate-bearing lead(II) oxyhalides Pb₄[SiO₄]Cl₄ and Pb₄[SiO₄]Br₄ were prepared and studied for their crystal structure with X-ray single crystal methods for the first time. The compounds crystallize in the monoclinic space group P2₁/c (No. 14) with following lattice parameters: Pb₄[SiO₄]Cl₄: A = 8.73(1) Å, b = 15.68(1) Å, c = 8.205(6) Å, β = 92.4(1)°, Z = 4 Pb₄[SiO₄]Br₄: A = 9.00(1) Å, b = 16.217(8) Å, c = 8.404(4) Å, β = 92.4(1)°, Z = 4. In contrast with further works about the group of nonstoichiometric lead oxyhalides Pb₈O₇Br₂ · SiO₂ in the present work all atomic positions were determined. The crystal structure shows single SiO₄ groups linked only by Pb²⁺ ions to form slightly undulated nets. Holes and interspaces of these nets are stuffed with halide ions.     

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.     

Metal derivatives of thiosemicarbazones: crystal structure of [chloro bis(triphenylphosphino) (thiophene-2-carbaldehyde thiosemicarbazone) copper(I)] complex

Reactions of copper(I) halides (X = Cl, Br, I) with thiophene-2-carbaldehyde thiosemicarbazone and triphenylphosphine in 1 : 1 : 2 molar ratio yield tetrahedral mononuclear complexes, [CuX(η¹-S-Httsc)(Ph₃P)₂] (X = Cl, 1; Br, 2; I, 3), characterized by elemental analysis, IR, NMR (¹H, ¹³C, ³¹P), and single crystal X-ray crystallography (1). The unit cell of 1 has two independent distorted tetrahedral molecules (1a and 1b) with different bond parameters. One acetonitrile is entrapped between them. Crystal data: C₈₆H₇₇Cl₂Cu₂N₇P₄S₄ 1: triclinic, P-1, a = 12.8810(9), b = 18.5049(13), c = 18.7430(13) Å, α = 63.7130(10), β = 89.0960(10), γ = 85.5010(10)°, V = 3992.4(5) ų, Z = 2, R _(int) = 0.0314. Bond parameters: 1a, Cu(1A)–Cl(1A), 2.3803(5); Cu(1A)–S(1A), 2.3822(5); Cu(1A)–P(1A), 2.2498(5) Å; P(1A)–Cu(1A)–P(2A), 124.294(19)°; 1b, Cu(1B)–Cl(1B), 2.3975(5); Cu(1B)–S(1B), 2.3756(5); Cu(1B)–P(1B), 2.2777(5) Å; P(1B)–Cu(1B)–P(2B), 127.156(19)°.     

Reversible SO2 Uptake by Tetraalkylammonium Halides: Energetics and Structural Aspects of Adduct Formation Between SO2 and Halide Ions

Contact with SO₂ causes almost immediate dissolution of tetraalkylammonium halides, R₄NX, (R = CH₃ (Me), X = I; R = C₂H₅ (Et), X = Cl, Br, I; R = C₄H₉ (nBu), X = Cl, Br), with the formation of an adduct, [R₄N]⁺[(SO₂)_nX]^– (n = 1–4). Vapor pressure measurements indicate the proclivity for SO₂ uptake follows the order N(CH₃)₄⁺ < N(C₂H₅)₄⁺ < N(C₄H₉)₄⁺. This trend is in accord with the Jenkins–Passmore volume‐based thermodynamic model. Born–Haber cycles, incorporating the lattice energy and gas phase energy terms, are used to evaluate the energetic feasibility of reactions. Density functional theory calculations (B3PW91; 6‐311+G(3df)) have been used to calculate the energetics of (SO₂)_nX^– (X = Cl and Br) anions in the gas phase. The experimental studies show that tetraalkylammonium halides are feasible sorbents for SO₂. In order to correlate the theoretical model, experimental enthalpy, Δ_rH° and entropy, Δ_rS° changes have been determined by the van't Hoff method for the binding of one SO₂ molecule to (C₂H₅)₄NCl, resulting in the liquid adduct (C₂H₅)₄NCl · SO₂. The structure of the analogous 1:1 bromide adduct, (C₂H₅)₄NBr · SO₂, has been determined by single‐crystal X‐ray diffraction (monoclinic, P2₁/c, a = 9.1409(14) Å, b = 12.3790(19) Å, c = 11.3851(17) Å, β = 107.952(2)°, V = 1225.6(3) ų). The structure consists of discrete alkylammonium cations, bromide anions and SO₂ molecules with short contacts between the anion and SO₂ molecules. The (C₂H₅)₄N⁺ cationadopts a transoid conformation with D_2d symmetry, and represents a rare example of a well‐ordered (C₂H₅)₄N⁺ cation in a crystal structure. The Br^– anions and SO₂ molecules forms a chain, (SO₂Br^–)_n, with bifurcated contacts. Non‐bonding electron pairs on the halide anions engage in electrostatic interactions with the sulfur atoms and charge‐transfer interactions with the antibonding S–O orbitals of the bound SO₂ moiety. Raman and ¹⁷O NMR spectra provide compelling evidence for a charge‐transfer interaction between SO₂ molecules and the halide ions.     

Einkristall-Röntgenstrukturanalysen an Verbindungen mit kovalenter Metall—Metall-Bindung. II. Die Molekül- und Kristallstruktur von X2Sn[Mn(CO)5]2 (XCl,Br) Verbindungen

Single Crystal X-Ray Analysis of Compounds with Covalent Metal–Metal Bonds. II. Molecular and Crystal Structure of X₂Sn[Mn(CO)₅]₂ (X?Cl, Br) Both X₂Sn[Mn(CO)₅]₂ compounds (X?Cl, Br) crystallize in the monoclinic crystal system with at times different values in the lattice parameters. They belong to the space group C_2h⁵. The structures have been solved using 2 107 symmetrical independent reflection for Cl₂Sn[Mn(CO)₅]₂ and 1 470 reflections for Br₂Sn[Mn(CO)₅)₂] by applying the heavy atom method. The following interatomic distances have been found: Cl₂Sn[Mn(CO)₅]₂, Sn? Mn = 2.635(1) Å, Sn? Cl = 2.385(2) Å, Mn? C = 1.852(8) Å, C? O = 1.128(10) Å; Br₂Sn[Mn(CO)₅]₂, Sn? Mn = 2.642(3) Å, Sn? Br = 2.548(2) Å, Mn? C = 1.851(21) Å, C? O = 1.124(25) Å. In addition, bond angles of X? Sn? X and Mn? Sn? Mn of these compounds have also been estimated in the case of X = Cl: 95.80(7)° and 126.25(4)° and for X?Br: 98.44(8)° and 125.88(9)°. The individual molecules of the X₂Sn[Mn(CO)₅]₂ solids are surrounded by ligands showing distorted tetrahedral configuration at the Sn atom and distorted octahedral configuration at the Mn atom.     

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.     

Mg2[BN2]Cl and Mg8[BN2]5I: Novel Magnesium Nitridoborate Halides — Syntheses,Crystal Structures,and Vibrational Spectra

The title compounds have been synthesized at 1473 K from stoichiometric mixtures of the binary components Mg₃N₂, MgX₂ (X = Cl, I) and BN in arc‐welded steel ampoules encapsulated in evacuated silica tubes. Mg₂[BN₂]Cl ( 1 ) and Mg₈[BN₂]₅I ( 2 ) crystallize in the orthorhombic space groups Pbca (no. 61) and Imma (no. 74), respectively, with a = 6.6139(8)Å, b = 9.766(1)Å, c = 10.600(1)Å, Z = 8 for 1 and a = 13.535(3)Å, b = 9.350(2)Å, c = 11.194(2)Å, Z = 4 for 2 . The crystal structures are characterized mainly by Mg₆ trigonal prisms which are condensed to 3D frameworks in different ways. Part of the trigonal prisms are centered by the [N—B—N]^3— anions and other voids in the framework by the X^— anions. The magnesium environment around Cl^— is a very distorted monocapped trigonal prism (CN = 6+1) and that of I^— is a bicapped heptagonal prism (CN = 14+2). The bond lengths and bond angles for the relevant [BN₂]^3— anions are d(B—N) = 1.330 — 1.338Å, ∠N—B—N = 175.8° in 1 and d(B—N) = 1.330 — 1.339Å, ∠N—B—N = 176.8° — 178.0° in 2 . The vibrational spectra of the title compounds have been recorded and interpreted based on the D_∞h symmetry of the relevant [N—B—N]^3— groups considering the site symmetry splitting.