Hydrothermal Syntheses and Crystal Structures of Two New Three‐dimensional Coordination Polymers Based on 4‐Pyrid‐3‐ylbenzoic Acid

Two new coordination polymers [Co₂(pbc)₄(H₂O)]_n ( 1 ) and [Mn(pbc)₂] ( 2 ) (Hpbc = 4‐pyrid‐3‐ylbenzoic acid) were obtained by hydrothermal reaction and characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction. Compound 1 features a 3D network with a four‐connected 6⁶ net constructed from secondary building units of dinuclear cobalt. Compound 2 exhibits a six‐connected 4¹² · 6³ topology based on dinuclear manganese.     

A Three‐dimensional DyIII‐based Metal‐organic Framework: Smart Drug Carrier and Anti‐lung Cancer Activity

A 3D lanthanide metal‐organic framework (MOF) with the formula [Dy₂(L)₂(H₂O)₂]_n ( 1 ) (H₃L = biphenyl‐3,4′,5‐tricarboxylic acid) was synthesized under solvothermal conditions and structurally characterized by elemental analysis, powder X‐ray diffraction analysis, infrared spectroscopy, and single‐crystal X‐ray diffraction analysis. Compound 1 features a 3D porous framework based on 1D rod‐shaped Dy^III‐carboxylate chains. The efficient encapsulation and controllable release of an anticancer drug (5‐Fu) make it a promising drug delivery host. Furthermore, the GCMC simulation was used to probe the drug‐framework interaction at the atomic lever. The in vitro anti‐lung cancer activity of 1 and 5‐Fu loaded 1a were also evaluated using MTT assay.     

One‐ and Two‐Dimensional PbII Complexes Constructed from N‐Donor Chelating Ligands with Extended π‐System and Organic Dicarboxylates

Two new coordination polymers [Pb(TIP)(1,3‐bdc)]_n ( 1 ) and [Pb(Dpq)(fum)]_n ( 2 ) (TIP = 2‐(2‐thienyl)imidazo[4,5‐f]1,10‐phenanthroline, Dpq = dipyrido[3,2‐d:2′,3′‐f]quinoxaline, 1,3‐H₂bdc = benzene‐1,3‐dicarboxylic acid, fum = fumaric acid) were synthesized by hydrothermal reactions and were characterized by elemental analyses, IR spectroscopy and single‐crystal X‐ray diffraction. Complex 1 is a one‐dimensional (1D) chain, which is bridged by 1,3‐bdc ligands. This is further extended into a three‐dimensional (3D) supramolecular structure by hydrogen bonding interactions. Compound 2 exhibits a two‐dimensional (2D) network structure, which is further stacked by π–π interactions to form a 3D supramolecular framework. The most important feature of these two complexes is that the N‐donor ligands with an extended π‐system play a crucial role in the formation and stabilization of the final supramolecular frameworks. Moreover, the fluorescence property of complex 1 was also investigated in the solid state at room temperature.     

Two Zinc(II) Coordination Polymers Based on Terphenyl‐2,2′,4,4′‐tetracarboxylate and Dipyridyl Ligands: Syntheses,Crystal Structures,and Luminescent Properties

Two coordination polymers, {[Zn₂(L)(bpy)] · 2H₂O}_n ( 1 ) and [Zn₂(L)(bpe)]_n ( 2 ) [H₄L = terphenyl‐2,2′,4,4′‐tetracarboxylic acid, bpy = 4,4′‐bipyridine, and bpe = 1,2‐bis(4‐pyridyl)ethane], were hydrothermally synthesized under similar conditions and characterized by elemental analysis, IR spectroscopy, TGA, and single‐crystal X‐ray diffraction analysis. Compound 1 has a 3D framework containing Zn–O–C–O–Zn 1D chains. Compound 2 exhibits a 3D framework, which features tubular channels. The channels are occupied by bpe molecules. The differences in the structures demonstrate that the auxiliary dipyridyl‐containing ligand has a significant effect on the construction of the final framework. Additionally, the fluorescent properties of the two compounds were also studied in the solid state at room temperature.     

Three Coordination Polymers based on 3,5‐Bis(imidazole‐1‐yl)pyridine and Benzoic Acid: Synthesis,Crystal Structures and Photoluminescent Properties

Three metal coordination polymers {[Co(L)₂(H₂O)₂]²⁺ · 2NO₃^–}_n ( 1 ), {[Mn(L)₂(H₂O)₂]²⁺ · 2Cl^– · 3H₂O}_n ( 2 ), and [ZnL(ba)₂]_n ( 3 ) [L = 3,5‐bis(imidazole‐1‐yl)pyridine and Hba = benzoic acid] were synthesized and structurally characterized by IR spectroscopy, elemental analysis, X‐ray powder diffraction, and X‐ray single crystal diffraction. Complex 1 shows a one‐dimensional (1D) chain structure. Adjacent chains are connected by hydrogen bonding and nitrate groups to form a 3D network. Complex 2 features a 2D layer structure. A three‐dimensional network is constructed through the cluster consisting of two chloride ions and three water molecules. Complex 3 shows a 1D zigzag chain structure that further twists together to form a 3D network. The X‐ray powder diffraction patterns were compared with the simulated ones. Moreover, the luminescent properties of 1 – 3 were investigated in the solid state at room temperature, and the thermogravimetric analyses were carried out to study the thermal stability of the three complexes.     

Tetranuclear and One‐dimensional Cobalt Complexes with 5‐tert‐Butyl Isophthalic Acid and Chelating Neutral Ligands

Two new Co^II coordination polymers [Co₄(tbip)₄(bipy)₄(H₂O)₄] ( 1 ) and [Co(tbip)(phen)(H₂O)] · H₂O ( 2 ) (H₂tbip = 5‐tert‐butyl isophthalic acid, bipy = 2,2′‐bipyridine, phen = 1,10‐phenanthroline) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction. Compound 1 is a tbip‐bridged tetranuclear cobalt(II) complex, which is further linked by hydrogen bonds to form a supramolecular network. Compound 2 shows a tbip‐bridged linear chain structure, which is extended by hydrogen bonds to generate a double chain. Magnetic measurements show that there are weak ferromagnetic interactions between the adjacent Co^II ions in 1 .     

Structures and Properties of Three Solvent‐Dependent Chiral Compounds Based on N‐Benzoyl‐L‐glutamic Acid

Three solvent‐dependent chiral copper(II) compounds, {[Cu₂(bzgluO)₂(H₂O)₂]·4H₂O}_n ( 1 ), {[Cu₂(bzgluO)₂(DMSO)₂]·H₂O}_n ( 2 ) and [Cu₂(bzgluO)₂(DMF)₂]_n ( 3 ) (H₂bzgluO=N‐benzoyl‐L‐glutamic acid) have been synthesized under ambient temperature conditions and characterized by elemental analysis, IR spectra, UV spectra, thermogravimetric analysis, powder X‐ray diffraction (PXRD) and single‐crystal X‐ray diffraction. Compounds 1 and 2 both crystallize in the orthorhombic space group P2₁2₁2₁. Compound 3 crystallizes in the tetragonal space group P4₃. Compound 1 exhibits a ladder‐like 1D chain structure, which is extended by hydrogen‐bonding interactions to form a 3D supramolecular network. Compounds 2 and 3 both give a diamond‐like 3D structure. Besides, there are hydrogen‐bonding interactions in 2 . The structural difference indicates that the solvent system plays a crucial role in modulating structures of coordination compounds. Circular dichroism (CD) and the magnetic properties of the compounds have also been investigated.     

Coordination Frameworks based on 3,5‐Bis(imidazole‐1‐yl)­pyridine and Aromatic Dicarboxylate Ligands: Synthesis,Crystal Structures,and Photoluminescent Properties

Three metal coordination polymers [Zn(bdc)(L)(H₂O)]_n ( 1 ), [Co(pta)(L)(H₂O)₂]_n ( 2 ), and [Cd(tda)(L)(H₂O)]_n ( 3 ) [H₂bdc = 1,2‐benzene dicarboxylate acid, H₂pta = terephthalic acid, H₂tda = 2,5‐thiophenedicarboxylic acid, L = 3,5‐bis(imidazole‐1‐yl)pyridine] were synthesized and structurally characterized by IR spectroscopy, elemental analysis, X‐ray powder diffraction, and X‐ray single crystal diffraction. Complex 1 shows a three‐dimensional (3D) structure with cco topology with the symbol 6⁵ · 8, whereas complex 2 features a 3D structure with cds topology with the symbol 6⁵ · 8. Complex 3 has a 2D network constructed by the cadmium atoms bridged through the ligands tda and L. Their X‐ray powder diffraction patterns were compared with the simulated ones. Moreover, their luminescent properties were investigated in the solid state at room temperature, and the thermogravimetric analyses were carried out to study the thermal stability of the 3D networks.     

Two Zinc(II) Coordination Polymers Based on the Ligand 1, 4‐Bis[(2‐methyl‐imidazol‐1‐yl)methyl]benzene: Syntheses,Crystal Structures and Properties

Two coordination polymers (CPs), {[Zn₂(BMB)(5‐AIPA)₂] · 2H₂O}_n( 1 ) and [Zn(BMB)(5‐NIPA)]_n( 2 ) {BMB = 1, 4‐bis[(2‐methyl‐imidazol‐1‐yl)methyl]benzene, 5‐AIPA = 5‐aminoisophthalic acid, 5‐NIPA = 5‐nitroisophthalic acid}, were synthesized under hydrothermal conditions. Compound 1 displays a 2D double‐layer structure, which is packed into a 3D supramolecule by interlayer hydrogen bonds and π–π stacking interactions. Compound 2 displays a threefold interpenetrating 3D network, which is composed of left‐handed helical chains and two types of meso‐helical chains along different directions.     

pH Dependent Synthesis of Two Manganese Compounds based on 5‐(2‐Pyrimidyl)tetrazole‐1‐acetic Acid

Reactions of Hpymtza [Hpymtza = 5‐(2‐pyrimidyl)tetrazole‐1‐acetic acid] with MnCl₂ · 4H₂O under different pH conditions, afforded the complexes [Mn(pymtza)₂(H₂O)₄] ( 1 ) and [Mn₂(pymtza)₂Cl₂(EtOH)] · H₂O ( 2 ). The compounds were structurally characterized by elemental analysis, IR spectroscopy and single‐crystal X‐ray diffraction. Compound 1 shows a mononuclear structure, whereas complex 2 has a 1D chain structure. In compound 1 , the pymtza ligand only acts in a monodentate manner to coordinate to one central Mn^II atom by one carboxylate atom, In 2 , pymtza acts as tetradentate ligand to connect three Mn^II ions. Compounds 1 and 2 display 3D networks by hydrogen bonding interactions. Furthermore, the luminescence properties of Hpymtza as well as compounds 1 and 2 were investigated at room temperature in the solid state.     

Two Coordination Polymers based on 2‐Ethyl‐1H‐imidazole‐4,5‐dicarboxylic Acid and 1,3‐Bis(4‐pyridyl)propane: Synthesis,Crystal Structures,and Photoluminescent Properties

Two coordination polymers, [Cd(Heidc)(bpp)]_n ( 1 ) and [Zn₃ (eidc)₂(bpp)(H₂O)₂] · 2H₂O}_n ( 2 ) (H₃eidc = 2‐ethyl‐4,5‐imidazole dicarboxylic acid, bpp = 1,3‐bis(4‐pyridyl)propane) were hydrothermally synthesized and characterized by elemental analysis, IR, spectroscopy single‐crystal X‐ray diffraction, and thermogravimetric analyses. Compound 1 features a 2D layer formed by C–H ··· π stacking interactions between adjacent chains, whereas compound 2 shows a 3D (8³)₂(8⁵.10)‐tfc framework constructed of the 2D (6,3) layer. The result demonstrates that the central metal atoms play a key role in governing the coordination motifs. Moreover, solid‐state properties such as thermal stabilities and photoluminescence of 1 and 2 were also investigated.     

Syntheses,Crystal Structures,and Luminescence Properties of Four Coordination Polymers Based on 1,3,5‐Tris (imidazol‐1‐yl)benzene

Based on the tripodal 1,3,5‐tris(imidazol‐1‐yl)benzene (tib) ligand, four transition metal coordination polymers, namely, {[Ni₃(tib)₂(H₂O)₁₂] · (SO₄)₃}_n ( 1 ), {[Co_1/6(tib)_1/3] · (O)_1/3}_n ( 2 ), and [M(tib)(hip)]_n (M = Mn for 3 , and M = Co for 4 ) (hip = 5‐hydroxyisophthalic acid), were synthesized through solvothermal method. Their structures were defined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses (EA), IR spectra, powder X‐ray diffraction (PXRD), and thermogravimetric analyses (TGA). Complex 1 displays a 2D 3‐connected (6³) hcb net. Complex 2 is a 2D (3,6)‐connected (4³)₂(4⁶.6⁶.8³) kgm net. Complex 3 and 4 present similar 2D 4‐connected (4⁴.6²) sql net. Moreover, the solid state luminescence properties of complexes 1 and 3 were investigated.     

Six Coordination Polymers based on 4‐(1H‐Imidazol‐1‐yl)phthalic Acid: Structural Diversities,Magnetism and Luminescence Properties

The coordination polymers (CPs), [Ni(L)(H₂O)₄]_n ( 1 ), [Co(HL)₂(H₂O)₂]_n ( 2 ), {[Cu(L)(H₂O)₃] · H₂O}_n ( 3 ), [Mn(L)(H₂O)₂]_n ( 4 ), [Cd(L)(H₂O)₂]_n ( 5 ), and {[Zn₂(L)₂] · H₂O}_n ( 6 ), were solvothermally synthesized by employing the imidazol‐carboxyl bifunctional ligand 4‐(1H‐imidazol‐1‐yl) phthalic acid (H₂L). Single‐crystal X‐ray diffraction indicated that the L^2–/HL^– ligands display various coordination modes with different metal ions in 1 – 6 . Complexes 1 and 2 show one‐dimensional (1D) chain structures, whereas complexes 3 – 6 show 2D layered structures. The magnetic properties of these complexes were investigated. Complexes 1 and 3 indicate weak ferromagnetic interactions, whereas complexes 2 and 4 demonstrate antiferromagnetic interactions. In addition, luminescence properties of 5 and 6 were measured and studied in detail.     

A new two‐dimensional ZnII coordination polymer based on 1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene and 5‐nitrobenzene‐1,3‐dicarboxylic acid: synthesis,crystal structure and physical properties

A novel two‐dimensional (2D) Zn^II coordination framework, poly[[μ‐1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene](μ‐5‐nitrobenzene‐1,3‐dicarboxylato)zinc(II)], [Zn(C₈H₃NO₆)(C₁₄H₁₄N₄)]_n or [Zn(NO₂‐BDC)(1,3‐BMIB)]_n [1,3‐BMIB is 1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene and NO₂‐H₂BDC is 5‐nitrobenzene‐1,3‐dicarboxylic acid], has been prepared and characterized by IR, elemental analysis, thermal analysis and single‐crystal X‐ray diffraction. Single‐crystal X‐ray diffraction analysis revealed that the compound is a new 2D polymer with a 6³ topology parallel to the (10) crystal planes based on left‐handed helices, right‐handed helical NO₂‐BDC–Zn chains and [Zn₂(1,3‐BMIB)₂]_n clusters. In the crystal, adjacent layers are further connected by C—H…O hydrogen bonds, C—H…π interactions, C—O…π interactions and N—O…π interactions to form a three‐dimensional structure in the solid state. In addition, the compound exhibits strong fluorescence emissions in the solid state at room temperature.     

Syntheses,Crystal Structures,and Fluorescence Properties of Two Transition Metal‐Organic Coordination Polymers Based on 4,4′‐Dimethyl‐2,2′‐bipyridine

Two transition metal‐organic coordination polymers, [Mn₂(1,3‐bdc)₂(Me₂bpy)₂] · Me₂bpy ( 1 ) and [Co(4,4′‐oba)(Me₂bpy)] ( 2 ) were hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, TG, and single‐crystal X‐ray diffraction [1,3‐H₂bdc = benzene‐1,3‐dicarboxylic acid, H₂oba = 4,4′‐oxybis(benzoic acid) Me₂bpy = 4,4′‐dimethyl‐2,2′‐bipyridine]. Compound 1 crystallizes in the orthorhombic system, space group P2₁2₁2₁, with a = 23.371(5), b = 14.419(3), and c = 14.251(3) Å. Compound 2 crystallizes in the monoclinic system, space group P2₁/c, with a = 7.4863(15), b = 18.272(4), c = 16.953(5) Å, and β = 107.44(3)°. The crystal structure of complex 1 is a wave‐like layer with central Mn²⁺ atoms bridged by 1,3‐bdc ligands, whereas the structure of compound 2 presents a ladder chain of hexacoordinate Co²⁺ atoms, in which the metal atoms are bridged by 4,4′‐oba ligands and decorated by Me₂bpy ligands. The two compounds are further extended into 3D supramolecular structures through π–π stacking interactions. Additionally, the compounds show intense fluorescence in solid state at room temperature.     

Pseudohalide‐directed Assembly of Two Zinc(II) Coordination Polymers with a 3,4‐Bis(3‐pyridyl)‐5‐(4‐pyridyl)‐1,2,4‐triazole Tecton

The zinc(II) pseudohalide complexes {[Zn(L³³⁴)(SCN)₂(H₂O)](H₂O)₂}_n ( 1 ) and [Zn(L³³⁴)(dca)₂]_n ( 2 ) were synthesized and characterized using the ligand 3,4‐bis(3‐pyridyl)‐5‐(4‐pyridyl)‐1,2,4‐triazole (L³³⁴) and ZnCl₂ in presence of thiocyanate (SCN^–) and dicynamide [dca, N(CN)₂^–] respectively. Single‐crystal X‐ray structural analysis revealed that the central Zn^II atoms in both complexes have similar octahedral arrangement. Compound 1 has a 2D sheet structure bridged by bidentate L³³⁴ and double μ_N,S‐thiocyanate anions, whereas complex 2 , incorporating with two monodentate dicynamide anions, displays a two‐dimensional coordination framework bridged by tetradentate L³³⁴ ligand. Structural analysis demonstrated that the influence of pseudohalide anions plays an important role in determining the resultant structure. Both complexes were characterized by IR spectroscopy, microanalysis, and powder X‐ray diffraction techniques. In addition, the solid fluorescence and thermal stability properties of both complexes were investigated.     

Observation of a Less Stable Conformer of N,N′‐Piperazine‐bis(methylenephosphonate) Ligand in a Six‐coordinated ­Samarium Phosphonate Framework

The three‐dimensional (3D) samarium phosphonate framework [Sm₂(H₂L)₃]_n · 5n(H₂O) ( 1 ) [H₄L = N,N′‐piperazine‐bis(methylenephosphonic acid)] was synthesized by hydrothermal reaction of Sm₂O₃ with N,N′‐piperazine‐bis(methylenephosphonic acid) hydrochloride in the presence of glutaric acid. Single‐crystal X‐ray diffraction analysis reveals that it has a 3D open framework structure with helical channels along the crystallographic c axis. The channels are filled up by discrete pentameric water clusters, which are hydrogen‐bonded to the host. Compound 1 displays two interesting structural features: (a) two of three H₂L^2– ligands adopt the less stable a,e‐cis conformation; (b) both of the Sm^III ions exhibit rather unusual octahedral coordination arrangements. In addition, the photoluminescent property was investigated.     

Hydrothermal Syntheses,Crystal Structures,and Luminescent Properties of Two Zinc(II) Coordination Polymers

Two zinc(II) compounds, namely [Zn₅(AmTAZ)₆(OH)₂]_n · 2n(NO₃) · 6n(H₂O) ( 1 ) and [Zn₃(AmTAZ)₂(mal)₂]_n ( 2 ) (HAmTAZ = 3‐amino‐1,2,4‐triazole, H₂mal = malonic acid), were hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, and X‐ray diffraction. Single crystal X‐ray diffraction analysis reveals that compound 1 features a 3D framework with dodecahedral cages occupied by free nitrate ions and lattice water molecules and can be reduced into a (4, 8)‐connected flu topological network. Compound 2 features a 3D framework based on two different 1D chains. Moreover, the thermal stabilities and luminescent properties of compounds 1 and 2 were investigated.     

Two 3D Polyoxometalate‐based Frameworks Constructed from Silver(I)‐triazole/tetrazole Units: Hydrothermal Syntheses,Crystal Structure and Properties

Two polyoxometalate‐based compounds constructed by Keggin/Ag/ L , namely [Ag₁₀( L₁ )₆(H L₁ )₂][HPMo₂^VMo^VI₁₀O₄₀] ( 1 ) and [Ag₁₀( L₂ )₈(H₂SiMo₁₂O₄₀)] ( 2 ) ( L₁ = 1,2,4‐1H‐triazole and L₂ = 1H‐tetrazole), were synthesized under hydrothermal conditions and characterized by single‐crystal X‐ray diffraction, elemental analyses, and IR spectroscopy. In compound 1 , the tetra‐nuclear Ag cycles constructed by four L₁ ligands, two Ag1 ions, and two Ag2 ions. Compound 1 exhibits a two dimensional (2D) metal‐organic layer containing adjacent tetra‐nuclear Ag cycles. Furthermore, the adjacent 2D layers are further extended by Ag ions to form a three dimensional (3D) channel‐like framework, with Keggin anions embedding in the channels. Compound 2 is isostructural with 1 . Additionally, the electrochemical and photocatalytic properties of the title compounds were investigated.     

Syntheses,Crystal Structures,and Photocatalytic Activities of Three Copper Coordination Polymers Based on Bis(1H‐imidazol‐4‐yl)benzene/3‐(2‐Pyridyl)pyrazole

Three copper(II) coordination polymers (CuCPs), namely, [Cu_0.5(1,4‐bib)(SO₄)_0.5]_n ( 1 ), {[Cu(1,3‐bib)₂(H₂O)] · SO₄ · H₂O}_n ( 2 ), and [Cu(bpz)(SO₄)_0.5]_n ( 3 ), were assembled from the reaction of three N‐donors [1,4‐bib = 1,4‐bis(1H‐imidazol‐4‐yl)benzene, 1,3‐bib = 1,3‐bis(1H‐imidazol‐4‐yl)benzene, and Hbpz = 3‐(2‐pyridyl)pyrazole] with copper sulfate under hydrothermal conditions. Their structures were determined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses (EA), IR spectroscopy, powder X‐ray diffraction (PXRD), and thermogravimetric analyses (TGA). Structure analyses reveal that complex 1 is a 3D 6‐connected {4¹² · 6³}‐ pcu net, complex 2 is a fourfold 3D 4‐connected 6⁶‐ dia net, whereas complex 3 is a 1D snake‐like chain, which further expanded into 3D supramolecular architectures with the help of C–H ··· O hydrogen bonds. Moreover, the photocatalytic tests demonstrate that the obtained CuCPs are photocatalysts in the degradation of MB with the efficiency is 86.4 % for 1 , 75.3 % for 2 , and 91.3 % for 3 after 2 h, respectively.