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Efficiently constructing structures with high thermal stability is a key objective in the development of energetic compounds. However, the existing synthesis processes for heat‐resistant energetic materials are frequently hampered by their complexity and low yields. This study presents a significant breakthrough in addressing these challenges. It successfully synthesizes 4‐amino‐5‐(3‐amino‐1H‐pyrazole‐4‐yl)‐2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐one (APTO) using a streamlined two‐step process, achieving an impressive high yield of 87.5 %. The structure was determined through X‐ray single crystal diffraction analysis, revealing a nearly planar intramolecular structure. Hirshfeld surface analysis, weak interaction analysis, and aromaticity analysis were conducted, illustrating a substantial presence of hydrogen bonds and π ‐ π stacking interactions within and between molecules. These interactions contribute significantly to exceptional thermal stability of ATPO. Furthermore, the thermal stability of ATPO was confirmed through DSC analysis, exhibiting a decomposition temperature as high as 365.2°C. This temperature surpasses that of the heat‐resistant explosive HNS (325°C), further validating its excellent thermal stability. The construction of this conjugated structure offers valuable guidance for the future structural design of heat‐resistant energetic materials. It opens up possibilities for the development of novel compounds with improved thermal stability based on similar conjugated architectures. [ABSTRACT FROM AUTHOR]

A quinoline-containing semi-salamo-type ligand, HL, was synthesized and a dinuclear Ni(II) complex, [Ni2(L)2(NCS)2], was produced. The complex was experimentally analyzed by elemental analysis, fluorescence, and UV–Vis spectroscopy. X-ray single crystal diffraction experiments showed that the complex is a six-coordinate, structurally symmetric, phenoxy-bridged dinuclear Ni(II) dimer with the participation of SCN− in the coordination to satisfy charge neutrality. The self-assembly forms a 2-D supramolecular network structure through hydrogen bonding and π⋯π interactions. DFT calculations were performed on the complex to analyze its energy gaps, and UV–Vis experiment was verified by TD-DFT calculation. In addition, close intermolecular contacts were investigated by Hirshfeld surface analysis to quantify the crystal structure interaction. [ABSTRACT FROM AUTHOR]

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]

A penta-coordinated dinuclear Zn(II) complex, [Zn2(L)(μ-PhCOO)(EtOH)] (1), and a hexa-coordinate tetranuclear Cd(II) complex, [{Cd2(L)(EtOH)(η-OAc)}2]·2CH2Cl2 (2), have been synthesized by reactions of a single-armed salamo-based ligand, H3L, and two kinds of transition metal salts, (Zn(NO3)2·6H2O and Cd(OAc)2·2H2O), respectively. Complexes 1 and 2 have been characterized by elemental analyses, single crystal X-ray diffraction, IR spectra and UV-Vis spectra. Complex 1 is composed of a totally deprotonated ligand (L)3- moiety, two Zn(II) ions, one μ-PhCOO- counter-anion and one coordinated ethanol molecule. The (L)3- unit packages two Zn(II) ions, the μ-PhCOO- counter-anion bridges two adjacent Zn(II) ions and one ethanol molecule coordinates with the Zn2 ion, so that both Zn(II) ions are penta-coordinated with slightly distorted trigonal bipyramidal configurations, and the τ5 values of Zn1 and Zn2 are 0.86 and 0.65, respectively. Complex 2 consists of two discrete and similar electroneutral tetra-nuclear units, 2 A and 2B, and two crystallized dichloromethane molecules. Each unit has a symmetric structure that is made up of two completely deprotonated ligand (L)3- moieties, four Cd(II) ions, two η-OAc- counter-anions and two coordinated ethanol molecules. Fluorescence properties and Hirshfeld surfaces analyses have been studied as well. [ABSTRACT FROM AUTHOR]

The coordination behaviors of asymmetric quinoline-decorated half-salamo-type ligand HL1 with Cu(NO3)2·3H2O and Cu(OAc)2·H2O were studied. Two Cu(II) complexes, [Cu(L1)(NO3)]·CH3CH2OH (1) and [Cu2(L2)2] (2), were isolated and characterized by X-ray crystallography, FTIR, UV–vis, and fluorescence spectroscopies. Structural analyses showed that 1 is a mononuclear species, whereas 2 is a binuclear entity. Spontaneous cleavage along the oxime N-O bond close to quinoline ring of the ligand HL1 occurred upon reaction with Cu(OAc)2·H2O, yielding an unexpected complex 2. Moreover, DFT theoretical calculations and Hirshfeld surfaces analyses of the ligand HL1 and its corresponding Cu(II) complexes were investigated in detail. [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]

d-Block transition metal(II)-lanthanide(III) (3d-4f) hetero‐trinuclear [Cu(II)2Ln(III)] (Ln = La and Ce) complexes [Cu2La(L)(ƞ2-NO3)3(CH3OH)2]·2CH3OH (1) and [Cu2Ce(L)(ƞ2-NO3)3(CH3OH)2]·2CH3OH (2) are described, both of which are formed by a flexible symmetrical bis(salamo)-type ligand H4L. The two 3d-4f complexes have been synthesized and characterized by elemental analyses, IR spectra and UV–Vis spectroscopy. The crystal structures of 1 and 2 were determined by single-crystal X-ray diffraction analyses. In 1 and 2, each Cu(II) ion (Cu1 or Cu2) is located in the N2O2 cavity of an (L)4− unit, while the apex is occupied by one oxygen atom of the coordinated methanol molecule, forming a penta-coordinated square pyramidal geometry. The lanthanide(III) (La or Ce) ion is located in the O6-donor coordination sphere of the completely deprotonated (L)4− unit and coordinated with the other six oxygen atoms of the three nitrate ligands to form a twelve-coordinated icosahedron. At the same time, the supramolecular structures are formed by intermolecular hydrogen bonding interactions and quantitatively determined by Hirshfeld surfaces analyses. Fluorescence properties and DFT calculations of 1 and 2 were also studied. [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]

A family of rare structurally different homometal multinuclear CuII bis(salamo)‐based complexes, [Cu4(L)2(MeOH)2](ClO4)2·2MeOH (1), [Cu4(L)2(EtOH)2](NO3)2·2EtOH (2) and [Cu2(HL)(EtOH)Br2]·CHCl3 (3), has been successfully synthesized by the reactions of cupric salts with a bis(salamo)‐based multidentate chelate ligand (H3L). The salamo‐based ligand [R‐CH=N—O—(CH2)n—O—N=CH—R] is a new type of salen‐based analog. Complexes (1) and (2) are isostructural structures, and crystallize in monoclinic space group P21/n with centrosymmetric spiral structures, where the main structures contain two fully deprotonated ligand (L)3− units, a charged tetranuclear CuII folding center and two coordinated solvent molecules. Complex (3) crystallizes in monoclinic space group Cc and consists of two CuII cations, one incompletely deprotonated ligand (HL)2− unit and one coordinated ethanol molecule, and forms a novel homo‐binuclear CuII complex structure due to Br− counter anions. Complexes (1)–(3) have zero‐dimensional cluster‐based structures and are further assembled into three‐dimensional frameworks via intermolecular interactions. Because of the different solvents and counter anions which have a significant influence on the structures of complexes (1)–(3), the interactions were quantitatively evaluated by Hirshfeld surfaces analyses. Complexes (1)–(3) have been characterized by elemental analyses, IR spectra, UV–vis spectra and X‐ray crystallography analyses. In addition, fluorescence properties are evaluated and DFT calculations are performed. [ABSTRACT FROM AUTHOR]

A new salamo-based ligand and its two new dinuclear complexes [{Co(L)}2(4,4′-bipy)] (1) and [{Cu(L)}2] (2), were designed and self-assembled, and characterized by elemental analyses, FT-IR, UV–vis absorption spectroscopy and X-ray crystallography. In 1, two [Co(L)] units are bridged by the auxiliary bidentate ligand 4,4′-bipy with nitrogen-donor atoms to form a centrosymmetric dimeric structure. Both Co(II) ions are five-coordinate and possess distorted trigonal bipyramidal configurations. Complex 2 is composed of two Cu(II) ions and two completely deprotonated ligand (L)2– units. Interestingly, the two [Cu(L)] units form a dimer bridged by two oxime O atoms. This structure is rare in reported salamo-based Cu(II) complexes. Both Cu(II) ions are five-coordinate and possess distorted tetragonal pyramidal geometries. Hirshfeld surface analyses showed that the O–H/H–O interactions of 1 and 2 are weaker than that of H2L. This phenomenon indicates that H2L forms corresponding complexes with the Co(II) and Cu(II) ions through the deprotonation of phenolic hydroxyl groups. The fluorescence spectra showed that the fluorescence of the ligand is almost completely quenched due to the coordination of the Cu(II) ions with H2L. DFT calculations show that 1 and 2 have higher chemical stability than that of H2L. [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 quinoline-appended acylhydrazone H 2 L was designed and prepared. • The Zn(II) acylhydrazone complex [Zn(HL) 2 ]·H 2 O was prepared and elucidated tructurally. • The ligand HL and its Zn(II) complex showed unique luminescent mechanochromism. • The self-assembly process and weak intermolecular forces of complexes were explained. In the work, a quinoline-appended acylhydrazone H 2 L was designed and prepared via a Schiff base condensation reaction of quinoline-2-formaldehyde and salicylhydrazide. Further, a new zinc(II) complex, [Zn(HL) 2 ]·H 2 O was synthesized by the reacting of the ligand H 2 L and Zn(NO 3) 2 ·6H 2 O in dichloromethane/ethanol solution. The ligand and its Zn(II) complex were elucidated via UV–Vis, FT-IR, DFT calculation, Hirshfeld surfaces, MEP & IRI analyses, and X-ray single-crystal diffractions. The results of Hershfield surface analysis showed that there are obvious hydrogen bond interactions and C H···π mutual effect in the Zn(II) complex. In addition, solid-state photoluminescence properties indicated that H 2 L and its Zn(II) complex represent uncommon luminescent mechanochromism tuned via intermolecular hydrogen bonds. A quinoline-appended acylhydrazone ligand H 2 L and its Zn(II) complex [Zn(HL) 2 ]·H 2 O, were prepared and elucidated structurally. The results of Hershfield surface analysis showed that there are obvious hydrogen bond interactions and C H···π mutual effect in the Zn(II) complex. In addition, solid-state photoluminescence properties indicated that H 2 L and its Zn(II) complex represent uncommon luminescent mechanochromism tuned via intermolecular hydrogen bonds. [Display omitted] [ABSTRACT FROM AUTHOR]

A formyl-coordinated phenoxo-bridged homopolynuclear dimeric Cu(II) complex of a salamo-like N 2 O 3 -donor ligand, [(L) 2 Cu 3 (MeOH) 2 ](ClO 4) 2 , has been synthesized and characterized structurally. The weak interactions of the Cu(II) complex were studied via MEPs, IRI and Hirshfeld surfaces analyses, and the energy gaps and electronic properties of H2L and the Cu(II) complex were investigated through DFT & TD-DFT calculations. [Display omitted] • A rare trinuclear Cu(II) complex was synthesized and characterized structurally. • Both phenoxy and formyl oxygen atoms participate in coordination. • The weak interactions were studied via MEPs, IRI and Hirshfeld surfaces analyses. • The energy gaps and electronic properties were investigated through DFT & TD-DFT calculations. A formyl-included salamo-based N 2 O 3 -donor ligand (H 2 L) was synthesized, and has two cavities of N 2 O 2 and O 3. Coordination reactivity of the ligand H 2 L toward Cu(II) atoms can result in an unprecedented centrosymmetric sandwich-like homotrinuclear Cu(II) complex, [(L) 2 Cu 3 (MeOH) 2 ](ClO 4) 2 , here Cu1 lies in the N 2 O 2 positions, Cu2 is surrounded at the O 6 coordination sphere and bridged via two metalated [(L)Cu(MeOH)] units, and coordinates further with two oxygen atoms of formyl groups of another two ligand (L)2- moieties. Finally, the dimeric structure's complex was elucidated by elemental analyses and infrared spectroscopy, and fluorescence behaviors of the formyl-included ligand and the title complex were investigated. The weak interactions of the title complex were studied via MEPs, IRI and Hirshfeld surfaces analyses. Finally, the energy gaps and electronic properties of H 2 L and the title complex were investigated through DFT & TD-DFT calculations. [ABSTRACT FROM AUTHOR]

• The quinoline-decorated N 3 O-donor half-salamo type ligand HL was designed and synthesized. • Two novel Co(Ⅱ) complexes [Co(L)Cl] (1) and [Co(L)(NCS)] (2) were obtained by the reaction of HL with different Co(Ⅱ) salts. • Quantitative analyses of intermolecular interactions in the crystalline structures were performed by Hirshfeld surfaces analysis. Self-assembly through a quinoline-decorated N 3 O donor half-salamo-type tetradentate ligand HL and coordinative preference of Co(II) ion, two novel Co(II) complexes [Co(L)Cl] (1) and [Co(L)(NCS)] (2) were synthesized and characterized. X-ray crystallography revealed that both complexes 1 and 2 have similar mononuclear structure, in which the five-coordinated Co(II) atoms are not only surrounded by the N 3 O cavity of the deprotonated ligand (L)− unit, but also coordinated with different Cl− and NCS− anions. For the involvement of different anions, the crystal structures of the two complexes exhibit intermolecular C H···Cl and C H···S hydrogen interactions in building supramolecular assemblies, respectively. The two complexes are stabilized by C H···O, C H···N, C H···C, C H···S bonds and C H···π, π···π interactions. The spectral properties of the complexes were investigated through UV–Vis and fluorescence spectroscopy. In addition, the detailed analyses of Hirshfeld surfaces and fingerprint plots provide the basis of the intermolecular interactions in building crystal blocks. Two novel Co(II) complexes, [Co(L)Cl] (1) and [Co(L)(NCS)] (2) with a quinoline-decorated half-salamo type ligand HL were synthesized and characterized structurally. In addition, spectroscopic properties, DFT calculations and Hirshfeld surfaces analyses of HL and its two Co(II) complexes were investigated in detail. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] Three new Co(II) complexes containing half-salamo type ligand HL viz. [Co(L)Cl] (1), [Co(L)(NO 3)] (2) and [Co(L)(NCS)] (3) were synthesized and characterized by single crystal X-ray diffraction. The results showed that the central Co(II) atoms in mononuclear complexes 1 – 3 are all located in the N 3 O cavity of the deprotonated ligand (L)− unit, while coordinated with different counteranions. The presence of counteranions in complexes 1 – 3 are Cl−, NO 3 − and NCS−, respectively. The spectral properties of these complexes were investigated in detail. In addition, the structural descriptions were corroborated with theoretical calculations. The Hirshfeld surface analysis combined with 2D fingerprint plots revealed the short-range intermolecular interactions of these complexes. [ABSTRACT FROM AUTHOR]

• Heterobimetalic [Cu(II)2Ln(III)] (Ln = La and Ce) complexes were synthesized and characterized structurally. • It can be seen from complex 2 that the coordination ability of nitrate is stronger than that of acetic acid. • Hirshfeld surface analyses, DFT calculations and luminescences of the complexes 1 and 2 were investigated. Two heterobimetallic [Cu(II) 2 Ln(III)] (Ln = La and Ce) complexes composed of flexible bis(salamo)‐type ligand H 4 L with Cu(II) and Ln(III) atoms, [Cu 2 La(L)(ƞ 2-NO 3) 3 ]·EtOH (1) and [Cu 2 Ce(L)(ƞ 2-NO 3) 3 ]·EtOH (2) have been successfully synthesized, and characterized by IR spectra, elemental analyses, UV–Vis spectroscopy, the crystal structures of the complexes 1 and 2 were determined by single-crystal X-ray diffraction analyses. Each Cu(II) atom of the complexes 1 and 2 is located in the N 2 O 2 -donor of the completely deprotonated (L)4− unit, so that the two Cu(II) atoms have tetra-coordinated slightly distorted square planar geometries, while the Ln(III) (La or Ce) atom is located in the O 5 cavity of the ligand (L)4− unit. At the same time, there are six oxygen atoms from three bidentate nitrate groups coordinated with the Ln(III) (La or Ce) atom, resulting in the formation of an eleven-coordinated augmented sphenocorona J87. In addition, DFT calculations and Hirshfeld surfaces analyses are performed and fluorescence properties are evaluated. [Display omitted] Two heterobimetalic [Cu(II)2Ln(III)] (Ln = La and Ce) complexes composed of a flexible bis(salamo)‐type ligand H4L with Cu(II) and lanthanide(III) atoms, [Cu 2 La(L)(ƞ2-NO 3) 3 ]·EtOH (1) and [Cu 2 Ce(L)(ƞ2-NO 3) 3 ]·EtOH (2) have been successfully synthesized. The central lanthanide(III) atom forms eleven-coordinated augmented sphenocorona J87. At the same time, DFT calculations are performed and fluorescence properties are evaluated. [ABSTRACT FROM AUTHOR]

• Solvent-driven self-assembly of two novel homopolynuclear Cu(II) complexes 1 and 2 were synthesized and characterized structurally. • The influence of the various solvent molecules and the counteranions make it form tetra-nuclear dimerization structure in complex 2 , where two [Cu 2 (HL)Cl] metallized ligand units were bridged by two μ 2 -chloride ions. • DFT calculations, ESP studies and Hirshfeld surfaces of complexes 1 and 2 were investigated. Two novel di- and tetra-nuclear Cu(II) complexes, [Cu 2 (HL)Cl 2 (MeOH)]·MeOH (1) and [Cu 4 (HL) 2 Cl 2 (μ 2 -Cl) 2 ]·4EtOH·H 2 O (2) (where H 3 L= bis(salamo)-based ligand) have been synthesized, and structurally characterized by elemental analysis, infrared and electronic absorption spectroscopy. The molecular structures of complexes 1 and 2 were defined by using single crystal X-ray diffraction experiment. The structural results indicated that complexes 1 and 2 have a close comparable [Cu 2 (HL)Cl 2 ] unit in the unit cell where the ligand acts as a two-compartmental species chelating the metal ions Cu1 and Cu2. However, in complex 2 , the [Cu 2 (HL)Cl 2 ] complexes are paired in a centrosymmetric fashion to form a tetra-nuclear arrangement, connected by μ 2 -bridging chlorides. The observed different nuclearity is likely induced by the different solvent molecules used in the syntheses, methanol and ethanol in complexes 1 and 2 , respectively. A methanol molecule participates in coordination of complex 1 , while ethanol species in complex 2 is rather distant from one of the Cu(II) ions (ca 2.82 Å). The molecular frontier orbitals HOMO and LUMO of the complexes were analyzed by DFT calculations, and the results showed that the energy gaps of complexes 1 and 2 are particularly small compared to H 3 L, which may be caused by the combination of the orbitals of the central atoms and the donor atoms. The reaction sites of the ligand H 3 L with the metal Cu(II) were analyzed by ESP studies, and the results showed that the experiments were in agreement with the theory. Finally, Hirshfeld surfaces analyses were performed to quantitatively show various weak interactions of complexes 1 and 2. Two novel homopolynuclear Cu(II) complexes [Cu 2 (HL)Cl 2 (MeOH)]·MeOH (1) and [Cu 4 (HL) 2 Cl 2 (μ 2 -Cl) 2 ]·4EtOH·H 2 O (2) from a new bis(salamo)-based ligand H 3 L have been synthesized and characterized structurally. [Display omitted] [ABSTRACT FROM AUTHOR]

• Two trinuclear Co(II) and Ni(II) complexes with a unsymmetrically salamo type ligand were synthesized and characterized structurally. • Two terminal Co(II) atoms of complex 1 possess penta-coordinated trigonal bipyramid geometries, the central Co(II) atom exhibits a hexa-coordinated octahedral geometry, while all three Ni(II) atoms of complex 2 have hexa-coordinated octahedral geometries. • Molecular electrostatic potential analysis, hirshfeld surface analysis, and interaction region indicator analysis of complexes 1 and 2 were investigated. Two trinuclear Co(II) and Ni(II) complexes, [{Co 3 (L) 2 (μ -OAc) 2 } 2 ]·3CH 2 Cl 2 (1) and [Ni 3 (L) 2 (μ -OAc) 2 (EtOH) 2 ]·2EtOH (2) have been successfully obtained by a new nonsymmetrical salamo type ligand H 2 L with Co(OAc) 2 ·4H 2 O and Ni(OAc) 2 ·6H 2 O, respectively. Single crystal X-ray diffraction analysis revealed that complex 1 is an unsymmetric trinuclear structure, two tetradentate N 2 O 2 -donor ligand (L)2- units are coordinated to three Co(II) atoms where two terminal Co(II) atoms are penta-coordinated lateral twisting trigonal bipyramidal geometries but central Co(II) atom is hexa-coordinated lateral twisting octahedral configuration. Complex 2 is a centrosymmetrical trinuclear structure, all of the three Ni(II) atoms are hexa-coordinated lateral twisting octahedral configurations. In addition, complexes 1 and 2 have been characterized by physicochemical and spectroscopic methods. Molecular electrostatic potential analysis revealed that the phenolic oxygen atoms in the ligand H 2 L have nucleophilic reactions with Co(II) and Ni(II) atoms to form chemical bonds. Hirshfeld surfaces analyses showed that H···H/H···H interactions are the predominant, indicating the presence of great amount hydrogen bonds in complexes 1 and 2. IRI analyses indicated the presence of weak hydrogen bonding interactions that made complexes 1 and 2 more stable. Two trinuclear Co(II) and Ni(II) nonsymmetrically salamo type complexes, [{Co 3 (L) 2 (μ -OAc) 2 } 2 ]·3CH 2 Cl 2 (1) and [Ni 3 (L) 2 (μ -OAc) 2 (EtOH) 2 ]·2EtOH (2) 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 Co(Ⅱ) and Ni(Ⅱ) complexes were also studied. [Display omitted] [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]

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]

A new salamo-type probe H 2 L and its Co2+ complex [Co 3 (L) 2 (MeOH) 2 (μ -OAc) 2 ]·2MeOH were synthesized and characterized structurally. Fluorescence of Co2+ selectively response showed "off" when cations were sequentially detected. Meanwhile, the mechanism of recognition of Co2+ by H 2 L was got. DFT calculation and Hirshfeld surfaces analyses were investigated to further understand the experimental results observed. [Display omitted] • The probe H 2 L could efficiently detect Co2+ ion. • The probe H 2 L could detect Co2+. Meanwhile, H 2 L and Co2+ complex were characterized. • Hirshfeld surfaces analyses and DFT calculation were studied. A new salamo-type fluorescence probe H 2 L was synthesized by a series of reactions and corroborated by single-crystal X-ray crystallography and 1H NMR spectra. Fluorescence of Co2+ selectively response showed "off" when cations were sequentially detected. The LOD of H 2 L to Co2+ was calculated to be 3.73 × 10-7 M in DMF/water (9:1, v/v) solution system. Meanwhile, the single crystal of the Co2+ complex with H 2 L was obtained by solvent evaporation. The structure of the complex [Co 3 (L) 2 (MeOH) 2 (μ -OAc) 2 ]·2MeOH was validated by single-crystal X-ray diffraction, IR, and elemental analyses, and the mechanism of recognition of Co2+ by H 2 L was got. Density functional theory (DFT) and Hirshfeld surface analyses were investigated to further understand the experimental results observed. [ABSTRACT FROM AUTHOR]

A new pyridine-decorated half-salamo-like ligand (HL) was designed and synthesized. Three novel anion-dependent Cu(II) complexes [Cu(L)Cl]·CH 3 OH (1), [Cu(L)Br] (2) and [Cu(L)(NO 3)] (3) have been synthesized and characterized structurally. Furthermore, DFT calculations were investigated in the complexes 1 , 2 and 3. Paradoxically, the fluorescence intensities of these Cu(II) complexes are significantly increased compared to the ligand. [Display omitted] • A new pyridine-decorated half-salamo-like ligand was synthesized. • Three anion-dependent Cu(II) complexes 1 , 2 and 3 have been synthesized and characterized structurally. • The fluorescence intensities of these Cu(II) complexes are significantly increased compared to the ligand. A new pyridine-decorated half-salamo-like ligand (HL) was designed and synthesized by a one-pot method. Based on this ligand, the single crystals of three anion-dependent Cu(II) complexes [Cu(L)Cl]·CH 3 OH (1), [Cu(L)Br] (2) and [Cu(L)(NO 3)] (3) have been cultivated successfully and the structural features were determined by single crystal X-ray diffraction analyses. The results showed that the complexes 1 , 2 and 3 have homologous mononuclear structures, in which the five-coordinated Cu(II) atom is not only surrounded by the N 3 O cavity of the ligand (L)- unit, but also coordinated with Cl−, Br− and NO 3 − as auxiliary coordination, respectively. The ligand HL and the complexes 1 , 2 and 3 were characterized via elemental analyses, IR and UV–Vis spectroscopy. The short-range interactions of the complexes 1 , 2 and 3 were investigated by Hirshfeld surfaces analyses. Furthermore, DFT calculations were investigated in the complexes 1 , 2 and 3. Paradoxically, the fluorescence intensities of these Cu(II) complexes are significantly increased compared to the ligand. [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]