Search

Centrosymmetric homopolynuclear Cu(II) and Co(II) chelated complexes, [Cu2(L)(H2O)2] (1) and [Co4(L)(μ-OAc)2(CH3OH)4(OAC)2]⋅2CH2Cl2 (2), were synthesized using a new symmetrical methoxy-disubstituted bis(salamo)-type ligand, H4L, with Cu(II) and Co(II) salts in organic solvents. Complexes 1 and 2 were structurally characterized by single-crystal X-ray crystallography. The results indicated that 1 is a five-coordinate dinuclear structure containing Cu(II) and 2 is a tetranuclear Co(II) complex with two distinct six-coordinate environments. Furthermore, 1 and 2 pack into three-dimensional and two-dimensional extended networks, respectively. The UV–Vis spectra, IR spectra, and Hirshfeld surface analyses of the complexes were carried out to further characterize the coordination between H4L and the metal(II) ions. Fluorescence methods were used to interrogate the coordination, where changes in emission with varied amounts of ligand supported solution-phase coordination ratios of H4L with Cu(II) ion of 1:2 and with Co(II) ion of 1:4, respectively. [ABSTRACT FROM AUTHOR]

Two structurally different Cu(II) and Co(II) complexes, [Cu(L)] (1) and [Co2(L)2]⋅2CH3OH (2), constructed from a new polyhalogen-substituted unsymmetric salamo-based ligand (H2L, 4-chloro-4′-bromo-6-bromo-6′-tert-butyl-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol) were synthesized by wet-chemical methods. Complexes 1 and 2 were characterized through elemental analyses, IR and UV-vis spectroscopies and single crystal X-ray crystallography. In addition, the differences of the structures, electronic absorption characteristics and fluorescence property transitions from the ligand to complexes 1 and 2 were studied. The largest difference is that the ligand H2L can react with M(OAc)2 (M = Cu(II) and Co(II)) to give two complexes with distinct structures and behaviors. There are two chemically identical but crystallographically independent structural units (molecules A and B) in 1. Moreover, each Cu(II) ion (Cu1 or Cu2) is four-coordinate and possesses a square planar geometry, but both Co(II) ions of 2 are bridged by phenoxide ions and possess five-coordinate trigonal bipyramidal configurations. At the same time, Hirshfeld surface analyses showed there are short-range interaction features from the ligand to complexes 1 and 2, the O···H/H···O interactions of the ligand are significantly stronger than those of 1 and 2. [ABSTRACT FROM AUTHOR]

A relatively rigid acyclic salamo-type ligand H2L and its square planar Cu(II) complex, [Cu(L)]·CH3OH, were synthesized and characterized by X-ray crystallography, as well as Fourier-transform infrared spectra, UV–Vis spectra, Hirshfeld surface analyses and DFT calculations. The ligand crystallizes in monoclinic space group P 21/c and has pairs of intramolecular hydrogen bonds between the oxime nitrogen atoms and the hydroxyl groups. The Cu(II) complex crystallizes in the monoclinic space group P 21/c. The Cu(II) ion is located in the N2O2 cavity of the fully deprotonated salamo-type ligand (L)2− unit, thus forming a four-coordinate distorted square planar geometry. At the same time, a belt-like, 2-D supramolecular structure is formed by the interaction of intermolecular hydrogen bonds, and the intermolecular interaction force is quantitatively analyzed by Hirshfeld surfaces. Significantly, fluorescence properties of the ligand and its Cu(II) complex were also studied. The coordination ratio of the Cu(II) complex was proved by UV–Vis and fluorescence titration experiments. [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]

• A nonsymmetric salamo-type ligand H 2 L with an exposed aldehyde was synthesized. • Novel Zn(II) complex and Ni(II) CP were synthesized and characterized. • The theoretical calculations to verify the stability and electroneutrality of the Zn(II) complex and Ni(II) CP. In the first step, we synthesized a nonsymmetric salamo-like ligand, H 2 L, featuring 4-hydroxyisophthalaldehyde and 6‑methoxy-2-[ O -(1-ethoxyamide)]oxime phenol. In the subsequent phase, Zn(II) and Ni(II) complexes, namely [Zn 2 (L) 2 ]·2CH 3 CN·CH 3 OH and [Ni(L)(H 2 O)] n ·nCH 3 COCH 3 , were obtained by treating H 2 L with Zn(II) and Ni(II) ions via a solvent volatilization method. Structural characterizations were carried out using various techniques, including 1H NMR, MS, and X-ray diffraction analysis. Where the phenolic oxygen atoms (O4, O8) bridging two metal atoms (Zn1, Zn2), both five-coordinated Zn(II) atoms are in twisted triangular bipyramidal geometrical configurations, while the Ni(II) atom exhibits a six-coordinated octahedral geometric configuration, the formyl group only participates in the coordination of Ni(II) atom. The existence of multiple interactions, as well as charge distributions between the complexes or CPs (coordination polymers), has also been demonstrated through theoretical calculations IRI (Interaction region indicator), MESP (Molecular electrostatic potential) and Hirshfeld, etc. Fluorescence experiment revealed a significant enhancement in fluorescence intensity upon addition of Zn(OAc) 2 ·2H 2 O, while the fluorescence intensity was quenched upon addition of Ni(NO 3) 2 ·6H 2 O. [Display omitted] [ABSTRACT FROM AUTHOR]

• Two different Cu(II) salamo-salen-salamo-hybrid complexes were synthesized • Salen on the hybrid ligand has stronger coordination ability than salamo moiety • Salamo chain orientation and structure of the complexes vary due to solvent effect • H 4 L and its complexes were characterized by MESP, IRI analyzes and DFT calculation Based on the condensation reaction of a containg-formyl asymmetric salamo-based ligand with ethylenediamine, a salamo-salen-salamo-hybrid multi-compartment ligand possessing both salen and salamo structural moieties was prepared, and its different types (Cu(II): H 2 L)2−) of copper(II) complexes, confirmed as [Cu(H 2 L)] 2 ·4EtOH (1) and [Cu 2 (H 2 L) 2 ]·2MeOH·(Me) 2 CO (2), have been synthesized and elucidated structurally. In the complexes, Cu(II) ion is sited at the salen's N 2 O 2 cavity, while the salamo structural moieties do not participate in coordination. This coordination characteristic indicates that the coordination ability of salen and salamo structural moieties in salamo-salen-salamo-hybrid ligand varies, with salen having relatively stronger coordination ability, which may be due to the incorporation of more electronegative multiple O atoms on C=N bonds, resulting in a decrease in the electron cloud density on the N atoms of the multi-oxime groups and a decrease in the coordination ability. Thus, Salen structural moiety on the hybrid ligand has stronger coordination ability than salamo structural moieties. In addition, due to the solvent effect, the extension direction of the single salamo long chain is different, and the configurations of the complexes are also different. Through X-ray diffraction analysis and DFT theoretical computations of the ligand and the complexes, the weak intramolecular and intermolecular interactions of the complexes, as well as the intermolecular C-H···π & π···π interactions of the complexes, were discussed. The ligand and the copper(II) complexes were analyzed for their MESP, as well as to show the mobile regions of the molecules in the complex molecules. Due to the solvent effect, the spatial orientation of the long chain of salamo has undergone significant changes, changing the region where the complex molecules move in a specific space. [Display omitted] [ABSTRACT FROM AUTHOR]

• A novel three-bridged trinuclear [{Co 3 (L) 2 (µ 3 OAc) 2 } 2 ] complex with acetate was constructed. • Fluorescence properties of the ligand and its complexes were studied. • A series of theoretical calculations of the ligand and its complexes were investigated. • The softness of the complexes was proposed and energy gaps were analyzed by DFT calculation. • Quantitative analyses of intermolecular interactions in the crystalline structures were performed by Hirshfeld surfaces analysis. A more flexible 3-methoxysalamo-like ligand H 2 L and its dinuclear Cu(II) complex [Cu 2 (L)(NO 3) 2 ] (1) and novel trinuclear Co(II) complex [{Co 3 (L) 2 (µ 3 OAc) 2 } 2 ]⋅9CH 2 Cl 2 (2) were synthesized. The self-assembly reaction was driven by the unique N , O-donor coordination environments. Single crystal X-ray diffraction analysis showed that two Cu(II) atoms occupy the N 2 O 2 and O 4 cavities of the ligand (L)2− unit in complex 1 , respectively, and two oxygen atoms on the two mono-dentate nitrate groups have also participated in the coordination for the charge balance of complex 1. The stretching of chemical bonds of complex 1 can be perfectly explained by the Jahn-Teller effect. The novel salamo-based Co(II) complex 2 containing µ 3 OAc− coordination mode was discovered for the first time. The trinuclear Co(II) complex embodies the advantage of the salamo-based ligand, which has a good flexible form. The binding ratio of the ligand to the Co(II) center was verified by a UV–Vis titration experiment, which is consistent with the single crystal X-ray diffraction result. The energy gaps between the ligand and complexes 1 and 2 were obtained by DFT calculations, and a new theory-softness was proposed. The degree of softness affected the shapes of the complexes. Hirshfeld analysis, IRI, and electrostatic potential proved the existence of hydrogen bond, π···π, C H···π interactions, and van der Waals force. These weak interaction forces affected the structures of the complexes. Finally, the fluorescence properties of the ligand and its complexes were studied. [ABSTRACT FROM AUTHOR]

• An unexpected mono-nuclear Cu(II) complex was successfully prepared. • The complex is formed by the reaction of Cu(II) acetate with H 2 L1, not by the H 3 L. • DFT, ESP and Hirshfeld surfaces analyses of the Cu(II) complex were investigated. An unexpected mono-nuclear Cu(II) complex [Cu(L1)] was successfully prepared by a bis(salamo)-type ligand H 3 L and Cu(OAc) 2 ·H 2 O in ethanol/acetone mixed solvent, and its structure and properties were analyzed. The crystal structure analysis showed that the Cu(II) complex is obtained by the reaction of copper(II) acetate with a new single salamo-type ligand H 2 L1, not obtained from the original ligand H 3 L. The molecular front orbitals HOMO and LUMO of the ligand H 3 L and the Cu(II) complex were analyzed by quantum chemical calculations, and the results showed that the energy gap of the Cu(II) complex is reduced due to the combination of orbitals compared to the ligand. The theoretical reaction sites of the ligand H 3 L with the Cu(II) were analyzed by ESP studies, and the results showed that the crystal structure of the Cu(II) complex is consistent with the theoretical predictions. Hirshfeld surfaces analyses confirmed the rich and diverse interactions present in the Cu(II) complex, which is essential for the stability of the molecules. [Display omitted] The unexpected Cu(II) complex [Cu(L1)] was successfully prepared by a bis(salamo)-type ligand H 3 L, and its structure and properties were analyzed. Unexpectedly, the obtained complex was not formed by the original ligand, but the new ligand formed, H 2 L1, reacted with copper acetate to obtain a mononuclear copper complex due to the catalytic effect of copper acetate on the ligand at N O bond in the oxime group leading to the breakage of the ligand. [ABSTRACT FROM AUTHOR]

• A rigid bis(salamo)-like ligand H 4 L was designed and synthesized successfully. • A structurally novel tetranuclear Ni(II) complex was synthesized and characterized structurally, acetylacetone anions participate in the coordination as auxiliary bidentate ligands. • The Ni(II) complex was analyzed by MEPs and IRI, and the intermolecular interactions were clarified. Novel tetranuclear Ni(II) complex [Ni 4 (L)(acac) 4 (EtOH) 2 ]⋅4CH 2 Cl 2 was synthesized by a rigid bis(salamo)-like ligand H 4 L and Ni(acac) 2 in ethanol/dichloromethane mixed solvents, and characterized by different physicochemical methods. The X-ray diffraction result showed that all Ni(II) atoms are hexa-coordinated with slightly distorted octahedral geometries, and four Ni(II) atoms are correlated with each other through inversion. Acetylacetone anions acted as auxiliary ligands for bidentate chelation, and the monodentate ethanol molecules of solvent participated in the coordination. The properties of the ligand H 4 L and its Ni(II) complex were studied, including molecular electrostatic potential surface (MEPs), Hirshfeld surface and interaction region indicator (IRI) analysis. Through the above study, the reaction active sites were visualized, and the intermolecular interactions of the Ni(II) complex were clarified, which is consistent with the crystal structure of the Ni(II) complex. In addition, fluorescence spectra of the ligand H 4 L and its Ni(II) complex were investigated. Novel tetranuclear Ni(II) bis(salamo)-like complex [Ni 4 (L)(acac) 4 (EtOH) 2 ]⋅4CH 2 Cl 2 was synthesized and characterized structurally. All the Ni(II) atoms are hexa-coordinated with slightly distorted octahedral geometries, acetylacetone anions as auxiliary bidentate ligands participate in chelation. The reaction active sites were visualized, and the intermolecular interactions of the Ni(II) complex were clarified, which is consistent with the crystal structure of the Ni(II) complex. Fluorescence properties of H 4 L and its Ni(II) complex were investigated. [Display omitted] [ABSTRACT FROM AUTHOR]

A nonsymmetric salamo-like ligand (H 2 L, 5-(N,N′-diethylamino)-2,2′-[ethylenedioxybis(nitrilomethylidyne)]phenolnaphthol) has been synthesized, and its two homotrinuclear complexes [{Zn 3 (L) 2 (μ -OAc) 2 } 2 ]·5EtOH and [Ni 3 (L) 2 (μ -OAc) 2 (MeOH) 2 ]·2MeOH and single crystals of the ligand have been successfully synthesized and characterized structurally. Molecular electrostatic potential analysis, interaction region indicator analysis, Hirshfeld surfaces analyses, DFT calculations and fluorescent properties of the Zn(Ⅱ) and Ni(Ⅱ) complexes were also studied. [Display omitted] • Single crystals of H 2 L and its Zn(II) and Ni(II) complexes have been determined. • The Zn(II) complex possesses two crystallographically and chemically identical trinuclear clusters. • Experimental and theoretical investigation of the Zn(II) and Ni(II) complexes were performed. Neutral homotrinuclear complexes [{Zn 3 (L) 2 (μ -OAc) 2 } 2 ]·5EtOH and [Ni 3 (L) 2 (μ -OAc) 2 (MeOH) 2 ]·2MeOH were obtained in the reactions of a new non-symmetric salamo-like ligand H 2 L (5-(N,N′-diethylamino)-2,2′-[ethylenedioxybis(nitrilomethylidyne)]phenolnaphthol) with the respective salts of M(OAc) 2 ·2H 2 O (M = Zn(II) and Ni(II)), respectively. Single crystals of the ligand were also obtained. All the Zn(Ⅱ) and Ni(Ⅱ) complexes were structurally characterized by single crystal X-ray diffraction. Both Zn(Ⅱ) and Ni(Ⅱ) complexes are composed of two (L)2− units combined with three metal(Ⅱ) ions, where a pair of μ -OAc− ions bridging Zn1⋯Zn2 and Zn2⋯Zn3 or Ni1⋯Ni2 and Ni2⋯Ni1#1 neutralize the charge of the Zn(II) and Ni(II) complexes and stabilize the trinuclear structure. The two μ -OAc− ions are located on the same side of the Zn(Ⅱ) complex, while on different sides of the Ni(Ⅱ) complex. In addition, there are two methanol molecules in the Ni(Ⅱ) complex involved in the coordination. UV–vis absorption spectral analyses showed that the ligand (L)2− units have coordinated with Zn(Ⅱ) and Ni(Ⅱ) atoms. DFT calculations exhibited that the Zn(II) and Ni(II) complexes have higher kinetic stability and lower chemical reactivity. Fluorescence spectrum analyses indicated that the electrons of the ligand have transferred to the empty orbitals (LMCT) of the Zn(Ⅱ) and Ni(Ⅱ) atoms. Furthermore, to discern the interactions in the crystal structures, Hirshfeld surfaces analyses were evaluated. Molecular electrostatic potentials were calculated in order to find electrophilic and nucleophilic sites favorable for hydrogen bonds. [ABSTRACT FROM AUTHOR]

Two novel complexes [Cu(L)(OAc)]·CH 3 OH (1) and [Ni(L)(OAc)] (2) formed with a quinolone-modified half-salamo-like ligand (HL) were successfully synthesized and characterized structurally. In addition, Fluorescence properties, DFT theoretical calculations and Hirshfeld surfaces analyses of the ligand HL and its corresponding complexes were also investigated. [Display omitted] • The introduction of quinoline into half-salamo-like ligand HL has been developed triumphantly. • Two novel complexes [Cu(L)(OAc)]·CH 3 OH (1) and [Ni(L)(OAc)] (2) were synthesized and ascertained structurally. • Fluorescence properties, DFT theoretical calculation and Hirshfeld surfaces analyses were investigated. Two novel Cu(II) and Ni(II) complexes, [Cu(L)(OAc)]·CH 3 OH (1) and [Ni(L)(OAc)] (2) formed with a newly designed quinolone-modified half-salamo-like ligand (HL) were successfully obtained. Elemental analyses, infrared spectra and UV–visible absorption spectra were employed triumphantly to characterize the complexes 1 and 2. X-ray single-crystal diffraction analysis results indicated that the complex 1 is composed of a fully deprotonated ligand (L)- unit, one Cu(II) atom and one monodentate coordinated acetate ion. For the complex 1 , the central Cu(II) atom is five coordinated adopting a slightly distorted triangular biconical geometry, while the complex 2 has two independent structural units (molecules A and B), which shows chemically identical but crystallographically independent. The central Ni(II) atom is six coordinated possessing a distorted octahedral configuration. In addition, Fluorescence properties, DFT theoretical calculations and Hirshfeld surfaces analyses of the ligand HL and its corresponding complexes 1 and 2 were also investigated in detail. [ABSTRACT FROM AUTHOR]

Two unusual heterobimetallic [CuII 4 LnIII 2 ] complexes were constructed from a N 2 O 2 - and O 6 -donor bis(salamo)-based ligand (H 4 L), and characterized structurally. The intermolecular interactions were quantitatively analyzed by Hirshfeld surfaces, as well as, fluorescence properties have also been studied. [Display omitted] • Two structurally novel heterobimetallic hexanuclear [CuII 4 LnIII 2 ] complexes were prepared using a designed N 2 O 2 - and O 6 -donor bis(salamo)-based ligand. • The different natures of three-compartmental H 4 L lead to the site‐selective introduction of two various metalII/III atoms. • Quantitative analyses of intermolecular interactions were evaluated by Hirshfeld surfaces analyses. • The fluorescence properties were further discussed. Two unusual heterobimetallic [CuII 4 LnIII 2 ] complexes, [{Cu 4 (L) 2 La 2 (ƞ 2-NO 3) 6 (EtOH)}]·2Me 2 CO (1) and [{Cu 4 (L) 2 Ce 2 (ƞ 2-NO 3) 6 (EtOH)} 2 ]·4Me 2 CO·MeOH (2) were constructed from a N 2 O 2 - and O 6 -donor bis(salamo)-based ligand (H 4 L). The structures were characterized by physical chemistry and spectroscopy methods. The two complexes 1 and 2 have similar structures, two heterotrinuclear parts with the same structure are linked by the coordination between one CuII atom and oxime-type oxygen atoms to obtain the heterohexanuclear complexes 1 and 2. Four penta-coordinate CuII atoms are located at the N 2 O 2 cavities of the ligand (L)4- units, two LaIII/CeIII atoms are surrounded by the open-chain 18-crown-6 (O 6) coordination environment. At the same time, eight bridged phenol oxygen atoms connect the six CuII/LnIII atoms. Infinite three-dimensional supra-molecular structures are formed in complexes 1 and 2 through H-bonds. The intermolecular interactions were quantitatively analyzed by Hirshfeld surfaces, as well as, fluorescence properties have also been studied. [ABSTRACT FROM AUTHOR]

• The pyridine-including half-salamo-like ligands HL1 and HL2 have been developed successfully. • Two first Co(III) complexes, [Co(L1)(N 3) 2 ] (1), and [Co(L2)(N 3) 2 ] (2) were synthesized and ascertained structurally. • The complexes 1 and 2 are unusual salamo-like Co(III) complexes with variable valence. This situation has never reported in the previous salamo-based complexes. Two structurally novel Co(III) complexes have been successfully constructed from the pyridine-including half-salamo-like ligands (HL1 and HL2), namely as [Co(L1)(N 3) 2 ] (1) and [Co(L2)(N 3) 2 ] (2). The structural features of complexes 1 and 2 have been confirmed by means of single crystal X-ray diffraction experiment. The structural studies revealed that complexes 1 and 2 have similar structures. The characterization of the two ligands and their Co(III) complexes was ascertained by means of infrared spectra, ultraviolet spectra and Hirshfeld surfaces analyses. In addition, compared with the ligands HL1 and HL2, the fluorescence intensities of the corresponding complexes 1 and 2 decreased significantly. When Co(II) salt was gradually added to the ligand solution, the intensity of the fluorescence emission peak decreased with the continuous addition of Co(II) salt until this trend stopped, which indicates that the introduction of Co(II) ion leads to the charge transfer from the ligand to Co(III) ion. Two structurally novel Co(III) complexes have been successfully constructed from the pyridine-including half-salamo-like ligands (HL1 and HL2), namely as [Co(L1)(N 3) 2 ] (1) and [Co(L2)(N 3) 2 ] (2). The characterization of the two ligands and their Co(III) complexes was ascertained by means of infrared spectra, ultraviolet spectra, X-ray crystallography, fluorescence spectra and Hirshfeld surfaces analyses. [Display omitted] [ABSTRACT FROM AUTHOR]

• A new kind of single‐armed salamo‐type ligand H 3 L and two corresponding Zn(II) complexes have been synthesized. • All of the Zn(Ⅱ) atoms in complexes 1 and 2 are penta-coordinated, highly distinct configurations are obtained because of the introduction of two kinds of counter-anions. • Fluorescence properties of H 3 L and complexes 1 and 2 were also investigated. Di- and tetra-nuclear Zn(II) complexes, [Zn 2 (L)(µ -OAc)(CH 3 OH)]·CH 3 OH (1) and [Zn 4 (L) 2 (OMe) 2 ]·2CH 3 COCH 3 ·CH 3 OH (2) have been successfully self-assembled by the reaction of a single‐armed salamo‐type ligand (H 3 L), Zn(OAc) 2 ·2H 2 O and Zn(NO 3) 2 ·6H 2 O, respectively. In the ligand H 3 L, tetradentate N 2 O 2 donor part of pocket I and NO 2 donor part of pocket II are designed to bond Zn(II) atoms, then unusually structural complexes were obtained by counteranion-driven self-assembled. Both complexes 1 and 2 are characterized by elemental analyses, IR spectra, UV-Vis spectra and single crystal X-ray diffraction. All of the Zn(II) atoms in complexes 1 and 2 are penta-coordinated, but highly distinct configurations are obtained because of the introduction of two kinds of counter-anions. In complex 1 , μ- OAc− counter-anion connects the two Zn(II) atoms in one ligand. In complex 2 , μ- OMe− counter-anions link the Zn(II) atoms within two ligand molecules and the structure of complex 2 is more complicated. What's more, in complex 1 , all Zn(II) atoms have the geometries of distorted trigonal bipyramid, while in complex 2 , all Zn(II) atoms have the geometries of distorted square pyramid. There are obvious π···π stacking interactions existing in complexes 1 and 2 , which are quantitatively valued by Hirshfeld surfaces analyses. Fluorescence properties are also investigated. Di- and tetra-nuclear Zn(II) complexes, [Zn 2 (L)(µ -OAc)(CH 3 OH)]·CH 3 OH (1) and [Zn 4 (L) 2 (OMe) 2 ]·2CH 3 COCH 3 ·CH 3 OH (2) have been successfully synthesized and structurally characterized. The fluorescence properties were also investigated. [Display omitted] [ABSTRACT FROM AUTHOR]

Two penta-coordinated multinuclear copper(II) complexes, [Cu 2 (L)(µ -OAc)]·MeOH (1) and [Cu 4 (L) 2 Cl 2 ]·EtOH·CH 2 Cl 2 (2) have been synthesized and characterized structurally. IR spectra, UV–vis spectra and fluorescence properties of complexes 1 and 2 have been investigated. [Display omitted] • Two copper(II) complexes were synthesized and characterized structurally. • All of Cu(II) atoms have the geometries of almost perfect tetragonal pyramid. • Fluorescence properties of complexes 1 and 2 have been investigated. With the reactions of a single-armed salamo-based ligand H 3 L and two kinds of copper(II) salts (Cu(OAc) 2 ·H 2 O or CuCl 2 ·2H 2 O) in mixed organic solvents, respectively, two penta-coordinated Cu(II) complexes [Cu 2 (L)(µ -OAc)]·MeOH (1) and [Cu 4 (L) 2 Cl 2 ]·EtOH·CH 2 Cl 2 (2) have been successfully constructed. The precise structures of the two Cu(II) complexes obtained by solvent evaporation method are measured by single crystal X-ray diffraction analyses. The di-nuclear complex 1 crystallizes in triclinic space group P -1, where the main structure is compose of two Cu(II) atoms, one completely deprotonated ligand (L)3− unit, one bridged μ -OAc− counter-anion and one crystallized methanol molecule. The tetra-nuclear complex 2 with an inversion center crystallizes in the same space group as 1 and contains four Cu(II) atoms, two fully deprotonated salamo-based ligand (L)3− units, two bridged Cl− counter-anions, one crystallized dichloromethane and one ethanol molecules. Compared to preceding complexes based on other single-armed salamo-based ligands, the structure of complex 2 reported in this work is unique and has never been found in previous literatures. All of Cu(II) atoms in complexes 1 and 2 are penta-coordinated with the geometries of distorted tetragonal pyramid, and the τ 5 value of all Cu(II) atoms have been calculated and all results are less than 0.5. Hirshfeld surfaces analyses of complexes 1 and 2 have been established to explain the interactions of crystal structures, and the corresponding two-dimensional (2D) fingerprint plots have been carried out to quantify the intermolecular interactions. In addition, fluorescence properties of complexes 1 and 2 have been investigated. [ABSTRACT FROM AUTHOR]

Three novel N 4 -cavity Cu(II), Ni(II) and Zn(II) complexes were successfully synthesized via the reactions of a novel pyridine-containing N 4 -cavity bisoxime ligand L. All three complexes are monoclinic systems. Complexes 2 and 3 form centrosymmetric helical molecules. Complexes 1 – 3 have been characterized by elemental analysis, IR, UV–Vis spectroscopy and single crystal X-ray crystallography. In addition, supramolecular interactions, Hirshfeld surface analysis to analyze the crystal properties have been studied. [Display omitted] • A novel ligand L with N4 cavity was synthesized and characterized. • Three excess metal single crystals were synthesized via the ligand L. • Hirshfeld surface analysis was performed on single crystals. Three novel N 4 -cavity Cu(II), Ni(II) and Zn(II) mononuclear complexes, [Cu(L)(NO 3) 2 ][Cu(L)(NO 3)]NO 3 (1) [Ni(L)(NO 3) 2 ] (2) and [Zn(L)(NO 3) 2 ] (3) were successfully synthesized via the reactions of a pyridine-containing N 4 -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. [ABSTRACT FROM AUTHOR]

Three trinuclear complexes 1 - 3 possessed inversion centers have been successfully synthesized by wet-chemical method using asymmetric salamo-based polydentate chelating ligand (H 2 L) with Co(OAc) 2 ·4H 2 O and Ni(OAc) 2 ·4H 2 O, respectively. [Display omitted] Three trinuclear complexes, [{CoL(MeOH)(μ -OAc)} 2 Co] (1), [{CoL(EtOH)(μ -OAc)} 2 Co]·2CH 3 CH 2 OH (2) and [{NiL(MeOH)(μ -OAc)} 2 Ni]·2CH 3 OH (3) have been successfully synthesized by wet-chemical method using asymmetric salamo-based polydentate chelating ligand (H 2 L) with transition metal(II) acetate (Co(OAc) 2 ·4H 2 O or Ni(OAc) 2 ·4H 2 O). The ligand H 2 L with N 2 O 2 coordination cavity can accommodate transition metals, at the same time, the oxygen atoms of the phenolic hydroxyl groups can bridge the metal atoms to obtain muiltnuclear metal complexes. There are inversion centers in complexes 1 – 3 and all M(II) atoms possess six-coordinated distorted octahedral geometries. Complexes 1 and 3 are further assembled into extended two-dimensional supramolecular via intermolecular interactions, but complex 2 forms three-dimensional supramolecular structure. The interactions were quantitatively determined by Hirshfeld surfaces analyses. Significantly, complexes 1 – 3 have been characterized by elemental analyses, IR spectra, UV–Vis spectroscopy and X-ray crystallography analyses. Fluorescence properties were also investigated. [ABSTRACT FROM AUTHOR]