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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]

ABSTRACT A mono‐salamo‐type ligand H2L was prepared to utilize 3‐methoxysalicylaldehyde and a semi‐salamo‐type compound, and its novel trinuclear Ni(II) cluster with two significantly various configurations in the solid state was obtained by reaction of H2L with Ni(II) ions. The trinuclear structure of the Ni(II) cluster was validated by x‐ray technique, and Ni(II) ions exhibited hexa‐coordinated twisted octahedrons. Its structural formula is [Ni3(L)2(μ2‐Cl)2(EtOH)2]. Chloride ions have also successfully double bridged to participate in coordination, and play a critical impact in the trinuclear configuration's stability and charge balance. Two solvent ethanol molecules are also participated in coordination. The coordination ratio of the ligand to the metal ion was verified to be 2:3 by UV–Vis absorption titration spectroscopy. The HOMO and LUMO energies of the frontline molecular orbitals of H2L and the complex were analyzed by DFT calculations, and the energy gap value of the ligand H2L was 4.29 eV, and that of the complex was 0.72 eV. The ligand combined with the metal decreased the energy gap value and produced a more active complex. Furthermore, Hirshfeld surface analysis visualizes the weak interactions of crystalline molecules, and these abundant weak interactions play an especially critical effect in the supramolecular structural self‐assembling. The fluorescent researches proclaimed that the fluorescence intensity of the cluster significantly decreased compared with the ligand, suggesting that this ligand and complex have greater promise for fluorescence sensing. [ABSTRACT FROM AUTHOR]

Salamo‐type ligand H2L was designed and synthesized and reacted with Cu (II) and Zn (II) acetate, respectively, to obtain two binuclear Cu (II) and Zn (II) complexes: [Cu2(L)2]·2CH3OH (1) and [Zn2(L)2] (2) having the same coordination number but distinct geometries. Complex 1 is a Cu (II) complex containing two crystalline ethanol molecules, where two Cu (II) atoms are surrounded by two utterly deprotonated (L)2− parts, forming slightly twisted tetragonal pyramidal configurations of pentacoordinate. In complex 2, two utterly deprotonated (L)2− parts surround two Zn (II) atoms, forming pentadentate twisted triangular bipyramidal configurations. The complexes were elucidated via IR analyses and ultraviolet spectroscopy. Using DFT theoretical calculation, MEPs, IRI, and Hirshfeld surface analysis to investigate further the molecular interactions and reaction sites. Ultimately, the fluorescence characteristics of H2L and its complexes 1 and 2 were discussed. [ABSTRACT FROM AUTHOR]

• A salamo‐like oligo(N,O-donor) ligand H3L has been synthesized. • Unusual di-nuclear Mn(III) and tetra-nuclear Cd(II) complexes have been successfully self-assembled. • The hexa-coordinated Mn(III) and Cd(II) atoms in complexes 1 & 2 form slightly distorted octahedral geometries. • Theoretical calculations and fluorescence properties of H3L and complexes 1 and 2 were also investigated. The self-assembled di-nuclear Mn(III) & tetra-nuclear Cd(II) salamo-like oligo(N,O-donor) complexes, [Mn 2 (L) 2 (CH 3 OH) 2 ]·4CH 3 OH (1) and [Cd 4 (L) 2 (η -OAc) 2 (CH 3 OH) 2 ] (2) have been constructed successfully applying the measure of solvent evaporation and characterized structurally by X-ray diffraction analyses of single crystal, IR & UV visible analyses. The single crystals of the salamo-like oligo(N,O-donor) compound H 3 L have been obtained by wet-chemical technique, its established structure is H 3 L∙CH 3 OH. The structure of complex 1 is centrally symmetrical, and both Mn(III) atoms are hexa-coordination and have slightly distorted octahedral geometries. There are two sets of intermolecular H-bonding interactions which are connected with adjacent units of the Mn(III) complexes and form a two-dimensional network structure. For the complex 2 , all of the Cd(II) atoms are also hexa-coordination and possess slightly twisted octahedral configurations. And five groups of intermolecular H-bonding interactions form a honeycomb shaped three-dimensional supramolecular structure. Additionally, the intermolecular interactions of H 3 L, complexes 1 and 2 have been quantified by Hirshfeld surface analysis for further study. Fluorescence emission spectra of H 3 L, complexes 1 and 2 were also investigated. [Display omitted] [ABSTRACT FROM AUTHOR]

• Synthesis of a uncommon chloride-bridged salamo-type Ni(II) complex. • The TD-DFT calculation verifies the type of ultraviolet electronic transition. • Quantitative analyzes of intermolecular interactions in the crystalline structures were performed by Hirshfeld analysis. • The reaction sites were predicted by IRI, ESP and other weak interaction force analysis. What is the shape of a more flexible salamo-type ligand? Unexpectedly single crystals of the ligand and a uncommon tetranuclear chloride-bridged complex with Ni(II) [Ni 4 (L) 2 (µ 2 Cl) 2 (µ 3 OMe) 2 (MeOH) 2 ] were acquired. Single-crystal X-ray analyzes revealed the true structure of the ligand to be a twisted rectilinear shape, with a unique structure providing a diverse coordination environment for the metal ions. The involvement of halogens in the bridging is uncommon, and Single-crystal X-ray analysis of the complex showed that each deprotonated methoxy group bridges three Ni(II) metals, and then three Ni(II) metals are bridged by two chloride ions, each chloride ion bridges two Ni(II) metals. At this point the geometries of all four Ni(II) atoms adopt 6-coordinated octahedral configurations. It was demonstrated in UV–visible titration test that the metal-to-ligand ratios in solution and the structure of the complex obtained by single-crystal X-ray analysis are consistent. The properties were predicted analytically by DFT theory calculations and the UV–vis absorption spectra obtained by TD-DFT theory calculations in general coincide with the test results. The weak interactions in the complex were analyzed by cell freedom, Hirshfed surface analysis, ESP and IRI calculations. Finally, the fluorescence properties were explored in detail. [Display omitted] [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]