Search

Molecular recognition based on hydrogen bond interaction plays a significant role in supramolecular self-assembly. In this work, we successfully developed a class of novel frameworks containing a urea in the recognition site and a carboxylate anion in the guest unit. The self-recognition model based on the interaction between urea and carboxylate anion could induce the molecules to assemble into a highly organized form. The crystal structures showed that they assembled in highly ordered two-dimensional architectures. The optical properties showed that the position of carboxylate anion on the diphenylacetylene backbone had an obvious influence on optical properties. The self-recognition strategy is useful for the construction of highly ordered self-assembled architectures.

An alkali metal selenite chloride, Rb2SeOCl4·H2O, has been hydrothermally synthesized and structurally characterized. It is the first example of an alkali metal selenite halide in the literature. The compound crystallizes in the noncentrosymmetric (NCS) space group, Cmc21(36), of the orthorhombic system with a = 10.342(3) A, b = 10.124(3) A, c = 9.158(3) A, and α = β = γ = 90°. The anionic [SeOCl4]2− groups are arranged in the crystal in nearly the same direction, giving rise to a relatively large macroscopic dipole moment, causing the compound to display second harmonic generation (SHG) eight times as strong as that of KDP, measured using the Kurtz–Perry method on powders. First-principle density functional theory (DFT) calculations were carried out to interpret the relationship between the crystal structure and properties.

Two copper-containing compounds based on MoO42–, [Cu4(phen)4(μ2-OH)2(μ3-OH)2(H2O)2][MoO4]2·10H2O (1) and [Cu(phen)2Mo2O7(phen)]·8H2O (2) (phen = 1,10-phenanthroline), were hydrothermally synthesized. In the crystal lattices of 1 and 2, discrete octameric water cycles and 2D layer water clusters were observed. The cyclic water octamer clusters exist stably in the channels constructed by [Cu4(phen)4(OH)4(H2O)2]2+ and MoO42– by hydrogen bonds in 1 at low temperature and 2D layer water clusters are formed by (H2O)16 units in 2.

Four new Zn(II) and Cu(II) coordinated polymers ([ZnL2N3]ClO4 (1), [Cu2L2(CH3CN)]Cl4 (2) [CuL](NO3)2 (3), [Cu(H2O)L](SO4) (4) L = 2-((4-phenyl-2H-1,2,3-triazol-2-yl)methyl) pyridine (ptmp)) have been reported. All the compounds have been characterized by IR spectrum, elemental analyses and X-ray crystallography diffraction. Single-crystal X-ray diffraction analyses show that one-dimensional polymers are formed in these four complexes. Chain-like structures are formed in complex 1, 2 and 3, which are connected by azide, chloride and nitrate anions, respectively. In complex 4, one-dimensional left-handed polymer is formed by a μ2-SO4 bridge. The fluorescent and electrochemical properties of these four complexes were investigated. It was found that these three Cu(II) complexes displayed a quenching of fluorescence, while Zn(II) complex exhibited a clear enhanced fluorescence.

Reactions of the diorganotin(IV) dichlorides with cyclohexanecarboxylate ligands yielded four new dimeric ladder-like tetraorganostannoxanes formulated as [R 4 Sn 2 (C 6 H 11 COO)( μ 3 -O)( μ -OH)] 2 [R = Et ( 1 ), n Bu ( 2 ), n Oct ( 3 ) and Ph ( 4 )]. All these complexes were characterized by elemental analysis, IR, NMR ( 1 H, 13 C, 119 Sn) spectra and in one case by X-ray diffraction analysis. The crystal structure of 1 reveals the formation of the tetranuclear species contains a planar Sn 4 O 4 core, consisting of three adjacent rhombs with bridging oxo and hydroxyl ligands. The central tin atoms are five-coordinated to assume a distorted trigonal bipyramidal configuration and the OH ligands act as monodentate O-bound planar. 2 exhibits good antitumor activity against KB cells (IC 50 = 0.90 μM) and 4 shows significant antibacterial activity against Gram-positive bacteria Staphylococcus aureus (MIC = 0.147 μg/ml), both being even higher than those of clinically used drugs.

To search for a new nonlinear optical (NLO) material to be used in the mid-IR region with excellent comprehensive performance including high laser damage threshold (LDT), K2SbF2Cl3 has been synthesized by the hydrothermal method, and its potential as such a new material is evaluated for the first time. Its powder shows phase-matchable second harmonic generation (SHG) response of approximately 4 times as strong as that of KH2PO4 (KDP). Its optical band gap is 4.01 eV, which is much wider than the band gaps of the currently commercialised IR NLO crystals. This means that K2SbF2Cl3 will exhibit a much higher LDT. Its powder also exhibits excellent transparency in the range of 0.31–14 μm and good thermal stability. The relationship between the composition, crystal structure and properties is discussed. These results indicate that K2SbF2Cl3 is a promising candidate for IR NLO materials.

Searching for new IR nonlinear optical (NLO) crystals with high laser damage threshold (LDT) has become one of the great challenges in this field. This paper reports the synthesis, single crystal structure and properties of noncentrosymmetric CsHgBr3, which is a new crystalline phase and shows a high LDT of about 226 MW cm−2, together with good comprehensive performance. Its crystal can be obtained by reaction of CsBr and HgCl2 in acetone. It crystallizes in the trigonal space group P32 (no. 145). Its powders show a phase-matchable second harmonic generation as strong as that of KH2PO4 (KDP). It also displays excellent transparency in the range of 0.42–31 μm and is thermally stable up to 250 °C. All these behaviors make it a promising new NLO crystal in the mid-IR region.

Solvothermal reactions of hexakis(4-formylphenoxy)cyclotriphosphazene (H(6)L1) with Cd(NO(3))(2)·4H(2)O in H(2)O/DMF under different synthesis temperatures produced two new compounds, namely, {[Cd(3)(C(42)H(24)O(18)P(3)N(3)) (H(2)O)(7)]·xGuest}(n) (1), and {[Cd(2)(C(42)H(24)O(18)P(3)N(3)) (H(2)O)(2)]·xGuest}(n) (2). Compound 1 exhibits a novel 3D framework adopting 2,4,6-connected 3-nodal topology with the point (Schläfli) symbol {4(4)·6(2)}{4(5)·6(2)·8(8)}{4} constructed from the joint of neutral Cd(2) SBUs, mono-Cd ions and L1 ligands. Compound 2 reveals a 2D crystal structure exhibiting a 3,6-connected 2-nodal kgd topology with the point (Schläfli) symbol {4(3)}(2){4(6)·6(6)·8(3)} constructed from the connection of Cd centers and L1 ligands. In these two compounds, the ligands L1 are fully deprotonated, whose six extended carboxyl arms connect six different/same metallic nodes to form high dimensional frameworks. The variable reaction temperature must be responsible for the higher coordination number and versatile coordination modes of carboxylates in 1 compared to the ones in 2, resulting in the formation of a distinct crystal structure. In the solid state, both complexes are photoluminescent (LMCT) at room temperature.

The significant involvement of weak intermolecular interactions and steric and/or symmetry-related packing features was assessed with supramolecular arrays of 4-hydroxyphenyl amides in the crystal structure. The one-dimensional chain is observed in the aryl substituted 4-hydroxyphenyl amides, while alkyl analogs generate 2D or 3D arrays. A comparison of supramolecular assemblies in the similar 4-hydroxyphenyl amide compounds in the Cambridge Structural Database has been presented. It is correlated with the different steric constraints of aryl and alkyl groups to create chains, 2D sheets and 3D-interpenetrated networks in the asymmetric 4-hydroxyphenyl amides. A comprehensive analysis of crystal packing and energy features of the selected 4-hydroxyphenyl amide derivatives is reported.

Three dinuclear Mn(II) complexes, [Mn2(EGTB)(NO3)2(H2O)4](NO3)2 (1), [Mn2(EGTB)(NO3)4] (2) and [Mn2(EGTB)(NO3)(H2O)](NO3)3 (3) (EGTB = N,N,N′,N′-tetrakis(2′-benzimidazolylmethyl)-1,4-diethylene amino glycol ether) were prepared and characterized. Their crystal structures revealed a relationship between synthesis temperature and structure. With increasing the reaction temperature from 60 to 120 °C or 160 °C, the Mn–Mn distances are shortened from 14.019 A in 1, 7.662 A in 2 to 5.662 A in 3. Additionally, polyphenol oxidase (PPO) activity of those three complexes was studied by measuring the rate of increase in absorbance at 320 nm of pyrogallol substrate. At pH 7.8 and 30 °C, the turnover numbers are 5.58 h−1 for 1, 11.38 h−1 for 2 and 13.97 h−1 for 3, respectively. Furthermore, in pH 7.8–8.2, their catalytic activity increased with rising pH.

The synthesis, crystal structure, nonlinear optical (NLO) property and some other properties of a new material, Hg(2)BrI(3), are reported. The crystal structure has been established by single crystal X-ray diffraction studies. Hg(2)BrI(3) belongs to the HgBrI type and crystallizes in the orthorhombic space group Cmc21 (No. 36). The compound shows a phase-matchable second harmonic generation (SHG) of about 1.2 times as strong as that of KTiOPO(4) (KTP) based on the powder SHG measurement. It exhibits a wide transparency in the IR region (from 2.5 to 30 μm), and a good thermal stability. It is believed that Hg(2)BrI(3) is a new candidate for NLO materials in the IR region.

Two new glycoluril derivatives, namely 6-phenyl-1,4-dioxo-2,2a,3,4,6,7-hexahydro-1H,5H-2,3,4a,6,7a-pentaazacyclopenta[cd]indene-2a,7b-dicarboxylate (1), and diethyl 6-(2,4-dichorophenyl)-1,4-dioxo-2,2a,3,4,6,7-hexahydro-1H,5H-2,3,4a,6,7a-pentaazacyclopenta[cd]indene-2a,7b-dicarboxylate (2) have been synthesized and structurally determined by X-ray diffraction analysis. Compound 1 is, monoclinic, space group C2/c, with a = 20.0784(7), b = 9.0316(3), c = 23.0980(8) A, β = 98.3930(10), V = 4143.7(2) A3, with Z = 8 for d calc = 1.338 Mg/m3. The analog 2 is, Triclinic, space group P-1, with a = 8.9353(18), b = 10.466(2), c = 14.679(3) A, β = 73.60(3), V = 1268.1(4) A3, with Z = 2 for d calc = 1.533 Mg/m3. X-ray analysis reveals that both glycoluril derivatives bearing two free syn-urea NH groups and two ureidyl C=O, assemble the same one-dimensional chains in the solid-state running parallel to the [110], [1–10] and [010] directions via N–H···O hydrogen bonds. Two new glycoluril derivatives, namely 6-phenyl-1,4-dioxo-2,2a,3,4,6,7-hexahydro-1H,5H-2,3,4a,6,7a-pentaazacyclopenta[cd]indene-2a,7b-dicarboxylate (1), and diethyl 6-(2,4-dichorophenyl)-1,4-dioxo-2,2a,3,4,6,7-hexahydro-1H,5H-2,3,4a,6,7a-pentaazacyclopenta[cd]indene-2a,7b-dicarboxylate (2), both bearing two free syn-urea NH groups and two ureidyl C=O, assemble the same one-dimensional chains in the solid-state running parallel to the [110], [1–10] and [010] directions via R 2 2 (8) N–H···O hydrogen bonds.

Two polymorphs of biphenyl-4,4'-diaminium bis(3-carboxy-4-hydroxybenzenesulfonate) dihydrate, C(12)H(14)N(2)(2+)·2C(7)H(5)O(6)S(-)·2H(2)O, have been obtained and crystallographically characterized. Polymorph (I) crystallizes in the space group P2(1)/c with Z' = 2 and polymorph (II) in the space group P-1 with Z' = 0.5. The benzidinium cation in (II) is located on a crystallographic inversion centre. In both (I) and (II), the sulfonic acid H atoms are transferred to the benzidine N atoms, forming dihydrated 1:2 molecular adducts (base-acid). In the crystal packings of (I) and (II), the component ions are linked into three-dimensional networks by combinations of X-H...O (X = O, N and C) hydrogen bonds. In addition, π-π interactions are observed in (I) between inversion-related benzene rings [centroid-centroid distances = 3.632 (2) and 3.627 (2) Å]. In order to simplify the complex three-dimensional networks in (I) and (II), we also give their rationalized topological analyses.

A new coordination polymer, {[Na2Cu(Ac)4(H2O)]·H2O} n (HAc = acetic acid), has been synthesized and structurally characterized by IR spectroscopy and X-ray crystallography. The compound crystallizes in the orthorhombic system, space group Pccn with a = 16.9076(17) A, b = 11.8375(12) A, c = 15.7567(16) A, V = 3153.6(6) A3. Four oxygen atoms from different Ac− groups coordinate to the copper atom in a square-planar arrangement. Each sodium ion is in a distorted octahedral environment, being coordinated by one aqua ligand and five acetate oxygen atoms from two adjacent [Cu(Ac)4] units. An alternating arrangement of metal ions and bridging acetate ligands results in the formation of two-dimensional sheets which are further linked into a three-dimensional network by the water molecules between the layers through rich hydrogen bonds. The title compound {[Na2Cu(Ac)4(H2O)]·H2O} n (HAc = acetic acid) was synthesized and structurally characterized by X-ray crystallography. Four oxygen atoms from different Ac– groups coordinate to the copper atom in a square-planar arrangement. Each sodium ion is in a distorted octahedral environment, being coordinated by one aqua ligand and five acetate oxygen atoms from two adjacent [Cu(Ac)4] units. An alternating arrangement of metal ions and bridging acetate ligands results in the formation of two-dimensional sheets which are further linked into a three-dimensional network by the water molecules between the layers through rich hydrogen bonds.

A new multinuclear dibutyltin(IV) complex [(n-Bu)4Sn2{2,5-F2C6H3C(O)NHO}2{2,5-F2C6H3C(NO)O}]21, was synthesized and structurally characterized by melting point measurement, elemental analysis, FT-IR, 1H, 13C, 119Sn NMR spectroscopies, and X-ray diffraction analysis. The complex exhibited in vitro antitumor activity against a murine sarcoma carcinoma cell line (S-180), which was higher than that of 5-fluorouracil (5-Fu), currently used clinically as an antitumor agent.

Cocrystallization of imidazole or 4-methylimidazole with 2,2'-dithiodibenzoic acid from methanol solution yields the title 2:1 and 1:1 organic salts, 2C(3)H(5)N(2)(+).C(14)H(10)O(4)S(2)(2-), (I), and C(4)H(7)N(2)(+).C(14)H(10)O(4)S(2)(-), (II), respectively. Compound (I) crystallizes in the monoclinic C2/c space group with the mid-point of the S-S bond lying on a twofold axis. The component ions in (I) are linked by intermolecular N-H...O hydrogen bonds to form a two-dimensional network, which is further linked by C-H...O hydrogen bonds into a three-dimensional network. In contrast, by means of N-H...O, N-H...S and O-H...O hydrogen bonds, the component ions in (II) are linked into a tape and adjacent tapes are further linked by pi-pi, C-H...O and C-H...pi interactions, resulting in a three-dimensional network.

A new 1:2 inclusion complex of cucurbit[8]uril (CB[8]) and protonated N-phenylpiperazine was synthesized and characterized by 1H NMR and X-ray crystallography. The crystal structure showed that the phenyl rings of the two equivalents of guest encapsulated in the cavity of CB[8] are parallel to one another with a mean plane separation of 3.899 A. In contrast, the piperazinyl phenyl ammonium moieties slightly protrude from the ureidyl carbonyl lined portals in order to accommodate the ion–dipole interaction between host and guest which provides a substantial driving force for the assembly. The oxygen atoms of the carbonyl groups form hydrogen bonds with the hydrogen atoms in both bridging methylene groups of CB[8] and water molecules. There are also hydrogen bonds formed among CB[8], water, and the protonated piperazinyl rings. These hydrogen bonds are formed between the ureidyl C=O groups and hydrogens in methylenes of piperazinyl rings; through hydrogen bonding N+–H···O(H)–H···O=C. The protonated piperazinyl rings connect the carbonyl groups with the bridging water molecules.

Three polynuclear transition metal complexes [Mn8(DMF)8(L1)8] · 4DMF (1), [Mn6(DMF)6(L2)6] · [Mn6(DMF)4(H2O)2(L2)6] · 2DMF (2), [Cu3(L3)2(py)2] (3) of the pentadentate ligands N-acyl-salicylhydrazides were synthesized and characterized, their crystal structures were investigated. The oxidation state and properties of the central metal ions are important in crystal structure formation, trivalent Mn(III) ion which easily form stable octahedral coordination metallamacrocycle complexes, metallacrowns 1 and 2 were obtained; while bivalent Cu(II) ion is easier to form square planar, trinuclear complexes 3 was obtained. The steric effect of the N-acyl side chains also plays an important role in the structures of these polynuclear complexes. The magnetic property of 1 was also investigated.

Two dinuclear complexes [M2(EGTB)(NO3)2(DMF)2](NO3)2 · 2DMF (M = Cu, 1; Co, 2) were synthesized and structurally characterized, EGTB is N,N,N′,N′-tetrakis (2-benzimidazolylmethyl)-1,4-diethylene amino glycol ether, and DMF is dimethylformamide. The polyphenol oxidase (PPO) activities of 1 and 2 on pyrogallol oxidation have been investigated, showing that the rate constants k cat increase with increases of reaction temperatures and pH.

The syntheses, IR, molecular structures, and luminescence of [M(HIMDC)(4, 4′-bipyO)0.5(H2O)] n [H3IMDC = 4, 5-imidazoledicarboxylate, 4, 4′-bipyO = 4, 4′-bipyridine-N, N′-dioxide, M = Co (1) and Zn (2)] are reported. The most notable structure feature of 1 and 2 is that the left-handed and right-handed helical chains constructed from 4,5-imidazoledicarboxylate and metal are linked by 4,4′-bipyO to generate infinite 2-D herringbone architectures. 2 exhibits strong fluorescent emission in the solid state at room temperature.

Two new trinuclear complexes, Cu3L2(py)2 (1) and Ni3L2(py)4 (2), have been synthesized and characterized, where L3− is N-2-methyl-acryloyl-salicylhydrazidate. Central metal ion and two terminal metal ions in the two complexes are combined by two bridging deprotonated L3− ligands, forming a bent trinuclear structure unit with an M–N–N–M–N–N–M core. The bent angles in complexes 1 and 2 are 167.6(1)° and 75.4(1)°, respectively. Three nickel ions in compound 2 exhibit alternating square-planar and octahedral geometries, while three copper ions in compound 1 follow square-planar mode. The studies in solution integrity and stability of compounds 1 and 2 show they are soluble and stable in DMF. UV–Vis titrations demonstrate compound 1 is stable in DMF even in the presence of excess metal ions. Antibacterial screening data indicate the two compounds all have stronger antimicrobial activities against the tested microorganisms than ligand. The trinuclear copper compound 1 is more active than monocopper compounds in the previous study, and the trinuclear nickel compound 2 is less active than tetranuclear nickel compound in the previous study.

Single crystals of a new polymorph of 1,4-bis(imidazol-1-ylmethyl)benzene dihydrate (bix x 2H(2)O), C(14)H(14)N(4) x 2H(2)O, have been obtained by the hydrothermal method. The asymmetric unit is composed of two independent half-bix molecules, one on an inversion center and one on a twofold axial site, and two water molecules. The disordered water molecules link into discrete tetrameric water units via two O-H...O hydrogen bonds, forming planar R(4)(4)(8) rings. These tetrameric water units and bix molecules are further linked by two O-H...N hydrogen bonds into a three-dimensional network in which an R(20)(20)(106) hydrogen-bonded ring is observed. These large rings lead to the formation of a fivefold interpenetrated network. If both the tetrameric water units and the bix molecules can be regarded as connected nodes, one single three-dimensional net can then be rationalized as a CdSO(4) network. This study indicates that topological methodology can be applied in some cases in order to understand the inherent characteristics of some hydrogen-bonded supramolecular assemblies.

Three inorganic-organic hybrid frameworks [Mn(HIMDC)(4,4′-bipyo)0.5(H2O)]n(1), [Cd(H2IMDC)2(2,2′-bipyo)] (2) and [Ca(HIMDC)(H2O)2·H2O]n(3) (H3IMDC = 4,5-imidazoledicarboxylate; 4,4′-bipyo = 4,4′-bipyridine-N,N′-dioxide; 2,2′-bipyo= 2,2′-bipyridine-N,N′-dioxide) have been hydrothermally synthesized and characterized by the elemental analyses, IR spectra, TG analysis and the single crystal diffraction. Both compounds 1 and 3 exhibit 2D layers while 2 is a monomer. It is noteworthy that compound 2 exhibits strong fluorescent emission in the solid state at room temperature.

Two bent trinuclear Cu(II)/Ni(II) complexes [Cu3(L1)2(py)2] (1) and [Ni3(L2)2(py)4] · DMF (2), where H3L1 = N-(3,5-dimethylbenzoyl)-5-bromosalicylhydrazide, H3L2 = N-(3,5-dimethyl benzoyl)-salicylhydrazide, were synthesized and structurally characterized. In complex 1, all three Cu(II) ions take distorted planar square geometry, while in complex 2, the two terminal Ni(II) ions are distorted planar square, the central Ni(II) ion is octahedral. The magnetism of complex 1 was also studied.

A series of 1,3-alternate conformation thiacalix[4]arenes containing different isomeric aminopyridyl pendent arms have been synthesized. It was found that their self-assembly behaviors and complexation properties strongly depended on the structures of aminopyridyl pendent arms. The crystal structures demonstrate that tetra(meta-aminopyridyl)-thiacalix[4]arene motif is capable of forming intramolecular hydrogen bondings between the sp2 nitrogen donors in the meta position of the aminopyridyl groups and the facing amide N–H of the adjacent aminopyridyl groups, and self-assembles via C–H⋯O weak hydrogen bondings and C–H⋯π interaction to generate a double stranded rectilineal networks. By contrast, in the case of tetra(para-aminopyridyl)-thiacalix[4]arene, the presence of para-aminopyridyl units enables the formation of N–H⋯N strong hydrogen bondings between the individual molecules leading to the solid-state structure with water-bridged double strands. Their complexation properties had been also studied by measurement of the stability constants for their complexation in a range of metal cations and investigation of their binding models via 1H NMR titration and ESI-MS experiments. It was found that the three ligands exhibited high and selective extractability toward Ag+, and their stoichiometry of ligand to Ag+ was 1:1, while the meta-aminopyridyl derivative showed the best extraction capacity and possessed the most efficient binding sites.

In both title compounds, C(18)H(24)N(2)O(2), (Ia), and C(18)H(26)N(2)O(2)(2+) x 2 ClO(4)(-), (II), respectively, the two aryl rings are strictly parallel, with an inversion centre lying at the mid-point of each central CH(2)-CH(2) bond. Molecules in (Ia) are linked into two-dimensional layers by N-H...O hydrogen bonds. The component ions in (II) are joined together by a combination of N/O/C-H...O hydrogen bonds and C-H...pi and anion...pi interactions, forming a three-dimensional network. A structural understanding of (Ia) and (II) may provide some useful information about how and why their metal-organic complexes display various biological activities and function in catalytic processes.

Two new glycoluril derivatives, namely diethyl 6-ethyl-1,4-dioxo-1,2,2a,3,4,6,7,7b-octahydro-5H-2,3,4a,6,7a-pentaazacyclopenta[cd]indene-2a,7b-dicarboxylate, C(14)H(21)N(5)O(6), (I), and 6-ethyl-2a,7b-diphenyl-1,2,2a,3,4,6,7,7b-octahydro-5H-2,3,4a,6,7a-pentaazacyclopenta[cd]indene-1,4-dione, C(20)H(21)N(5)O(2), (II), both bearing two free syn-urea NH groups and two ureidyl C=O groups, assemble the same one-dimensional chains in the solid state running parallel to the [010] direction via N-H...O hydrogen bonds. Furthermore, the chains of (I) are linked together into two-dimensional networks via C-H...O hydrogen bonds.

The two title proton-transfer compounds, 5-methylimidazolium 3-carboxy-4-hydroxybenzenesulfonate, C(4)H(7)N(2)(+).C(7)H(5)O(6)S(-), (I), and bis(5-methylimidazolium) 3-carboxylato-4-hydroxybenzenesulfonate, 2C(4)H(7)N(2)(+).C(7)H(5)O(6)S(2-), (II), are each organized into a three-dimensional network by a combination of X-H...O (X = O, N or C) hydrogen bonds, and pi-pi and C-H...pi interactions.

A novel linear trinuclear copper(II) complex bridged by phenoxy and benzyloxy oxygen atoms ([Cu3L2](ClO4)2 · (CH3CN)2, L = C11H13BrN2O2 2−) was synthesized and the crystal structure of the complex was determined by X-ray diffraction technique. The crystal structure of the complex contains a linear trinuclear array of copper(II) ions in which the central copper(II) ion is in an octahedron coordination sphere and lies on an inversion center of the molecule, the terminal ones are in an identical square pyramid structure. Variable-temperature magnetic data indicate that the complex displays a strong antiferromagnetic coupling with J = −270(8) cm−1 between the metal ions.

A novel linear trinuclear nickel(II) complex, [Ni3(H2O)2(DMA)2(acbshz)2]·2DMF (DMA = dimethylamine; acbshz = N-acryloyl-5-bromosalicylhydrazide), has been prepared by self-assembly approach. The three nickel atoms arrange in a strictly linear structure, adjacent molecules are linked by intermolecular H bonds to form a 2D infinite wave-like structure. Antibacterial screening data indicate the formation of the trinuclear complex reduced the antimicrobial activity of the ligand.

5-Sulfosalicylic acid (5-SSA) and 3-aminopyridine (3-APy) crystallize in the same solvent system, resulting in two kinds of 1:1 proton-transfer organic adduct, namely 3-aminopyridinium 3-carboxy-4-hydroxybenzenesulfonate monohydrate, C(5)H(7)N(2)(+).C(7)H(5)O(6)S(-).H(2)O or 3-APy.5-SSA.H(2)O, (I), and the anhydrous adduct, C(5)H(7)N(2)(+).C(7)H(5)O(6)S(-) or 3-APy.5-SSA, (II). Both compounds have extensively hydrogen-bonded three-dimensional layered polymer structures, with interlayer homo- and heterogeneous pi-pi interactions in (I) and (II), respectively.

The crystal structure of the nitroxide spin labeled derivative of podophyllotoxin was first reported. X-ray analysis demonstrated that four contiguous chiral centers in the molecule, C1, C2, C3, and C4, adopt cis- (1:2), trans- (2:3), and cis- (3:4) arrangement.Key words: crystal structure, synthesis, nitroxyl radical, podophyllotoxin.

This paper describes the synthesis, crystal structure, and photophysical properties of a new compound Rb2CdBr2I2. It crystallizes in the noncentrosymmetric space group Ama2. In the crystal, all the distorted tetrahedron [CdBr2I2](2-) groups are arranged in a way such that all the Cd-I bonds are located in the same side of the Cd atoms resulting in a net polarization. Rb2CdBr2I2 showed a powder second harmonic generation (SHG) response 4 times that of KH2PO4 (KDP). The preliminary measurement indicated that it exhibits a large laser-induced damage threshold (LDT) of 190 MW/cm(2) which is 6 times that of AgGaS2. It also exhibits a wide transparent region (0.37-14 μm) with a relatively high (up to 490 °C) thermal stability. All these indicate that Rb2CdBr2I2 is a new promising candidate for NLO materials in the IR region.

A new copper (II) complex [Cu(dtne)] · (ClO4)2 · CH3CH2OH, where dtne is 1,2-bis(1,4,7-triaza-1-cyclononyl)ethane, was prepared and characterized by X-ray crystallography. The result shows that in the complex the copper (II) adopts an octahedral coordination geometry. The cyclic voltammetry of the complex recorded in aqueous solution indicates a reversible one-electron redox reaction. The activity of dismutation of superoxide ( O 2 - ) of the complex in the riboflavin–methionine–nitro blue tetrazolium assay has been researched.

Cocrystallization of 2,2'-dithiodibenzoic acid with isonicotinohydrazide from methanol solution yields the 1:2 cocrystal 2,2'-dithiodibenzoic acid-isonicotinohydrazide (1/2), C(14)H(10)O(4)S(2) x 2 C(6)H(7)N(3)O. The component molecules are linked by intermolecular O-H...N, N-H...O, N-H...N and C-H...O hydrogen bonds into layers running parallel to the (010) plane, and these layers are further linked into a three-dimensional framework structure by means of weak aromatic pi-pi stacking interactions. As a potential cocrystallization agent, isonicotinohydrazide may be used for effective and versatile synthetic supramolecular strategies utilizing hydrogen bonding of specific molecular building blocks.

In the asymmetric unit of the structure of the solvate of bis­(benzimidazol-2-yl-meth­yl)amine (IDB), 2C16H15N5·C2H6O·2H2O, there are two mol­ecules of IDB, two uncoord­inated water mol­ecules and one ethanol solvent mol­ecule. In the crystal structure, IDB, water and ethanol mol­ecules are connected into a three-dimensional network via inter­molecular N—H⋯O, O—H⋯N, O—H⋯O and C—H⋯π(arene) inter­actions.

In the title compound, (C2H8N)3[Eu(C7H3NO4)3]·2H2O, the complex anion lies on a crystallographic twofold rotation axis and the EuIII atom is coordinated by three N and six O atoms from three pyridine-2,6-dicarboxyl­ate ligands, forming a distorted tricapped trigonal prismatic geometry. Dimethyl­ammonium cations and non-coordinated water mol­ecules show positional disorder. The crystal structure is stabilized by inter­molecular N—H⋯O and O—H⋯O hydrogen bonds.

A new binuclear complex, {[Cu(μ-PhPPy2)(CH3CN)]ClO4}2 (1) is synthesized by a direct reaction of [Cu(CH3CN)4]ClO4 with PhPPy2. Dimeric cation of 1, [ Cu ( μ - PhPPy 2 ) ( CH 3 CN ) ] 2 2 + , can be utilized as building block precursor to construct coordination polymer [Cu2(μ-PhPPy2)2(μ-SO4)]∞ (2) by replacement of coordinated acetonitrile molecules with bridging ligand ( SO 4 2 - ) . Both 1 and 2 exhibit strong green emissions in solid state at room temperature. Crystal structures of 1 and 2 have been determined by single crystal X-ray diffraction.

In the cation of the title compound, C38H40N102+·2ClO4−·2H2O, the cyclo­hexa­nediamine group has a twofold axis and two of the four pendant benzimidazole groups are protonated. There are hydrogen bonds and π–π inter­actions in the crystal structure.

The title salt, (C4H12N2)2[Bi2Cl7I3]·4H2O, was prepared by the reaction of bis­muth trichloride, potassium iodide and piperazine in a hydro­chloric acid medium. It is composed of piperazinium dications and dimeric [Bi2Cl7I3]4− tetra­anions, together with water of crystallization. The halobismuthate(III) tetra­anion is located on a center of inversion. Hydrogen bonds, including N—H⋯O, N—H⋯Cl, N—H⋯I, O—H⋯O, O—H⋯Cl and O—H⋯I inter­actions, are present in the crystal structure.

In the title compound, C18H12N2O2, the carbazole ring system is essentially planar and makes a dihedral angle of 53.08 (4)° with the plane of the nitro­benzene ring. In the crystal structure, inversion-related mol­ecules form a C—H⋯O hydrogen-bonded dimer.

In the title crystal structure, C16H17N52+·SO42−, cations and anions are linked via N—H⋯O hydrogen bonds, while ion pairs form extended one-dimensional chains through inter­molecular N—H⋯N hydrogen bonds.

The title salt, (C4H12N2)2[Bi2Cl10]·3H2O, was prepared by reaction of bismuth trichloride and piperazine in a hydro­chloric acid medium. It consists of piperazinium dications and dimeric [Bi2Cl10]4− tetra­anions, the latter with twofold rotation symmetry, together with water of crystallization. Hydrogen-bond inter­actions, including N—H⋯O, N—H⋯Cl and O—H⋯Cl inter­actions, stabilize the crystal structure.

Multinuclear multibenzimidazole metal complexes frequently exhibit novel structures and properties, and are an example of versatile compounds in bioinorganic chemistry. In this work, first, we synthesized the mononuclear complex [Cu(ntb)(H(2)O)](2+), 1, by using tris[(benzimidazol-2-yl)methyl]amine (ntb). Then, a library of multicationic ntb-Cu(II) complexes, 2-9, was prepared by replacing the labile water molecule in 1 with multifunctional carboxylates acting as a bridge linker between two or four ntb-Cu(II) units under slightly acidic or alkaline conditions. Their X-ray crystal structures reveal that these complexes contain one, two or four [Cu(ntb)](2+) units. The pH media used in preparation can control the coordination patterns of the carboxylates and the overall architecture of the complexes, although the Cu(II) centers in the complexes always maintain a five-coordinated structure regardless of the preparation conditions used. Both intra- and inter-molecular π···π interactions involved in the benzimidazoles, as well as extensive hydrogen bonding networks in the complexes were observed to occur in the crystal packing. We selected complexes 1 and the dicarboxylate-bridged 4-7 as potential DNA condensers, as they can be dissolved to the required levels for examining their DNA-binding and -condensing properties in the buffer solutions tested (pH 7.4). For these complexes, the effects of the structural variations, including the number of Cu(II) ions and positive charges, length of linkers, and overall architecture, on the DNA-binding and -condensing properties and cytotoxicity were assessed and compared by biophysical measurements. The results from absorption titration showed that the affinities of the complexes for DNA are dominated by both the electrostatic interaction between them and the π···π interactions through the intercalation of the benzimidazolyl groups in the complexes into DNA base pairs. The DNA-condensing ability was observed to be mainly controlled by the numbers of positive charges on the complexes, and less correlated with the carboxylate linkers. Moreover, no direct relationships have been found between the apparent DNA-binding affinity and DNA-condensing ability of the complexes. The ability of DNA condensation triggered by 7b that carries four ntb-Cu(II) units and six positive charges is much stronger than those by the other complexes, but it also exhibits the largest cytotoxicity. This work aids in understanding the structure-activity relationships for metal complexes likely acting as a new type of gene-delivery systems.

All three title compounds, C(4)H(7)N(2)(+).C(4)H(5)O(4)(-), (I), C(4)H(7)N(2)(+).C(5)H(7)O(4)(-), (II), and C(4)H(7)N(2)(+).C(6)H(9)O(4)(-).H(2)O, (III), can be regarded as 1:1 organic salts. The dicarboxylic acids join through short acid bridges into infinite chains. Compound (I) crystallizes in the noncentrosymmetric Cmc2(1) space group and the asymmetric unit consists of a hydrogen succinate anion located on a mirror plane and a 2-methylimidazolium cation disordered across the same mirror. The other two compounds crystallize in the triclinic P1 space group. The carboxylic acid H atom in (II) is disordered over both ends of the anion and sits on inversion centres between adjacent anions, forming symmetric short O...H...O bridges. Two independent anions in (III) sit across inversion centres, again with the carboxylic acid H atom disordered in short O...H...O bridges. The molecules in all three compounds are linked into two-dimensional networks by combinations of imidazolium-carboxylate N(+)-H...O and carboxylate-carboxylate O-H...O hydrogen bonds. The two-dimensional networks are further linked into three-dimensional networks by C-H...O hydrogen bonds in (I) and by O(water)-H...O hydrogen bonds in (III). According to the DeltapK(a) rule, such 1:1 types of organic salts can be expected unambiguously. However, a 2:1 type of organic salt may be more easily obtained in (II) and (III) than in (I).

Both the 1:1 and 2:1 molecular adducts of 4-methylimidazole (4-MeIm) and terephthalic acid (H2TPA) are organic salts, viz. C4H7N2+.C8H5O4-, (I), and 2C4H7N2+.C8H4O4(2-), (II), respectively. The component ions in (I) are linked by N-H...O and O-H...O hydrogen bonds into continuous two-dimensional layers built from R6(4)(32) hydrogen-bond motifs running parallel to the (100) plane. These adjacent two-dimensional layers are in turn linked by a combination of C-H...O, C-H...pi and pi-pi interactions into a three-dimensional network. In the crystal structure of (II), with the anion located on an inversion centre, only N-H...O hydrogen bonds result in two-dimensional layers built from R8(8)(42) hydrogen-bond motifs running parallel to the (102) plane. Being similar to those in (I), these layers are also linked by means of C-H...O, C-H...pi and pi-pi interactions, forming a three-dimensional network. This study indicates that, on occasion, a change of the reactant concentration can exert a pivotal influence on the construction of supramolecular structures based on hydrogen bonds.

The crystal structure and catecholase-like activity of a mononuclear complex, Cu(EDTB)(NO 3 ) 2 · C 2 H 5 OH (here EDTB stands N , N , N ′ , N ′ -tetrakis(2 ′ -benzimidazolyl methyl)-1,2-ethanediamine) has been studied in comparison with a binuclear complex Cu 2 (EDTB)(NO 3 ) 4 · 3H 2 O. The results show that the reactive rate constants increase with increases of reaction temperature and pH value of intermediate. Electrospray ionization mass spectrum (ESI-MS) shows that tautomerism isomers of catechol with the title complex exist in reaction solution, and catechol is oxidized to quinone, then it is further oxidized resulting in muconic acid and its derivatives via an intradiol mechanism, just like that catalyzed by a mononuclear non-heme iron-containing dioxygenase.

In the title compound, [Cu(C3H10N2)2(C6H6NO3S)2]·2H2O, the CuII atom lies on an inversion center and is hexa­coordinated by four N atoms from two 1,3-diamino­propane ligands and two O atoms from two 4-amino­benzene­sulfonate ligands in a trans arrangement, displaying a distorted and axially elongated octa­hedral coordination geometry, with the O atoms at the axial positions. A three-dimensional network is formed in the crystal structure through O—H⋯O, N—H⋯O and N—H⋯N hydrogen bonds.