Dibromomethyl- and bromomethyl- or bromo-substituted benzenes and naphthalenes: C—Br…Br interactions

The structures of six benzene and three naphthalene derivatives involving bromo, bromomethyl and dibromomethyl substituents, namely, 1,3-dibromo-5-(dibromomethyl)benzene, C₇H₄Br₄, 1,4-dibromo-2,5-bis(bromomethyl)benzene, C₈H₄Br₆, 1,4-dibromo-2-(dibromomethyl)benzene, C₇H₄Br₄, 1,2-bis(dibromomethyl)benzene, C₈H₆Br₄, 1-(bromomethyl)-2-(dibromomethyl)benzene, C₈H₇Br₃, 2-(bromomethyl)-3-(dibromomethyl)naphthalene, C₁₂H₉Br₃, 2,3-bis(dibromomethyl)naphthalene, C₁₂H₈Br₄, 1-(bromomethyl)-2-(dibromomethyl)naphthalene, C₁₂H₉Br₃, and 1,3-bis(dibromomethyl)benzene, C₈H₆Br₄, are presented. The packing patterns of these compounds are dominated by Br…Br contacts and C—H…Br hydrogen bonds. The Br…Br contacts, shorter than twice the van der Waals radius of bromine (3.7 Å), seem to play a crucial role in the crystal packing of all these compounds. The occurrence of Type I and Type II interactions is also discussed briefly, considering the effective atomic radius of bromine, as is their impact on the packing of molecules in the individual structures.     

Crystal structure of the clathrate compound [dibromotetra(pyridine)copper(II)]·pyridine. Characterization by EXAFS of the pyridine desorption product

Powder samples of the new compound [Cu(C₅H₅N)₄·Br₂](C₅H₅N) and of its desorption product have been studied by EXAFS. The crystal structure of [Cu(C₅H₅N)₄Br₂]·(C₅H₅N) has been determined from three-dimensional X-ray diffraction data and refined to theR value 0.038 for 379 observed reflections. (orthorhombic,Ccca,a=12.033(8),b=14.764(3),c=16.768 Å,V=1897(3) ų,Z=4). The copper atom lies on a 222 symmetry site and is hexacoordinated with four nitrogen and two bromine atoms, forming an elongated octahedron with the bromine atoms in apical positions (Cu–Br distance: 3.201(2) , Cu–N1/N2 distances: 2.02(1)/2,07(1) ). The host molecules (Cu(C₅H₅N)₄Br₂) form layers parallel to the (001) plane. Cavities in the space between these layers, bound by pyridine ligands protruding into this space, are occupied by the guest molecules (C₅H₅N). The guest desorption at room temperature is accompanied by a chemical and structural destruction of the host, leading to the known compound Cu(C₅H₅N)₂Br₂.Supplementary Data relevant to this article (lists of observed and calculated structure factors, calculated positional parameters of H atoms, root-mean-square amplitudes of thermal vibration and anisotropic thermal parameters) have been deposited with the British Library as Supplementary Publication SUP 82163 (5 pages)     

Dosage du silicium par précipitation du complexe silicomolybdique jaune par la quinoléine

The authors have studied the conditions of precipitation of complex silicomolybdic yellow by quinoline from the point of view of the determination of silicon.Under the conditions that produce complete development of the complex, the precipitation is itself quantitative in the presence of an excess of quinoline, the role of which is to make the precipitate insoluble in its formation surroundings. The precipitation of free molybdate is prevented by adding the quantity of acid necessary for complexing it.The precipitate thus obtained filters without difficulty, and only needs to be dried for 1 hour at 150° in order to attain constant weight. It corresponds then exactly to the formula: SiO₂.12MoO₃.4(C₉H₇N).2H₂O.     

Indenylvanadium(V)‐Verbindungen. Darstellung,Struktur und NMR‐spektroskopische Untersuchungen

Indenylvanadium(V) Compounds Synthesis, Structure, and NMR Spectroscopic Studies Syntheses of the indenylvanadium(V)compounds are described: ^tC₄H₉N = V(η⁵‐C₉H₇)Cl₂ ( 1 ), ^tC₄H₉N = V(η⁵‐C₉H₇)Br₂ ( 2 ), ^tC₄H₉N = V(η⁵‐C₉H₇)(O^tC₄H₉)Cl ( 3 ), ^tC₄H₉N = V(η¹‐C₉H₇)(O^tC₄H₉)₂ ( 4 ), ^tC₄H₉N = V(η¹‐C₉H₇)₂(O^tC₄H₉) ( 5 ), ^tC₄H₉N = V(η¹‐C₉H₇)(η⁵‐C₅H₅) · (O^tC₄H₉) ( 6 ), ^tC₄H₉N = V(η¹‐C₉H₇)(η⁵‐C₅H₅)(NH^tC₄H₉) ( 7 ). All compounds were totally characterized by spectroscopic methods (MS; ¹H, ¹³C, ⁵¹V NMR), 3 by single crystal X‐ray diffraction. For 6 the presence of the diastereomeres RR/SS and RS/SR was shown by NMR spectroscopy. The chlorovanadate (IV) complex [NHC₄H₉]₂⁺[(^tC₄H₉N)₇V₇ · (μ‐Cl)₁₄Cl₂]^2– has been obtained by decomposition of 1 in solution; the crystal structure indicates a wheel structure with hydrogen bonds between the tert‐butylammonium cations and the complex anion.     

Pseudosymmetry in a cyclopalladated compound

The enantiomerically pure title complex, [SP‐4‐4]‐(R)‐[2‐(1‐aminoethyl)phenyl‐κ²C¹,N]chlorido(quinoline‐κN)palladium(II) acetone hemisolvate, [Pd(C₈H₁₀N)Cl(C₉H₇N)]·0.5C₃H₆O, crystallizes with four molecules of the organopalladium complex and two molecules of acetone in the asymmetric unit. This corresponds to a discrete hydrogen‐bonded aggregate and to the content of the unit cell in the space group P1. Pronounced pseudo‐inversion symmetry relates pairs of these objects in the asymmetric unit.     

Synthesis, crystal structure and optical limiting properties of some W---Se---Cu clusters

A nest-shaped cluster [(C₄H₉)₄N]₂[WOSe₃Cu₃Br_1.67Cl_1.33] (1) and a cage-shaped cluster [(C₄H₉)₄N]₃[WSe₄Cu₃Br₂Cl₂] (2) were synthesized and their structures were determined by single-crystal X-ray diffraction. It was found that cluster 1 showed better optical limiting properties under an 8 ns pulsed laser at 532 nm but poorer optical limiting properties under a 35 ps pulsed laser compared with its analogue [(C₄H₉)₄N]₂[MoOS₃Cu₃BrCl₂]. The influence of the peripheral ligands of the cluster to the optical limiting properties was also discussed.     

Systematic Study of Quaternary Ammonium Cations for Bromine Sequestering Application in High Energy Density Electrolytes for Hydrogen Bromine Redox Flow Batteries

Bromine complexing agents (BCAs) are used to reduce the vapor pressure of bromine in the aqueous electrolytes of bromine flow batteries. BCAs bind hazardous, volatile bromine by forming a second, heavy liquid fused salt. The properties of BCAs in a strongly acidic bromine electrolyte are largely unexplored. A total of 38 different quaternary ammonium halides are investigated ex situ regarding their properties and applicability in bromine electrolytes as BCAs. The focus is on the development of safe and performant HBr/Br₂/H₂O electrolytes with a theoretical capacity of 180 Ah L⁻¹ for hydrogen bromine redox flow batteries (H₂/Br₂-RFB). Stable liquid fused salts, moderate bromine complexation, large conductivities and large redox potentials in the aqueous phase of the electrolytes are investigated in order to determine the most applicable BCA for this kind of electrolyte. A detailed study on the properties of BCA cations in these parameters is provided for the first time, as well as for electrolyte mixtures at different states of charge of the electrolyte. 1-ethylpyridin-1-ium bromide [C2Py]Br is selected from 38 BCAs based on its properties as a BCA that should be focused on for application in electrolytes for H₂/Br₂-RFB in the future.     

Nine compounds containing high‐nuclearity [CunX2n+2]2− (n = 4, 5 or 7; X = Cl or Br) quasi‐planar oligomers

The structures of seven A₂Cu₄X₁₀ compounds containing quasi‐planar oligomers are reported: bis(1,2,4‐trimethylpyridinium) hexa‐μ‐chlorido‐tetrachloridotetracuprate(II), (C₈H₁₂N)₂[Cu₄Cl₁₀], (I), and the hexa‐μ‐bromido‐tetrabromidotetracuprate(II) salts of 1,2,4‐trimethylpyridinium, (C₈H₁₂N)₂[Cu₄Br₁₀], (II), 3,4‐dimethylpyridinium, (C₇H₁₀N)₂[Cu₄Br₁₀], (III), 2,3‐dimethylpyridinium, (C₇H₁₀N)₂[Cu₄Br₁₀], (IV), 1‐methylpyridinium, (C₆H₈N)₂[Cu₄Br₁₀], (V), trimethylphenylammonium, (C₉H₁₄N)₂[Cu₄Br₁₀], (VI), and 2,4‐dimethylpyridinium, (C₇H₁₀N)₂[Cu₄Br₁₀], (VII). The first four are isomorphous and contain stacks of tetracopper oligomers aggregated through semicoordinate Cu...X bond formation in a 4(,) stacking pattern. The 1‐methylpyridinium salt also contains oligomers stacked in a 4(,) pattern, but is isomorphous with the known chloride analog instead. The trimethylphenylammonium salt contains stacks of oligomers arranged in a 4(,) stacking pattern similar to the tetramethylphosphonium analog. These six structures feature inversion‐related organic cation pairs and hybrid oligomer/organic cation layers derived from the parent CuX₂ structure. The 2,4‐dimethylpyridinium salt is isomorphous with the known (2‐amino‐4‐methylpyridinium)₂Cu₄Cl₁₀ structure, in which isolated stacks of organic cations and of oligomers in a 4(,) pattern are found. In bis(3‐chloro‐1‐methylpyridinium) octa‐μ‐bromido‐tetrabromidopentacuprate(II), (C₆H₇ClN)[Cu₅Br₁₂], (VIII), containing the first reported fully halogenated quasi‐planar pentacopper oligomer, the oligomers stack in a 5(,) stacking pattern as the highest nuclearity [Cu_nX_2n+2]²⁻ oligomer compound known with isolated stacking. Bis(2‐chloro‐1‐methylpyridinium) dodeca‐μ‐bromido‐tetrabromidoheptacuprate(II), (C₆H₇ClN)₂[Cu₇Br₁₆], (IX), contains the second heptacopper oligomer reported and consists of layers of interleaved oligomer stacks with a 7[(,)][(−,−)] pattern isomorphous with that of the known 1,2‐dimethylpyridinium analog. All the oligomers reported here are inversion symmetric.     

新型电荷转移配合物的合成与表征

近年来有关多金属氧酸盐与有机化合物间电荷转移配合物的光化学和光致变色过程的研究日趋活跃［１,２］,但迄今这类电荷转移配合物中的多金属氧酸盐基本上为Ｌｉｎｄｑｕｉｓｔ结构的同多酸或Ｋｅｇｇｉｎ结构的杂多酸,有机给体则基本上限于有机胺及其衍生物（如酰胺）...     

Properties of Bromine Fused Salts Based on Quaternary Ammonium Molecules and Their Relevance for Use in a Hydrogen Bromine Redox Flow Battery

Bromine complexing agents (BCA) in aqueous electrolytes for hydrogen bromine flow batteries are used to reduce bromine‘s vapour pressure, while an insoluble and liquid fused salt is formed. The properties (concentrations, composition, conductivity and viscosity) of this fused salt are investigated in this study systematically ex situ by using 7 BCAs at different state of charge in HBr/Br₂/H₂O electrolytes with a theoretical capacity of 179.6 Ah L⁻¹. Bromine is stored in the fused salt at concentrations up to 13.6 M, reaching theoretical volumetrical capacities up to 730 Ah L⁻¹ in fused salts. The fused salt consists of a pure, bromine- and water-free ionic liquid of organic [BCA]⁺ cations and polybromides, and its conductivity bases on a hopping mechanism among the polybromides. Alkyl side chain length of the BCAs and distribution of polybromides influence strongly the conductivity and viscosity of the fused salts. 1-ethylpyridin-1-iumbromide results to be favoured BCA for application.     

Halide and complex halogeno anions as salts of oxinate chelates of titanium(IV)

(η⁵-Cyclopentadienyl)(η⁵-pyrrolyl)titanium(IV) dichloride, (η⁵-indenyl)-(η⁵-pyrrolyl)titanium(IV) dichloride and (η⁵-cyclopentadienyl)(η⁵-indenyl)-titanium(IV) dichloride, when treated with 8-hydroxyquinoline (oxine) in aqueous medium form ionic derivatives of the type, [(η⁵-R)(η⁵-R′)TiL]⁺ Cl^- (R = C₅H₅, C₉H₇, R′ = C₄H₄N; R = C₅H₅, R′ = C₉H₇; L is the conjugate base of (oxine). A number of halide and complex halogeno anions present in aqueous solution were isolated as salts of these ionic complexes giving derivatives of the type, [(η⁵-R)(η⁵-R′)TiL]⁺ X^- (X = Br^-, I^-, ZnCl₃(H₂O)^-, CdCl₄^2-, HgCl₃^-). Conductivity measurements in nitrobenzene solution indicate that these complexes are electrolytes. Both the IR and ¹H NMR spectral studies demonstrate that the ligand L is chelating. Consequently there is tetrahedral coordination about the titanium(IV) ion.     

Hydrogen‐bonded structures of the isomeric compounds of quinoline with 2‐chloro‐5‐nitrobenzoic acid, 3‐chloro‐2‐nitrobenzoic acid, 4‐chloro‐2‐nitrobenzoic acid and 5‐chloro‐2‐nitrobenzoic acid

The structures of four isomeric compounds, all C₇H₄ClNO₄·C₉H₇N, of quinoline with chloro‐ and nitro‐substituted benzoic acid, namely, 2‐chloro‐5‐nitrobenzoic acid–quinoline (1/1), (I), 3‐chloro‐2‐nitrobenzoic acid–quinoline (1/1), (II), 4‐chloro‐2‐nitrobenzoic acid–quinoline (1/1), (III), and 5‐chloro‐2‐nitrobenzoic acid–quinoline (1/1), (IV), have been determined at 185 K. In each compound, a short hydrogen bond is observed between the pyridine N atom and a carboxyl O atom. The N...O distances are 2.6476 (13), 2.5610 (13), 2.5569 (12) and 2.5429 (12) Å for (I), (II), (III) and (IV), respectively. Although in (I) the H atom in the hydrogen bond is located at the O site, in (II), (III) and (IV) the H atom is disordered in the hydrogen bond over two positions with (N site):(O site) occupancies of 0.39 (3):0.61 (3), 0.47 (3):0.53 (3) and 0.65 (3):0.35 (3), respectively.     

TRANSITION METAL COMPLEXES WITH HYDRAZIDES AND HYDRAZONES. PART 81. X-RAY CRYSTAL STRUCTURE OF A CATENA-POLYBROMO (ACETONE-1-NAPHTHOYLHYDRAZONE) COPPER(II)-COPPER(I) COMPLEX

Abstract

The title compound [Cu₃Br₄C₂₈H₂₈N₄O₂] is a type of polymeric three-centre octahedral-trigonal planar coordination complex. The copper(II) atom located at a centre of symmetry is six-coordinate with two bidentate (N3, O1) ligands of acetone-1-naphthoylhydrazone forming the equatorial plane and two bromine ions in axial positions (Cul-Brl = 2.946(1)Å). The ligands are in trans positions. The Cu(I) atoms are in trigonal planar coordination by two bridging Br^? ions (Cu2-Br2 = 2.412(1)Å, Cu2-Br2? = 2.407(2)Å) which connect two Cu(I) atoms and a third bromine ion shared with the octahedral Cu(II) ion (Cu2-Br1 = 2.304(1)Å). The arrangement forms an infinite chain along the b axis.     

fac‐Trichloro(quinolin‐8‐ylimido‐N,N′)(triphenylphosphine‐P)rhenium(V)

The Re atom in [Re(C₉H₆N₂)Cl₃(C₁₈H₁₅P)] is octahedrally coordinated by three Cl atoms in facial positions, two N atoms from 8‐imido­quinoline (imq) and one P atom from tri­phenyl­phosphine. The Re—N(imido) distance [1.760 (9) and 1.772 (8) Å] for imq is very short and implies double‐bond character. The trans influence of the P atom is indicated. Intra‐ and intermolecular π–π interactions between the π‐rings in the complex are also observed.     

Hydrogen‐bonded chains in three cis‐dichloridoplatinum(II) complexes bearing piperidine and amine ligands

The crystal structures of cis‐dichlorido(ethylamine‐κN)(piperidine‐κN)platinum(II), [PtCl₂(C₂H₇N)(C₅H₁₁N)], (I), cis‐dichlorido(3‐methoxyaniline‐κN)(piperidine‐κN)platinum(II), [PtCl₂(C₅H₁₁N)(C₇H₉NO)], (II), and cis‐dichlorido(piperidine‐κN)(quinoline‐κN)platinum(II), [PtCl₂(C₅H₁₁N)(C₉H₇N)], (III), have been determined at 100 K in order to verify the influence of the nonpiperidine ligand on the geometry and crystal packing. The crystal packing is characterized by N—H...Cl hydrogen bonding, resulting in the formation of chains of molecules connected in a head‐to‐tail fashion. Hydrogen‐bonding interactions play a major role in the packing of (I), where the chains further aggregate into planes, but less so in the case of (II) and (III), where π–π stacking interactions are of greater importance.     

[Hg8(μ‐n‐C3H7Te)12(μ‐Br)Br3] — Synthesis and Structure

The novel mercury‐tellurium cluster [Hg₈(μ‐n‐C₃H₇Te)₁₂(μ₂‐Br)Br₃] is formed during the reaction of HgBr₂ and (n‐C₃H₇Te)₂Hg in DMSO. Its crystal structure has been elucidated showing [Hg₈(μ‐n‐C₃H₇Te)₁₂(μ₂‐Br)]³⁺ units with a bromine‐centered distorted Hg₈ cube. The mercury atoms are bridged by n‐C₃H₇Te^— ligands and the resulting clusters are linked to a three‐dimensional network by bromine atoms. The close packing of the cluster is mainly determined by the flexible n‐propyl residues of the telluride building blocks.     

Dichlorido{2‐[(2,6‐diethylphenyl)iminomethyl]quinoline‐κ2N,N′}palladium(II) acetonitrile monosolvate

The title complex, [PdCl₂(C₂₀H₂₀N₂)]·CH₃CN, was synthesized by the reaction of 2‐[(2,6‐diethylphenyl)iminomethyl]quinoline with dichlorido(cycloocta‐1,5‐diene)palladium(II) in dry CH₂Cl₂. The Pd^II ion is coordinated by two N atoms of the bidentate quinoline ligand and by two chloride anions, generating a distorted square‐planar coordination geometry around the metal centre. There is a detectable trans influence for the chloride ligands. The crystal packing is characterized by π–π stacking between the quinoline rings. The use of acetonitrile as the crystallization solvent was essential for obtaining good‐quality crystals.     

Crystal structure of [Co(N2C2H8)3] [AuBr4]2Br bis(tetrabromoaurate(III))tris(ethylenediamine) cobalt(III) bromide

A double complex salt [Co(N₂C2H₈)₃][AuBr₄]₂Br is obtained and characterized using single crystal X-ray diffraction analysis. The crystallographic data of C₆H₂₄Au₂Br₉CoN₆ are as follows: a = 21.6479(17) ?, b = 14.9085(12) ?, c = 8.2676(7) ?, β = 110.820(2)°, V = 1538.92(12) ?³, C2/c space group, Z = 4, d _x = 3.602 g/cm³. Square planar coordination of the gold atom in the complex anion is completed to a tetragonal pyramid by an additional bromine atom of the adjacent complex anion at the Au... Br distance of 3.677 ?.     

Solubility of bromine derivatives of C<Subscript>60</Subscript>Br<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript> fullerene in α-chloro- and α-bromonaphthalene in the temperature range 10–60°C

Isothermal saturation in ampoules was used to study the solubility of bromine derivatives of fullerene C₆₀Br _n (n = 6, 8, 24) in α-C₁₀H₇Cl and α-C₁₀H₇Br in the temperature range of 10–60°C. The corresponding solubility polytherms were characterized, and the compositions of the equilibrium crystal solvates and the density of the saturated solutions of C₆₀Br _n were determined.