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Acetate‐bridged binuclear Co(II) and Ni(II) complexes, [Co2(L)(μ‐OAc)(EtOH)] (1) and [Ni2(L)(μ‐OAc)(EtOH)] (2) were synthesized via the reaction of a new bis(salamo)‐like ligand with two different metal(II) acetates. X‐ray single crystal diffraction analyses showed that two metal(II) ions (Co or Ni) occupy two sets of N2O2 cavities, respectively. The acetate group bridges the two metals, and the ethanol oxygen atom participates in the coordination. Furthermore, UV–vis titration experiments clearly indicated that the complexation between H3L and M(II) ions leads to the 1:2 complexes [(L)M2]+ through a highly synergistic process. Bond valence sum (BVS) calculations exhibited that the Co(II) and Ni(II) ions are divalent. Secondly, the ligand H3L highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO‐LUMO) gap analysis and surface electrostatic potential were theoretically analyzed by theoretical calculation (density functional theory), and the reactivity of M(II) ions and the ligand in the complex formation process was demonstrated. Finally, the microscopic properties of the complexes were deeply understood through the calculation of the weak intramolecular interactions and the unstressed regions outside the complexes. [ABSTRACT FROM AUTHOR]

Two helical centrosymmetric homotetranuclear Cu (II) complexes, [Cu4(L)2(EtOH)2](ClO4)2·2EtOH·2CHCl3(1) and [{Cu4(L)2(EtOH)2}{Cu4(L)2(HNO3)2}](NO3)4·3EtOH·3MeOH (2), were synthesized by the reactions of a symmetric bis (salamo)‐based ligand H3L with Cu(ClO)2·6H2O and Cu(NO)3·3H2O, respectively, and certified by elemental analyses, UV–Visible absorption spectra, infrared spectra and single‐crystal X‐ray analysis techniques. X‐ray crystal structure analyses reveal that four Cu (II) atoms of complex 1 are attached to two deprotonated ligand (L)3− units with the help of two coordinated ethanol molecules, and then forming a helical centrosymmetric complex by H‐bonding and π⋯π interactions. While complex 2 unit cell contains two crystallographically independent but chemically identical homotetranuclear complexes (molecules A and B), eight Cu (II) atoms are coordinated by four deprotonated ligand (L)3− units. The coordination mode of four Cu (II) atoms from molecule A is the same as complex 1; at the same time, oxygen atoms on nitrates are involved in the coordination of another four Cu (II) atoms from molecule B. The short‐range interactions in complexes 1 and 2 were calculated by Hirshfeld surfaces analyses. The molecular orbital energy levels, molecular stabilities of complexes 1 and 2 were analyzed by DFT calculations. In addition, antibacterial assays were also investigated in detail. [ABSTRACT FROM AUTHOR]

Two novel homomultinuclear complexes [Co6(L)2(μ‐OAc)4]·2CHCl3·CH3COCH3 (1) and [Ni2(L)(H2O)2(Py)2]·2CHCl3 (2) with a newly designed rigid bis(salamo)‐type tetraoxime ligand (H4L) were synthesized and characterized by elemental analyses, Fourier transform infrared (FT‐IR) spectra, UV–Vis absorption spectra, and X‐ray single‐crystal diffractions. Complex 1 is a novel triple‐decker symmetrical six‐core cluster structure with twofold axis and inversion center. The Co(II) atoms were sandwiched between the bis(salamo)‐type ligands and possess two different geometries of distorted tetragonal pyramid and octahedron, respectively. Complex 2 possesses a dinuclear structure and the Ni(II) atoms are located in the N2O2 cavities of the ligand, and axial coordination atoms come from the coordinated water and pyridine molecules. Both Ni(II) atoms adopt distorted octahedral geometries. The interactions were quantitatively determined by Hirshfeld surfaces analyses of complexes 1 and 2. The coordination ratios were determined by studying the fluorescence properties of complexes 1 and 2. The results of fluorescence titration experiment show that the metals to ligand binding ratios are 6:2 and 2:1 for complexes 1 and 2, respectively. [ABSTRACT FROM AUTHOR]

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]

Using symmetrical bis (salamo)‐type tetraoxime ligand H3L and Cu (ClO4)2·6H2O in different solvent systems, two unusual homomultinuclear Cu (II) complexes, [Cu4(L)2(CH3CH2OH)2](ClO4)2·2H2O (1) and [Cu2(L)]n (ClO4)n·nCH3CN (2), were synthesized and characterized by single‐crystal X‐ray diffraction analyses, elemental analyses, infrared (IR), ultraviolet–visible (UV–Vis) spectroscopy, Hirshfeld surfaces analyses, and density functional theory (DFT) calculations. Complex 1 includes [Cu4(L)2(CH3CH2OH)2]2+ ion, two ClO4− counter anions, two coordinated ethanol molecules and two aquatic dissociative molecules, the two deprotonated ligand (L)3− units package around four Cu (II) ions yield a centrosymmetric helical molecules with a charged linear folding center, while complex 2 forms a 1‐D linear topology structure and is only the substitution of chloroform in the solvent system of complex 1 with acetonitrile. Coordination mode of complex 2 is widely different from that of complex 1. In the Cu (II) ions of complex 1, there are two coordination modes of Cu (II) ions, the hexa‐coordinated distorted octahedral structure and the penta‐coordinated distorted tetragonal pyramid structure, but complex 2 only has almost perfect tetragonal pyramid geometry. Fluorescence properties of H3L and its complexes 1 and 2 have also been explored. [ABSTRACT FROM AUTHOR]

Two newly designed heteromultinuclear [CuII4SmIII2] and [CuII2TbIII] bis (salamo)‐based complexes, [{Cu2(L)Sm (NO3)2(μ2‐NO3)(CH3OH)}2]·2CH3OH and [Cu2(L)Tb (NO3)2(μ2‐NO3)][Cu2(L)Tb (NO3)2(μ2‐NO3)(H2O)]·CH3OH, were synthesized and characterized by elemental analyses, Fourier transform infrared (FT‐IR) spectra, ultraviolet–visible (UV–vis) absorption spectra, and X‐ray crystallography. The ultraviolet titration experiments exhibited that the coordination ratio of the ligand, rare earth metal, and transition metal is 1:1:2. In the [CuII4SmIII2] complex, Cu1 atom has a distorted quadrilateral pyramid geometry, whereas Cu2 atom forms a slightly distorted octahedral geometry. The [CuII2TbIII] complex unit cell contains two crystallographically independent and chemically different heterotrinuclear complexes (Molecules A and B). In Molecule A, the Cu1 atom bears a four‐coordinated plane quadrilateral geometry, whereas the five‐coordinated Cu2 atom forms a slightly distorted tetragonal cone geometry. In Molecule B, the five‐coordinated Cu3 and Cu4 atoms possess slightly distorted tetragonal cone geometries. Noncovalent interactions like hydrogen bonding and π···π stacking interactions are operative in construction of supramolecular architectures. The [CuII2TbIII] complex behaves as a catalyst towards oxidative coupling of 2‐AP in MeCN medium. In addition, fluorescence properties of the ligand H4L and its [CuII4SmIII2] and [CuII2TbIII] complexes have also been discussed. [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]

Four new solvent‐induced Ni(II) complexes with chemical formulae [{NiL(μ2‐OAc)(MeOH)}2Ni]·2MeOH (1), [{NiL(μ2‐OAc)}2(n‐PrOH)(H2O)Ni]·n‐PrOH (2), [{NiL(μ2‐OAc)(DMF)}2Ni] (3) and [{NiL(μ2‐OAc)(DMSO)}2Ni]·2DMSO (4), (H2L = 4‐Nitro‐4′‐chloro‐2,2′‐[(1,3‐propylene)dioxybis(nitrilomethylidyne)]diphenol) have been synthesized and characterized by elemental analyses, FT‐IR, UV–Vis spectra and X‐ray crystallography. X‐ray crystal structure determinations revealed that each of the Ni(II) complexes 1–4 consists of three Ni(II) atoms, two completely deprotonated (L)2− units, two μ2‐acetate ions and two coordinated solvent molecules (solvents are methanol, n‐propanol, water, N,N‐dimethylformamide and dimethyl sulphoxide, respectively). Although the four complexes 1–4 were synthesized in different solvents, it is worthwhile that the Ni(II) atoms in the four complexes 1–4 adopt hexa–coordinated with slightly distorted octahedral coordination geometries, and the ratios of the ligand H2L to Ni(II) atoms are all 2: 3. The complexes 1–4 possess self‐assembled infinite 1D, 3D, 1D and 2D supramolecular structures via the intermolecular hydrogen bonds, respectively. In addition, fluorescence behaviors were investigated in the complexes 1–4. [ABSTRACT FROM AUTHOR]

A novel naphthalenediol‐based bis(salamo)‐type tetraoxime compound (H4L) was designed and synthesized. Two new supramolecular complexes, [Cu3(L)(μ‐OAc)2] and [Co3(L)(μ‐OAc)2(MeOH)2]·4CHCl3 were synthesized by the reaction of H4L with Cu(II) acetate dihydrate and Co(II) acetate dihydrate, respectively, and were characterized by elemental analyses and X‐ray crystallography. In the Cu(II) complex, Cu1 and Cu2 atoms located in the N2O2 sites, and are both penta‐coordinated, and Cu3 atom is also penta‐coordinated by five oxygen atoms. All the three Cu(II) atoms have geometries of slightly distorted tetragonal pyramid. In the Co(II) complex, Co1 and Co3 atoms located in the N2O2 sites, and are both penta‐coordinated with geometries of slightly distorted triangular bipyramid and distorted tetragonal pyramid, respectively, while Co2 atom is hexa‐coordinated by six oxygen atoms with a geometry of slightly distorted octahedron. These self‐assembling complexes form different dimensional supramolecular structures through inter‐ and intra‐molecular hydrogen bonds. The coordination bond cleavages of the two complexes have occurred upon the addition of the H+, and have reformed again via the neutralization effect of the OH−. The changes of the two complexes response to the H+/OH− have observed in the UV–Vis and 1H NMR spectra. [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]

Two hetero‐bimetallic [Zn(II)2M(II)] (M = Ca and Sr) complexes [Zn2Ca(L)(OAc)2] (1) and [Zn2Sr(L)(OAc)2] (2) with a novel asymmetrical bis(salamo)‐type tetraoxime ligand (H5L) were designed and synthesized, and characterized by elemental analyses, FT‐IR spectra, UV–vis absorption spectra, Density Functional Theory (DFT) calculation, Hirshfeld surface analyses and X‐ray single crystal diffractions. Compared with the symmetric bis(salamo)‐type ligands, the ligand H5L and its [Zn(II)2M(II)] (M = Ca and Sr) asymmetrical bis(salamo)‐type complexes synthesized for the first time in this paper have more novel structures and better properties. The results of ultraviolet titration show that the coordination ratio of ligand, alkaline earth metal and transition metal is 1:1:2. Complexes 1 and 2 have good luminescent properties and obvious antimicrobial activities. [ABSTRACT FROM AUTHOR]

Three multinuclear Cu (II), Zn (II) and Cd (II) complexes, [Cu2(L)(μ‐OAc)]·CHCl2 (1), [Zn2(L)(μ‐OAc)(H2O)]·3CHCl3 (2) and [{Cd2(L)(OAc)(CH3CH2OH)}2]·2CH3CH2OH (3) with a single‐armed salamo‐like dioxime ligand H3L have been synthesized, and characterized by FT‐IR, UV–vis, X‐ray crystallography and Hirshfeld surfaces analyses. The ligand H3L has a linear structure and C‐H···π interactions between the two molecules. The complex 1 is a dinuclear Cu (II) complex, Cu1 and Cu2 are all five‐coordinate possessing distorted square pyramidal geometries. The complex 2 also forms a dinuclear Zn (II) structure, and Zn1 and Zn2 are all five‐coordinate bearing distorted trigonal bipyramidal geometries. The complex 3 is a symmetrical tetranuclear Cd (II) complex, and Cd1 is a hexa‐coordinate having octahedral configuration and Cd2 is hepta‐coordinate with a pentagonal bipyramidal geometry, and it has π···π interactions inside the molecule. In addition, fluorescence properties of the ligand and its complexes 1–3 have also been discussed. [ABSTRACT FROM AUTHOR]

Three newly designed containing‐PMBP N2O2‐donors complexes, [Co(L1)(CH3OH)2] (1), [{Zn(L2)(CH3OH)(H2O)}3] (2) and [Cu4(L2)4]⋅2CHCl3 (3), have been synthesized and structurally characterized using elemental analyses, infrared and UV–visible spectroscopies and single‐crystal X‐ray diffraction. X‐ray crystal structure determinations revealed that 1 consists of one Co(II) atom, one completely deprotonated (L1)2− unit and two coordinated methanol molecules. Complex 2 consists of three Zn(II) atoms, three completely deprotonated (L2)2− units, three coordinated methanol molecules and three coordinated water molecules. However, 3 includes four Cu(II) atoms, four completely deprotonated (L2)2− units and two crystallization chloroform molecules. The Co(II) and Zn(II) atoms in the structures of 1 and 2 adopt slightly distorted octahedral geometries. While, Cu(II) atoms in 3 can be best described as adopting slightly distorted square planar geometries. Complex 2 is a novel structure, and the ratio of H2L2 to Zn(II) atom is 3:3. In addition, two‐, three‐ and three‐dimensional supramolecular structures were constructed for 1, 2 and 3. Most importantly, Hirshfeld surface analysis of 1, 2 and 3 was conducted and fluorescence properties were investigated. [ABSTRACT FROM AUTHOR]

Rare homo‐ and hetero‐polynuclear transition metal(II) complexes, [{Cu(L1)}2] (1) and [Cu(L2)Ni2(CH3OH)2] (2), were prepared and structurally characterized. Complex 1 possesses an uncommon dinuclear structure bonded by two alkoxy bridges, and all the Cu(II) atoms are tetra‐coordinated with slightly distorted square planar geometries. The Cu1─Cu2 bond distance is 2.994(3) Å. Complex 2 exhibits an unexpected trinuclear heterobimetallic structure from two chelating (L2)3− units in crossover mode, which is the first heterobimetallic 3d–3d salamo‐type transition metal complex. The two Ni(II) atoms are penta‐coordinated with slightly distorted square pyramidal geometries (τ = 0.269 (Ni1) and 0.498 (Ni2)), and the Cu(II) atom is tetra‐coordinated with a slightly distorted square planar geometry. Moreover, fluorescence behaviors of 1 and 2 were investigated, and electrochemical study reveals that the electrolytic redox reactions of 1 are irreversible processes. Rare homo‐ and hetero‐polynuclear transition metal(II) complexes, [{Cu(L1)}2] (1) and [Cu(L2)Ni2(CH3OH)2] (2), were prepared and characterized. Complex 1 possesses an uncommon dinuclear structure bonded by two alkoxy bridges. Complex 2 exhibits an unexpected trinuclear heterobimetallic structure from two chelating (L2)3− units in crossover mode. Fluorescence behaviors of 1 and 2 were investigated, and electrochemical experiments revealed that electrolytic redox reactions of 1 are irreversible processes. [ABSTRACT FROM AUTHOR]