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A novel “cage-in-cage” metal–organic framework based on nested cages originated from two-fold interpenetrated networks was reported, which indicates the potential of interpenetration in structure modulation of cage-based MOFs. [ABSTRACT FROM AUTHOR]

A new disulfoxide-La(III) complex {[La(L) 2 (DMF) 4 ](ClO 4 ) 3 } n (1) has been prepared by the reaction of La(ClO 4 ) 3   ·   n H 2 O and a flexible disulfoxide ligand, 1,6-bis(ethylsulfinyl)hexane (L), and characterized by elemental analysis, IR and single-crystal X-ray diffraction analysis (monoclinic system, space group C 2/ c , with a   =  24.94(2), b   =  12.012(8), c   =  20.81(1)  Å, β  =  117.57(1)°, V   =  5527(6)  Å 3 and Z   =  4). The crystal structure consists of polymeric chains of {[La(L) 2 (DMF) 4 ] 3+ } n cations and anions. In the cation of 1, each La(III) center is coordinated to eight O atoms from four distinct L ligands and four DMF molecules to give a square antiprism coordination geometry. The adjacent two La(III) ions are linked by two L ligands, which adopt bis-monodentate O-coordination bridging mode to form a double-bridging zigzag chain containing 22-membered macrocycles. [ABSTRACT FROM AUTHOR]

A pentacoordinate monomeric CuII complex, [Cu(H2O)(HL1)(L2)](NO3)(H2O) (1), with the mixed ligands (where H2L1=pyridine-2,6-dicarboxylic acid and L2=3-(2-pyridyl)pyrazole), has been synthesized and characterized by elemental analyses, IR, thermogravimetric analysis and X-ray diffraction techniques. X-ray structural analysis of complex 1 revealed that the CuII center has a CuN3O2 distorted square pyramid environment with three N atoms of two different ligands and an O atom of coordinated water molecule constituting the mean plane, and one O atom of ligand HL1 occupying the axial site. The H2L1 ligand is mono-deprotonated in this structure, and only one oxygen atom of the carboxylate group coordinates to the CuII center. A striking structural feature of complex 1 is the three-dimensional supramolecular architecture formed through intermolecular C–H⋯O, O–H⋯O and N–H⋯O hydrogen-bonding interactions. The IR and ESR spectra, and thermogravimetric analysis of complex 1 have been further investigated. [Copyright &y& Elsevier]

The mononuclear CuII complex [CuL(H2O)]·2H2O (1) with a diazamesocyclic ligand bearing two functional carboxylic donor groups, 1,5-diazacyclooctane-N,N′-diacetate acid (H2L), has been synthesized and characterized by elemental analyses, thermal analyses and IR spectrum. The crystal structure of 1 has been determined by X-ray diffraction analysis, which revealed that the CuII center coordinates to the tetradentate chelated ligand L and an axial water molecule, and the 1,5-diazacyclooctane (DACO) moiety adopts a boat/chair conformation that inhibits the axial coordination at the metal center to form this penta-coordinated pyramidal (CuN2O3) complex. The most striking feature of this structure is the formation of a novel two-dimensional joint-ladder like architecture through multiple inter- and intramolecular O–H⋯O hydrogen bonds. The solution behaviors of 1 have been further investigated by conductance, UV–Vis and ESR techniques. [Copyright &y& Elsevier]

Two novel dimeric palladium(II) complexes with flexible pyridyl dithioether bridging ligands, [Pd(L 1 )Cl 2 ] 2 ( 1 ) and [Pd(L 2 )Cl 2 ] ( 2 ), where L 1 =1,3-bis(2-pyridylthio)propane and L 2 =1,3-bis(4-pyridylthio)propane, have been synthesized and structurally characterized by X-ray diffraction analyses. In both complexes, each Pd II center is four-coordinated in the trans -form by two chloride anions and two nitrogen donors from two distinct ligands. Complex 1 exhibits a unique 20-membered metallomacrocyclic structure with twisted conformation, while 2 shows a dinuclear 28-membered metallomacrocycle with planar conformation. In addition, there are weak C-H⃛Cl or C-H⃛S hydrogen bonding interactions in both complexes, resulting in different 3-D supramolecular architectures. [ABSTRACT FROM AUTHOR]

The crystal structure of a one-dimensional ladder-shape complex [CoL(H2O)]·2H2O, (L being 1,5-diazacyclooctane- N, N′-diacetate acid), has been determined by X-ray diffraction analysis: monoclinic, space group P21/c with a = 14.406(4) Å, b = 7.380(2) Å, c = 14.594(5) Å, β = 112.685(2)°, M r = 341.23, V = 1431.5(8) Å3, Z = 4. The CoII center is penta-coordinated by two O atoms of the carboxylic pendant arms, two nitrogen donors of the 1,5-diazacyclooctane (DACO) moiety, and a water molecule. The coordination geometry of CoII could be described as a distorted square pyramid and the DACO backbone adopts a normal boat/chair conformation. The complex forms a one-dimensional ladder-shape structure through inter- and intra-molecular O—H···O hydrogen bonds. [ABSTRACT FROM AUTHOR]

With the aim of examining the metal-assisted rearrangement behaviors of 2,2′-pyridil (L), its reactions with M(ClO4)2·6H2O (M=CoII, NiII and CuII) were considered. X-ray diffraction analyses of the products reveal the formation of complexes containing 2,2′-pyridilate anion (L1) or picolinate anion (L2) as arrangement products of 2,2′-pyridil, induced by different metal ions. [CoIII(L1)2](ClO4)·CH3OH (1) and [NiII(L1)2]·2H2O (2) have similar mononuclear structures, and it should be noted that the CoII ion is unstable to oxidation in this process. However, [CuII(L2)2]·2H2O (3) forms a one-dimensional linear complex via Cu–O weak interactions. [Copyright &y& Elsevier]

Abstract: In our efforts to investigate the influence of the backbone of different triazole-based bridging ligands on the structure of their metal complexes, four new coordination polymers, {[Cu(L1 )2(H2O)2]Cl2} n (1), [Cu(L2 )2Cl2] n (2), [Co(L2 )2(SCN)2] n (3), and [Cu(L3 )2(NO3)2] n (4), (L1  = 1,2-bis(triazol-1-ylmethyl)benzene, L2  = 1,3-bis(triazol-1-ylmethyl)benzene, L3  = 1,4-bis(triazol-1-ylmethyl)benzene), have been synthesized. All the complexes have been structurally characterized by IR, elemental analysis and single-crystal X-ray diffraction. Structural analyses show that 1 and 4 possess 2D coordination networks with (4,4) topology, and 1 shows a diagonal–diagonal inclined interpenetration. 2 and 3 are isostructural and feature 1D double chain, which further connected by C–H···Cl or π···π weak interactions to form 2D supramolecular frameworks. The results show that the structures of ligands (with different non-coordination backbone spacers) play important roles in the formation of such coordination architectures. Furthermore, EPR (Electron Paramagnetic Resonance) spectra of CuII complexes (1, 2, and 4) have been investigated in the solid state at room temperature. [Copyright &y& Elsevier]

Abstract: A new ligand L, 1-[3-(2-pyridyl)pyrazol-1-ylmethyl]naphthalene, and its two metal complexes, [Cu(L)3](ClO4)2 (1) and [Zn(L)3](ClO4)2(H2O)2 (2), have been synthesized and characterized. The crystal structure of complex 1 was determined by single crystal X-ray diffraction, which crystallized in monoclinic, space group P21/n with unit cell parameters, a =12.710(4) Å, b =12.135(3) Å, c =33.450(9) Å, β =93.281(5)° and Z =4. The Cu atom was six-coordinated to N(1), N(2), N(4), N(5), N(7) and N(8) from three L ligands and formed a slightly distorted octahedral geometry. Complexes 1 and 2, and ligand L were subjected to biological tests in vitro using three different cancer cell lines (HL-60, BGC-823 and MDA-MB-435). Complex 1 showed significant cytotoxic activity against three cancer cell lines. The interactions of complexes 1 and 2, and ligand L with calf thymus DNA were then investigated by thermal denaturation, viscosity measurements and spectrophotometric methods. The experimental results indicated that complexes 1 and 2 bound to DNA by intercalative mode via the ligand L. The intrinsic binding constants of complexes 1 and 2, and ligand L with DNA were 1.8×104, 5.4×103 and 2.76×103 M−1, respectively. [Copyright &y& Elsevier]

Abstract: The self-assembly of a flexible disulfoxide ligand, meso-1,2-bis(ethylsulfinyl)ethane (L) with AgClO4 led to the formation of a novel tetra-nuclear complex, {[Ag2(O,O-L)(μ-O-μ-(SO)-L)2(ClO4)]ClO4}2, in which the AgI ions exhibit two kinds of coordination modes: trigonal–bipyramidal and octahedral, and the ligands take bidentate (O,O) chelating and tridentate μ-O-μ-(SO) bridging-chelating coordination modes. Such a ligand coordination mode is unprecedented in the metal-complexes of disulfoxides. [Copyright &y& Elsevier]

Abstract: In our continuous efforts to investigate the coordination architectures of silver(I) complexes with thioethers, we report herein the syntheses and crystal structures of three new silver(I) complexes, a trinuclear complex 2 and two one-dimensional chain complexes [Ag2L1 (BF4)2(CH3CN)2]∞ 1 and [Ag2L3 (NO3)2]∞ 3, where L1, L2 and L3 are three structurally related pyridyl dithioether ligands: 1,4-bis(2-pyridylthio)butane (L1), 1,5-bis(2-pyridylthio)pentane (L2) and 1,6-bis(2-pyridylthio)hexane (L3). The structural differences of 1, 2 and 3 show the influences of the ligand spacers on the coordination modes of the terminal pyridylsulfanyl groups and the coordination geometries of the AgI ion. There exist Ag⋯Ag contacts in the three complexes, C–H⋯F weak hydrogen bonds in 1, Ag⋯S weak coordination bonds in 2 and Ag⋯O weak interactions in 2 and 3, and these weak interactions link the low-dimensional complexes into high-dimensional supramolecular structures and further stabilize the crystal structures in the solid states. [Copyright &y& Elsevier]

In the first CuI coordination polymer containing an angular bipyridine-type ligand 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (bpo), {[Cu(bpo)2(CH3CN)]ClO4 · CH3CN · (H2O)1.5}n (1), the bpo molecules exhibit different monodendate and bidendate bridging modes in binding to the CuI center, forming a novel 1-D infinite comb-like polymeric chain with the monodendate ligands on one side. The most striking feature of this structure is the formation of a 3-D porous network with large rectangular channels through two distinct types of inter-chain π–π stacking interactions, which was further stabilized by weak hydrogen-bonding interactions. [Copyright &y& Elsevier]

A new flexible disulfoxide ligand 1,6-bis(benzylsulfinyl)hexane (L), which is a mixture of the meso and rac isomers, was treated with CuII or CdII nitrate and obtained dimeric complex [Cu2(L)3(H2O)2(NO3)4] 2 or [Cd2(L)3(H2O)2(NO3)4] 3. In the reacting system the crystals of meso isomer 1 of L together with 2 or 3 were obtained. 2 and 3 have similar molecular structures. In the neutral dimer, three ligands present two kinds of coordination models: monodentate and bis-monodentate. The neutral dimeric units in 2 and 3 are linked by hydrogen bonds to yield a chain structure. Crystal structures of all three compounds were determined by single-crystal X-ray diffraction methods. Crystal data for 1: monoclinic, space group Cc, a=41.95(2), b=5.132(2), c=8.660(4) A˚, β=94.898(9)°, V=1857.7(15) A˚3, Z=4, final refinement (I>2σ(I)): R1=0.0659, wR2=0.1415. Crystal data for 2: triclinic, space group P–1, a=9.242(4), b=9.539(4), c=21.042(9) A˚, α=83.888(9), β=87.971(8), γ=74.177(9)°, V=1774.6(13) A˚3, Z=2, final refinement (I>2σ(I)): R1=0.0577, wR2=0.0954. Crystal data for 3: triclinic, space group P–1, a=9.203(4), b=9.831(3), c=20.860(7) A˚, α=84.313(6), β=86.432(7), γ=74.188(6)°, V=1805.9(11) A˚3, Z=2, final refinement (I>2σ(I)): R1=0.0548, wR2=0.1192. [Copyright &y& Elsevier]

A bis-substituent diazamesocyclic compound containing bulky phenolic donor pendants, 1,4-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-1,4-diazacycloheptane, has been prepared from 1,4-diazacycloheptane (DACH) and 2-tert-butyl-4-methylphenol by the Mannich reaction, and structurally characterized by NMR, IR and X-ray diffraction techniques. The crystal structure of the title compound reveals that 1,4-diazacycloheptane (DACH) ring is folded up into unusual chair configuration, and the two phenol pendants of the compound are in unexpected trans positions, which is different from those in the transition metal complexes of DACH and its derivatives. There exist intra-molecular O–H⋯N hydrogen bonds between the phenolic O atoms and the DACH N donors which stabilize the crystal structure. [Copyright &y& Elsevier]

The synthesis of a new oxalato-bridged dinuclear Cu(II) complex, [Cu2(DACO)2(μ-ox)Br2]·CH3OH (1), where DACO=1,5-diazacyclooctane, together with its spectral and magnetic characterization, are reported. Crystal structure of 1 has been determined by X-ray diffraction analysis, which is made up of centrosymmetric dinuclear [Cu2(DACO)2(μ-ox)Br2] unit and noncoordinated methanol molecule, assembling into a novel two-dimensional step-like extended network through hydrogen bonds. The magnetic susceptibility indicates that complex 1 is anti-ferromagnetic coupling with 2J=−242 cm−1. The strength of the exchange interaction is discussed on the basis of the structural feature. [Copyright &y& Elsevier]

A series of penta-coordinated CoII complexes of 1,4-diazacycloheptane (DACH) functionalized by additional imidazole or pyridine donor pendants, [CoL1Cl](ClO4)·H2O (1), [CoL2Cl](ClO4) (2) and [CoL3Cl](ClO4)·CH3OH (3), where L1=1,4-bis(imidazole-4-ylmethyl)-DACH, L2=1,4-bis(N-1-methylimidazol-2-ylmethyl)-DACH and L3=1,4-bis(pyridyl-2-ylmethyl)-DACH have been synthesized and characterized by elemental analyses, IR and UV–Vis spectra. In all the mononuclear complexes, each CoII center is penta-coordinated to four nitrogen donors of the ligand and one axial chloride anion. The crystal structure of complex 2 has been determined by X-ray diffraction analysis, which forms a one-dimensional linear structure through inter-molecular C–H⋯Cl and C–H⋯O hydrogen-bonding. [Copyright &y& Elsevier]

A novel Cd(II) metal–organic framework, [Cd 3 L 3 (DMF) 2 ] n ( 1 ), was synthesized using 5-(1H-1,2,4-triazol-1-yl)isophthalic acid (H 2 L) and Cd(NO 3 ) 2 ·6H 2 O under solvothermal condition. The structure of 1 was characterized by X-ray crystallography, elemental analysis, and IR spectrum. Compound 1 possessed a fascinating three-dimensional (3D) double-walled framework with one-dimensional (1D) channels. The luminescence properties of compound 1 toward anion detection were systematically investigated. The results indicate that compound 1 behaves as a highly selective and sensitive ‘turn-off’ luminescence probe toward Cr 2 O 7 2− anion. [ABSTRACT FROM AUTHOR]

Two-dimensional lead halide perovskites (2D LHPs) can be generally categorized into the Ruddlesden-Popper (RP) and Dion-Jacobson (DJ) phases, with unbiased and biased structural packing manners, respectively. To distinguish the two different phases during materials discovery, the synthesis has heavily relied on the traditional trial-and-error methods which severely delay the rapid development of these emerging 2D materials. In this work, we applied machine learning (ML) to accelerate the synthetic development of (100)-oriented 2D A 2 BX 4 and ABX 4 LHPs (A = organic amine cation, B = Pb, X = halide). The experimentally available 264 crystal structures were used as training data for our ML model to identify the descriptors influencing the formation of the RP- and DJ-phases. The number of nitrogen atoms able to be protonated, the heteroatom type, and the nitrogen content of the organic amine are identified as the most influential factors. To validate our model, three organic amines were tested by growing single crystals and two of the three new structures are consistent with our ML results. This study takes one step further toward the rational synthesis of RP- and DJ-phase hybrid 2D LHPs via an approach of ML. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Two new three-dimensional (3D) porous metal-organic frameworks, [Ni(tpt)2/3(bpta)1/4(H2O)2(OH)]⋅solve (1) and [Cd(tpt)(H2bpta)]⋅solve (2) (tpt=2,4,6-tris(4-pyridyl)-1,3,5-triazine, H4bpta=(1,1''-biphenyl)-2,2'',6,6''-tetracarboxylic acid) have been prepared, and characterized by single-crystal X-ray diffraction, IR spectra, PXRD, and TG analysis. The results show that complex 1 has a 3D bor network structure with 56.9% solvent-accessible volume, and 2 reveals a novol 3,5-coordinated chiral topology with vertex symbol (4.72)(43.62.74.8) and 52.5% accessible void in the structure. Moreover, gas adsorption properties of desolvated 1 and 2 were investigated. [Copyright &y& Elsevier]

In our continuing efforts to explore the effects of substituting groups of bridging ligands on the structure and properties of their complexes, two structurally related bis(tetrazolate) ligands, 2,3-diethyl-5,6-di(1H-tetrazol-5-yl)pyrazine (H2L1) and 2,3-diphenyl-5,6-di(1H-tetrazol-5-yl)pyrazine (H2L2), have been designed, and seven ZnII and HgII complexes with the two ligands, [Zn2(L1)2(H2O)4](H2O)4 (1), {[Zn2(L1)2](H2O)0.5}∞ (2), [Zn6(L2)6(H2O)12] (3), [Zn(L2)]∞ (4), [Hg(L1)Br]∞ (5), {[Hg4(L2)4(H2O)6](H2O)}∞ (6), and [Hg3(L2)2(H2O)0.5Br2]∞ (7), have been synthesized and characterized. 1 has a dinuclear structure in which ZnII is four-coordinated to furnish a distorted tetrahedral geometry, and in the crystal structure the dinuclear units are further assembled to form a three-dimensional (3D) framework by hydrogen bonds. 2 possesses a 3D framework with (4,122) topology in which the ZnII center is four-coordinated by N atoms of the ligand. 3 has a hexanuclear structure comprised of two trinuclear motifs as basic building units each of which has three types of coordination environments around the ZnII ions, and the hexanuclear units are interlinked by O−H···N hydrogen-bonding to generate a two-dimensional (2D) framework. 4 takes a 3D (4,8,10) topology, in which ZnII ions act as three-connected nodes and the L2 ligand takes a chelating−bridging mode being similar to that in 1. 5 possesses a 2D (4,8,8) layer structure with one kind of HgII center four-coordinated by one Br anion, two N atoms from two L1 ligands, and one weakly coordinated N atom from another L1 ligand. 6 has two kinds of one-dimensional chain structures with two kinds of HgII ions, and one kind of these chains is further assembled into 2D sheets via hydrogen-bonding interaction. 7 has a 2D layer structure with one kind of HgII center coordinated by a Br anion, the other one being seven-coordinated by six N atoms from four L2 ligands and one weakly coordinated O atom from a water molecule. In this work, 1, 3, 5, and 6 were synthesized by the conventional method at room temperature, while 2, 4, 7 were prepared under hydrothermal conditions. These results show that the substituting groups of ligands and the reaction conditions have great influences on the formation of these complexes. In addition, the luminescent properties of complexes 1−7 have been briefly studied. Seven complexes with two structurally related 2,3-substituted-5,6-di(1H-tetrazol-5-yl)pyrazine ligands bearing different substituting groups have been synthesized under different reaction conditions, and structurally characterized. The influence of the substituting groups of ligands and synthetic conditions on the formation of such complexes was confirmed. Moreover, some complexes display luminescent properties in the solid state at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: Four new coordination complexes with azole heterocycle ligands bearing acetic acid groups, [Co(L 1 )2]n (1), [CuL 1 N3]n (2), [Cu(L 2 )2·0.5C2H5OH·H2O]n (3) and [Co(L 2 )2]n (4) (here, HL 1 =1H-imidazole-1-yl-acetic acid, HL 2 =1H-benzimidazole-1-yl-acetic acid) have been synthesized and structurally characterized. Single-crystal structure analysis shows that 3 and 4 are 2D complexes with 44-sql topologies, while another 2D complex 1 has a (43)2(46)-kgd topology. And 2 is a 3D complex composed dinuclear μ 1,1-bridging azido CuII entities with distorted rutile topology. The magnetic properties of 1 and 2 have been studied. [Copyright &y& Elsevier]

Abstract: The reaction of AgClO4 with anthracene-9,10-dicarboxylic acid (H2 L) and hexamethylenetetramine (hmt) in the presence of 2,6-dimethylpyridine afforded a photoluminescent three-dimensional (3D) AgI coordination polymer {[Ag8(L)3(μ4-hmt)2(H2O)6](ClO4)2}∞ (L =anthracene-9,10-dicarboxylate) exhibiting binodal 4-connected (43·63)2(42·62·82)3 topological network. The relevant result reveals that the anthracene skeleton of L ligand bearing a large π-conjugated ring system plays an important role in the formation of the final structure. [Copyright &y& Elsevier]

Abstract: Three new complexes [Cu(L)2(NO3)](NO3)(H2O)1/2(CH3OH)1/2 (1), [Cd(L)2(NO3)2](H2O)3 (2) and [Cd(L)2(ClO4)(CH3OH)](ClO4)(H2O)1/4(CH3OH) (3) (L =1-[3-(2-pyridyl)pyrazol-1-ylmethyl]naphthalene) were synthesized and characterized by elemental analyses, IR and X-ray diffraction analysis. Among them, the Cu(II) and Cd(II) ions were both coordinated by four N donors from two distinct L ligands via N,N-bidentate chelating coordination mode. Additional weak interactions, such as the face-to-face π–π stacking and C–H⋯O H-bonding interactions, linked the mononuclear unit into 1D chain and further into 2D network. Complexes 1–3 were subjected to biological assays in vitro against six different cancer cell lines. All of them exhibited cytotoxic specificity and notable cancer cell inhibitory rate. The interactions of 1–3 with calf thymus DNA were investigated by thermal denaturation, viscosity measurements, spectrophotometric and electrophoresis methods. The results indicate that these complexes bound to DNA by intercalation mode via the ligand L and had different nuclease activities, which were in good agreement with their DNA-binding strength. Moreover, the central metal ions of 1–3 played a vital role in DNA-binding behaviors, DNA-cleavage activities and cytotoxicities, whereas the contribution of the different counter anions to their bioactivities also should not be ignored. [Copyright &y& Elsevier]

Abstract: A new 3-D mixed valence copper-azido coordination polymer, [CuI ·CuII(N3)(pzc)2 (H2O)] n 1, has been synthesized and characterized, and its magnetic properties studied. In this compound, the azide acts as rare asymmetric μ 1,1,3 bridging mode. The azide ligands and the Cu(2) ions act as 3-connecting nodes, and the Cu(1) ions act as 4-connecting nodes. The overall net takes rare topology with the Schläfli symbol of (6.82)(6.82)(6.85). [Copyright &y& Elsevier]

Abstract: Two new 3-D supramolecular networks, {[Cd2(dap)2(tp)2(H2O)2]·2H2O} n (1) and {[Cu3(tp)2(dpq)2(OH)2]} n (2) (tp, terephthalate; dap, 5,6-diamino-1,10-phenanthroline; dpq, dipyrido[3,2-d:2′,3′-f]quinoxaline), have been synthesized and structurally characterized by X-ray diffraction. Single-crystal X-ray analyses show that complex 1 is constructed by CdII and mixed ligands of daps and tps to form a 1-D polymer chain. In complex 2, a tetra-coordinated CuII and two penta-coordinated CuII are linked by two bridging hydroxyl oxygen atoms to form a Cu3(OH)2(dpq)2 unit, which is a noteworthy feature in the framework, and such units are connected through tp to form a 2-D lamellar polymer. Moreover, complexes 1 and 2 are further extended into 3-D supramolecular networks by H-bonding and π–π stacking interactions, respectively. [Copyright &y& Elsevier]

Abstract: A new one-dimension complex, [Cd(μ2-L)2] n (1, HL=3-(2-pyridyl)pyrazole), has been hydrothermally synthesized and characterized by elemental analysis, IR, TGA, and single-crystal X-ray diffraction analysis. In 1, the L ligand takes tridentate chelating-bridging coordination mode via deprotonation of the pyrazolyl NH group and coordination of the pyrazolyl N atom to a second metal ion. In the solid state, complex 1 shows blue photoluminescent property at room temperature. [Copyright &y& Elsevier]

Abstract: A dinuclear CuII complex [Cu2(bpp)2(H2O)2](ClO4)2 (1) with 3,5-bis(2-pyridyl)pyrazole (Hbpp), has been synthesized and characterized by elemental analyses, thermal analysis, conductance, UV–vis and IR spectra. The crystal structure of 1, determined by X-ray diffraction technique, reveals that two centrosymmetric CuII centers are bridged by a pair of tetradentate anionic bpp ligands, adopting a square-pyramidal environment with the water ligand occupying the axial site. An interesting feature of this structure is the formation of a two-dimensional supramolecular network through O–H⋯O hydrogen bonds between the water moieties of the cationic [Cu2(bpp)2(H2O)2]2+ subunits and perchlorate anions. The magnetic properties of 1 have been investigated by variable-temperature magnetic susceptibility and EPR measurements. Very strong antiferromagnetic interaction between the CuII centers (with H=-JS1S2, J=-368.3cm-1) has been observed, and the magneto-structural correlations was analyzed. [Copyright &y& Elsevier]

The reactions of CoCl2 salt and piperazine (L) in the presence of different organic acid mediums afford a series of cobalt(II) complexes, the solid structures (determined by X-ray diffraction techniques) of which are controlled by the nature of the specific acid. When terephthalic acid was used, a novel mononuclear molecule [Co(HL)2Cl3]·Cl·(H2O) (1) was obtained [orthorhombic, Pnma, a=24.604(16) A˚, b=9.882(7) A˚, c=6.609(4) A˚, Z=4], in which the CoII center takes the unusual compressed trigonal-bipyramidal coordination geometry (CoN2Cl3) and multiple hydrogen-bonding interactions extend this structure into a three-dimensional supramolecular network. However, with the replacement of terephthalic acid with malonic acid in the above reaction, a one-dimensional coordination polymer [CoLCl2]n (2) was obtained [monoclinic, P21/n, a=6.363(3) A˚, b=10.244(5) A˚, c=12.124(5) A˚, β=103.560(8)°, Z=4], in which the tetrahedral CoII centers (CoCl2N2) are linked by the bidentate-coordinated piperazine molecules to form a zigzag chain array and these coordination chains are further expanded to a three-dimensional hydrogen-bonding architecture. In addition, a mononuclear complex [Co(gly)3]·(H2O) (3) [monoclinic, P21/c, a=6.261(5) A˚, b=14.280(9) A˚, c=12.182(8) A˚, β=101.450(14)°, Z=4] was yielded when glycine was used in the similar procedure. A three-dimensional framework is also observed through the hydrogen-bonding interactions between [Co(gly)3] moieties, in which the guest water molecules are included. These results unequivocally indicate that the nature of the organic acid templates play the key role in formation of these complexes. [Copyright &y& Elsevier]

A four-coordinated monomeric NiII complex with a new tetradentate diazamesocyclic ligand funtionalized by oxime donor pendants, [Ni(HL)]ClO4 (1), where H2L=N,N′-bis(acetophenoneoxime)-1,5-diazacyclooctane, has been synthesized and characterized by elemental analyses, IR, UV–vis and X-ray diffraction techniques. The crystal structure of complex 1 reveals that the NiII center has a NiN4 distorted planar environment and the 1,5-diazacyclooctane ring takes the unusual boat–boat configuration. The oxime groups exhibit the only N-binding mode with NiII ion. A striking structural feature of complex 1 residues in the formation of a two-dimensional (2D) hydrogen-bonding supramolecular architecture with (6,3) topology through intermolecular C–H⋯O interactions, in which both ClO4− counter anions and the coordination cations act as 3-connected nodes. The spectral properties of the title complex have been further analyzed in detail. [Copyright &y& Elsevier]

A new dithioether palladium(II) complex {Pd[PhS(CH2)5SPh]Cl2}n (1) has been prepared by the reaction of PdCl2 and bis(phenylthio)pentane [PhS(CH2)5SPh, bptf] in acetonitrile/chloroform (1:1), and structurally characterized by X-ray crystallography. It crystallized in orthorhombic system, space group Pbcn, with a=9.744(3),b=14.452(4),c=27.393(8) A˚, and Z=8. There are two palladium(II) ions in the same structure unit and each is coordinated by two chloride anions and two sulfur atoms of two distinct ligands in trans positions, forming a rhombic planar geometry. The flexible bptf ligand acts as bridge to link palladium(II) ions to form a coordination polymer with one-dimensional chain structure. [Copyright &y& Elsevier]

A series of four-coordinated monomeric CuII, CoII, and NiII complexes of a tetradentate diazamesocyclic ligand containing bulky phenolate donor pendants, [CuL] (1), [Cu(HL)]ClO4 (2), [CoL] (3), and [NiL] (4), where H2L=1,4-bis-(3-tert-butyl-5-methyl-2-hydroxybenzyl)-1,4-diazacycloheptane, have been synthesized and characterized by elemental analyses, IR, UV–vis and ESR spectra. The crystal structure of complex 1 has been determined by X-ray diffraction analysis. [Copyright &y& Elsevier]

A new Mn(II) complex with the planar ligand 6,7-dicycanodipyrido[2,2-d:2′,3′-f]quinoxaline (L) [MnL(NO3)(H2O)3]NO3·CH3OH (1) has been synthesized and characterized by elemental analysis, IR, TG-DTA and molar conductance. Its crystal structure was determined by X-ray diffraction, crystal data: yellow, triclinic, space group P1¯, Z=2, a=7.3743(8) A˚, b=11.2487(15) A˚, c=14.1655(15) A˚, α=79.412(2)°, β=83.208(2)°, γ=80.466(2)°. The Mn atom was hexa-coordinated to form a distorted octahedral geometry by two nitrogen atoms of L and four oxygen atoms of three H2O and NO3− in the complex. The binding mode of the complex with calf thymus DNA has also been investigated with spectrophotometric methods, viscosity and thermal denaturation measurements. The experimental results indicate that the complex intercalated into DNA base pairs via the ligand L. The intrinsic binding constant Kb values for 1 (5.00×105 M−1) and L (1.65×105 M−1) were determined by absorption titration and calculated with the model of McGhee and Von Hippel. Biological tests against four different cell lines (HL-60, KB, Hela and BGC-823) in vitro showed that the complex had significant antitumor properties since the 50% inhibition concentrations (IC50) of the complex were within a μM range similar to those of antitumor drug 5-fluorouracil. [Copyright &y& Elsevier]

A novel phenoxo-bridged dinuclear CoII complex with a diazamesocyclic ligand bearing one additional phenol functional donor group, [CoLCl]2·2C3H6O (1) (where HL=1-(2-hydroxybenzyl)-1,5-diazacyclooctane), has been synthesized and characterized by elemental analyses, conductance, thermal analyses, IR and UV–vis spectra. The crystal structure of complex 1 has been determined by X-ray diffraction technique, which reveals that it is a neutral complex and resides on a crystallographic inversion center. The two CoII centers bridged by the phenoxo groups are penta-coordinated, taking a coordination sphere in the midst of the ideal square-pyramid and trigonal bipyramid. 1,5-Diazacyclooctane of the ligand takes a boat/chair conformation and an H atom from it effectively blocks the axial coordination site opposite the Cl− ligand to form CoN2O2Cl geometry. The crystal structure is stabilized by the N–H⋯O hydrogen bond between the amino group and the acetone molecule. [Copyright &y& Elsevier]

A new potential tetradentate ligand, 1,4-bis(N-1-methylimidazol-2-ylmethyl)-1,4-diazacycloheptane (l), together with its CuII complex [CulCl]ClO4 (1), has been reported. The crystal structure of 1, determined by single-crystal X-ray analysis, shows that it is in chiral P212121 space group. The CuII centre is penta-coordinated in square pyramidal geometry and the diazacycloheptane (DACH) ring adopts normal boat configuration. The most striking feature of this complex is the formation of a 3D network bridged through the C–H⋯Cl hydrogen bonds with the perchlorate anions in the cavities, and stabilized via π–π stacking interactions along the a-direction. The solution behaviour of 1 has been further investigated by UV/Vis and ESR techniques. [Copyright &y& Elsevier]

The complex [Mn(L)(NO3)2(H2O)2] (1) (L=2H-5-hydroxy-1,2,5-oxadiazo[3,4-f]1,10-phenanthroline) was synthesized and characterized by elemental analysis, IR and UV. The crystal and molecular structure of 1 was determined by single-crystal X-ray diffraction; crystal data: light yellow, monoclinic, space group P21/n, Z=4, a=7.432(2) A˚, b=9.582(3) A˚, c=23.445(7) A˚, β=90.519(5)°. The Mn atom in 1 is hexa-coordinated in a distorted octahedral arrangement by two N atoms of the ligand L and four O atoms of two water molecules and two nitrate anions. Biological tests in vitro showed that 1 has significant antitumor activity against HL-60, KB, Hela and BGC-823 cells. The interaction of 1 with calf thymus DNA was investigated by absorption titration, thermal denaturation and viscosity measurements. The results suggest that 1 binds with DNA by intercalating via the ligand L. [ABSTRACT FROM AUTHOR]

Two mononuclear RuII complexes of polypyridyl ligands, cis-[Ru(bpy)2(4,4′-bpy)Cl](PF6)·H2O (1) and cis-[Ru(phen)2(CH3CN)2](PF6)2 (2) (bpy=2,2′-bipyridyl, 4,4′-bpy=4,4′-bipyridyl, and phen=1,10-phenanthroline), have been synthesized and characterized by elemental analyses, IR and UV–vis spectra. The crystal structures of both complexes have been determined by X-ray diffraction, indicating that each RuII center is hexa-coordinated (RuN5Cl for 1 and RuN6 for 2) and takes a distorted octahedral geometry. The favored feature of both complexes is that they are quite useful complex precursors for further constructing new functional architectures. [Copyright &y& Elsevier]

Two three-dimensional (3D) supramolecular compounds of the general formula [M(L)2(NCS)2(H2O)2], where M is MnII or CoII and L is 2,5-bis(4-pyridyl)-1,3,4-oxadiazole), have been synthesized and structurally determined by X-ray diffraction analyses. The crystal structures of both complexes reveal that they are isomorphic neutral molecules and the metal ions are at the center of symmetry. Each metal center is six-coordinated and the MN4O2 coordination sphere can be considered as an octahedron. The most striking feature of both complexes resides in the formation of a 3D network through hydrogen bonds and π–π stacking co-effection. [Copyright &y& Elsevier]

Two new platinum(II) complexes with dithioether ligands, cis-[Pt(L1)Cl2] (1) and cis-[Pt(L2)Cl2]2 (2), where L1=1,3-bis(phenylthio)propane and L2=1,5-bis(n-propylthio)pentane, have been synthesized and structurally characterized by X-ray diffraction analyses. In 1, the Pt(II) center is four-coordinated and forms a six-membered chelated ring with L1, while 2 exhibits a unique di-nuclear structure containing a 16-membered metallomacrocyles with chair-shaped conformation, in which each Pt(II) center is coordinated by two chloride anions and two sulfur-donors from two L2 ligands. [Copyright &y& Elsevier]