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A new type of multifunctional bis(salamo)-based fluorogenic sensor H2BS was designed and synthesized. Under the action of VDMF: VH2O = 9: 1, the fluorogenic sensor can identify Cu2+ and B4O72−, in which N and O atoms can serve as binding sites for Cu2+ and B4O72−, the stoichiometry of the binding of the fluorogenic sensor H2BS and Cu2+ has been confirmed by titration experiment, working curve, ESI-MS analysis and DFT calculation. The pH response experiment also confirmed that the fluorogenic sensor can recognize Cu2+ and B4O72− in the pH range applicable to the physiological environment. The minimum detection limit of H2BS for Cu2+ and B4O72− recognition reaches 1.12 × 10−7 and 5.56 × 10−8 M, and the fluorogenic sensor H2BS has been successfully applied to Cu2+ detection in actual water samples, and the test strip for detecting Cu2+ and B4O72− was obtained. Meanwhile, the success of the test strip experiment made the fluorogenic sensor H2BS to recognize Cu2+ and B4O72− widely used in daily life.

Three novel multinuclear NiII complexes, namely, bis{μ-2-methoxy-6-[8-(pyridin-2-yl)-3,6-dioxa-2,7-diazaocta-1,7-dien-1-yl]phenolato}bis[thiocyanatonickel(II)], [Ni2(L)2(NCS)2], 1, bis{μ-2-methoxy-6-[8-(pyridin-2-yl)-3,6-dioxa-2,7-diazaocta-1,7-dien-1-yl]phenolato}bis[azidonickel(II)], [Ni2(L)2(N3)2], 2, and catena-poly[[{2-methoxy-6-[8-(pyridin-2-yl)-3,6-dioxa-2,7-diazaocta-1,7-dien-1-yl]phenolato}nickel(II)]-μ-dicyanamidato], [Ni(L)(dca)] n , 3 {dca is dicyanamide, C2N3, and HL is 2-methoxy-6-[8-(pyridin-2-yl)-3,6-dioxa-2,7-diazaocta-1,7-dien-1-yl]phenol, C16H17N3O4}, with a half-salamo-based pyridine-containing HL ligand have been synthesized and characterized by FT–IR, UV–Vis absorption spectroscopy, X-ray crystallography, Hirshfeld surface analysis and density functional theory (DFT) calculations. The central NiII ions in complexes 1–3 are hosted in the half-salamo-based N3O-donor cavity of the organic ligand. Complex 1 is a centrosymmetric dimer and two [Ni(L)(NCS)] units form a centrosymmetric dimeric structure, which is bridged by two phenolate O atoms. The two N atoms at the axial ends are provided by two NCS− ligands. In complex 1, each NiII ion has a six-coordinated octahedral geometry. Complex 2 is similar to 1, but they differ in that the auxiliary NCS− ligand is replaced by N3 −. However, complex 3 is a one-dimensional coordination polymer constructed from [Ni(L)(dca)] units, which are connected by the auxiliary bidentate dca ligand via N-donor atoms. As with complexes 1 and 2, the NiII ion in 3 has a six-coordinated octahedral geometry.

Two mononuclear Cu(II) and Co(II) halogen-substituted salamo-based complexes of the formulas [Cu(L)] and [Co(L)(H2O)2] have been synthesized and characterized by elemental analyses, FT-IR and UV-Vis absorption spectra, and X-ray crystallography. The Cu(II) complex has crystallized in the monoclinic system, space group P21/n with Cu(II) atom located in the N2O2 cavity. In the Co(II) complex, the center Co(II) atom has exhibited a slightly distorted octahedral geometry with halogen-substituted salamo-based bisoxime forming the basal N2O2 coordination plane and two oxygen atoms of two coordinated water molecules in the axial positions. Non-covalent interactions like hydrogen bonding and π···π stacking interactions are operative in construction of supramolecular architectures. The crystal structures and supramolecular features of the complexes have been discussed in details. Hirshfeld surfaces analyses has indicated stability of both complexes. The Cu(II) complex has demonstrated excellent bio-inspired catalytic properties towards oxidative coupling of 2-AP in MeCN medium. Fluorescence properties of H2L and its Cu(II) and Co(II) complexes have also been discussed.

A structurally novel Cd(II) coordination polymer (CP), [Cd(H2L)2(NCS)2]n, has been self-assembled from a newly designed salamo-like ligand H2L bearing double terminal pyridine groups, Cd(II) and KSCN. The Cd(II) ion is not located in the N2O2 cavity of the ligand H2L and forms a six-coordinate octahedral geometrical configuration. Using Cd(II) ion as a node, the undeprotonated salamo-like ligand H2L units extend in space to give a Cd(II)CP with a 2D pore structure. Spectroscopic analysis of the ligand H2L and its Cd(II)CP is performed using IR, UV-Vis and fluorescence spectroscopy. Various short-range interactions in the Cd(II)CP are investigated on the basis of Hirshfeld surfaces analysis.

An asymmetric salamo-based probe molecule (H2 L) was synthesized and characterized structurally. When DMF/H2 O (9:1) was used as the solvent, it was shown probe H2 L has high sensitivity to Cu2+ . Using high-resolution mass spectrometry and theoretical calculation, it was found that probe H2 L could form a more stable complex (1:1) with Cu2+ , the minimum limit of detection (LOD) of H2 L for Cu2+ was calculated as 9.95 × 10-8 M. In addition, probe H2 L could also be used to identify B4 O72- under the same detection conditions and the minimum LOD of H2 L for B4 O72- was calculated as 4.98 × 10-7 M. At the same time, density functional theory theoretical calculation further proved the flexibility of probe H2 L. Through the action of EDTA, probe H2 L had a cyclic ability to recognize Cu2+ , and showed a better response in the physiological pH range; probe H2 L had the characteristics of fast recognition speed and high efficiency. In addition, with probe H2 L test paper for Cu2+ and B4 O72- , the effect was more obvious. Meanwhile, probe H2 L can be used to quantitatively detect Cu2+ in water samples.

This paper presents a concurrent dual-band radar system for noncontact tracking of vital signs (e.g., respiration and heartbeat), and indoor short-range localization. The proposed sensor, which has been achieved with our own customized concurrent dual-band subsystems, operates at 1.67 and 2.06 GHz synchronously. Based on the Doppler principle, tiny vital signs are obtained by analysis of spectrum of the signals received at each individual frequency band. Moreover, the location of a target is estimated based on the phase difference between these two closely spaced frequencies. The azimuth information is obtained by beam scanning. Combining the results of range and azimuth information allows the radar system to plot two-dimensional maps. As a result, the proposed radar is capable of monitoring human’s life activities and tracking the location of individuals continuously. System-level experiments were carried out to reveal the versatile capability of the life activity monitoring system.

Investigation of dried whole herb of Callicarpa macrophylla Vahl. resulted in the isolation of two new phenylethanoid glycosides, macrophylloside E (1), macrophylloside F (2), together with eight known phenylethanoid glycosides (3-10). Their structures were established by extensive spectroscopic methods. In addition, all phenylethanoid glycosides (1–10) were evaluated for their antioxidant activity by DPPH assay and showed high to moderate effect (IC50 from 2.72 to 38.65 μM).

An independent self-assembling heterobimetallic [Ni(II)–Eu(III)] salamo-like coordination polymer, $$^1_\infty$$ [Ni(L)Eu(NO3)3(4,4′-bipy)], is synthesized by the one-pot reaction of a symmetrical salamo-like hexadentate ligand (H2L = 6,6′-dimethoxy-2,2′-[1,2-ethylenedioxybis(nitrilomethylidyne)]diphenol), Ni(OAc)2·4H2O, Eu(NO3)3·6H2O, and 4,4′-bipy. The coordination polymer is obtained by the reaction in the 1:1:1:1 ratio and characterized by elemental analyses, IR and UV-Vis absorption spectra, and single crystal X-ray diffraction. The newly synthesized polymer is constructed from heterobimetallic [Ni(II)(L)Eu(III)] units connected by the 4,4′-bipy exodentate ligand bearing N donor atoms. Meanwhile, the hydrogen bonding, π⋯π stacking and C–H⋯π interactions play an important role in the structure of the coordination polymer. In terms of the antibacterial activity, the polymer dissolved in DMF has a good antibacterial effect on Staphylococcus aureus.

Callicarpa kwangtungensis Chun is a traditional Chinese medicine that has various therapeutic effects. Despite its wide use in Chinese medicine, the study is still quite limited, especially its chemical compositions. In this research, an ultra-high-pressure liquid chromatography coupled with Q Exactive hybrid quadrupole-orbitrap high-resolution accurate mass spectrometry tandem mass spectrometry method was utilized to analyze its chemical compositions for the first time. As a result, a total of 124 compounds, including 20 phenylethanoid glycosides, 31 flavonoids, 36 organic acids, 26 terpenoids and 11 phenols, were identified or tentatively characterized in 30 min. Among them, 49 compounds, including 5 phenylethanoid glycosides, 12 flavonoids, 16 organic acids, 12 terpenoids, and 4 phenols, were identified in Callicarpa kwangtungensis Chun for the first time. Besides, the fragmentation pathways were also discussed. This research established a rapid and reliable method to analyze the chemical compositions of complicated herb without the process of isolation, and provide abundant information on the chemical material basis for further bioactivity and quality control studies.

Multiple dopants contained carbon dots (CDs) with enhanced selectivity have aroused extensive attentions. In this work, three heteroatoms (nitrogen, sulfur, boron) and flavonoid moiety derived from the extracts of Ginkgo biloba leaves co-incorporated CDs were synthesized based on the hydrothermal strategy for novel carbon materials investigation and sensing applications. Nitrogen and flavonoid moiety co-doped CD (N-CD-Fla), nitrogen, sulfur, and flavonoid moiety co-doped CD (NS-CD-Fla), nitrogen, sulfur, boron and flavonoid moiety co-doped CD (NSB-CD-Fla) were prepared, respectively. Three CDs had diversities in nanoparticle sizes, chemical structures, and luminescence properties. NS-CD-Fla exhibited blue luminescence and had higher quantum yield (QY) than N-CD-Fla (yellow-green) and NSB-CD-Fla (blue-green), which can be attributed to its higher N content and N, S synergistic enhancement effect. The luminescence of the three CDs was speculated to be related with the electron transition of C N bonds derived from grafting amines groups onto the flavonoid-related moieties. N-CD-Fla, NS-CD-Fla, and NSB-CD-Fla were further proved to be sensitive to fenitrothion (Fen), dithianon (Dit), dinoseb (Din) and their structural analogues, they were employed as superior chemosensors for the three pesticides sensitive and selective detection. The application potentials of the novel chemosensors based analytical methods were further evaluated by real sample analysis.

C35H32N4O7, triclinic, P1̄ (no. 2), a = 9.3625(6) Å, b = 12.7558(7) Å, c = 14.5965(9) Å, α = 68.833(2)°, β = 80.891(2)°, γ = 69.242(2)°, V = 1519.15(16) Å3, Z = 2, R gt(F) = 0.0447, wR ref(F 2) = 0.1500, T = 296(2) K.

Carbon nanotubes (CNTs) based magnetic composites have great exploration and application potentials in magnetic solid-phase extraction (MSPE) technology due to their unique structures and extraordinary physic-chemical properties, which have attracted continued attentions from different analytical fields. In the review, magnetic CNTs composites based MSPE procedures are introduced, and the modification strategies for magnetic pure CNTs based on functional groups, reagents and materials are detailedly discussed. In addition, the applications of CNTs based magnetic composites in inorganic and organic analysis (drug and pesticide residues, chemical industry pollutants, foods, and biochemical analytes) are respectively presented. Finally, the research prospects and directions of CNTs based magnetic composites in MSPE are further identified.

A new rigid and symmetrical tetracarboxylic ligand 2,3,5,6-tetrakis(4-carboxyphenyl)pyrazine (H4TCPP) ligand was employed in the construction of a new Zn(II)-based metal–organic framework [Zn3(OH)2(H2TCPP)2](DMF)3 (1). Complex 1 not only displays bright blue luminescence arising from the matrix coordination-induced emission effect of the TCPP2− ligand, but also exhibits effective detection for picric acid in the solution with the quenching constant of 3.59 × 104 M−1. In the biological study, we investigated the effect of compound on Hep laryngeal cancer cell viability and proliferation with CCK8 assay, analyzed the production of autophagy in Hep cells by flow cytometer, and the western blot was also used to detect the expression of autophagy-related proteins. Moreover, the autophagy inhibitor 3-MA was used in this study to explore the role of autophagy in the anti-cancer activity of compound.

One mononuclear Ni(II) complex [Ni(L1)(MeOH)2]·MeOH (1) and two novel trinuclear Ni(II) complexes [Ni3(L2)3(EtOH)6] (2) and [Ni3(L2)3(H2O)6] (3) constructed from symmetric N2O2-donors chelating ligands (H2L1 and H2L2) were synthesized and characterized by elemental analyses, FT-IR, UV–Vis spectra and fluorescence spectra. The structures of all three complexes were confirmed by single crystal X-ray diffraction analyses. Complex 1 includes one Ni(II) atom, one completely deprotonated (L1)2− unit and two coordinated methanol molecules, and forms an infinite 2D supramolecular network via the intermolecular hydrogen bonds. While complex 2 or 3 is trinuclear with three Ni(II) atoms, three completely deprotonated (L2)2− units and six coordinated ethanol or H2O molecules. These self-assembling complexes form different dimensional supramolecular structures through inter- and intramolecular hydrogen bonds. Hirshfeld surface analyses for complexes 1, 2 and 3 were mapped with various functions and further quantification of intermolecular interactions was made through the generation of 2D fingerprint plots. In addition, the fluorescence titration experiments were used to characterize fluorescence properties of complexes 1 and 2.

Enhanced optical transmission (EOT), which results from the incident light interacting with the subwavelength nanostructures patterned in a metallic film, showcases the excitation of surface plasmon modes on both surfaces of the metallic film and their intercoupling effects. Here, we numerically study the EOT phenomenon from the incident light acting on the periodic subwavelength hybrid arrays in a metallic film, which contains annular concentric core and aperture unit structure undergoing multiple geometrical configurations. It is shown that several configurations, which consist of a core with a different number of apertures, of the unit structure, are possible to facilitate the intercoupling between the surface plasmon polariton resonance mode of the core and the localized surface plasmon resonance mode of the aperture. Moreover, taking advantage of the EOT effect realized in the periodic structure arrays including a concentric core with triple-aperture unit structure, we propose a plasmonic optical filter (POF) in the near-infrared region. By adjusting both the periods and the width difference between the nearest-neighbor two apertures of the unit structure, the realization of near-infrared POF accompanies with tunable positions and amplitudes of the EOT peaks. Additionally, these behaviors could also be extended to the case of a concentric core with a multiple-aperture unit structure for actualizing near- or mid-infrared POF effect. Our results promise new avenues for plasmonic devices and enrich the application range of metallic structures in the field of optical communications and information processing.

Two trinuclear Ni(II) and Cu(II) coordination compounds [{Ni(L1)(C2H5OH)}2(μ-OAc)2Ni]·2C2H5OH (1) and [{Cu(L2)(CH3OH)}2(μ-OAc)2Cu]·2CH3OH (2) constructed from asymmetrical Salamo-type ligands H2L1 and H2L2 (H2L1 = 5-(N,Nʹ-diethylamino)-2,2ʹ-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol and H2L2 = 2,2ʹ-[ethylenediyldioxybis(nitrilomethylidyne)]naphtholphenol) were synthesized and characterized by physicochemical and spectroscopic methods. Complex 1 is a centrosymmetrical trinuclear Ni(II) coordination compound. Three hexa-coordinated Ni(II) atoms have slightly distorted octahedral geometries. Complex 2 contains three hexa-coordinated Cu(II) atoms bearing distorted octahedral geometries too. In addition, the thermal analyses and Hirshfeld surfaces analyses of complexes 1 and 2 have been discussed in detail.

Homo-trinuclear [Zn3(L)(μ2-OAc)2(H2O)].CH2Cl2 (1) and hetero-pentanuclear [Zn4(L)2Eu(NO3)3(H2O)] (2) and [Zn4(L)2Nd(NO3)3(H2O)]·CH3CH2OH (3) complexes containing a coumarin-skeleton bis(salamo) ligand H4L, were successfully prepared and characterized via the means of elemental analyses, single crystal X-ray crystallography, FT-IR, UV–Vis absorption spectroscopy and Hirshfeld surfaces analyses. Complex 1 is a 1:3 ((L)4−:ZnII) structure, and complexes 2 and 3 are 2:4:1 ((L)4−:ZnII:LnIII) structure. All ZnII atoms in complexes 1–3 occupied the N2O2 sites are five-coordinated with geometries of slightly distorted tetragonal pyramid and trigonal bipyramid. Rare earth metal (EuIII and NdIII) atoms are both coordinated with phenolic oxygen atoms, and eight-coordinated with the square antiprism geometries in complexes 2 and 3. Water molecules as coordinating solvents participate in the coordination. Supra-molecular structures are built by C H…π and hydrogen bonding interactions in complexes 1–3. Moreover, Hirshfeld surfaces analyses of complexes 1–3 were also analysed in detail. Most important of all, luminescences of complexes 1–3 were discussed.

A concise and highly efficient method for the construction of valuable 4-alkynylquinazolines under transition-metal-free conditions was developed via [4 + 2] annulation of 4-alkynylbenzoxazinanones with acylhydroxamates in good to excellent yields. The reaction featured the use of low-cost bases NaOAc or NaOMe, simple operation and high chemoselectivity. The broad substrate scope and the typical maintenance of high efficiency on a gram scale made this protocol a potentially practical method to synthesize 4-alkynylquinazolines.

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.

One homo-trinuclear 3d and five novel windmill-type hetero-pentanuclear 3d-4f complexes [Zn3(L)(OAc)2(H2O)]·CH2Cl2 (1), [Zn4(L)2Sm(NO3)2(EtOH)2]NO3·H2O·2CHCl3 (2), [Zn4(L)2Eu(NO3)2(EtOH)2]NO3·C2H5OH·2CHCl3 (3), [Zn4(L)2Gd(NO3)2(EtOH)2]NO3·C2H5OH·2CHCl3 (4), [Zn4(L)2Tb(NO3)2(EtOH)2]NO3·C2H5OH (5) and [Zn4(L)2Dy(NO3)2(EtOH)2]NO3·C2H5OH·2CHCl3 (6) were synthesized by the reactions of a new bis(Salamo)-based tetraoxime ligand (H4L) with Zn(OAc)2·2H2O and Ln(NO3)3·6H2O (Ln = Sm, Eu, Gd, Tb and Dy), respectively. The structures of complexes 1–6 were characterized via elemental analyses, FT-IR spectroscopy, UV-Vis spectroscopy and single crystal X-ray crystallography, and their fluorescence properties, catalytic activities and Hirshfeld surface analyses were studied.

An unprecedented trinuclear Ni(II) complex assembled from an asymmetric Salamo-type ligand 6-ethoxy- 4′,6′-dichloro-2,2′-[(1,3-propylene)dioxybis(nitrilomethylidyne)]diphenol (H2L) is synthesized. The Ni(II) complex with the general formula [Ni3(L)2(μ3-OAc)2]·3CH3CN is characterized by IR, UV-vis, and fluorescence spectra and the single crystal X-ray analysis. All the Ni(II) atoms are hexacoordinated with slightly distorted octahedral symmetries. Interestingly, each Ni(II) atom is not located on the N2O2 cavity of the asymmetric Salamo-type (L)2– unit, and two μ3-OAc ions adopt an uncommon μ3-η2:η1 binding mode connecting the Ni1, Ni2, and Ni3 atoms. Furthermore, the crystallizing acetonitrile molecules successfully assemble into an infinite 2D network by hydrogen bonding and C–H···π interactions.

An unusual self-assembled hetero-bimetallic [Ni(II)-Sm(III)] coordination polymer, [Ni(L)Sm(NO3)3(4,4&prime, bipy)]n, is prepared through a hexadentate chelating ligand 2,2&prime, [1,2-ethylenedioxybis(nitrilomethylidyne)]diphenol (H2L). The Ni(II)-Sm(III) coordination polymer is validated through elemental analyses, Fourier-transform infrared and UV-Visible spectroscopies, and X-ray single-crystal diffraction. The Ni(II) atom forms a twisted six-coordinated octahedron, and the Sm(III) atom is ten-coordinated, adopting a twisted bicapped square antiprism. An infinite three-dimensional-layer supramolecular structure is obtained through extensive &pi, &middot, &pi, stacking and intermolecular hydrogen bonding interactions. The polymer has a good antibacterial effect against Staphylococcus aureus.

A novel 3D Cd(II)-based luminescent metal-organic framework {[Cd(L)(bpe)0.5]·H2O}n (1) [L = 6-(3-pyridyl)isophthalic acid and 1,2-bis(4-pyridyl)ethane], has been successfully assembled by a solvothermal reaction. The structure displays 4,5-connnected framework and exhibits solvent stability. More importantly, the excellent sensitivity and selectivity of compound 1 as luminescence probes for detecting CrO42−/Cr2O72− and a wide range of nitro aromatic compounds (NACs).

Two newly di- and tri-nuclear Cu(II) and Ni(II) complexes constructed from a half-salamo chelating ligand (HL: 2-[O-(1-ethyloxyamide)]oxime-6-methoxyphenol), [Cu2(L)2(μ-OAc)2] (1) and [{Ni3(μ-OAc)2(L)2(OAc)2]·CHCl3 (2), and one tetranuclear Co(II) complex [Co4(L′)4(MeOH)4] (3) based on an unexpected ligand H2L′ derived from the cleavage of HL have been synthesized and characterized by elemental analyses, IR, UV–vis spectra, and single crystal X-ray diffraction analyses. The single crystals of complexes 1, 2 and 3 in the process of synthesis are obtained through different routes. The complex 1 includes two Cu(II) atoms, two completely deprotonated (L)− units and two μ-acetate ions, which displays a propeller-type motif. The complex 2 contains three Ni(II) atoms, two completely deprotonated (L)− units, two μ-acetate ions, two chelating acetate ions and one crystallizing chloroform molecule, the crystal structure of complex 2 reveals a butterfly-type motif. The complex 3 is made up of four Co(II) atoms, four completely deprotonated (L′)2− units (HL′: 2-[O-(1-hydroxyethyl)]oxime-6-methoxyphenol) and four coordinated methanol molecules, which shows a windmill-type motif. Besides, magnetic properties and Hirshfeld surface analyses were discussed.

wo unusual Cu(II) complexes [{Cu(L1)}2] (1) and [Cu2(L2)] (2), with an asymmetric salamo-type bisoxime ligand H2L1 were synthesized and characterized by elemental analyses, UV-Vis, fluorescent spectra, Hirshfeld surface analyses and single-crystal X-ray diffraction analyses. For the complex 1, two Cu(II) ions are penta-coordinate by N2O2 donor atoms from the (L1)2- unit and one bridged phenol oxygen atom from another (L1)2- unit. Complex 1 does not have intermolecular hydrogen bonds, formed an isolated zero dimensional structure. Meanwhile, for the complex 2, an unexpected ligand H4L2 was synthesized by aldol condensation reaction of H2L1 and acetone upon coordination, then the new ligand and Cu(II) ions combined, formed a highly symmetrical structure, and two Cu(II) ions of the complex 2 have tetra-coordinate environment. With the help of intermolecular hydrogen bonding CH⋯O interactions, a self-assembled infinite 1D supramolecular structure was formed. Meanwhile, the photophysical spectra and Hirshfeld surface analyses of the complexes 1 and 2 were also measured and discussed.

Four homo/heterometallic complexes [Cu3(L)(μ2-OAc)9(CH3OH) 9]·3CHCl3 (1), [Cu2(L)Ca(μ2-NO3)9] (9), [{Cu2(L)Sr(μ2-NO3)9}9]·CH3CH2OH (11) and [Cu2(L)Ba(μ2-OAc)9(OAc)] (14), containing an acyclic naphthalenediol-based ligand H4L, were synthesized and characterized by elemental analyses, IR, UV–Vis, fluorescence spectra, TG-DTA and X-ray crystallography. The complex 1 was obtained by the reaction of H4L with 11 equivalents of Cu(OAc) 9·2H2O. The heterometallic complexes 9, 11, 14 were acquired by the reaction of H4L with 9 equivalents of Cu(OAc)9·2H2O or Cu(NO3)9·2H2O and 1 equivalent of M(OAc)9 (M = Ca, Sr and Ba). Owing to the different coordination cavities of the N2O2 and O6 of the completely deprotonated (L)14- unit, the crystal structures showed the N2O2 sites were occupied by Cu(II) atoms, alkaline earth metal(II) atoms occupied the O6 site of the ligand (L)14- unit, respectively. Furthermore, the fluorescence properties and TG-DTA analyses were discussed.

Two new complexes [{Zn(L1)(μ-OAc)Zn(CH3CHOHCH3)}2] and [Ni(L2)(H2O)(CH3OH)] with asymmetric Salamo-type ligands (H3L1 and H2L2) are synthesized and structurally characterized. In the Zn(II) and Ni(II) complexes, the terminal and central Zn(II) atoms are found to have slightly distorted square pyramidal and trigonal bipyramidal symmetries respectively, while the Ni(II) atom is hexa-coordinated and has a slightly distorted octahedral symmetry. Interestingly, a self-assembling continual zigzag 1D chain is formed by intermolecular hydrogen bonds in the Ni(II) complex. Furthermore, the Zn(II) and Ni(II) complexes in the ethanol solution show intense photoluminescence.

A new sensor H5L for continuous identification of Cu2+, Al3+ and lysine was synthesized by Schiff base reactions. The sensor could specifically recognized Cu2+ in the EtOH/H2O (1:1 v/v) solution by UV–vis spectra, and the binding constant with Cu2+ can reach 1011 M−1, meanwhile, it was found by the naked-eye that the color of the solution was changed from colorless to yellow. The copper complex L-Cu2+ formed by the sensor H5L and Cu2+ could further recognize Al3+ and lysine in the fluorescence spectra. The LOD values of the three objects were 2.67 × 10−8, 1.96 × 10−8 and 5.59 × 10−9 M, respectively. In addition, fluorescence intracellular images of Al3+ and lysine were performed and obtained satisfactory results.

In this study, The Zn-Cr nanocomposite was synthesized using the hydrothermal method show good adsorption property. The as-prepared LDHs absorbent were characterized by Powder X-ray Diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier Transform Infrared (FT-IR), BET surface area, and simultaneously UV-visible spectrophotometer. The nanocomposites of Zn-Cr layered double hydroxides, the strong adsorptive adsorbents for anions. Zn-Cr LDHs with various Zn/Cr molar ratios for 2, 3, 4. The nanocomposites quickly adsorbed the anionic dyes such as methyl orange (MO) without the light illumination. The effects of Zn/Cr molar ratio on the adsorption performance of Zn-Cr LDHs were investigated.

A new trinuclear Zn(II) complex [(ZnL)2(OAc)2Zn]·2THF with a Salamo-type bisoxime ligand H2L (2,2′-[ethylenedioxybis(nitrilomethylidyne)]dinaphthol) is synthesized and structurally characterized. The luminescence study demonstrates that the Salamo-type ligand exhibits a good antennae effect with respect to the Zn(II) ion due to an efficient intersystem crossing and ligand-to-metal energy transfer. From a more general perspective, this work opens interesting perspectives for the development of efficient luminescent stains to obtain a novel luminescent Zn(II) complex with Salamo-type derivatives.

A novel supramolecular Cu(ΙΙ) complex [Cu2(L2)2] (H2L2 = 4-bromosalicylaldehyde O-(2-hydroxyethyl)oxime) is synthesized through the complexation of Cu(OAc)2·H2O with an asymmetric salamo-type ligand 4-bromo-6′-hydroxy-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol (H3L1) and is structurally characterized by single crystal X-ray diffraction. The X-ray crystal structure of the Cu(ΙΙ) complex reveals it to crystallize in the triclinic system, space group $$P\overline1$$ , in which each Cu(II) atom is in a distorted square pyramidal geometry. The whole Cu(ΙΙ) complex consists of a series of [Cu2(L2)2] units, forming an infinite 1D chain supramolecular structure. Meanwhile, the Cu(II) complex exhibits emission with the maximum emission wavelength λmax = 431 nm when excited at λex = 367 nm.

A trinuclear Co(II) complex, [{CoL(C4H9OH)}2-(OAc)2Co]·C3H7NO, was synthesized by the reaction of a Salamo-type chelating ligand (H2L=4,42′-dinitro-2,2′-[1,2-ethylenedioxybis(nitrilomethylidyne)]diphenol) with cobalt(II) acetate tetrahydrate inn-butanol, and characterized by elemental analyses, X-ray crystallography, FT-IR and UV/Vis spectra. In the Co(II) complex, there are two ligand L2−units, twoμ2-acetate ions, two coordinatedn-butanol molecules and one non-coordinatedN,N-dimethylformamide molecule. The Co(II) atoms in the structure of the Co(II) complex adopt slightly distorted octahedra geometries. Furthermore, through intermolecular C–H···O, O–H···O and C–H···π interactions, infinite layer-like, plane-like and 3D supramolecular structures are constructed. The fluorescence and electrochemical properties of the Co(II) complex have also been investigated.

A binder-free Ni3S2 electrode was prepared directly on a graphene-coated Ni foam (G/Ni) substrate through surface sulfiding of substrate using thiourea as the sulfur source in this work. The Ni3S2 showed a flower-like morphology and was uniformly distributed on the G/Ni surface. The flower-like Ni3S2 was composed of cross-arrayed nanoflakes with a diameter and a thickness of 1-2 μm and ~50 nm, respectively. The free space in the flowers and the thin feature of Ni3S2 buffered the volume changes and relieved mechanical strain during repeated cycling. The intimate contact with the Ni substrate and the fixing effect of graphene maintained the structural stability of the Ni3S2 electrode during cycling. The G/Ni-supported Ni3S2 maintained a reversible capacity of 250 mAh.g−1 after 100 cycles at 50 mA.g−1, demonstrating the good cycling stability as a result of the unique microstructure of this electrode material.

A novel magnetic solid-phase extraction (MSPE) coupled with high performance liquid chromatography (HPLC) method was explored for aflatoxin B1 (AFB1) and zearalenone (ZON) simultaneous determination. This method was based on a newly explored extractant of Fe3O4 nanoparticle-filled amino-modified multi-walled carbon nanotubes (Fe3O4-MWCNTs-NH2) composite, which was sensitive to analytes with structure of multi-aromatic rings and abundant hydrogen bond acceptors, based on the extraction mechanism of π–π EDA and hydrogen-bonding interactions. The morphology, structure and magnetic properties of the extractant were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and vibrating sample magnetometry (VSM). Adsorption isotherms and kinetics for two mycotoxins were investigated and proved to be the best fit by Dubinin–Astakhov and pseudo-second-order models. Critical MSPE parameters, including solution pH, extraction time, salt addition and temperature, were investigated and optimized and the proposed analytical method was validated. Subsequently, the method was successfully applied for AFB1 and ZON analysis from wheat flour samples. The proposed method proved to be an excellent green analysis with a score of 89 in analytical Eco-Scale evaluation. It also has good linearities in the range of 1.0–100.0 ng g−1 with linear coefficients (r) above 0.99, desirable recoveries ranging from 88.8% to 96.0%, satisfactory precision with relative standard deviation (RSD) in the range of 2.1–2.8%, and low limits of detection (LODs) of 0.15 and 0.24 ng g−1 for AFB1 and ZON, respectively. This novel magnetic-extractant-based green MSPE-HPLC method has great potential for mycotoxin analysis from complex matrix samples.

Two newly designed fluorescent complexes, [Zn(L)(MeOH)]·CH2Cl2 (1) and [{NiL(MeOH)(μ-OAc)}2Ni]·4CH2Cl2 (2) based on a coumarin-containing N2O2 chelating ligand H2L have been synthesized and characterized by elemental analyses, IR and UV–Vis spectra, fluorescence spectra and X-ray crystallography. Complex 1 includes one Zn(II) atom, one completely deprotonated (L)2− unit, one coordinated methanol molecule and one crystalling dichloromethane molecule, and forms an infinite 2D supramolecular network. While complex 2 contains three Ni(II) atoms, two completely deprotonated (L)2− units, two μ2-acetate ions, two coordinated methanol molecules and four crystalling dichloromethane molecules, and possesses an infinite 3D supramolecular structure. The fluorescence titration experiment is used to characterize fluorescence properties of complexes 1 and 2. The normalized fluorescent spectra show clearly that complexes 1 and 2 have favorable fluorescent emissions in different solvents.

C34H36CoN4O5, triclinic, P1̅ (no. 2), a = 8.7040(5) Å, b = 12.7375(9) Å, c = 14.2626(9) Å, α = 99.054(2)°, β = 95.727(2)°, γ = 92.477(2)° V = 1550.96(17) Å3, Z = 2, R gt(F) = 0.0554, wR ref(F 2) = 0.1369, T = 296(2) K.

C24H22Cl2N4O4, triclinic, P1̄ (no. 2), a = 9.7533(6) Å, b = 10.2969(8) Å, c = 17.9128(12) Å, α = 104.131(2)°, β = 99.242(2)°, γ = 91.106(2)°, V = 1718.7(2) Å3, Z = 3, R gt(F) = 0.0502, wR ref(F 2) = 0.1256, T = 153(2) K.

A novel bifunctional-group multi-purpose dye probe p-TNS has been designed and synthesized. The probe p-TNS has unique excited-state intramolecular proton transfer (ESIPT) and resonance-assisted hydrogen bonding (RAHB) coupled system, was confirmed to detect cyanide and hydrazine by blocking the ESIPT effect. Cyanide can change the fluorescence of the solution from bright green to orange-red (116 nm Stokes shift), while hydrazine causes the bright green fluorescence to be quenched. The recognition mechanism of the probe p-TNS to CN− and N2H4 was proposed reasonably through spectral characterizations and theoretical calculations. Combined with theoretical calculations, it was speculated that the solvent dependence may be caused by the ICT effect in the molecule. The probe p-TNS could be prepared into test strips for the detection of cyanide and hydrazine. In addition, the probe molecule can also be used to detect trace amounts of cyanide in agricultural products, and respond to gaseous hydrazine by direct contact, indicating that the probe p-TNS has good practical application prospects. Therefore, this molecular framework provides a new way of thinking about detecting multiple target substances.

A new symmetrical multi-halogen-substituted bis(salamo)-based tetraoxime ligand H3L and its corresponding penta-coordinated homo-binuclear Co(II) and Zn(II) complexes have been successfully synthesized. The three complexes, [{Co2(L)(OCH3)}2]·CHCl3 (1), [{Zn2(L)(OCH3)}2]·CH3OH (2) and [{Co2(L)(OCH2CH3)}3]·2CH3CH2OH·CHCl3 (3), have been characterized by elemental analyses, FT-IR and UV–Vis absorption spectroscopy as well as X-ray single-crystal structure analyses. In complexes 1 and 2, two crystallographically independent but chemically identical binuclear complex molecules A and B were detected by X-ray analysis. However, in complex 3, three crystallographically independent but chemically identical binuclear complex molecules A, B and C were detected. All the penta-coordinated Co(II) and Zn(II) atoms in complexes 1 and 2 are located in the N2O2 cavities of the completely deprotonated (L)3- units and coordinated to one oxygen atom from one μ2-bridged methoxyl group. The coordination environment of the Co(II) atoms in complexes 1 and 3 are similar, except that the μ2-bridged methoxyl group is replaced with the μ2-bridged ethoxyl group. Additionally, both of complexes 1 and 3 form 3D supramolecular structures through abundant intermolecular interactions, while complex 2 forms 1D supramolecular structure through intermolecular hydrogen bonds. The C H···π interactions have been established in complexes 1 and 2, where the π-system of H3L participates as π-donor. Through the means of Hirshfeld surfaces and 2D fingerprint plot analyses, existing different non-covalent supramolecular interactions in the Co(II) and Zn(II) complexes have been explained. Furthermore, to obtain a better understanding of the fluorescence properties of H3L and its complexes 1–3, fluorescence titration experiments have been performed.

Three trinuclear complexes, [{CoL(MeOH)(μ-OAc)}2Co] (1), [{CoL(EtOH)(μ-OAc)}2Co]·2CH3CH2OH (2) and [{NiL(MeOH)(μ-OAc)}2Ni]·2CH3OH (3) have been successfully synthesized by wet-chemical method using asymmetric salamo-based polydentate chelating ligand (H2L) with transition metal(II) acetate (Co(OAc)2·4H2O or Ni(OAc)2·4H2O). The ligand H2L with N2O2 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.

A novel sensor PNS for the continuous recognition of Cu2+ and S2− was synthesized, specifically recognizes Cu2+ in DMSO/H2O (9:1 v/v) solution by fluorescence emission spectroscopy. The colour of the PNS solution changed from colourless to yellow when Cu2+ was added under the fluorescent lamp, and at excitation wavelengths of 301 and 365 nm, the violet fluorescence of the PNS solution was quenched. The PNS-Cu complex formed by the sensor PNS and Cu2+ can further identify S2− in the fluorescence spectra. The LOD values of the two substances both Cu2+ and S2− are 1.21 × 10−8 and 5.58 × 10−9 M. In addition, single crystals of the PNS-Cu complex were also obtained to verify the principle of this continuous identification process.

The tetranuclear Zn(II) complex, [{ZnL(μ-OAc)Zn(CH3CH2CH2OH)}2], derived from an asymmetrical Salamo-type chelate ligand H3L (5-methoxy-6′-hydroxy-2,2′-[ethanedioxybis(nitrilomethylidyne)]diphenol) has been synthesized and structurally characterized by elemental analysis, IR spectrum, X-ray crystallography, UV/Vis and fluorescence spectra. The structure is made up of four Zn(II) atoms,μ2-coordinated acetate ions and two coordinatedn-propanol molecules, and forms an infinite one-dimensional supramolecular structure via intermolecular C–H···π interactions. The four Zn(II) atoms are penta-coordinated and show slightly distorted trigonal bipyramidal and tetragonal pyramidal symmetries.

Phenotypic plasticity and/or pollinator-mediated selection may be responsible for the changes in floral traits of plants when they are forced to live in new conditions. Although the two events could be independent, we hypothesized that phenotypic plasticity in floral traits might help to coordinate plant-pollinator interactions and enhance plant reproductive success in changing habitats. To test this hypothesis, we investigated floral traits and pollination on three natural populations of a lousewort (Pedicularis siphonantha) ranging at different elevations, as well as two downward transplanted populations in Shangeri-La County and Deqin County, northwest Yunnan, China. The results indicated that floral traits, i.e. phenology, longevity, display size, corolla tube length and pollen production differed significantly among populations. Moreover, or the two transplanted populations, floral traits diverged from their original populations, but converged to their host populations. Although the phenotypic plasticity in floral traits might be a rapid response to abiotic factor such as warmer environment, the changes in floral traits were found to be well adapted to pollination environment of the host population. Compared with plants of their original habitats in higher elevation, the transplanted individuals advanced flowering time, shortened flower longevity, reduced floral display size and pollen production, received higher visiting frequency and yielded more seeds. These findings suggested that phenotypic plasticity of floral traits might help plants adjust their resource allocation strategy between preand post-pollination stages in response to harsh or temperate conditions, which might correspondingly meet a pollinator-poor or hyphen rich environment. This would be beneficial for the widely-distributed species to adapt to various environmental changes.

C44H49Cl2Co3N6O12, Triclinic, P1̅, a = 9.7415(9) Å, b = 13.6440(14) Å, c = 17.5241(11) Å, α = 72.807(10)°, β = 83.019(9)°, γ = 72.246(9)°, V = 2450.6(5) Å3, Z = 2, R gt(F) = 0.0700, wR ref(F 2) = 0.1505, T = 291(2) K.

Heterotrinuclear 3d-4f complexes with a naphthalenediol-based acyclic bis(salamo)-type ligand have been synthesized and structurally characterized. Spectral titrations clearly show that the heterotrinuclear complexes [Zn2(L)La(OAc)3] (1), [Zn2(L)Ce(OAc)3] (2) and [Zn2(L)Dy(OAc)3(CH3OH)]·CH2Cl2 (3) are acquired by the substitution reaction of the obtained homotrinuclear Zn(II) complex with 1 equiv. of Ln(NO3)3 (Ln3+=La3+, Ce3+ and Dy3+). Two Zn(II) ions are penta- and hexa-coordinated with geometries of distorted tetragonal pyramid and octahedron. La(III) ion is deca-coordinated, adopting a distorted bicapped square antiprism geometry. Ce(III) ion is nona-coordinated with geometry of distorted capped square antiprism as well as Dy(III) ion. The different coordination modes of acetate ions in complexes 1, 2 and 3 lead to different coordination numbers of the lanthanide(III) ions. Furthermore, the structures and fluorescence properties have been discussed.

A highly sensitive and selective fluorescence sensor for the detection of Zn2+ and Cu2+ was derived from a Salamo-type bisoxime ligand. The developed sensor is capable of detecting Zn2+ and Cu2+ in aqueous media through fluorescence turn on and off, respectively. In addition, the complexes of Zn2+ and Cu2+ could successfully sense the presence of H+/OH− via increase (ON)/decrease (OFF) in fluorescence intensity. Single crystal structures of Cu2+, Ni2+ and Cd2+ complexes have been characterized using X-ray crystallography, respectively. The Cu2+ complex forms a dinuclear structure with both Cu2+ being five-coordinated with square pyramidal geometries; the Ni2+ and Cd2+ complexes are both tetranuclear structures where the Ni2+ and Cd2+ are almost six-coordinated with slightly distorted octahedral geometries. More specifically, one of the Cd2+ forms a novel six-coordinated triangular prism geometry which is rarely reported.

A novel magnetic adsorbent was designed and synthesized for adsorption and determination of hazardous aromatic acids (AAs) based on the zeolite imidazolate frameworks of Eu (ZIF-Eu), Fe3O4 and carboxyl multi-walled carbon nanotubes (MWCNTs-COOH). ZIF-Eu was fabricated for the first time, and Fe3O4 nanoparticles were encapsulated in MWCNTs-COOH, which made the separation procedure simple and easy-realizable. Adsorption experiments indicated that the adsorbent had superior affinity and selectivity to adsorbates with multi-ring, multi-carboxylic and electron-withdrawing group substituted structures, and it can achieve the selective adsorption of AAs from the aromatic mixture, the mechanism of which was evaluated and attributed to the intermolecular π-π electron-donor-acceptor (EDA) and hydrogen-bonding interactions. Seven AAs with different substituents were selected as target adsorbates to investigate the influences of critical experimental conditions on the adsorption efficiencies. Adsorption isotherms and kinetics were investigated and indicated that Dubinin-Ashtakhov model and pseudo-second-order model could well describe the adsorption of AAs on the nanocomposite. Adsorption thermodynamics study suggested that the adsorption reactions were spontaneous, endothermic and thermodynamically favorable. In addition, desorption conditions for AAs, and reusability of the novel adsorbent was evaluated, which confirmed the recyclability of the novel adsorbent.

A novel magnetic solid-phase extraction (MSPE) based method was established for aromatic amino acids (AAAs) selective determination. Central to the method was the adopted extractant. An explored composite of metal organic frameworks (MOFs) and magnetic carbon nanotubes (CNTs) was employed for that, which exhibited superior adsorption affinity and selectivity to AAAs as compared to other amino acids with the mechanisms attributed to multiple hydrogen bonding and π-π electron-donor-acceptor (EDA) interactions. The morphology, structure and magnetic behavior of the composite were characterized and related MSPE procedure was established. Critical extraction conditions including pH, extraction time, temperature and salt addition were investigated and optimized. Subsequently the concentrations of three AAAs tryptophan (Trp), tyrosine (Tyr) and phenylalanine (Phe) in Lanzhou lily were determined by the composite based MSPE procedure coupled with high performance liquid chromatography-ultraviolet detection (HPLC-UV). The composite provided a superior sample clean-up function and many of the matrix interferences were eliminated, thus ensured AAAs were accurately and efficiently determined. The results showed that the method had good linearities with the linear coefficients above 0.99, desirable recoveries ranged from 88.0% to 96.8% with the RSD less than 5.1%, satisfactory precision and low limits of detection (LODs) which were respectively 0.04, 0.11, and 0.87ng/g for Trp, Tyr and Phe. The composite based MSPE-HPLC-UV method has great potentials for the AAAs selective determination from complex matrix samples.

A novel naphthalenediol-based bis(Salamo)-type tetraoxime compound (H4L) was synthesized and characterized. Its Zn2+ complex was found to be highly sensitive for the detection of Pic− when dissolved in water-containing organic solvent. Sensor H4L acts as a relay-sensor for recognition of Zn2+ while the L-Zn2+ complex recognizes Pic− with high selectivity and sensitivity in acceptable physiological pH range. Moreover, The L-Zn2+ and its Pic− polymer complex display successive sensing of H+/OH− via increase (ON) and decrease (OFF) in fluorescence intensity. The crystal structure of the Zn2+ complex has been determined by single-crystal X-ray diffraction.