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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]

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

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

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

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

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 viaN‐donor atoms. As with complexes 1 and 2, the NiII ion in 3 has a six‐coordinated octahedral geometry. [ABSTRACT FROM AUTHOR]

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

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

A novel dinuclear Zn(II) complex with the chemical formula [Zn2(L)(OCH3)] has been synthesized by a bis(salamo)‐type tetraoxime ligand based on 3‐bromo‐5‐chlorosalicylicaldehyde, and characterized by elemental analyses, IR, UV–vis, and fluorescent spectra, and single‐crystal X‐ray diffraction analysis. All the Zn(II) atoms are pentacoordinated by N2O2 donor atoms from the (L)3− unit and one oxygen atom from one μ2‐methoxyl group. The Zn(II) (Zn1 and Zn4) atoms have distorted square pyramidal geometries (τ1 = 0.458, τ4 = 0.388), whereas the Zn2 and Zn3 atoms adopt trigonal bipyramidal (τ2 = 0.675, τ3 = 0.550) geometries. The Zn(II) complex is self‐assembled by intermolecular CH···O interactions to form an infinite three‐dimensional supramolecular structure. Interestingly, the intermolecular CH···π interactions in the Zn(II) complex is involved not in the formation of three‐dimensional structures but rather in the formation of the 0D dimer structure. Meanwhile, the optical properties of the Zn(II) complex were also measured and are discussed. [ABSTRACT FROM AUTHOR]

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

A new tetranuclear Zn( II) complex, [{Zn(L)(μ- OAc)Zn( H2O)}2], based on an asymmetrical salamo-type bisoxime chelating ligand H3L (6-hydroxy-4′-chloro-2,2′-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol) was synthesized and characterized by elemental analyses, differential thermal methods, single-crystal X-ray crystallography, and IR, UV-vis, and fluorescence spectra. The Zn( II) complex crystallizes in the triclinic system, space group P-1 with cell parameters a = 9.0742(6) Å, b = 11.8225(5) Å, c = 12.4182(8) Å, Z = 2, V = 1212.56(12) Å3, R1 = 0.0572, and wR2 = 0.1734. The environment of the tetranuclear Zn(II) complex is penta-coordinated having a slightly distorted trigonal bipyramidal geometry. Moreover, a 1D chain supramolecular structure is formed along the c-axis by the intermolecular C1-H1B⋯O14 hydrogen bonds; in the same manner, C2-H2C⋯Cg2 functions in the formation of supramolecular structures along the a-axis of the 1D chain. A 2D supramolecular structure along the ac plane extends infinitely under the force of intermolecular hydrogen bonds. Differential scanning calorimetry-thermogravimetry thermal analysis provides evidence of the coordination of Zn(II) atoms to the ligand H3L. The Zn(II) complex shows intense photoluminescence with a maximum emission at ~453 nm upon excitation at 360 nm. [ABSTRACT FROM AUTHOR]

Mononuclear copper(II) and trinuclear cobalt(II) complexes, namely [Cu(L1)]2 ·CH2Cl2 and [{Co(L2)(EtOH)}2Co(H2O)] ·EtOH {H2L1 = 4,6-dichloro-6′-methyoxy-2,2′-[1,1′-(ethylenedioxydinitrilo)dimethylidyne]diphenol and H3L2 = 6-ethyoxy-6′-hydroxy-2,2′-[1,1′-(ethylenedioxydinitrilo)dimethylidyne]diphenol}, were synthesized and characterized by elemental analyses, IR and UV/Vis spectroscopy, and single-crystal X-ray diffraction. In the CuII complex, the CuII atom is four-coordinate, with a N2O2 coordination sphere, and has a slightly distorted square-planar arrangement. Interestingly, the obtained trinuclear CoII complex is different from the common reported 2:3 (L:CoII) salamo-type CoII complexes. Infinite 2D layer supramolecular structures are formed via abundant intermolecular hydrogen bonding and π ···π stacking interactions in the CuII and CoII complexes. [ABSTRACT FROM AUTHOR]

A Salamo-type ligand 6,6′-diethoxy-2,2′-[1,1′-(ethylenedioxydinitrilo)dimethylidyne]diphenol (H2L) and its pentacoordinate copper(II) complex [CuL(H2O)] were synthesized and structurally characterized. The molecule of H2L is located in a crystallographic inversion center and adopts E configuration with respect to the C=N bond. In the complex [CuL(H2O)], the CuII atom has a tetragonally elongated square-pyramidal configuration with donor atoms N2O2 forming a perfect basal plane. And an infinite 2D layer supramolecular structure is formed through intermolecular C1-H1A ···O5 and C2-H2A ···O3 hydrogen bonding interactions. [ABSTRACT FROM AUTHOR]

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

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

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