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Two dinuclear Ni (II) and Zn (II) salamo‐type complexes, [Ni2(L)(μ‐OAc)(MeOH)]·2CHCl3 (1) and [{Zn2(L)(μ‐OMe)}3]·3CHCl3·MeOH (2), have been successfully synthesized by wet‐chemical method and characterized by elemental analyses, IR spectra, UV–Vis spectra and single crystal X‐ray diffraction. Complex 1 consists of two closely related dinuclear units 1A and 1B, and complex 2 consists of three closely related dinuclear units 2A, 2B and 2C. The five units are unique example of crystallographically independent but chemically identical molecules. The Ni (II) atoms of complex 1 are located in the N2O4 coordination cavities, possessing six‐coordinated distorted octahedral geometries, but all Zn (II) atoms in complex 2 are located in the N2O3 coordination cavities, possessing five‐coordinated distorted square‐pyramid and triangular bipyramid geometries, the geometries about the Zn (II) atoms (Zn3 and Zn6) that obtain in 2B and 2C where τ5 is very close to 0.500, which is τ5Zn3 = 0.5006 and τ5Zn6 = 0.4941, respectively. The interactions were quantitatively determined by Hirshfeld surfaces analyses. Significantly, fluorescence properties were also investigated. [ABSTRACT FROM AUTHOR]

Two new tetranuclear NiII complexes, [Ni4(L1)2(N3)4(MeOH)2]·CH3COCH3(1) and [Ni4(L2)2(N3)4(MeOH)2]·4CH3COCH3(2), were synthesized using NiCl2·6H2O, NaN3, and asymmetric salamo‐based ligands H2L1 and H2L2, respectively. The structural characterization was made by elemental analyses, infrared (IR) and ultraviolet‐visible (UV‐vis) spectra, and X‐ray diffraction analyses. The results of X‐ray diffraction analyses show that the NiII atoms in complexes 1 and 2 are distorted octahedral geometries. Interestingly, the degree of distortion of the ligands in complexes 1 and 2 is different, which indicates that the interaction of NiII ions on different ligands is different. Meanwhile, the investigation of molecular packing by employing the Hirshfeld surface analysis exhibits that the percentages of C–H/H–C, O–H/H–O, and H–H/H–H contacts of the complex 1 (or 2) are calculated to be 17.7%, 7.9%, and 53.7% (or 18.8%, 13.8%, and 52.5%), respectively, where the H–H/H–H contacts have the characteristics of strong contacts whereas the O–H/H–O hydrogen bonds are considerably weak, and the studies on fluorescence properties further confirm the NiII atoms have different binding abilities to the different ligands. [ABSTRACT FROM AUTHOR]

A water stable tetrazolate‐containing metal‐organic framework, [Cd2(L)(OH)(H2O)2]n (1) [H3L = 5‐(4‐(tetrazol‐5‐yl)phenyl)isophthalic acid], was synthesized under solvothermal conditions and structurally characterized. Compound 1 displays a three dimensional porous network with one dimensional tubular channels based on trinuclear cluster [Cd3(μ3‐OH)N4C] units. Notably, 1 exhibits highly sensitive response to Cu2+ and Cr2O72– through luminescence quenching effects with the detection limit of 0.666 ppm for Cu2+ and 0.846 ppm for Cr2O72–, respectively. The possible mechanism of the luminescence quenching was discussed in detail. [ABSTRACT FROM AUTHOR]

A series of homo- and hetero-trinuclear cobalt(II) complexes [Co3(L)(OAc)2(CH3CH2OH)(H2O)] (1), [Co2Ba(L)(OAc)2] (2) and [Co2Ca(L)(OAc)2]·CHCl3 (3), containing an acyclic naphthalenediol-based ligand H4L were synthesized. All the three complexes were characterized by elemental analyses, IR, UV–vis spectra and single crystal X-ray diffraction analyses. Comparative studies of the structures and spectroscopic properties are carried out on these complexes. All of the complexes show catechol oxidase activities in MeCN. Using UV–vis spectroscopy, we monitored the aerial oxidation of 3,5-di-tert-butylcatechol (3,5-DTBCH2) to 3,5-di-tert-butylquinone (3,5-DTBQ), which confirms the essential role of these complexes in enhancing the catalytic reaction. [ABSTRACT FROM AUTHOR]

The asymmetric Salamo-type N2O2 ligand H2L and its corresponding CuII and ZnII complexes [CuL] and [{ZnL}2]·2CH3CN were synthesized and structurally characterized. Crystallographic data of the CuII complex revealed that the CuII ion is tetracoordinate with a slightly distorted square planar arrangement forming a 2D supramolecular plane structure by hydrogen bonding and π···π stacking interactions. In the ZnII complex, the ZnII ions are pentacoordinate in N2O2 tetradentate fashion and intermolecular contacts between ZnII and oxygen atoms result in a head-to-tail dimer. The ZnII ions were found to have slightly distorted square pyramidal and trigonal bipyramidal arrangements, respectively. Hydrogen bonding interactions stabilized the ZnII complex to facilitate self-assembly to a 1D linear chain. The CuII and ZnII complexes show intense photoluminescence with maximum emissions at approx. 426 and 411 nm upon excitation at 360 and 350 nm, respectively. [ABSTRACT FROM AUTHOR]

A hydrated 5-azotriazolyl salicylic acid of [(H3ATSA)]⋅2 H2O ( 1) and its CdII complex of [Cd2(H2ATSA)4]⋅13 H2O ( 2) have been synthesized and characterized by single-crystal X-ray diffraction analysis and a neutral trans- Z-enol form of H3ATSA and another anionic trans- E-enol H2ATSA− isomer have been found in 1 and 2, respectively. The yellow crystal of 2 can be transformed in situ into red crystals in NaOH solution. The diffuse reflectance and photoluminescent spectra for the crystal powder samples and the aqueous solutions of 1 and 2 have been investigated. The DFT and TDDFT calculations at B3LYP/6-31G* level for 1 and B3LYP/Lanl2dz level for 2 have been used to demonstrate the characteristic absorption spectra and the trans-enol to cis-keto photo- and thermoisomeric reaction for the ATSA3− anion. The onion cell imaging taken by confocal laser scanning microscope was observed with 1 and 2 as fluorescent labels. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]