Dimethylformamide Disolvate Research Articles

Low-dimensional compounds containing bioactive ligands. XXII. First crystal structure, cytotoxic activity and DNA and HSA binding of a zirconium(IV) complex with 8-hydroxyquinoline-2-carboxylic acid.

A new zirconium(IV) complex, diaquabis(8-hydroxyquinoline-2-carboxylato-κ3N,O2,O8)zirconium(IV) dimethylformamide disolvate, [Zr(C10H5NO3)2(H2O)2]·2C3H7NO or [Zr(QCa)2(H2O)2]·2DMF (1) (HQCaH is 8-hydroxyquinoline-2-carboxylic acid and DMF is dimethylformamide), was prepared and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray structure analysis. Complex 1 is a mononuclear complex in which the ZrIV atoms sit on the twofold axis and they are octacoordinated by two N and six O atoms of two tridentate anionic QCa2- ligands, and two aqua ligands. Outside the coordination sphere are two DMF molecules bound to the complex unit by hydrogen bonds. The structure and stability of complex 1 in dimethyl sulfoxide were verified by NMR spectroscopy. The cytotoxic properties of 1 and HQCaH were studied in vitro against eight cancer cell lines, and their selectivity was tested on the BJ-5ta noncancerous cell line. Both the complex and HQCaH exhibited low activity, with IC50 > 200 µM. DNA and human serum albumin (HSA) binding studies showed that 1 binds to calf thymus (CT) DNA via intercalation and is able to bind to the tryptophan binding site of HSA (Trp-214).

Crystal structures of two dioxomolybdenum complexes stabilized by salan ligands featuring phenyl and cyclo-hexyl backbones.

Two cis-dioxomolybdenum complexes based on salan ligands with different backbones are reported. The first complex, dioxido{2,2'-[l,2-phenyl-enebis(imino-methyl-ene)]bis-(phenolato)}molybdenum(VI) di-methyl-formamide disolvate, [Mo(C20H18N2O2)O2]·2C3H7NO (PhLMoO2, 1b), features a phenyl backbone, while the second complex, (6,6'-{[(cyclo-hexane-1,2-di-yl)bis(aza-nedi-yl)]bis-(methyl-ene)}bis-(2,4-di-tert-butyl-phenolato))dioxidomolybdenum(VI) methanol disolvate, [Mo(C36H56N2O2)O2]·2CH3OH (CyLMoO2, 2b), is based on a cyclo-hexyl backbone. These complexes crystallized as solvated species, 1b·2DMF and 2b·2MeOH. The salan ligands PhLH2 (1a) and CyLH2 (2a) coordinate to the molybdenum center in these complexes 1b and 2b in a κ2 N,κ2 O fashion, forming a distorted octa-hedral geometry. The Mo-N and Mo-O distances are 2.3475 (16) and 1.9567 (16) Å, respectively, in 1b while the corresponding measurements are Mo-N = 2.3412 (12) Å, and Mo-O = 1.9428 (10) Å for 2b. A key geometrical feature is that the N-Mo-N angle of 72.40 (4)° in CyLMoO2 is slightly less than that of the PhLMoO2 angle of 75.18 (6)°, which is attributed to the flexibility of the cyclo-hexane ring between the nitro-gen as compared to the rigid phenyl ring in the PhLMoO2.

A self-penetrated three-dimensional zinc(II) coordination framework based on 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tribenzoic acid and 1,3-bis[(imidazol-1-yl)methyl]benzene ligands: synthesis, structure and properties.

With the rapid development of metal-organic frameworks (MOFs), a variety of MOFs and their derivatives have been synthesized and reported in recent years. Commonly, multifunctional aromatic polycarboxylic acids and nitrogen-containing ligands are employed to construct MOFs with fascinating structures. 4,4',4''-(1,3,5-Triazine-2,4,6-triyl)tribenzoic acid (H3TATB) and the bidentate nitrogen-containing ligand 1,3-bis[(imidazol-1-yl)methyl]benzene (bib) were selected to prepare a novel ZnII-MOF under solvothermal conditions, namely poly[[tris{μ-1,3-bis[(imidazol-1-yl)methyl]benzene}bis[μ3-4,4',4''-(1,3,5-triazine-2,4,6-triyl)tribenzoato]trizinc(II)] dimethylformamide disolvate trihydrate], {[Zn3(C24H12N3O6)2(C14H14N4)3]·2C3H7NO·3H2O}n (1). The structure of 1 was characterized by single-crystal X-ray diffraction, IR spectroscopy and powder X-ray diffraction. The properties of 1 were investigated by thermogravimetric and fluorescence analysis. Single-crystal X-ray diffraction shows that 1 belongs to the monoclinic space group Pc. The asymmetric unit contains three crystallographically independent ZnII centres, two 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tribenzoate (TATB3-) anions, three complete bib ligands, one and a half free dimethylformamide molecules and three guest water molecules. Each ZnII centre is four-coordinated and displays a distorted tetrahedral coordination geometry. The ZnII centres are connected by TATB3- anions to form an angled ladder chain with large windows. Simultaneously, the bib ligands link ZnII centres to give a helical Zn-bib-Zn chain. Furthermore, adjacent ladders are bridged by Zn-bib-Zn chains to form a fascinating three-dimensional self-penetrated framework with the short Schläfli symbol 65·7·813·9·10. In addition, the luminescence properties of 1 in the solid state and the fluorescence sensing of metal ions in suspension were studied. Significantly, compound 1 shows potential application as a fluorescent sensor with sensing properties for Zr4+ and Cu2+ ions.

Synthesis, crystal structure and photoluminescence of a three-dimensional zinc coordination compound with NBO-type topology.

The assembly of metal-organic frameworks (MOFs) with metal ions and organic ligands is currently attracting considerable attention in crystal engineering and materials science due to their intriguing architectures and potential applications. A new three-dimensional MOF, namely poly[[diaqua(μ8-para-terphenyl-3,3',5,5'-tetracarboxylato)dizinc(II)] dimethylformamide disolvate monohydrate], {[Zn2(C22H10O8)(H2O)2]·2C3H7NO·H2O}n, was synthesized by the self-assembly of Zn(NO3)2·6H2O and para-terphenyl-3,3',5,5'-tetracarboxylic acid (H4TPTC) under solvothermal conditions. The compound was structurally characterized by FT-IR spectroscopy, elemental analysis and single-crystal X-ray diffraction analysis. Each ZnII ion is located in a square-pyramidal geometry and is coordinated by four carboxylate O atoms from four different TPTC4- ligands. Pairs of adjacent equivalent ZnII ions are bridged by four carboxylate groups, forming [Zn2(O2CR)4] (R = terphenyl) paddle-wheel units. One aqua ligand binds to each ZnII centre along the paddle-wheel axis. Each [Zn2(O2CR)4] paddle wheel is further linked to four terphenyl connectors to give a three-dimensional framework with NBO-type topology. The thermal stability and solid-state photoluminescence properties of the title compound have also been investigated.

One-dimensional networks formed via the self-assembly of anthracenedibenzoic acid with zinc(II).

Self-assembly of metal-organic coordination polymers occurs because of enthalpically favorable interactions. In the case of the bulky 4,4'-(anthracene-9,10-diyl)dibenzoic acid ligand (abdH2), we demonstrate that the presence of numerous π-π and C-H...π interactions outweigh the formation of saturated coordination complexes with zinc, leading to the formation of a dimethylformamide (DMF) solvate, namely 4,4'-(anthracene-9,10-diyl)dibenzoic acid dimethylformamide disolvate, C28H18O4·2C3H7NO or [(abdH2)(DMF)2], at low concentrations of zinc. Meanwhile, at higher zinc concentrations, the abdH2 ligand gives rise to the nonporous one-dimensional coordination polymer catena-poly[[bis(dimethylformamide-κO)zinc(II)]-μ-4,4'-(anthracene-9,10-diyl)dibenzoato-κ2O:O'], [Zn(C28H16O4)(C3H7NO)2]n or [Zn(abd)(DMF)2]n, when assembled in dimethylformamide, while a related compound is observed when N,N-dimethylacetamide (DMA) is used as the solvent, namely catena-poly[[[bis(N,N-dimethylacetamide-κO)zinc(II)]-μ-4,4'-(anthracene-9,10-diyl)dibenzoato-κ2O:O'] N,N-dimethylacetamide monosolvate], {[Zn(C28H16O4)(C4H9NO)2]·C4H9NO}n or {[Zn(abd)(DMA)2]·DMA}n. Attempts to use other amide-based solvents did not give rise to any other assembled structures.

Two furan-2,5-dicarboxylic acid solvates crystallized from dimethylformamide and dimethyl sulfoxide.

Furan-2,5-dicarboxylic acid (FDCA) has been ranked among the top 12 bio-based building-block chemicals by the Department of Energy in the US. The molecule was first synthesized in 1876, but large-scale production has only become possible since the development of modern bio- and chemical catalysis techniques. The structures of two FDCA solvates, namely, FDCA dimethylformamide (DMF) disolvate, C6H4O5·2C3H7NO, (I), and FDCA dimethyl sulfoxide (DMSO) monosolvate, C6H4O5·C2H6OS, (II), are reported. Solvate (I) crystallizes in the orthorhombic Pbcn space group and solvate (II) crystallizes in the monoclinic P-1 space group. In (I), hydrogen bonds form between the carbonyl O atom in DMF and a hydroxy H atom in FDCA. Whilst in (II), the O atom in one DMSO molecule hydrogen bonds with hydroxy H atoms in two FDCA molecules. Combined with intermolecular S...O interactions, FDCA molecules form a two-dimensional network coordinated by DMSO.

Guest-driven unusual conformations in two calix[6]arene solvates and a new calix[8]arene

Abstract Unusual conformations have been found in a new calix[8]arene and in new solvates of two known calix[6]arenes. The chair-like conformation with 2/m point group symmetry was found for the first time in the dimethylformamide (DMF) disolvate of the basic calix[6]arene (1) without substituents in the lower and upper rims. Such symmetry is driven by the guest geometry allowing for two equivalent hydrogen bonding patterns in the chair seat. This avoids cone distortion found in the other chair-like conformers, although they have energies lower than that of new symmetrical conformer. The molecular conformation of hexa(carboxymethoxy)calix[6]arene (2) is also described as a dimethylsulfoxide (DMSO) pentasolvate. Its conformation can be described as a 1,3,5-closed cone with three alternate phenyl rings inclined inwards to the cone, thereby closing the cone entrance. Such a conformation also suggests five acid groups are pointed towards the same side of the calyx base and are able to bind metal ions or basic compounds in the lower rim, while inclusion of guests into the cone cavity is hindered. Both inclusion and cooperative acid binding/coordination abilities are still more hindered in the lowest energy 1,2,3-alternate cone conformer of 2. The role of the solvent in avoiding cone distortion was highlighted by inspecting the conformations of 5,11,17,23,29,35,41,47-octanitro-49,50,51,52,53,54,55,56-octa-n-butoxycalix[8]arene (3) and the known nitro analogues having methyl instead of n-butyl groups. Cone distortion is found in the non-solvated crystal form of 3, while non-classical hydrogen bonds with tetrahydrofuran preclude this in the literature analogue.

Two cobalt(II) supramolecular isomers based on N,N'-bis(pyridin-3-yl)oxalamide induced by the molecular orientation of lattice DMF molecules.

Supramolecular isomerism for coordination networks refers to the existence of different architectures having the same building blocks and identical stoichiometries. For a given building block, different arrangements can lead to the formation of a series of supramolecular isomers. Two one-dimensional Co(II) coordination polymers based on N,N'-bis(pyridin-3-yl)oxalamide (BPO), both catena-poly[[[dichloridocobalt(II)]-bis[μ-N,N'-bis(pyridin-3-yl)oxalamide-κ(2)N:N']] dimethylformamide disolvate], {[CoCl2(C12H10N4O2)2]·2C3H7NO}n, have been assembled by the solvothermal method. Single-crystal X-ray diffraction analyses reveal that the two compounds are supramolecular isomers, the isomerism being induced by the orientation of the dimethylformamide (DMF) molecules in the crystal lattice.

Supramolecular architecture of metal–organic frameworks involving dinuclear copper paddle-wheel complexes

The two centrosymmetric dinuclear copper paddle-wheel complexes tetrakis(μ-4-hydroxybenzoato-κ(2)O:O')bis[aquacopper(II)] dimethylformamide disolvate dihydrate, [Cu2(C7H5O3)4(H2O)2]·2C3H7NO·2H2O, (I), and tetrakis(μ-4-methoxybenzoato-κ(2)O:O')bis[(dimethylformamide-κO)copper(II)], [Cu2(C8H7O3)4(C3H7NO)2], (II), crystallize with half of the dinuclear paddle-wheel cage unit in the asymmetric unit and, in addition, complex (I) has one dimethylformamide (DMF) and one water solvent molecule in the asymmetric unit. In both (I) and (II), two Cu(II) ions are bridged by four syn,syn-η(1):η(1):μ carboxylate groups, showing a paddle-wheel cage-type structure with a square-pyramidal coordination geometry. The equatorial positions of (I) and (II) are occupied by the carboxylate groups of 4-hydroxy- and 4-methoxybenzoate ligands, and the axial positions are occupied by aqua and DMF ligands, respectively. The three-dimensional supramolecular metal-organic framework of (I) consists of three different R2(2)(20) and an R4(4)(36) ring motif formed via O-H···O and OW-HW···O hydrogen bonds. Complex (II) simply packs as molecular species.

A one-dimensional coordination polymer of 5-[(imidazol-1-yl)methyl]benzene-1,3-dicarboxylic acid with CuIIcations

5-[(Imidazol-1-yl)methyl]benzene-1,3-dicarboxylic acid (H2L) was synthesized and the dimethylformamide- and dimethylacetamide-solvated structures of its adducts with Cu(II), namely catena-poly[[copper(II)-bis[μ-3-carboxy-5-[(imidazol-1-yl)methyl]benzoato]] dimethylformamide disolvate], {[Cu(C12H9N2O4)2]·2C3H7NO}n, (I), and catena-poly[[copper(II)-bis[μ-3-carboxy-5-[(imidazol-1-yl)methyl]benzoato]] dimethylacetamide disolvate], {[Cu(C12H9N2O4)2]·2C4H9NO}n, (II), the formation of which are associated with mono-deprotonation of H2L. The two structures are isomorphous and isometric. They consist of one-dimensional coordination polymers of the organic ligand with Cu(II) in a 2:1 ratio, [Cu(μ-HL)2]n, crystallizing as the dimethylformamide (DMF) or dimethylacetamide (DMA) disolvates. The Cu(II) cations are characterized by a coordination number of six, being located on centres of crystallographic inversion. In the polymeric chains, each Cu(II) cation is linked to four neighbouring HL(-) ligands, and the organic ligand is coordinated via Cu-O and Cu-N bonds to two Cu(II) cations. In the corresponding crystal structures of (I) and (II), the coordination chains, aligned parallel to the c axis, are further interlinked by strong hydrogen bonds between the noncoordinated carboxy groups in one array and the coordinated carboxylate groups of neighbouring chains. Molecules of DMF and DMA (disordered) are accommodated at the interface between adjacent polymeric assemblies. This report provides the first structural evidence for the formation of coordination polymers with H2L via multiple metal-ligand bonds through both carboxylate and imidazole groups.

Five pseudopolymorphs of 6-amino-2-thiouracil: absence of N—H...S hydrogen bonds

In order to study the preferred hydrogen-bonding pattern of 6-amino-2-thiouracil, C(4)H(5)N(3)OS, (I), crystallization experiments yielded five different pseudopolymorphs of (I), namely the dimethylformamide disolvate, C(4)H(5)N(3)OS·2C(3)H(7)NO, (Ia), the dimethylacetamide monosolvate, C(4)H(5)N(3)OS·C(4)H(9)NO, (Ib), the dimethylacetamide sesquisolvate, C(4)H(5)N(3)OS·1.5C(4)H(9)NO, (Ic), and two different 1-methylpyrrolidin-2-one sesquisolvates, C(4)H(5)N(3)OS·1.5C(5)H(9)NO, (Id) and (Ie). All structures contain R(2)(1)(6) N-H...O hydrogen-bond motifs. In the latter four structures, additional R(2)(2)(8) N-H...O hydrogen-bond motifs are present stabilizing homodimers of (I). No type of hydrogen bond other than N-H...O is observed. According to a search of the Cambridge Structural Database, most 2-thiouracil derivatives form homodimers stabilized by an R(2)(2)(8) hydrogen-bonding pattern, with (i) only N-H...O, (ii) only N-H...S or (iii) alternating pairs of N-H...O and N-H...S hydrogen bonds.

N,N,N′,N′-Tetrakis(2-hydroxy-5-methylbenzyl)ethane-1,2-diamine dimethylformamide disolvate

The title compound, C34H40N2O4·2C3H7NO, was synthesized by the Mannich condensation of ethane­diamine, formaldehyde and p-cresol. In the crystal, the tetra­phenol mol­ecule is arranged around an inversion center. The mol­ecule and the dimethyl­formamide solvate are linked through an O—H⋯O hydrogen bond. An intra­molecular O—H⋯N hydrogen bond occurs in the tetra­phenol mol­ecule, which may influence the mol­ecular confomation. Futhermore, C—H⋯O and π–π stacking inter­actions [centroid–centroid distance = 3.7081 (14) Å] stabilize the crystal packing, building a three-dimensional network.

1,5-Bis[1-(2,4-dihydroxyphenyl)ethylidene]carbonohydrazide dimethylformamide disolvate

In the title compound, C17H18N4O5·2C3H7NO, two solvent mol­ecules are linked to the main mol­ecule via N—H⋯O and O—H⋯O hydrogen bonds, forming a hydrogen-bonded trimer. Intra­molecular O—H⋯N hydrogen bonds influence the mol­ecular conformation of the main mol­ecule, and the two benzene rings form a dihedral angle of 10.55 (18)°. In the crystal, inter­molecular O—H⋯O hydrogen bonds link hydrogen-bonded trimers into ribbons extending along the b axis.

Bis[N-(isonitrosoacetophenone)-N′-benzoylhydrazonato-k3O,N,N′]nickel(II) dimethylformamide disolvate hemihydrate: Synthesis, crystal structure, and spectroscopic and electronic properties

In the title complex, [Ni(C30H24N6O4)]2 · 4C3H7NO · H2O (I), the Ni(II) atoms are six-coordinated by two N atoms and one O atom of each of the two tridendate benzoylhydrazone ligands, leading to a distorted octahedral geometry. In the environment of Ni(II) atoms, the equatorial planes are approximately perpendicular. The structure is stabilized by O-H...O, O-H...N, and C-H...O intra- and intermolecular hydrogen bonding, resulting in the formation of infinite chains running along the x axis of the triclinic cell. The structure of the compound was characterized by IR and UV spectra, elemental analyses, and X-ray diffraction techniques.

Diaqua[N,N′-bis(3-carboxyprop-2-enoyl)pyridine-2,6-dicarbohydrazidato(2–)]cadmium(II)N,N-dimethylformamide disolvate

In the title complex, [Cd(C15H11N5O8)(H2O)2]·2C3H7NO, the CdII ion is located on a twofold rotation axis and is seven-coordinated in a distorted penta­gonal-bipyramidal manner. The asymmetric unit comprises one metal ion, one doubly deprotonated N,N′-bis­(3-carboxy­prop-2-eno­yl)pyridine-2,6-dicarbohydrazide ligand, two coordinating water mol­ecules and two dimethyl­formamide solvent mol­ecules. In the crystal, a two-dimensional network is formed through N—H⋯O and O—H⋯O hydrogen bonds.

2,2′-Dihydroxy-3,3′-[(1E,1′E)-hydrazine-1,2-diylidenedimethylidyne]dibenzoic acidN,N-dimethylformamide disolvate

The title compound, C16H12N2O6·2C3H7NO, lies across a crystallographic inversion centre which is situated at the midpoint of the central N—N bond. The substitution at the C=N bond adopts a trans configuration and it is essentially coplanar with the benzene ring [N—C—C—C torsion angles = −173.9 (4) and 6.4 (6)°]. All torsion angles involving non-H atoms are close to 180°. Intra­molecular O—H⋯O and weak C—H⋯O hydrogen bonds form S(6) and S(5) ring motifs, respectively, while inter­molecular O—H⋯O and weak C—H⋯O hydrogen bonds connect the Schiff base mol­ecule to solvent dimethyl­formamide mol­ecules.

Bis[benzylN′-(1H-indol-3-ylmethylene)hydrazinecarbodithioato-κ2N′,S]nickel(II)N,N-dimethylformamide disolvate

In the title compound, [Ni(C17H14N3S2)2]·2C3H7NO, the Ni atom (site symmetry ) is N,S-chelated by two deprotonated Schiff base anions in a distorted square-planar geometry. The dihedral angle between the aromatic ring planes within the ligand is 86.37 (13)°. In the crystal structure, an N—H⋯O hydrogen bond links the complex to the dimethyl­formamide solvent mol­ecule.

6-Bromo-3-hydroxy-4-oxo-2-phenyl-4H-chromene-8-carboxylic acid dimethylformamide disolvate

In the title compound, C16H9BrO5·2C3H7NO, the chromene ring system is essentially planar. The two dimethyl­formamide solvent mol­ecules are linked by inter­molecular O—H⋯O hydrogen bonds to the 6-bromo-3-hydr­oxy-4-oxo-2-phenyl-4H-chromene-8-carboxylic acid molecules.

Bis{μ-2,2′-[o-phenylenebis(nitrilomethylidyne)]diphenolato}dicopper(II)N,N′-dimethylformamide disolvate

The title compound, [Cu2(C20H14N2O2)2]·2C3H7NO, consists of a centrosymmetric dimer composed of two copper(II) ions and two tetra­dentate salphen ligands {H2salphen is 2,2′-[o-phenyl­enebis(nitrilo­methyl­idyne)]diphenol}, and two dimethyl­formamide solvent mol­ecules. The CuII atom is bonded to two N imino atoms and three phenolate O atoms of salphen. One deprotonated phenol group of each ligand bridges two Cu atoms, forming the dimer. The geometry about the five-coordinate Cu atom can best be described as slightly distorted recta­ngular pyramidal. The crystal structure is stabilized by π–π inter­actions [centroid-centroid distance 3.779 (2) Å] and C—H⋯O hydrogen bonds.

Trichlorido(N,N-dimethylformamide-κO)bis(1,10-phenanthroline-κ2 N,N′)lanthanum(III) N,N-dimethylformamide disolvate

In the title compound, [LaCl3(C12H8N2)2(C3H7NO)]·2C3H7NO, the LaIII ion is eight-coordinated by four N donors from two 1,10-phenanthroline ligands, one O atom from one N,N-dimethylformamide molecule and three chloride anions. In the crystal structure, the LaIII mononuclear units are linked to form a chain along the a axis by weak C—H...Cl hydrogen bonds. The chains are crosslinked to form a two-dimensional network parallel to the ab plane by π–π stacking interactions between the phen rings [centroid–centroid seperations range from 3.589 (2) to 3.708 (2) Å].