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Three Ni(II) complexes {[NiL(μ-OAc)(CH3CH2OH)]2Ni} (1), {[NiL(μ-OAc)(CH3OH)]2Ni]·2CH2Cl2·2CH3OH (2) and {[NiL(μ-OAc)(CH3OH)]2Ni}·1.5CH3OH (3) based on a Salamo-type bis-oxime ligand (H2L = 2,2′-[ethylenedioxybis(nitrilo-methylidyne)]dinaphthol) have been synthesized and characterized by physicochemical and spectroscopic methods. The complexes 1, 2 and 3 are all trinuclear structures, and the center Ni(II) ions are six-coordinated and show the slightly distorted octahedral coordination. They all consist of three Ni(II) ions, two deprotonated L2- units, two μ-acetato ligands and two coordinated solvent molecules, as well as the crystallizing solvent molecules. Although the molecular structures of the Ni(II) complexes 1, 2 and 3 are similar to each other, obtained in different solvents, the supramolecular structures are entirely different. The complexes 1, 2 and 3 possess the self-assembled infinite 1D, 3D and 2D supramolecular structures via different intermolecular interactions (hydrogen bonds, C–H···π and π···π stacking interaction), respectively. But complex 2 formed a 3D structures by intramolecular hydrogen bonds. It is significant that the solvent molecules have obvious effects on the optical properties and molecular configuration. The Hirshfeld surface analysis showed that the short-range forces of the hydrogen bonds in complexes 1, 2 and 3 accounted for 67.8%, 44.6% and 52.7%, respectively. The molecular orbital energies for ligand H2L and complex 1 were obtained by DFT calculation, and the electron distribution, energy level and energy gap of HOMO and LUMO were given.

Four new hetero-pentanuclear 3d–4f complexes [Zn4(L)2La(NO3)2(OEt)(H2O)] (1), [Zn4(L)2Ce(NO3)2(OMe)(MeOH)] (2), [Zn4(L)2Pr(NO3)2(OEt)(EtOH)] (3) and [Zn4(L)2Nd(NO3)2(OMe)(MeOH)] (4) were synthesized by the reactions of a newly synthesized octadentate bis(salamo)-based tetraoxime ligand (H4L) with Zn(OAc)2·2H2O and Ln(NO3)3·6H2O (Ln = La, Ce, Pr and Nd), respectively, and characterized via elemental analyses, FT-IR, UV-Vis spectroscopy and single crystal X-ray crystallography. The X-ray crystallographic investigation revealed that all ZnII ions were located in N2O3 coordination spheres, and possessed a trigonal bipyramid coordination environment. The LnIII ion lay in an O8 coordination sphere, and adopted a distorted square antiprismatic coordination environment. Furthermore, supramolecular interactions and fluorescence properties were investigated.

Three novel N4-cavity Cu(II), Ni(II) and Zn(II) mononuclear complexes, [Cu(L)(NO3)2][Cu(L)(NO3)]NO3 (1) [Ni(L)(NO3)2] (2) and [Zn(L)(NO3)2] (3) were successfully synthesized via the reactions of a pyridine-containing N4-cavity bisoxime ligand L (L = 2,2'-[Ethylenedioxobis(azetidinyl)]pyridine) with Cu(II), Ni(II) and Zn(II) nitrates, respectively. Complexes 1-3 were characterized via elemental analysis, IR, UV-Vis spectra and X-ray crystallography. All three complexes are monoclinic systems, containing one M(II) atom and one (L) ligand moiety. Complexes 2 and 3 form centrosymmetric molecules. In addition, supramolecular interactions, Hirshfeld surface analysis were used to analyze the crystal properties that have been studied.

An unprecedented dinuclear CuII complex, [Cu2(L2)2], derived from a salamo-like chelating ligand H2L2, was produced by the cleavage of a newly synthesized, half-salamo-like ligand HL1 (2-[O-(1-ethyloxyamide)]oxime-3,5-dichloro-phenol). This was synthesized and characterized by elemental analyses, IR, UV&ndash, Vis and fluorescent spectra, single crystal X-ray diffraction analysis, and Hirshfeld surface analysis. X-ray crystallographic analysis indicated that the two CuII (Cu1 and Cu2) ions bore different (N2O3 and N2O2) coordination environments, the penta-coordinated Cu1 ion possessed a slightly twisted tetragonal pyramid geometry with the &tau, value &tau, = 0.004, and the tetra-coordinated Cu2 ion showed a slightly twisted square planar geometry. Interestingly, one oxime oxygen atom participated in the coordination reported previously. Moreover, an infinite two-dimensional layered supramolecular network was formed. Compared with HL1, the CuII complex possessed the characteristic of fluorescence quenching.

Binuclear CoIII complex [Co2(L)3(DMF)3] containing a Schiff ligand H2L was synthesized and analyzed by elemental analysis, single crystal X-ray crystallography, FT-IR, UV–Vis absorption spectroscopy, Hirshfeld surface analysis and DFT calculation. The CoIII complex was a 3:2 ((L)2− : CoIII) binuclear structure. The spatial configuration of central CoIII ions was six-coordinated slightly twisted octahedron. The 3D supramolecular network structure was linked by intermolecular hydrogen bonds, C H···π and π···π stacking interactions. The Schiff ligand H2L exhibits weak luminescence, but this weak fluorescence is turned on after coordination with the ZnII ion. Furthermore, H2L could as an “OFF-ON” chemosensor for fluorescent recognition of ZnII.

Three trinuclear complexes constructed from a naphthalenediol-based bis(Salamo)-type tetraoxime ligand (H4L1), [Cu3(L1)(OAc)2]·CH3OH (1), [Zn3(L1)(OAc)2(CH3OH)2]·4CHCl3 (2), and [Cu2(L1)Na(NO3)(CH3OH)] (3), and one dinuclear complex, [{Cu(L2)}2] (4), based on an unexpected ligand H2L2 derived from the cleavage of H4L1 have been synthesized and characterized by X-ray diffraction analyses. Different anionic sources, transition metal salts, and rationally controlled reaction conditions play important roles in the construction of the resulting complexes with variable coordination geometries (coordination number ranges from 4 to 7), and four types of supramolecular network were controlled by noncovalent interactions, such as hydrogen bond, π···π stacking, C–H···π, Cu···π, and halogen-related interactions. The fluorescence properties of H4L1 and its complexes were investigated, and 2 exhibits unique bright cyan–yellow visible fluorescent emissions in different solvents.

A new Cu(II) complex with asymmetric Salamo-type ligand (H2L, 4-bromo-6′-ethoxy-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol) has been synthesized and characterized structurally. The X-ray crystal structure of the Cu(II) complex shows it to be a binuclear complex, in which each Cu(II) atom is in a distorted square-pyramidal geometry. The Cu(II) complex crystallizes in the monoclinic system, space group P21/c, with unit cell parameters a = 14.7109(1), b = 8.6254(7), c = 30.124(3) A, β = 100.7400(1), and Z = 4. The Cu(II) complex consists of two Cu(II) atoms, and two L2– units, and each Cu(II) complex molecule links four other molecules into an infinite 2D-layer supramolecular structure. Meanwhile, the Cu(II) complex exhibits emission with the maximum emission wavelength λmax = 443 nm when excited at λex = 340 nm.

Two new Co(II) complexes, [{Co(L)}2{Co(Pic)2(CH3OH)2}] (1) and [{CoL(μ-OAc)}2Co] (2), where H2L = 2,2′-[Ethylenedioxybis(nitrilomethylidyne)]dinaphthol, were designed, synthesized and characterized by elemental analysis, FT-IR spectra, UV-Vis spectra, and X-ray crystallography. Complex 1 consists of two [CoL] and one [Co(Pic)2(CH3OH)2] (Pic = picrate) units and in the [CoL] unit, the Co(II) atom is tetra-coordinated with a slightly distorted square-planar geometry. In the [Co(Pic)2(CH3OH)2] unit, the Co(II) atom is hexa-coordinated with a slightly distorted octahedral geometry. Meanwhile in complex 2, two acetate ions coordinate to three Co(II) atoms through Co-O-C-O-Co bridges and four μ-naphthoxo oxygen atoms from two [CoL] units also coordinated to the central Co(II) atom. Thus, complex 2 has two distorted square pyramidal coordination geometries around the terminal Co(II) atom and an octahedral geometry around the central Co(II) atom. The supramolecular structures of complex 1 is a 3D-network supramolecular structure linked by C-H···O hydrogen bonds and π···π stacking interaction, but complex 2 possesses a self-assembled 2D-layer supramolecular structure linked by C-H···π and π···π stacking interactions. The structure determinations show that the coordination anions are important factors influencing the crystalline array.

The supramolecular interaction between cucurbit[7]uril (CB[7]) as the host and the anti-cancer drug methotrexate (MTX) as the guest was studied using fluorescence spectroscopy, UV-visible absorption spectroscopy, 1H NMR, 2D NOESY, and theoretical calculations. The experimental results confirmed the formation of 1:2 inclusion complex with CB[7] and indicated a simple and sensitive competitive method for the fluorescence detection of MTX. It was found that the fluorescence intensities of CB[7]-palmatine, CB[7]-berberine and CB[7]-coptisine were quenched linearly upon the addition of MTX. The linear ranges obtained in the detection of MTX were 0.1-15μgmL-1, 0.2-15μgmL-1, and 0.4-15μgmL-1 with detection limits of 0.03μgmL-1, 0.06μgmL-1, and 0.13μgmL-1, respectively. This method can be used for the determination of MTX in biological fluids. These results suggested that cucurbit[7]uril is a promising drug carrier for targeted MTX delivery and monitoring, with improved efficacy and reduced toxicity in normal tissues.

The complex characteristics of p-sulfonated calix[n]arene (SCnA) and two tryptophans N-[(tert-butoxy) carbonyl]-tryptophan (trp-A) and N-carbobenzoxy-tryptophane (trp-B) were examined through various techniques. Spectrofluorimetry was performed at different temperatures to determine the stability constants and evaluate the thermodynamic parameters of the two complexes. The effect of pH on complex formation was estimated. According to the fluorescence data, the assumption about the steric hindrance of the tert-butyl group of trp-A and the phenyl group of trp-B was put forward. (1)H NMR was also performed to determine the binding interaction mechanism. Results showed that the indole benzene rings of the two tryptophans partly penetrated into the cavity of p-sulfonated calix[n]arene. The shift in Ha, Hb and Hc, Hd positions became more significant as the number of phenolic units of the calixarene ring increased. Molecular modeling of the complexes elucidated the assumption about the steric hindrance of the tert-butyl group of trp-A and the phenyl group of trp-B. These observations of molecular modeling computation are consistent with previous fluorescence data and (1)H NMR results.

A new mononuclear CdII complex, [CdL(H2O)2], with halogen-substituted Salen-type bisoxime ligand (H2L = 4,4′-dibromo- 6,6′-dichloro-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol), was synthesized and structurally characterized. The CdII complex crystallizes in the monoclinic system, space group C2/c. The CdII center exhibits a slightly distorted octahedral geometry with halogen-substituted Salen-type bisoxime ligand forming the basal N2O2 coordination plane and two oxygen atoms from the coordinated water molecules in the axial position. An infinite 1D metal-water chain is formed by intermolecular hydrogen-bonding and π-π stacking interactions of neighboring benzene rings. Supplemental materials are available for this article. Go to the publisher's online edition of Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry to view the supplemental file.

A new trinuclear Ni(II) complex {[NiL(DMF)]2(OAc)2Ni}·2DMF (H2L = 4,4′-dichloro-2,2′-[(1,3-propylene)dioxybis(nitrilomethylidyne)]diphenol) is synthesized and characterized by elemental analyses, IR spectra, UV-Vis spectra and X-ray crystallography. The results show that the Ni(II) complex consists of three Ni(II) ions, two tetradentate (μ-L)2− units, two coordinated μ-acetate ions, two coordinated DMF molecules, and two crystallization DMF molecules. All hexacoordinated Ni(II) ions of the complex have a slightly distorted octahedral geometry. The crystal packing of the Ni(II) complex reveals a notable feature of this structure: the formation of an infinite supramolecular 2D layered structure by virtue of intermolecular C-H…O hydrogen bonding.

A new Cu(II) complex, [Cu(L)2], has been synthesized via the complexation of copper(II) acetate monohydrate with a new oxime-type ligand (HL = 1-(3-{[(E)-3-bromo-5-chloro-2-hydroxybenzylidene]amino}phenyl)ethanone oxime). X-ray crystallographic analysis reveals that the complex is a mononuclear complex. The Cu(II) atom is four-coordinated by the phenolate O atoms and imine N atoms from two oxime-type ligands, in a square-planar geometry in which the dihedral angle of two coordination plane (Cu1N1O1 and Cu1N#1O#1) is 0°. The crystal packing of the Cu(II) complex shows that a notable feature of this structure resides in the formation of a novel 3D supramolecular networks through intermolecular O–H···N, C–H···O, and C–H···π interactions. Supplemental materials are available for this article. Go to the publisher's online edition of Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry to view the supplemental file.

A supramolecular CoII complex, [CoL(H2O)2], bearing Salen-type bisoxime chelate ligand 4,4′,6,6′-tetrachloro-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol (H2L), has been synthesized and structurally characterized by elemental analyses, IR spectra, UV–vis spectra, and X-ray diffraction techniques. The crystal structure of [CoL(H2O)2] indicates that the CoII complex consists of one CoII atom, one L2– unit, and two coordinated water molecules. The CoII complex exhibits slightly distorted octahedral geometry with the Salen-type bisoxime ligand forming the basal N2O2 coordination plane and two oxygen atoms from the coordinated water molecules in the axial positions. An infinite 1D metal–water chain and 2D supramolecular network structure were formed by intermolecular O-H···O, O-H···Cl, and C-H···O hydrogen bonding and π-π stacking interactions. Supplemental materials are available for this article. Go to the publisher's online edition of Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Met...

The insecticide cartap (CP) is non-fluorescent in aqueous solutions. This property makes its determination through direct fluorescent method difficult. In acidic medium and at room temperature, palmatine (PAL) can react with cucurbit[7]uril (CB[7]) to form stable complexes, and the fluorescence intensity of the complex is greatly enhanced. Significant quenching of the fluorescence intensity of the CB[7]-PAL complex was observed with the addition of cartap. Based on the significant quenching of the supramolecular complex fluorescence intensity, a new spectrofluorimetric method with high sensitivity and selectivity was developed to determine cartap in aqueous solution. The fluorescence quenching values (ΔF) showed good linear relationship with cartap concentrations from 0.009 to 2.4 μg mL−1 with a detection limit 0.0029 μg mL−1. The proposed method had been successfully applied to the determination of cartap residues in grain and vegetable with recoveries of 87.4-103%. In addition, the association constants of the complexes formed between the host and the guest were determined. The competing reaction and the supramolecular interaction mechanisms between the cartap and PAL as they fight for occupancy of the CB[7] cavity were studied using spectrofluorimetry, 1H NMR and molecular modeling calculations.

A supramolecular CuII complex, [Cu(L)(H2O)] (H2L: 4,4′,6,6′-tetrachloro-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol), has been synthesized and structurally characterized. X-ray crystallographic analysis shows that the complex is a centrosymmetric mononuclear CuII complex, and the CuII atom is penta-coordinated by two phenolic O atoms and two oxime N atoms from the deprotonated Salen-type ligand, and one oxygen atom from the coordinated water molecule. A self-assembling continual supramolecular structure is formed by intermolecular O3-H3···O2 and O3-H3···Cl1 hydrogen bonds.

Two nickel(II) complexes, namely {[NiL(MeOH)(μ-OAc)]2Ni}·2CH2Cl2·2MeOH (1) and {[NiL(EtOH)(μ-OAc)]2Ni}·2EtOH (2) {H2L = 5, 5′-dimethoxy-2, 2′-[(ethylene)dioxybis(nitrilomethylidyne)]diphenol}, were synthesized and structurally characterized. Two trinuclear NiII complexes are both hexacoordinate around the central NiII atoms, showing octahedral coordination arrangements, and each complex comprises three divalent NiII atoms, two deprotonated L2– ligands, in which four μ-phenoxo oxygen atoms forming two [NiL(X)] (X = MeOH or EtOH) units, and coordinated and non-coordinated solvent molecules. Complex 1 exhibits a 2D supramolecular network through intermolecular O–H···O, C–H···O and C–H···π interactions, whereas complex 2 forms an infinite 1D chain by intermolecular C–H···O hydrogen bonding interactions.

Salen-type bisoxime 5,5′-dimethoxy-2,2′-[(ethylenedioxy)bis(nitrilomethylidyne)]diphenol (H2L) and its trinuclear Ni(II) cluster {[(NiL)(n-BuOH)]2(μ-OAc)2Ni} · n-BuOH have been synthesized and structurally characterized. The structure of H2L adopts an L-shape conformation where the two salicylaldoxime moieties are well separated. In the trinuclear Ni(II) cluster, two acetates coordinate to three Ni(II)'s through Ni–O–C–O–Ni bridges, four μ-phenoxos from two [NiL(n-BuOH)] units also coordinate to Ni(II), and two n-butanols coordinate to two terminal Ni(II)'s forming a distorted octahedral geometry. The Ni–O–C–O–Ni and μ-phenoxo bridges play important roles in assembling Ni(II) and the ligands. H2L forms a rectangle-like large cave structure through O–H ··· N, C–H ··· O, and C–H ··· π hydrogen-bond interactions, whereas its trinuclear Ni(II) cluster exhibits a 3-D supramolecular network structure through intermolecular O–H ··· O, C–H ··· O, and C–H ··· π hydrogen-bond interactions.

An unexpected dinuclear Cu(II) complex, [Cu2(L2)2] (H2L2 = 3-methoxysalicylaldehyde O-(2-hydroxyethyl)oxime), has been synthesized via complexation of Cu(II) acetate monohydrate with H4L1. Catalysis by Cu(II) results in unexpected cleavage of two N–O bonds in H4L1, giving a dialkoxo-bridged dinuclear Cu(II) complex possessing a Cu–O–Cu–O four-membered ring core instead of the usual bis(salen)-type tetraoxime Cu3–N4O4 complex. Every complex links six other molecules into an infinite-layered supramolecular structure via 12 intermolecular C–H ··· O hydrogen bonds. Furthermore, Cu(II) complex exhibits purple emission with maximum emission wavelength λmax = 417 nm when excited with 312 nm.

Two solvent-induced complexes, [CoL2(CH3OH)2] (1) and [CoL2(CH3CH2OH)2] (2), have been synthesized by the reaction of an oxime-type ligand (HL, 4-[(Ethoxyimino)(phenyl)methyl]-5-methyl-2-phenyl-1H-pyrazol-3(2H)-one) with cobalt(II) acetate tetrahydrate in different solvents. X-ray crystallographic analyses have indicated that complexes 1 and 2 have a similar structure, consisting of one CoII atom, two L− units, and two coordinated methanol or ethanol molecules. Interestingly, two CoII atoms in the structures of complexes 1 and 2 are all six-coordinated, approaching a staved octahedral geometry, but complexes 1 and 2 are grown up in methanol/chloroform and ethanol, respectively. Right because of this, solvent effect cause to the difference of the crystal structures: complex 1 forms an infinite supramolecular chain by intermolecular hydrogen bonds, while complex 2 exhibits three-dimensional supramolecular networks through intermolecular hydrogen bonds and C-H···π interactions.

Two new Cu(II) complexes, [Cu(L1)2] (1) and [Cu(L2)2] (2) (HL1 = (E)-3-bromo-5-chloro-2-hydroxy benzaldehyde O-methyl oxime; HL2 = (E)-3-bromo-5-chloro-2-hydroxy benzaldehyde O-ethyl oxime), have been synthesized and characterized by physicochemical and spectroscopic methods. X-ray crystallographic analyses show that complexes 1 and 2 have similar structures, consisting of one Cu(II) atom and two L− units. In both complexes, the Cu(II) atom, lying on an inversion center, is four-coordinated in a trans-CuN2O2 square-planar geometry by two phenolate O and two oxime N atoms from two symmetry-related N,O-bidentate oxime ligands. Moreover, both complexes form an infinite three-dimensional supramolecular structure involving intermolecular C–H···Br hydrogen bonds and π···π stacking interactions between the metal chelate rings and aromatic rings. Substituent effects in the two complexes are discussed.

A complexation of non-fluorescent phenformin hydrochloride (PFH) with cucurbit [7]uril (CB [7]) in aqueous solution was investigated using the fluorescent probe of palmatine (PAL) coupled with CB [7]. The fluorescent probe of CB [7]-PAL exhibited strong fluorescence in aqueous solution, which was quenched gradually with the increase of PFH. This effect is observed because when PFH was added to the host-guest system of CB [7]-PAL, PFH and PAL competed to occupy the CB [7] cavity. Portions of the PAL molecule were expelled from the CB [7] cavity owing to the introduction of PFH. Based on the significant quenching of the supramolecular complex fluorescence intensity, a fluorescence method of high sensitivity and selectivity was developed to determine PFH with good precision and accuracy for the first time. The linear range of the method was 0.005-1.9 μg mL(-1) with a detection limit of 0.003 μg mL(-1). In this work, association constants (K) of PFH with CB [7] were also determined. KCB [7]-PFH=(2.52±0.05)×10(5) L mol(-1). The ability of PFH to bind with CB [7] is stronger than that of PAL. The results of a density functional theory calculation authenticated that the moiety of PFH was embedded in the hydrophobic cavity of CB [7] tightly, and the nitrogen atom is located in the vicinity of a carbonyl-laced portal in the energy-minimized structure. The molecular modelling of the interaction between PFH and CB [7] was also confirmed by (1)H NMR spectra (Bruker 600 MHz).

A new dinuclear CuII complex, [Cu2(3-MeOSalamo-2)(H2O)3]·2pic·CH3COCH3·H2O, has been synthesized by the reaction of copper(II) picrate tetrahydrate with H2(3-MeOSalamo-n) (n = 2). X-ray crystallographic analysis reveals that the complex is a dinuclear structure when the O-alkyl chain length is relatively short (two CH2 groups), while a tetranuclear structure is obtained when the O-alkyl chain length becomes longer (four CH2 groups). In the complex, the μ-phenoxo bridging, picratol, and intermolecular hydrogen bonds play important roles in assembling CuII ions and ligands. Interestingly, the complex not only has a helical chain, but has an infinite metal–water chain supramolecular structure.

A new Co(II) cluster, {[CoL(DMF)]2(OAc)2Co}·2DMF (H2L = 4,4′-dichloro-2,2′-[(1,3-propylene)dioxybis (nitrilomethylidyne)]diphenol), has been synthesized and characterized by elemental analysis, IR spectrum, UV–Vis spectrum, and X-ray diffraction method. The results indicate that the Co(II) cluster consists of three Co(II) ions, two tetradentate (μ-L) 2− units, two coordinated μ-acetate ions, two coordinated DMF, and two crystallizing DMF molecules. All the hexa-coordinated Co(II) ions of the Co(II) cluster have a slightly distorted octahedral geometry. The crystal packing of the Co(II) cluster shows that a notable feature of this structure resides in the formation of a novel 2D supramolecular structure through intermolecular C‒H···O interaction and weak intramolecular C‒H···(Ph) interaction along the b-axes.

Two new complexes, [Cu(L1)2] (1) and [Cu(L2)2(H2O)]·CH3OH (2), have been synthesized via the complexation of copper(II) acetate monohydrate with two mono-oxime chelating ligands (HL1: 4-[(Methoxyimino)(phenyl)methyl]-5-methyl-2-phenyl-1H- pyrazol-3(2H)-one and HL2: 4-[(Ethoxyimino)(phenyl)methyl]-5-methyl-2-phenyl-1H-pyrazol-3(2H)-one), respectively. X-ray crystal structure determination of the two complexes show that complex 1 consists of one copper(II) ion, two bidentate (L1)− units, and the copper atom of complex 1 has a square planar geometry distorted tetrahedrally with four-coordination, while complex 2 consists of one copper(II) ion, two bidentate (L2)− units, one coordinated H2O, and one crystallizing methanol molecule, as expected from the analytical data. And the copper atom of complex 2 has a slightly distorted tetragonal pyramid geometry with five-coordination. Complex 2 is a self-assembling infinite chain supramolecular structure formed by intermolecular hydrogen bonds. Meanwhile, the photoph...

Two CoII complexes, namely {[CoL(MeOH)(μ-OAc)]2Co}·2MeCN·2MeOH (1) and {[CoL(EtOH)(μ-OAc)]2Co}·3EtOH (2) (H2L=3,3′-dimethoxy-2,2′-[(1,3-propylene)dioxybis(nitrilomethylidyne)]diphenol), have been synthesized and characterized by X-ray crystallography. Both complexes contain octahedral coordination geometries, comprising three CoII atoms, two deprotonated bisoxime L2− units in which four μ-phenoxo oxygen atoms form two [CoL(X)] (X = MeOH or EtOH) units, two acetate ligands coordinated to three CoII centers through Co–O–C–O–Co bridges, and coordinated and non-coordinated solvent. Both complexes exhibit 2D supramolecular networks through different intermolecular hydrogen-bonding interactions.

Four supramolecular complexes [MnL1(H2O)2] (1), {[CoL2(OAc)(H2O)]2Co}·5CH3CH2OH (2), {[NiL3(OAc)(CH3OH)]2Ni}·2CH3COCH3·2CH3OH (3) and {[ZnL2(OAc)]2Zn}·CHCl3 (4), have been synthesized and characterized by elemental analyses, IR, UV–Vis spectra and X-ray diffraction techniques. All the complexes have the trinuclear configuration except for MnII complex being mononuclear configuration. Every trinuclear complex contains two acetate ions coordinate to the three metal ions via a familiar M–O–C–O–M (M = Co, Ni, Zn) coordinated mode. Although complexes 1 and 3 display 1D supramolecular chains, the different coordination environments (mononuclear in 1, trinuclear in 3) provoke divergence in the structures and aggregations of the chain subunits. Complex 2 forms a 3D hydrogen-bonding supramolecular networks possessing a channel composing of six O–H···O hydrogen bonds, while complex 4 exhibits a 2D hydrogen-bonding supramolecular networks with the formation of “grottos” occupied by chloroform molecules through intermolecular hydrogen-bond interactions. The spectral properties of the title complexes have been further discussed in detail.

Two new mono- and dinuclear Cu(II) complexes, namely [CuL1]·0.5H2O (1) and [(Cu2(L2)2)(DMF)]·0.5DMF (2) (H2L1 = 1,2-bis{[(Z)-(3-methyl-5-oxo-1-phenyl-1H-pyrazolidin-4(4H)-yl)(phenyl)]methylene-aminooxy}ethane; H2L2 = 1,3-bis{[(Z)-(3-methyl-5-oxo-1-phenyl-1H-pyrazolidin-4(4H)-yl)(phenyl)] methyleneaminooxy}propane), have been synthesized and characterized by X-ray crystallography. The unit cell of complex 1 contains two crystallographically independent but chemically identical [CuL1] molecules and one crystalline water molecule, showing a slightly distorted square-planar coordination geometry and forming a wave-like pattern running along the a-axis via hydrogen bonding and π···π stacking interactions. Complex 2 has a dinuclear structure, comprising two Cu(II) atoms, two completely deprotonated phenolate bisoxime (L2)2− moieties (in the form of enol), and both coordinated and hemi-crystalline DMF molecules. Complex 2 has square-planar and square-pyramidal geometries around the two copper centers, whose basic coordination planes are almost perpendicular and form an infinite three-dimensional supramolecular network structure involving intermolecular C–H···N, C–H···O, and C–H···π(Ph) hydrogen bonding and π···π stacking interactions of neighboring pyrazole rings.

Three new supramolecular complexes, [Cu(L1)H2O]n (1), [Zn(L2)(H2O)2]n (2), and [Cd(L2)(H2O)2]n (3), have been synthesized and characterized by FT-IR spectra, fluorescence spectra, and thermal analyses. And the structures of complexes 1–3 have been elucidated by X-ray analyses. Complex 1 is square pyramidal geometry with an unusually long bond (2.262 A) from penta-coodinated CuII center to the oxygen atom of the apical coordinated water molecule. Molecules are linked by hydrogen bonding between the coordinated water and the phenolic oxygen atoms of adjacent molecules, thus formed a self-assembling continual zigzag chain supramolecular structure. The crystal structure of complex 2 (or 3) has indicated that the complex consists of one ZnII (or CdII) atom, one L2− unit and two coordinated water molecules, the coordination number of the ZnII (or CdII) atom is six, and formed an infinite metal–water chain supramolecular structure by intermolecular hydrogen bonds and π–π stacking of neighboring benzene rings. Meanwhile, the thermal and photophysical properties of the resulted complexes have also been discussed.

A new hexa-coordinated zinc(II) complex, namely [ZnL(H2O)2]n, with N2O2 coordination sphere (H2L=4,4'-dibromo-6,6'-dichloro-2,2'-[ethylenedioxybis(nitrilomethylidyne)]diphenol) has been synthesized and structurally characterized by elemental analyses, IR, UV-vis spectra and TG-DTA analyses, etc. Crystallographic data are monoclinic, space group P2(1)/c, a=24.634(2)A, b=10.144(1)A, c=7.9351(6)A, β=91.371(2)°, V=1982.4(3)A(3), Dc=2.099 g/cm(3), Z=4. The zinc(II) complex exhibits a slightly distorted octahedral geometry with halogen-substituted Salen-type bisoxime forming the basal N2O2 coordination sphere and two oxygen atoms from two coordinated water molecules in the axial position. The hydrogen-bonding and π-π stacking interactions have stabilized the zinc(II) complex molecules to form a self-assembling infinite dual metal-water chain-like structure with the nearest Zn⋯Zn distance of 4.954(4)A.

Mononuclear and trinuclear Cu(II) complexes with chemical formula [CuL].CH3OH (1) and [{(Cu(mu-L))2(OAc)2}Cu] (2), where H2L = 2,2'-[1,1'-(ethylenedioxydinitrilo)diethylidyne]diphenol, have been synthesized and characterized by elemental analyses, 1H NMR, IR and UV-vis spectra et al. Crystallographic data of complex 1 reveal the formation of an asymmetric mononuclear structure and a slight distortion toward tetrahedral geometry from the square planar structure, in which the introduction of the non-coordinated methanol molecule lead to the assembly of the 1D chains by hydrogen bonding, Cu...pi and pi...pi interactions. Complex 2 have the elongated square pyramidal geometries for the two terminal Cu(II) ions and an octahedral coordinated geometry for the central Cu(II) ion. In complex 2, two acetate ions coordinate to three Cu(II) ions adopting a familiar syn-syn (muM-O-C-O-M) coordinated fashion. The central Cu(II) ion sits in a crystallographic inversion centre. Therefore, the whole molecule of complex 2 is rigorously centrosymmetric, and forms a 3D supramolecular networks through intermolecular C-H...O and C-H..pi interactions.

A supramolecular Cu(II) complex [CuL(H2O)] with an asymmetric salen-type bisoxime ligand (H2L = 4-nitro-6ʹ-methoxy-2,2ʹ-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol) has been synthesized and characterized by elemental analysis, IR and UV/Vis spectroscopy, TG-DTA analysis, and molar conductance measurements. The crystal structure of the Cu(II) complex has been determined by single-crystal X-ray diffraction. The Cu(II) atom is penta-coodinated by N2O2 donor atoms from the asymmetic salen-type bisoxime L2− unit and one oxygen atom from the coordinated water molecule, resulting in an almost regular square-pyramidal geometry. With the help of intermolecular O-H· · ·O, C-H· · ·O hydrogen bonding and π · · ·π stacking interactions, a self-assembled 3D supramolecular structure is formed.