1‐Carboxymethyl‐3‐methyl‐1H‐imidazol‐3‐ium chloride 2‐(3‐methyl‐1H‐imidazol‐3‐ium‐1‐yl)acetate monohydrate: a crystal stabilized by imidazolium zwitterions

The title compound, C₆H₉N₂O₂⁺·Cl⁻·C₆H₈N₂O₂·H₂O, contains one 2‐(3‐methyl‐1H‐imidazol‐3‐ium‐1‐yl)acetate inner salt molecule, one 1‐carboxymethyl‐3‐methyl‐1H‐imidazol‐3‐ium cation, one chloride ion and one water molecule. In the extended structure, chloride anions and water molecules are linked via O—H...Cl hydrogen bonds, forming an infinite one‐dimensional chain. The chloride anions are also linked by two weak C—H...Cl interactions to neighbouring methylene groups and imidazole rings. Two imidazolium moieties form a homoconjugated cation through a strong and asymmetric O—H...O hydrogen bond of 2.472 (2) Å. The IR spectrum shows a continuous D‐type absorption in the region below 1300 cm⁻¹ and is different to that of 1‐carboxymethyl‐3‐methylimidazolium chloride [Xuan, Wang & Xue (2012). Spectrochim. Acta Part A, 96 , 436–443].     

A new two‐dimensional managnese(II) coordination polymer constructed by 2,2′‐(1,2‐phenylene)bis(1H‐imidazole‐4,5‐dicarboxylate)

In recent years, N‐heterocyclic carboxylate ligands have attracted much interest in the preparation of new coordination polymers since they contain N‐atom donors, as well as O‐atom donors, and have a rich variety of coordination modes which can lead to polymers with intriguing structures and interesting properties. A new two‐dimensional coordination polymer, namely poly[[μ₃‐2,2′‐(1,2‐phenylene)bis(4‐carboxy‐1H‐imidazole‐5‐carboxylato)‐κ⁶O⁴,N³,N^3′,O^4′:O⁵:O^5′]manganese(II)], [Mn(C₁₆H₈N₄O₈)]_n or [Mn(H₄Phbidc)]_n, has been synthesized by the reaction of Mn(OAc)₂·4H₂O (OAc is acetate) with 2,2′‐(1,2‐phenylene)bis(1H‐imidazole‐4,5‐dicarboxylic acid) (H₆Phbidc) under solvothermal conditions. In the polymer, each Mn^II ion is six‐coordinated by two N atoms from one H₄Phbidc²⁻ ligand and by four O atoms from three H₄Phbidc²⁻ ligands, forming a significantly distorted octahedral MnN₂O₄ coordination geometry. The Mn^II ions are linked by hexadentate H₄Phbidc²⁻ ligands, leading to a two‐dimensional structure parallel to the ac plane. In the crystal, adjacent layers are further connected by N—H…O hydrogen bonds, forming a three‐dimensional structure in the solid state.     

A new one‐dimensional CdII coordination polymer incorporating 2,2′‐(1,2‐phenylene)bis(1H‐imidazole‐4,5‐dicarboxylate)

Imidazole‐4,5‐dicarboxylic acid (H₃IDC) and its derivatives are widely used in the preparation of new coordination polymers owing to their versatile bridging coordination modes and potential hydrogen‐bonding donors and acceptors. A new one‐dimensional coordination polymer, namely catena‐poly[[diaquacadmium(II)]‐μ₃‐2,2′‐(1,2‐phenylene)bis(1H‐imidazole‐4,5‐dicarboxylato)], [Cd(C₁₆H₆N₄O₈)_0.5(H₂O)₂]_n or [Cd(H₂Phbidc)_1/2(H₂O)₂]_n, has been synthesized by the reaction of Cd(OAc)₂·2H₂O (OAc is acetate) with 2,2′‐(1,2‐phenylene)bis(1H‐imidazole‐4,5‐dicarboxylic acid) (H₆Phbidc) under solvothermal conditions. In the polymer, one type of Cd ion (Cd1) is six‐coordinated by two N atoms and two O atoms from one H₂Phbidc⁴⁻ ligand and by two O atoms from two water molecules, forming a significantly distorted octahedral CdN₂O₄ coordination geometry. In contrast, the other type of Cd ion (Cd2) is six‐coordinated by two N atoms and two O atoms from two symmetry‐related H₂Phbidc⁴⁻ ligands and by two O atoms from two symmetry‐related water molecules, leading to a more regular octahedral coordination geometry. The Cd1 and Cd2 ions are linked by H₂Phbidc⁴⁻ ligands into a one‐dimensional chain which runs parallel to the b axis. In the crystal, the one‐dimensional chains are connected through hydrogen bonds, generating a two‐dimensional layered structure parallel to the ab plane. Adjacent layers are further linked by hydrogen bonds, forming a three‐dimensional structure in the solid state.     

The interplay of solvation,molecular conformation and supramolecular assembly in 1,1′‐({[(ethane‐1,2‐diyl)dioxy](1,2‐phenylene)}bis(methanylylidene))bis(thiosemicarbazide) and its N,N‐dimethylformamide disolvate

The wide diversity of applications of thiosemicarbazones and bis(thiosemicarbazones) has seen them used as anticancer and antitubercular agents, and as ligands in metal complexes designed to act as site‐specific radiopharmaceuticals. Molecules of 1,1′‐({[(ethane‐1,2‐diyl)dioxy](1,2‐phenylene)}bis(methanylylidene))bis(thiosemicarbazide) {alternative name: 2,2′‐[ethane‐1,2‐diylbis(oxy)]dibenzaldehyde bis(thiosemicarbazide)}, C₁₈H₂₀N₆O₂S₂, (I), lie across twofold rotation axes in the space group C2/c, with an O—C—C—O torsion angle of −59.62 (13)° and a trans‐planar arrangement of the thiosemicarbazide fragments relative to the adjacent aryl rings. The molecules of (I) are linked by N—H...S hydrogen bonds to form sheets containing R²₄(38) rings and two types of R²₂(8) ring. In the N,N‐dimethylformamide disolvate, C₁₈H₂₀N₆O₂S₂·2C₃H₇NO, (II), the independent molecular components all lie in general positions, but one of the solvent molecules is disordered over two sets of atomic sites having occupancies of 0.839 (3) and 0.161 (3). The O—C—C—O torsion angle in the ArOCH₂CH₂OAr component is −75.91 (14)° and the independent thiosemicarbazide fragments both adopt a cis‐planar arrangement relative to the adjacent aryl rings. The ArOCH₂CH₂OAr components in (II) are linked by N—H...S hydrogen bonds to form deeply puckered sheets containing R²₂(8), R²₄(8) and two types of R²₂(38) rings, and which contain cavities which accommodate all of the solvent molecules in the interior of the sheets. Comparisons are made with some related compounds.     

A novel two‐dimensional CuSCN network templated by 2,2′‐dimethyl‐1,1′‐(butane‐1,4‐diyl)bis(1H‐imidazol‐3‐ium) cations

The cation‐templated self‐assembly of 1,4‐bis(2‐methyl‐1H‐imidazol‐1‐yl)butane (bmimb) with CuSCN gives rise to a novel two‐dimensional network, namely catena‐poly[2,2′‐dimethyl‐1,1′‐(butane‐1,4‐diyl)bis(1H‐imidazol‐3‐ium) [tetra‐μ₂‐thiocyanato‐κ⁴S:S;κ⁴S:N‐dicopper(I)]], {(C₁₂H₂₀N₄)[Cu₂(NCS)₄]}_n. The Cu^I cation is four‐coordinated by one N and three S atoms, giving a tetrahedral geometry. One of the two crystallographically independent SCN⁻ anions acts as a μ₂‐S:S bridge, binding a pair of Cu^I cations into a centrosymmetric [Cu₂(NCS)₂] subunit, which is further extended into a two‐dimensional 4⁴‐sql net by another kind of SCN⁻ anion with an end‐to‐end μ₂‐S:N coordination mode. Interestingly, each H₂bmimb dication, lying on an inversion centre, threads through one of the windows of the two‐dimensional 4⁴‐sql net, giving a pseudorotaxane‐like structure. The two‐dimensional 4⁴‐sql networks are packed into the resultant three‐dimensional supramolecular framework through bmimb–SCN N—H...N hydrogen bonds.     

Synthesis and crystal structures of some bis(3‐methyl‐1H‐indol‐2‐yl)(salicyl)methanes

Four 2,2′‐bisindolylmethanes (BIMs), a useful class of polyindolyl species joined to a central carbon, were synthesized using salicylaldehyde derivatives and simple acid catalysis; these are 2‐[bis(3‐methyl‐1H‐indol‐2‐yl)methyl]‐6‐methylphenol, (IIa), 2‐[bis(3‐methyl‐1H‐indol‐2‐yl)methyl]‐4,6‐dichlorophenol, (IIb), 2‐[bis(3‐methyl‐1H‐indol‐2‐yl)methyl]‐4‐nitrophenol, (IIc), and 2‐[bis(3‐methyl‐1H‐indol‐2‐yl)methyl]‐4,6‐di‐tert‐butylphenol, (IId). BIMs (IIa) and (IIb) were characterized crystallographically as the dimethyl sulfoxide (DMSO) disolvates, i.e. C₂₆H₂₄N₂O·2C₂H₆OS and C₂₅H₂₀Cl₂N₂O·2C₂H₆OS, respectively. Both form strikingly similar one‐dimensional hydrogen‐bonding chain motifs with the DMSO solvent molecules. BIM (IIa) packs into double layers of chains whose orientations alternate every double layer, while (IIb) forms more simply packed chains along the a axis. BIM (IIa) has a remarkably long c axis.     

2,2′‐(1,2‐Ethanediyldithio)bis(1,3‐benzothiazole)

In the title compound, C₁₆H₁₂N₂S₄, which is the result of the S‐alkyl­ation reaction of 2‐mercapto­benzo­thia­zole with ethyl­ene dibromide, the planes of the two benzo­thia­zole moieties form a dihedral angle of 3.84 (14)°. The bridging chain moiety, –SCH₂CH₂S–, adopts an antiperiplanar conformation. There are intermolecular S⃛S non‐bonded contacts of 3.6471 (9) Å, which stabilize the crystal packing.     

Synthesis and crystal structure of a two‐dimensional sodium coordination polymer of 4,4′‐(diazenediyl)bis(1H‐1,2,4‐triazol‐5‐one)

The crystal engineering of coordination polymers has aroused interest due to their structural versatility, unique properties and applications in different areas of science. The selection of appropriate ligands as building blocks is critical in order to afford a range of topologies. Alkali metal cations are known for their mainly ionic chemistry in aqueous media. Their coordination number varies depending on the size of the binding partners, and on the electrostatic interaction between the ligands and the metal ions. The two‐dimensional coordination polymer poly[tetra‐μ‐aqua‐[μ₄‐4,4′‐(diazenediyl)bis(5‐oxo‐1H‐1,2,4‐triazolido)]disodium(I)], [Na₂(C₄H₂N₈O₂)(H₂O)₄]_n, (I), was synthesized from 4‐amino‐1H‐1,2,4‐triazol‐5(4H)‐one (ATO) and its single‐crystal structure determined. The mid‐point of the imino N=N bond of the 4,4′‐(diazenediyl)bis(5‐oxo‐1H‐1,2,4‐triazolide) (ZTO²⁻) ligand is located on an inversion centre. The asymmetric unit consists of one Na⁺ cation, half a bridging ZTO²⁻ ligand and two bridging water ligands. Each Na⁺ cation is coordinated in a trigonal antiprismatic fashion by six O atoms, i.e. two from two ZTO²⁻ ligands and the remaining four from bridging water ligands. The Na⁺ cation is located near a glide plane, thus the two bridging O atoms from the two coordinating ZTO²⁻ ligands are on adjacent apices of the trigonal antiprism, rather than being in an anti configuration. All water and ZTO²⁻ ligands act as bridging ligands between metal centres. Each Na⁺ metal centre is bridged to a neigbouring Na⁺ cation by two water molecules to give a one‐dimensional [Na(H₂O)₂]_n chain. The organic ZTO²⁻ ligand, an O atom of which also bridges the same pair of Na⁺ cations, then crosslinks these [Na(H₂O)₂]_n chains to form two‐dimensional sheets. The two‐dimensional sheets are further connected by intermolecular hydrogen bonds, giving rise to a stabile hydrogen‐bonded network.     

A three‐dimensional CdII coordination polymer constructed from 1,1′‐biphenyl‐2,2′,5,5′‐tetracarboxylate and 1,4‐bis(1H‐imidazol‐1‐yl)benzene ligands

The title coordination polymer, poly[[aqua(μ₅‐1,1′‐biphenyl‐2,2′,5,5′‐tetracarboxylato)bis[μ₂‐1,4‐bis(1H‐imidazol‐1‐yl)benzene]dicadmium(II)] dihydrate], {[Cd₂(C₁₆H₆O₈)(C₁₂H₁₀N₄)₂(H₂O)]·2H₂O}_n, was crystallized from a mixture of 1,1′‐biphenyl‐2,2′,5,5′‐tetracarboxylic acid (H₄bpta), 1,4‐bis(1H‐imidazol‐1‐yl)benzene (1,4‐bib) and cadmium nitrate in water–dimethylformamide. The crystal structure consists of two crystallographically independent Cd^II cations, with one of the Cd^II cations possessing a slightly distorted pentagonal bipyramidal geometry. The second Cd^II centre is coordinated by carboxylate O atoms and imidazole N atoms from two separate 1,4‐bib ligands, displaying a distorted octahedral CdN₂O₄ geometry. The completely deprotonated bpta⁴⁻ ligand, exhibiting a new coordination mode, bridges five Cd^II cations to form one‐dimensional chains viaμ₃‐η¹:η²:η¹:η² and μ₂‐η¹:η¹:η⁰:η⁰ modes, and these are further linked by 1,4‐bib ligands to form a three‐dimensional framework with a (4².6⁴)(4.6²)(4³.6⁵.7²) topology. The structure of the coordination polymer is reinforced by intermolecular hydrogen bonding between carboxylate O atoms, aqua ligands and crystallization water molecules. The solid‐state photoluminescence properties were investigated and the complex might be a candidate for a thermally stable and solvent‐resistant blue fluorescent material.     

Reaction‐path calculations and crystal structures of 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dichloride dihydrate and 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dibromide

The design of new organic–inorganic hybrid ionic materials is of interest for various applications, particularly in the areas of crystal engineering, supramolecular chemistry and materials science. The monohalogenated intermediates 1‐(2‐chloroethyl)pyridinium chloride, C₅H₅NCH₂CH₂Cl⁺·Cl⁻, (I′), and 1‐(2‐bromoethyl)pyridinium bromide, C₅H₅NCH₂CH₂Br⁺·Br⁻, (II′), and the ionic disubstituted products 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dichloride dihydrate, C₁₂H₁₄N₂²⁺·2Cl⁻·2H₂O, (I), and 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dibromide, C₁₂H₁₄N₂²⁺·2Br⁻, (II), have been isolated as powders from the reactions of pyridine with the appropriate 1,2‐dihaloethanes. The monohalogenated intermediates (I′) and (II′) were characterized by multinuclear NMR spectroscopy, while (I) and (II) were structurally characterized using powder X‐ray diffraction. Both (I) and (II) crystallize with half the empirical formula in the asymmetric unit in the triclinic space group P. The organic 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dications, which display approximate C2h symmetry in both structures, are situated on inversion centres. The components in (I) are linked via intermolecular O—H…Cl, C—H…Cl and C—H…O hydrogen bonds into a three‐dimensional framework, while for (II), they are connected via weak intermolecular C—H…Br hydrogen bonds into one‐dimensional chains in the [110] direction. The nucleophilic substitution reactions of 1,2‐dichloroethane and 1,2‐dibromoethane with pyridine have been investigated by ab initio quantum chemical calculations using the 6–31G** basis. In both cases, the reactions occur in two exothermic stages involving consecutive S_N2 nucleophilic substitutions. The isolation of the monosubstituted intermediate in each case is strong evidence that the second step is not fast relative to the first.     

Triclinic and monoclinic polymorphs of meso‐(E,E)‐1,1′‐[1,2‐bis(4‐chlorophenyl)ethane‐1,2‐diyl]bis(phenyldiazene): the high‐yield synthesis of an unexpected product,concomitant polymorphism and configurational disorder

Pyrazolidine‐3,5‐diones and their derivatives exhibit a wide range of biological activities. Seeking to explore the effect of combining a hydrocarbyl ring substituent, as present in sulfinpyrazone (used to treat gout), with a chlorinated aryl ring, as present in muzolimine (a diuretic), we explored the reaction between 1‐phenylpyrazolidine‐3,5‐dione and 4‐chlorobenzaldehyde under mildly basic conditions in the expectation of producing the simple condensation product 4‐(4‐chlorobenzylidene)‐1‐phenylpyrazolidine‐3,5‐dione. However, the reaction product proved to be meso‐(E,E)‐1,1′‐[1,2‐bis(4‐chlorophenyl)ethane‐1,2‐diyl]bis(phenyldiazene), C₂₆H₂₀Cl₂N₄, and a tentative mechanism is proposed. Crystallization from ethanol produces two concomitant polymorphs, i.e. a triclinic form, (I), in the space group P, and a monoclinic form, (II), in the space group C2/c. In both polymorphs, the molecules lie across centres of inversion, but in (II), the molecules are subject to whole‐molecule disorder equivalent to configurational disorder with occupancies of 0.6021 (19) and 0.3979 (19). There are no hydrogen bonds in the crystal structure of polymorph (I), but the molecules of polymorph (II) are linked by C—H...π(arene) hydrogen bonds into complex chains, which are further linked into sheets by C—H...N interactions.     

2,2′‐(Iminodimethylene)bis(1H‐benzimidazolium)(1+) chloride

The title compound, C₁₆H₁₆N₅⁺·Cl⁻ (nbbH⁺·Cl⁻), displays N—H⋯N, N—H⋯Cl and π–π inter­actions in the crystal packing. The Cl⁻ anion is chelated by the nbbH⁺ cation via two N—H⋯Cl hydrogen bonds. Inter‐ion N—H⋯N and N—H⋯Cl hydrogen bonds link ions related by 2₁ screw axes into chains along the c axis. These chains are further linked by glide‐plane operations to generate a three‐dimensional network, which is additionally stabilized by inter­chain π–π inter­actions.     

A triangular palladium(II) supramolecular coordination complex based on 1,4‐bis(1H‐imidazol‐1‐yl)benzene and (2,2′‐bipyridyl)palladium(II) nitrate: synthesis and crystal structure

The self‐assembly of ditopic bis(1H‐imidazol‐1‐yl)benzene ligands ( L ^H) and the complex (2,2′‐bipyridyl‐κ²N,N′)bis(nitrato‐κO)palladium(II) affords the supramolecular coordination complex tris[μ‐bis(1H‐imidazol‐1‐yl)benzene‐κ²N³:N^3′]‐triangulo‐tris[(2,2′‐bipyridyl‐κ²N,N′)palladium(II)] hexakis(hexafluoridophosphate) acetonitrile heptasolvate, [Pd₃(C₁₀H₈N₂)₃(C₁₂H₁₀N₄)₃](PF₆)₆·7CH₃CN, 2 . The structure of 2 was characterized in acetonitrile‐d₃ by ¹H/¹³C NMR spectroscopy and a DOSY experiment. The trimeric nature of supramolecular coordination complex 2 in solution was ascertained by cold spray ionization mass spectrometry (CSI–MS) and confirmed in the solid state by X‐ray structure analysis. The asymmetric unit of 2 comprises the trimetallic Pd complex, six PF₆^? counter‐ions and seven acetonitrile solvent molecules. Moreover, there is one cavity within the unit cell which could contain diethyl ether solvent molecules, as suggested by the crystallization process. The packing is stabilized by weak inter‐ and intramolecular C—H…N and C—H…F interactions. Interestingly, the crystal structure displays two distinct conformations for the L ^H ligand (i.e. syn and anti), with an all‐syn‐[Pd] coordination mode. This result is in contrast to the solution behaviour, where multiple structures with syn/anti‐ L ^H and syn/anti‐[Pd] are a priori possible and expected to be in rapid equilibrium.     

Synthesis,characterization, X‐ray crystal structure and in vitro antitumour activity of sodium bis(2‐(3′,6′,9′‐trioxadecyl)‐1,2‐dicarba‐closo‐dodecaborane‐1‐carboxylato)triphenylstannate

Sodium bis[2‐(3′,6′,9′‐trioxadecyl)‐1,2‐dicarba‐closo‐dodecaborane‐1‐carboxylato]triphenylstannate, [(CH₃OCH₂CH₂OCH₂CH₂OCH₂CH₂)‐1,2‐C₂B₁₀H₁₀‐9‐COO)₂SnPh₃]^? Na⁺, compound 1, was synthesized by the 1:1 condensation of triphenyltin(IV) hydroxide with 2‐(3′,6′,9′‐trioxadecyl)‐1,2‐dicarba‐closo‐dodecaborane‐1‐carboxylic acid and crystallized in the presence of sodium bicarbonate. Its structure was determined by spectroscopy, elemental analysis and X‐ray diffraction. The structure of 1 consists of trigonal bipyramidal [Sn(Ph)₃(L)₂]^? anions and Na⁺ cations coordinated by oxygen atoms of polyoxaalkyl chains of different stannate anions, forming cation–anion chains elongated along the c axis. Compound 1 is significantly more active in vitro against seven tumour cell lines of human origin than 5‐fluorouracil, cis‐platin, carboplatin, and previously reported organotin carboranecarboxylates, but is less active than organotin polyoxaalkylcarboxylates. Copyright © 2004 John Wiley & Sons, Ltd.     

Tuning the energy level of TAPC: crystal structure and photophysical and electrochemical properties of 4,4′‐(cyclohexane‐1,1‐diyl)bis[N,N‐bis(4‐methoxyphenyl)aniline]

The energy level of a hole‐transporting material (HTM) in organic electronics, such as organic light‐emitting diodes (OLEDs) and perovskite solar cells (PSCs), is important for device efficiency. In this regard, we prepared 4,4′‐(cyclohexane‐1,1‐diyl)bis[N,N‐bis(4‐methoxyphenyl)aniline] ( TAPC‐OMe ), C₄₆H₄₆N₂O₄, to tune the energy level of 4,4′‐(cyclohexane‐1,1‐diyl)bis[N,N‐bis(4‐methylphenyl)aniline] ( TAPC ), which is a well‐known HTM commonly used in OLED applications. A systematic characterization of TAPC‐OMe , including ¹H and ¹³C NMR, elemental analysis, UV–Vis absorption, fluorescence emission, density functional theory (DFT) calculations and single‐crystal X‐ray diffraction, was performed. TAPC‐OMe crystallized in the triclinic space group P, with two molecules in the asymmetric unit. The dihedral angles between the central amine triangular planes and those of the phenyl groups varied from 26.56 (9) to 60.34 (8)° due to the steric hindrance of the central cyclohexyl ring. This arrangement might be induced by weak hydrogen bonds and C—H…π(Ph) interactions in the extended structure. The emission maxima of TAPC‐OMe showed a significant bathochomic shift compared to that of TAPC . A strong dependency of the oxidation potentials on the nature of the electron‐donating ability of substituents was confirmed by comparing oxidation potentials with known Hammett parameters (σ).     

Crystallographic report: 1,1‐Diphenyl‐3‐(triphenylgermyl)‐3‐(4‐chlorophenyl) propanol

The germanium atom in [(C₆H₅)₃GeCH(4‐ClC₆H₄)CH₂C(C₆H₅)₂OH] is in a distorted tetrahedral geometry. Steric hindrance precludes O? H···O intra‐ or inter‐molecular bonding. Copyright © 2005 John Wiley & Sons, Ltd.     

A three‐dimensional ZnII coordination polymer constructed from 1,1′‐biphenyl‐2,2′,4,4′‐tetracarboxylate and 1,4‐bis(1H‐imidazol‐1‐yl)benzene ligands exhibiting photoluminescence

Ligands based on polycarboxylic acids are excellent building blocks for the construction of coordination polymers; they may bind to a variety of metal ions and form clusters, as well as extended chain or network structures. Among these building blocks, biphenyltetracarboxylic acids (H₄bpta) with C ₂ symmetry have recently attracted attention because of their variable bridging and multidentate chelating modes. The new luminescent three‐dimensional coordination polymer poly[(μ₅‐1,1′‐biphenyl‐2,2′,4,4′‐tetracarboxylato)bis[μ₂‐1,4‐bis(1H‐imidazol‐1‐yl)benzene]dizinc(II)], [Zn₂(C₁₆H₆O₈)(C₁₂H₁₀N₄)]_n , was synthesized solvothermally and characterized by single‐crystal X‐ray diffraction, elemental analysis and IR spectroscopy. The crystal structure contains two crystallographically independent Zn^II cations. Both metal cations are located on twofold axes and display distorted tetrahedral coordination geometries. Neighbouring Zn^II centres are bridged by carboxylate groups in the syn –anti mode to form one‐dimensional chains. Adjacent chains are linked through 1,1′‐biphenyl‐2,2′,4,4′‐tetracarboxylate and 1,4‐bis(1H‐imidazol‐1‐yl)benzene ligands to form a three‐dimensional network. In the solid state, the compound exhibits blue photoluminescence and represents a promising candidate for a thermally stable and solvent‐resistant blue fluorescent material.     

Side‐chain conformations in the isomorphous polyfluorinated {4,4′‐bis[(2,2‐difluoroethoxy)methyl]‐2,2′‐bipyridine‐κ2N,N′}dichloridopalladium and ‐platinum complexes

The polyfluorinated title compounds, [M Cl₂(C₁₆H₁₆F₄N₂O₂)] or [4,4′‐(HCF₂CH₂OCH₂)₂‐2,2′‐bpy]M Cl₂ [M = Pd, ( 1 ), and M = Pt, ( 2 )], have –C(H_α)₂OC(H_β)₂CF₂H side chains with H‐atom donors at the α and β sites. The structures of ( 1 ) and ( 2 ) are isomorphous, with the nearly planar (bpy)M Cl₂ molecules stacked in columns. Within one column, π‐dimer pairs alternate between a π‐dimer pair reinforced with C—H…Cl hydrogen bonds (α,α) and a π‐dimer pair reinforced with C—H_β…F(—C) interactions (abbreviated as C—H_β…F—C,C—H_β…F—C). The compounds [4,4′‐(CF₃CH₂OCH₂)₂‐2,2′‐bpy]M Cl₂ [M = Pd, ( 3 ), and M = Pt, ( 4 )] have been reported to be isomorphous [Lu et al. (2012). J. Fluorine Chem. 137 , 54–56], yet with disorder in the fluorous regions. The molecules of ( 3 ) [or ( 4 )] also form similar stacks, but with alternating π‐dimer pairs between the (α,β; α,β) and (β,β) forms. Through (C—)H…Cl hydrogen‐bond interactions, one molecule of ( 1 ) [or ( 2 )] is expanded into an aggregate of two inversion‐related π‐dimer pairs, one pair in the (α,α) form and the other pair in the (C—H_β…F—C,C—H_β…F—C) form, with the plane normals making an interplanar angle of 58.24 (3)°. Due to the demands of maintaining a high coordination number around the metal‐bound Cl atoms in molecule ( 1 ) [or ( 2 )], the ponytails of molecule ( 1 ) [or ( 2 )] bend outward; in contrast, the ponytails of molecule ( 3 ) [or ( 4 )] bend inward.     

A three‐dimensional ZnII coordination framework: poly[[μ2‐(E)‐1,2‐bis(pyridin‐4‐yl)ethene][μ4‐(E)‐2,2′‐(diazene‐1,2‐diyl)dibenzoato][μ2‐(E)‐2,2′‐(diazene‐1,2‐diyl)dibenzoato]dizinc(II)]

In the title coordination polymer, [Zn₂(C₁₄H₈N₂O₄)₂(C₁₂H₁₀N₂)]_n, the asymmetric unit contains one Zn^II cation, two halves of 2,2′‐(diazene‐1,2‐diyl)dibenzoate anions (denoted L²⁻) and half of a 1,2‐bis(pyridin‐4‐yl)ethene ligand (denoted bpe). The three ligands lie across crystallographic inversion centres. Each Zn^II centre is four‐coordinated by three O atoms of bridging carboxylate groups from three L²⁻ ligands and by one N atom from a bpe ligand, forming a tetrahedral coordination geometry. Two Zn^II atoms are bridged by two carboxylate groups of L²⁻ ligands, generating a [Zn₂(CO₂)₂] ring. Each loop serves as a fourfold node, which links its four equivalent nodes via the sharing of four L²⁻ ligands to form a two‐dimensional [Zn₂L₄]_n net. These nets are separated by bpe ligands acting as spacers, producing a three‐dimensional framework with a 4⁶6⁴ topology. Powder X‐ray diffraction and solid‐state photoluminescence were also measured.     

Crystal structures of the anhydrous and two solvated forms of methyl 4‐(4‐fluorophenyl)‐6‐methyl‐2‐oxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylate

Methyl 4‐(4‐fluorophenyl)‐6‐methyl‐2‐oxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylate, ( I ), was found to exhibit solvatomorphism. The compound was prepared using a classic Biginelli reaction under mild conditions, without using catalysts and in a solvent‐free environment. Single crystals of two solvatomorphs and one anhydrous form of ( I ) were obtained through various crystallization methods. The anhydrous form, C₁₃H₁₃FN₂O₃, was found to crystallize in the monoclinic space group C2/c. It showed one molecule in the asymmetric unit. The solvatomorph with included carbon tetrachloride, C₁₃H₁₃FN₂O₃·0.25CCl₄, was found to crystallize in the monoclinic space group P2/n. The asymmetric unit revealed two molecules of ( I ) and one disordered carbon tetrachloride solvent molecule that lies on a twofold axis. A solvatomorph including ethyl acetate, C₁₃H₁₃FN₂O₃·0.5C₄H₈O₂, was found to crystallize in the triclinic space group P with one molecule of ( I ) and one solvent molecule on an inversion centre in the asymmetric unit. The solvent molecules in the solvatomorphs were found to be disordered, with a unique case of crystallographically induced disorder in ( I ) crystallized with ethyl acetate. Hydrogen‐bonding interactions, for example, N—H…O=C, C—H…O=C, C—H…F and C—H…π, contribute to the crystal packing with the formation of a characteristic dimer through N—H…O=C interactions in all three forms. The solvatomorphs display additional interactions, such as C—F…N and C—Cl…π, which are responsible for their molecular arrangement. The thermal properties of the forms were analysed through differential scanning calorimetry (DSC), hot stage microscopy (HSM) and thermogravimetric analysis (TGA) experiments.