Three ligands with different 6-substituent based on 5-bromo-pyridine-2-carboxylic acid (5-Br-Hpyc) skeleton, namely 3-Br-pyridine-2,6-dicarboxylic acid (3-Br-H2pydc), 5-bromo-6-methyl-pyridine-2-carboxylic acid (5-Br-6-Me-Hpyc) and itself, were used to react with CuCl2·2H2O under solvothermal conditions and generated five diverse copper(II) compounds [Cu(3-Br-pydc)(H2O)3] (Cu1), [Cu(5-Br-6-Me-pyc)2(H2O)·2H2O] (Cu2), [Cu(5-Br-pyc)2]n (Cu3), [Cu(5-Br-pyc)2(H2O)] (Cu4) and [Cu(5-Br-pyc)2(H2O)2] (Cu5), of which the latter three were the products of one-pot crystallization. Structural analysis indicated that Cu1, Cu2, Cu4, Cu5 were all monomuclear complexes and the corresponding anion among them were tridentate (Cu1) or bidentate chelate ligand (Cu2, Cu4, Cu5). While Cu3 was a 1D linear polymer and 5-Br-pyc anion in it adopted tridentate chelate bridging μ2 linking fashion. The coordination geometry of Cu(II) center for them was octahedron (Cu1, Cu3, Cu5) or square pyramid (Cu2, Cu4). Various non-covalent interactions of hydrogen bonds (O–H···O/C–H···O/C–H···Br), halogen bonds (Br···Br/Br···O), Br···π interaction (Br···C) and/or π···π staking played an important part in their 3D crystal packing, which have been confirmed by the careful Hirshfeld surface analysis. After the deeply structural comparison and synthesis condition exploration, it can be proposed that the space steric hindrance of the large -Br substituent and the different 6-substituent (-COOH, -Me, -H) on ligand may be the decisive factors for producing the finally structural types. Besides, the magnetic characterizations showed that between the neighbouring Cu(II) ions, there were weak ferromagnetic exchange in Cu1 but antiferromagnetic coupling in Cu2, respectively.

The crystal structures of five cocrystals based on 2,1,3-benzoselenadiazole and distinct fluorinated isophthalic acids reveal that fluorine substitution exerts a very pronounced effect on crystal packing.

A cobalt(II) complex cocrystal [Co(3,5,6-tcpa)2(H2O)4]center dot[Co(3,5,6-tcpa)2(H2O)2] (A) and a molecular cocrystal [(3,5,6-Htcpa)2(1,4-bpb)] (B) have been cosynthesized by the solvothermal reaction of cobalt(II) chloride hexahydrate with triclopyr (systematic name 2-((3,5,6-trichloropyridin-2-yl) oxy)acetic acid, abbreviation 3,5,6-Htcpa) and 1,4-bis(4-pyridyl)benzene (1,4-bpb). Structural analyses indicated that A is a doubly mononuclear cocrystal and contains two discrete and stereochemically different complexes: one octahedral, the other tetrahedral about the cobalt(II) centres. While in B, every two hydroxyls of 3,5,6-Htcpa as donors form O-H center dot center dot center dot N hydrogen bonds with the two pyridyl nitrogen atoms of one 1,4-bpb to fabricate an interesting organic acid-base molecule cocrystal B. The non-covalent interactions of Cl center dot center dot center dot Cl/Cl center dot center dot center dot O halogen bonds and O-H center dot center dot center dot O/O-H center dot center dot center dot N/ C-H center dot center dot center dot O hydrogen bonds have an crucial role in 3D crystal packing, which have been proved by the detailed Hirshfeld surface analyses. After deeply conformational comparisons and synthetic conditions explorations, it was proposed that the conformational flexibility of 3,5,6-tcpa anion or 3,5,6-Htcpa molecule and the synergistic effect in the given solvothermal system could be responsible for the cocrystallization of A and B. Besides, the magnetic measurements displayed weak antiferromagnetic coupling between the two cobalt(II) centers in A.

Polylactic acid (PLA) poses significant challenges in practical processing and application because of its inherently slow crystallization kinetics. This paper proposes a green and low-cost modification strategy by investigating the effect of waste biomass, tomato peel residue (TP), on the crystallization performance and melting behavior of PLA. The results demonstrate that TP with an average particle size of 4.56 μm after ultrafine grinding can significantly promote the crystallization process of PLA. Under isothermal crystallization conditions at 96 °C, the addition of 5 wt

A novel zinc(II) polymer based on pyridine sulfonyl amino acid, namely [Zn(HL)(H2O)2]n4H2O (1) (HL=(1-carboxylato-2-hydroxypropyl)(pyridin-3-sulfonyl)-threonine), was synthesized by reacting Zn(NO3)26H2O with H3L in a mixed solvent solution of MeCN/EtOH/H2O under acidic conditions. Single crystal X-ray diffraction analysis revealed that the polymer 1 crystallized in trigonal crystal system, space group P3121. Notably, the unit cell of the as-formed polymer 1 contains only one crystallographically independent zinc(II) ion, and the divalent anion ligand HL adopts a coordination pattern of eta 1:eta 2:mu 2. The zinc(II) central ions are connected by bridging coordination with the HL ligand through pyridyl nitrogen and carboxy oxygen atoms to form an infinite helix chain. Furthermore, numerous hydrogen bonds were observed among these chains, joining them into a 2D supramolecular network. Finally, the complex is stacked along the 31 helical axis to yield a three-dimensional supramolecular structure. Additionally, the thermal stability and photoluminescence properties of 1 were determined and discussed.

A pair of cobalt(II) complexes with formulas of [Co(3,5,6-tcpa)(2,2 '-bpy)Cl] (1A) and [Co(3,5,6-tcpa)2(2,2 '- bpy)]n (1B) have been cocrystallized by the solvothermal reaction of cobalt chloride hexahydrate with triclopyr (systematic name 2-((3,5,6-trichloropyridin-2-yl) oxy)acetic acid, abbreviation 3,5,6-Htcpa) and 2,2 '-bipyridine (2,2 '-bpy). Single-crystal X-ray diffraction analysis indicated that both 1A and 1B crystallized in triclinic system, space group P1 (no. 2). Compound 1A is mononuclear and 3,5,6-tcpa anion in it is a bidentate chelate ligand. In contrast, 1B is a 1D double-stranded chain structure in which 3,5,6-tcpa are bidentate bridging-mu 2 linkers. The non-covalent interactions of Cl center dot center dot center dot Cl halogen bonds, C-H center dot center dot center dot O/Cl hydrogen bonds as well as 7L center dot center dot center dot 7L stacking interactions play an important part in their crystal packing, which have been confirmed by the careful Hirshfeld surface analyses. After deeply structural analyses, it was proposed that flexible conformation alteration of 3,5,6-tcpa might be in charge of the cocrystallization phenomenon of 1A and 1B. In addition, the magnetic characterizations suggested antiferromagnetic coupling between neighbouring cobalt(II) centers in 1B.

A pair of cobalt(II) compounds with formulas of [Co(3,5,6-tcpa)2(4,4 '-bipy)(EtOH)]n (1A) and [Co(3,5,6tcpa)2(4,4 '-bipy)(EtOH)2]n (1B), have been cosynthesized through the solvothermal reaction of cobalt chloride hexahydrate with triclopyr (systematic name 2-((3,5,6-trichloropyridin-2-yl) oxy)acetic acid, abbreviation 3,5,6Htcpa) and 4,4 '-bipyridine (4,4 '-bipy) coligands. Single-crystal X-ray diffraction analysis indicated that complex 1A has orthorhombic system, space group Aea 2 (no. 41), while 1B showed monoclinic system, space group I2/a (no. 15). Compound 1A displays a 1D linear chain but 1B presents a zigzag chain, and 3,5,6-tcpa anion are both unidentate between them. The non-covalent interactions of C-H center dot center dot center dot O/C-H center dot center dot center dot Cl hydrogen bonds and Cl center dot center dot center dot O/ Cl center dot center dot center dot Cl halogen bonds undertake a significant role in their 3D molecule packing, which have been further verified by the careful Hirshfeld surface analyses. Based on the deeply structural comparisons, it was supposed that conformational flexibility of 3,5,6-tcpa might be responsible for the cocrystallization of 1A and 1B. Besides, the magnetic determinations revealed weak antiferromagnetic interactions for intrachain cobalt(II) ions in 1B.

The widespread application of lithium-ion batteries (LiBs) has driven an increasing demand for advanced anodes with high-energy density and high-power density. Electroactive transition metal oxides (TMOs) are considered as promising candidates due to their high theoretical capacity. However, practical application has been hampered by their low conductivity and poor stability. In this study, tin-doped Co3O4 porous nanoarrays were successfully assembled on stainless steel mesh (SSM) using Co/Sn bimetallic organic frameworks as precursors. The resulting (Co/Sn)3O4@SSM was employed as a free-standing anode for LiBs. The lattice doping with tin atoms significantly enhances the internal conductivity of Co3O4, as confirmed by first-principle calculations. Benefiting from its hybrid advantages, such as a binder-free porous architecture and the improved conductivity, (Co/Sn)3O4@SSM exhibits dramatically enhanced energy storage capability, including high specific capacity, excellent cycling stability, and superior rate performance.

Abstract A new cobalt(II) compound with the formula [Co(5-Br-pyc)(2,2′-bipy)(H2O)(Cl)]·2H2O (1·H2O) (5-Br-Hpyc = 5-bromo-pyridine-2-carboxylic acid, 2,2′-bipy = 2,2′-bipyridine) has been hydrothermally synthesized and well characterized. The X-ray single-crystal diffraction analysis showed that 1⋅2H2O has crystallizes in the monoclinic system, space group P21/c (no. 14). The Co(II) center was octahedrally bonded by one bidentate chelate 5-Br-pyc anion and one 2,2′-bipy, one water molecule as well as one chloride anion to form the mononuclear structure of 1⋅2H2O. Complex 1⋅2H2O forms a 3D network through abundant O–H⋅⋅⋅O hydrogen bonds and π⋅⋅⋅π stacking interactions. Notably, the 5-Br-Hpyc ligand was in situ generated by decarboxylation of the 3-bromo-pyridine-2,6-dicarboxylic acid (3-Br-H2pydc) precursor selectively on 2-position under hydrothermal conditions. The magnetic properties, the Hirshfeld surface structure and the synthetic process for 1⋅2H2O have been carefully described and discussed.

Two pairs of cobalt(II) complexes with formulas of [Co(3,5,6-tcpa)(2,2’-bipy)Cl] (1A), [Co(3,5,6-tcpa)2(2,2’-bipy)]n (1B), [Co(3,5,6-tcpa)2(4,4’-bipy)(EtOH)]n (2A) and [Co(3,5,6-tcpa)2(4,4’-bipy)(EtOH)2]n (2B) have been cocrystallized by the solvothermal reaction of cobalt chloride hexahydrate with triclopyr (2-((3,5,6-trichloropyridin-2-yl) oxy)acetic acid, 3,5,6-Htcpa) and 2,2’-bipyridine (2,2’-bipy) or 4,4’-bipyridine (4,4’-bipy) coligands. Single-crystal X-ray diffraction analysis indicated that both 1A and 1B crystallized in triclinic system, space group P (no. 2). Compound 1A is mononuclear and 3,5,6-tcpa anion in it is a bidentate chelate ligand, while 1B is a 1D double-stranded chain structure in which 3,5,6-tcpa are bidentate bridging-μ2 linkers. In contrast, 2A has orthorhombic system, space group Aea 2(no. 41) and 2B showed monoclinic system, space group I2/a (no. 15). Complex 2A displays a 1D linear chain but 2B presents a zigzag chain, and 3,5,6-tcpa are both unidentate in them. The non-covalent interactions of Cl•••Cl/O halogen bonds, H•••O/Cl hydrogen bonds and/or π•••π stacking interactions play an important part in their crystal packing, which have been confirmed by the careful Hirshfeld surface analyses. It was proposed that flexible conformation alteration of 3,5,6-tcpa might be in charge of the cocrystallization phenomenon for 1A, 1B and 2A, 2B. The magnetic characterizations suggested antiferromagnetic coupling between neighbouring cobalt(II) centers both for 1B and 2B.

Abstract A new copper(II) complex [Cu(3,5,6-tcpa)(2,2′-bipy)Cl] (1) has been obtained through the one-pot hydrothermal reaction of copper chloride dihydrate with triclopyr (systematic name 2-((3,5,6-trichloropyridin-2-yl)oxy)acetic acid, abbreviation 3,5,6-Htcpa) and 2,2′-bipyridine (2,2′-bipy) coligands. 1 has crystallized in triclinic crystal system, P 1 ‾ $\overline{1}$ space group. The central copper(II) ion displayed a distorted square–pyramidal geometry and was connected by one chlorido co-ligand (Clˉ), one 3,5,6-tcpa anionic chelator and one chelating 2,2’-bipy ligand to afford a mononuclear structure. 1 is further extended into a 3D network by the non-covalent interactions of H⋯Cl, H⋯O hydrogen bonds, aromatic π⋯π stacking together with Cl⋯Cl halogen bond interactions. The co-crystallization process, the crystal structure of 1 as well as the Hirshfeld surface analysis for 1 have been analyzed and described. In addition, the flexible conformation of phenoxy methylene group among 1, triclopyr acid and its previously reported co-crystallized compound also have been carefully compared and discussed.

Two new discrete compounds with the formula [Ni(3,5,6-tcpa)(2,2 & PRIME;-bipy)Cl] (1) and [Ni-2(3,5,6-tcpa)(2)(2,2 & PRIME;- bipy)(2)(ox)].2EtOH (2) (3,5,6-Htcpa = 2-((3,5,6-trichloro pyridin-2-yl)oxy)acetic acid, 2,2 & PRIME;-bipy = 2,2 & PRIME;-bipyridine, ox = oxalate dianion) have been co-synthesized under solvothermal conditions in the same medium. Single-crystal X-ray diffraction analysis shows that both 1 and 2 have crystallized in triclinic system, space group P(1) over bar and the central Ni-II ions are both in deformed square-pyramids. The Ni-II ion in 1 was bonded by one chloride ion (Cl-), one bidentate chelate 3,5,6-tcpa anion and one 2,2 & PRIME;-bipy to give a mononuclear complex 1. While for 2, the Ni-II ion was coodinated with one monodentate 3,5,6-tcpa, one oxalate anion and one 2,2 & PRIME;-bipy. The oxalate anion linked two equivalent NiII ions to form the binuclear cluster 2. The Cl...Cl halogen bonds, pi...pi stacking interactions and/or O-H...O hydrogen bonds play an important part in the crystal packing for 1 and 2. Their deeply structural analyses revealed that the similar structure features and conformation alteration of 3,5,6-tcpa may be responsible for the cocrystallization phenomenon of 1 and 2. The magnetic measurements indicated the presence of intramolecular weak ferromagnetic coupling with J = 1.02 cm(-1) in 2.

Through the hydrothermal reaction of cobalt(II) perchlorate hexahydrate with 5-bromo-6-methyl-pyridine-2-carboxylic acid (5-Br-6-Me-Hpyc) and 1,4-bis(4-pyridyl)benzene (1,4-bpb) coligands, a cobalt(II) complex [Co(5-Br-6-Me-pyc)2(H2O)]·2H2O (1) and an organic-inorganic adduct [H2(1,4-bpb)]·2ClO4 (2) have been co-synthesized in the same medium. Structural analyses indicated that the cobalt(II) ion in 1 is penta-coordinated by one water and two bidentate chelate 5-Br-6-Me-pyc anionic ligands to obtain an asymmetric mononuclear species. While in 2, the two pyridyl groups of 1,4-bpb acquire two protons forming a bivalent cation pyridinium, which combine two perchlorate anions via N–H⋯O hydrogen bonds to fabricate an interesting anion-cation supramolecular adduct 2. The magnetism for 1, fluorescence for 2 as well as the hirshfeld surface structures for them have been carefully described and discussed.

Heterostructured 8-MnO2/Fe2O3 nanoarrays layer-by-layer assembled on stainless-steel mesh was fabricated via a two-step hydrothermal synthesis. Compared to the corresponding individual phases such as 8-MnO2@SSM and Fe2O3@SSM, 8-MnO2/Fe2O3@SSM delivers a high initial discharge capacity of 1821 mAh g-1, and retain 1464 mAh g-1 after 200 cycles at 200 mA g-1, moreover, about 1135 mAh g-1 can still be achieved at 2.0 A g-1 after 500 cycles, demonstrating excellent long-term cycling performance. Furthermore, the composite demonstrates superior rate capability as well, about 503 mAh g-1 can be remained at a high current density of up to 10 A g-1. Besides a comprehensive contribution from electroactive 8-MnO2 and Fe2O3, the significantly enhanced performance is attributed to the unique porous structure and the heterointerfaces that would induce more active sites and improve electronic conductivity. This research reveals that 8-MnO2/Fe2O3@SSM is a promising anode material for advanced LIBs with high energy density and high power density.

Abstract Triclopyr ethyl ester (1) has been co-synthesized through one-pot solvothermal reaction and the crystal structure has been determined by single crystal X-ray structure analysis. The compound C18H16Cl6N2O6 crystallizes in the monoclinic crystal system, P21/c space group with unit-cell parameters: a = 4.9615(2) Å, b = 30.9297(14) Å, c = 15.9155(10) Å, β = 91.466(4)° and Z = 4. Each unit cell is composed of two discrete, similar but reversely arranged triclopyr ethyl ester organic molecules. In the 3D packing plot, 1 is further assembled into a network structure via rich Cl⋯Cl halogen bond interactions. In addition, the crystal structure, the flexible conformation of phenoxy methylene group of 1 has been carefully compared and discussed with those of triclopyr acid.

Four new binary complexes with 2-carboxyphenoxyacetic acid ligand (2-H2cpa), namely [Mn(2-cpa)(H2O)3] (0D-Mn), [Cu(2-cpa)(H2O)3] (0D-Cu), [Mn(2-cpa)(H2O)]n (1D-Mn) and [Cu(2-cpa)(H2O)]n (2D-Cu), have been successfully prepared and systematically characterized. Structure analyses indicated that 0D-Mn and 0D-Cu are isomorphous mononuclear species in which the 2-carboxyphenoxyacetate (2-cpa) is a tridentate chelate anionic ligand. 1D-Mn is a 1D zigzag chain structure formed by the tetradentate bridging chelate-μ2 coordination pattern of 2-cpa connecting adjacent MnII ions. While 2D-Cu is a 2D corrugated (4,4)-connected layer and 2-cpa adopts pentadentate double bridging chelate-μ3 coordination mode in it. The different synthetic conditions, crystal structures and conformation of 2-cpa in the above compounds have been carefully analyzed and the results revealed that the synthetic conditions and flexible conformation of 2-cpa may be responsible for the structural diversity of binary 2-cpa metal complex system. In addition, the magnetic measurements showed that between the neighbouring metal ions there are weak ferromagnetic exchange in 0D-Mn and 0D-Cu, but antiferromagnetic coupling in 1D-Mn and 2D-Cu, respectively.

Coordination nature in the structures between the heterocyclic sulfonic acid group and heavy metal atoms, structural optimization, their physical and chemical properties have been studied. Herein, a new compound [Hg2(P–SO3)(NO3)]n (1) has been synthesized via solvent volatilization method, according to which pyrazine sulfonic acid (P–SO3H) has been used as the major ligand, and nitrate has been used as the precursor. X-Ray single-crystal diffraction analysis demonstrates that 1 belongs to the Pca21 space group. Both pyrazine sulfonate and nitrate serve as chelate bridging linkers for the dimercury(I) ions (Hg22+or HgI–HgI) forming the 2D layer coordination polymer involved in further construction of the stable 3D network through the π–π stacking of pyrazine rings. Thermal stability and fluorescence properties of 1 have been closely studied.

Sulfonic acid groups with C3ν symmetry can coordinate with metal ions to produce multidimensional structures due to their flexible coordination modes. They can also penetrate into supramolecular structures through an intriguing bridging pattern and weak interactions. Herein, a novel heterocyclic sodium sulfonate supramolecular structure, namely [Na(Pyr-SO3)(H2O)]n where Pyr-SO3H is pyrazine sulfonic acid, is synthesized by utilizing NaBF4 to coordinate with the P–SO3H ligand through the solvent evaporation method. The single crystal X-ray diffraction (XRD) data indicate that the as-formed structure belongs to the Pbca space group. Additional properties are characterized by powder XRD, thermal analysis, and solid-state fluorescence. In particular, the introduction of a soft alkali metal ion can coordinate with the oxygen atom of the sulfonate ligand and form a Na–O bridging configuration that can not only significantly improve the pyrazine sulfonic acid ligand coordination ability, but also provide a reference for the extended study of functional sulfonate polymers in the future.