Syntheses and Crystal Structures of Two Apigenin Alkylation Derivatives

Abstract Two apigenin alkylation derivatives, 4′,7-dimethoxyl-5-hydroxyflavone (I) and 4′,7-diethoxyl-5-hydroxyflavone (II), have been synthesized and their crystal structures were determined by ¹H NMR and single crystal X-ray diffraction study. (I) is triclinic, space group P−1 with a = 7.120(5) ?, b = 7.297(5) ?, c = 13.559(10) ?, α = 89.313(12)°, β = 86.298(12)°, γ = 83.999(13)° and Z = 2. (II) is monoclinic, space group P 2₁ /c with a = 16. 309(4) ?, b = 7.303(2) ?, c = 15.185(4) ?, α = 90.00°, β = 115.70(2)°, γ = 90.00° and Z = 4. They have the same flavone skeleton which is composed of a benzopyranone moiety and a phenyl moiety. Molecules of (I) are linked into a two-dimensional network by a combination of C–H···O hydrogen bond and π–π stacking interactions. (II) shows some discrepancies with (I) and the molecules are linked into a column by π–π stacking interaction. Graphical Abstract Two apigenin alkylation derivatives, 4′,7-dimethoxyl-5-hydroxyflavone (I) and 4′,7-diethoxyl-5-hydroxyflavone (II) were synthesized and their crystal structures were determined by single-crystal X-ray diffraction. Hydrogen bonding and π–π stacking interactions assemble (I) into a two-dimensional network, and in the crystal structure of (II), π–π stacking interaction leads to the formation of a column.      

Syntheses and Crystal Structures of Two Ferrocenyl Dicarboximides

Abstract  

Reactions of 1,1′-ferrocenedicarboxylic chloride with 2-aminopyrimidine and 2-aminopyrazine produce organometallic dicarboximides I and II, respectively. They crystallize in space groups F dd2 and P2₁/c, respectively. The molecules of I lying on twofold rotation axes are linked into a B-faced sheet by a C–H···O=C hydrogen bond [H····O = 2.46, C···O = 3.163(7) ? and C–H···O = 132°]. The sheets are linked into a layered structure by two types of weak C–H···O=C hydrogen bonds [H···O = 2.71, C···O = 3.340(8) ? and C–H···O = 126°; H···O = 2.69, C···O = 3.303(10) ? and C–H···O = 124°]. The molecules of II are linked into a centrosymmetric R ₂²(12) dimer by a C–H···O hydrogen bond [H···O = 2.40, C···O = 3.321(10) ? and C–H···O = 172°]. The dimers are further packed along the a axis by a C–H···O hydrogen bond [H···O = 2.69, C···O = 3.416(9) ? and C–H···O = 135°] to give an [100] double-chain. The double-chain is packed in the [010] direction by a C–H···O=C hydrogen bond [H···O = 2.69, C···O = 3.532(9) ? and C–H···O = 150°]. Further the intermolecular C–H···N hydrogen bond involving the cyclopentadienyl group as a hydrogen-bond donor and pyrazine N atom as an acceptor [H···O = 2.71, C···N = 3.536(10) ? and C–H···N = 148°] leads to a three-dimensional framework structure.     

Syntheses and Crystal Structures of Two 2-Aminoisoflavones

Abstract  

2-Amino-7,4′-dimethoxyisoflavone (I), C₁₇H₁₅NO₄ and 2-amino-7-methoxy-4′-hydroxyisoflavone (II), C₁₆H₁₃NO₄ were synthesized and their crystal structures were determined by single-crystal X-ray diffraction. They all crystallize in the monoclinic crystal system, space group P21/c. The cell dimensions of I are a = 15.6673(17) ?, b = 7.3998(8) ?, c = 13.2919(14) ?, β = 111.4460(10)°, D _c = 1.377 mg/mm³, V = 1,434.3(3) A³, Z = 4 and those of II are a = 10.990(7) ?, b = 11.879(7) ?, c = 10.422(6) ?, β = 96.904(11)°, D _c = 1.393 mg/mm³, V = 1,350.8(14) A³, Z = 4. A combination of F-type and T-type aromatic–aromatic interaction and hydrogen bonding links the molecules of I into a tri-dimensional framework structure. In the crystal structure of II, paired tri-centered hydrogen bond generates a R₄²(21) ring and the R₄²(21) rings link the molecules into a sheet.     

Syntheses and Crystal Structures of New Unsymmetrical Tetrathiafulvalene-Based Amidoquinline Derivatives

Abstract  

Two new unsymmetrical tetrathiafulvalene-based amidoquinline derivatives of 8-amide quinline of PDT-TTF and BTTF (PDT = propylenedithio, TTF = tetrathiafulvalene, BTTF = benzotetrathiafulavalene) (6, 11) have been synthesized and characterized by ¹H NMR, MS, and X-ray crystal structural determination. The crystal structures determination shows that they have completely different solid-state constructs due to the different functional group on the side of tetrathiafulvalene group. The molecules of compound 6 are assembled into 1D helical chain along c-axis via hydrogen bond interactions; these helical chains are further connected by the transverse S⋯S van der Waals interactions, thus, resulting to form a layered architecture. The molecules of compound 11 are assembled into 1D chain along c-axis via hydrogen bond and the S⋯S van der Waals interactions. Structures analysis indicate that compound 6 belong to orthorhombic system, space group P2(1)2(1)2(1), with crystal data a = 6.140(7) ?, b = 12.628(14) ?, c = 23.707(3) ?, V = 1838.0(4) ?³, Z = 4, F(000) = 872, R ₁ = 0.0570, wR ₂ = 0.0910. Compound 11 belong to triclinic system, space group P-1, with crystal data a = 9.532 (2) ?, b = 10.194(2) ?, c = 10.848(3) ?, α = 79.980(5)°, β = 89.342(4)°, γ = 75.226(5)°, V = 1003.1(4) ?³, Z = 2, F(000) = 492, R ₁ = 0.0686, wR ₂ = 0.1656.     

Syntheses and Crystal Structures of Three Electron Poor N-Vinyltheophylline Derivatives

Abstract  

Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and alkyl acetylenecarboxylates (or dialkyl acetylenedicarboxylates) by theophylline leads to vinyltriphenylphosphonium salts, which undergo Michael addition reaction with conjugate base to produce phosphorus ylides. Silica gel was found to catalyze conversion of the phosphorus ylides to electron-poor N-vinyl imidazoles in solvent-free conditions under thermal (90 °C, 1 h) conditions. The structures of these compounds were confirmed by IR, ¹H, and ¹³C NMR spectroscopy, and single crystal X-ray structure determination. The structural analysis of the products indicated that the reaction is completely regio- and stereoselective.     

Syntheses,Crystal Structures and Fluorescence Properties of Zn(II) Complexes with Pyrazolone Derivatives

Abstract   N-(1,3-Diphenyl-4-benzal-5-pyrazolone)-salicylidene hydrazone(H₂L ¹ ) and its zinc complex Zn(HL ¹ )₂ · 2CH₃OH (1) have been synthesized and characterized by elemental analyses, IR spectra, thermal analyses and single-crystal X-ray diffraction studies. The X-ray diffraction analyses of the complex Zn(HL ¹ )₂ · 2CH₃OH (1) and the known compound Zn₄(L ² )₄ (2) (H₂L ²  = N-(1,3-diphenyl-4-phenylethylene-5-pyrazolone)-salicylidene hydrazone) show that different acyl groups in position 4 of pyrazolones may lead to the different coordination mode of the ligands and distinctive structures of the same central metal Zn(II) complexes, of which 1 is a mononuclear complex while 2 is a tetranuclear complex. Meanwhile, two Zn(II) complexes have different thermal stabilities and fluorescence properties. Graphical Abstract        

The Syntheses and Crystal Structures of Metronidazole-derived Compounds

Abstract Metronidazole (MET-OH), widely used as an antibacterial agent, is found to have some side effects on human bodies. Due to these disadvantages, people have been looking for its modification compounds for substituents. In this article, four MET-OH derivatives were designed, prepared, and structurally characterized by single crystal X-ray diffraction. These compounds are MET-OTs (1), MET-Br (2), MET-Cl (3), and MET-I (4). X-ray structure analyses revealed that, 1 crystallized in the monoclinic system with space group P2 ₁ /c, with a = 16.1178, b = 7.5473, c = 13.4161 ?, V = 1520.3 ?³, β = 111.3210^o and Z = 4. 2 crystallized in the monoclinic system with space group P2 ₁ /c, with a = 12.079, b = 11.089, c = 6.380 ?, V = 847.1 ?³, β = 97.57^o and Z = 4. 3 crystallized in the monoclinic system with space group P2 ₁ /c, with a = 12.098, b = 11.007, c = 6.295 ?, V = 830.3 ?³, β = 97.886^o and Z = 4. 4 crystallized in the triclinic system with space group P1, with a = 6.192, b = 7.740, c = 10.001 ?, V = 457.9 ?³, α = 89.073, β = 86.903, γ = 73.097^o and Z = 2. Index Abstract In this article, metronidazole-derived compounds were prepared and structurally characterized by single crystal X-ray diffraction      

Synthesis and Crystal Structures of Two Complexes with Carboxylic Derivatives of Nitrogen-containing Heterocycle Ligands

Abstract  

Two new complexes [Zn(pcn)₂(H₂O)₂] (1) and [Cd(inic)₂(H₂O)₄] (2) (pcn = 2-pyrazinecarboxylate, inic = isonicotinic acid) were synthesized by the hydrothermal reaction and characterized by single crystal X-ray diffraction, elemental analysis, IR spectrum and UV spectrum. In complex 1, the Zn(II) central ion is six-coordinated by two oxygen atoms and two nitrogen atoms from pcn ligands and two oxygen atoms from two coordinated water molecules. In complex 2, the Cd(II) central ion is six-coordinated by two nitrogen atoms from isonicotinate ligands and four oxygen atoms from the coordinated water molecules. Both complexes are mononuclear but hydrogen bonds enrich the structural construction. The visible spectra of the complexes between 200 and 300 nm are assigned to intraligand (IL) π–π* transitions of the pyridyl or pyrazine ligands.     

Synthesis,Crystal Structure and Biological Activity of Two 1,2,3-Thiadiazole Derivatives

Abstract  

The title compounds, quinolin-8-yl 4-methyl-1,2,3-thiadiazole-5-carboxylate 2a and 2-nitrophenyl 4-methyl-1,2,3-thiadiazole-5-carboxylate 2b, synthesized by the reaction of 4-methyl-1,2,3-thiadiazole-5-carbonyl chloride with 8-hydroxyquinoline and 2-nitrophenol, were confirmed by single-crystal X-ray diffraction [CCDC 783328 and 784970]. The 2a crystallizes in triclinic space group P-1 with cell parameters a = 7.957(7) ?, b = 8.378(7) ?, c = 10.097(10) ?, α = 100.63(2)°, β = 112.742(17)°, γ = 93.287(4)° and Z = 2. The 2b crystallizes in triclinic space group P-1 with cell parameters a = 7.134(4) ?, b = 8.154(4) ?, c = 10.254(5) ?, α = 99.501(9)°, β = 91.311(7)°, γ = 109.518(8)° and Z = 2. Packing in the compound 2a is dominated by weak C–H···N and C–H···O hydrogen bonds. In the compound 2b, molecules are linked through intermolecular C–H···O hydrogen bonds interactions. The preliminary bioassay showed that the title compound 2a had excellent antifungal activity with the EC₅₀ detected as from 2.99 to 28.35 μg/mL and the EC₉₀ detected as from 21.041 to 175.17 μg/mL. Both of the title compounds 2a and 2b had good inhibition activity of tobacco mosaic virus (TMV) and good induction activity of tobacco against TMV with potential systemic acquired resistance.