Syntheses, Crystal Structures and Antibacterial Activities of Cobalt(Ⅱ) and Manganese(Ⅱ) Complexes with Schiff Base Ligand Derived from Tryptamine

Two new mononuclear complexes, namely [Co（L）2]（1） and [Mn（L）2]（2）（HL = N-（3-methylsalicylidene）tryptamine）, have been synthesized by the reactions of the ligand with cobalt acetate or manganese acetate in anhydrous ethanol. The crystal structures of the complexes were characterized by IR spectrum, elemental analysis, PXRD and single-crystal X-ray diffraction analysis. Complex 1 crystallizes in monoclinic, space group C2/c, with a = 23.146（2）, b = 9.4864（10）, c = 13.9261（15）A, β = 102.898（2）°, V = 2980.6（5） ？3, Z = 4, Dc = 1.367 g/cm3, F（000） = 1284 and μ = 0.616 mm^-1. Complex 2 crystallizes in monoclinic, space group P21/n, with a = 14.807（11）, b = 13.118（10）, c = 16.663（13） A, β = 111.237（14）°, V = 3017（4） A^3, Z = 4, Dc = 1.342 g/cm^3, F（000） = 1276 and μ = 0.477 mm-1. The units of complex 1 are linked by intermolecular N–H…π hydrogen bonds into infinite 1D chains, which are further extended into a 3D supramolecular structure by a series of π···π stacking interactions. The units of complex 2 are linked by intermolecular N–H…π hydrogen bonds and C–H…π hydrogen bonds into an infinite 3D supramolecular structure. Meanwhile, the antibacterial activities of the ligand and its complexes have been tested against four kinds of bacteria. The results show that the three compounds all have excellent antibacterial activities and that 1 and 2 possess stronger inhibiting effects against the bacteria than the Schiff base.

Syntheses, Crystal Structures and Antibacterial Activities of Schiff Base Ligand and Its Nickel(Ⅱ) Complex

A complex [NIL2] was synthesized, in which L, or to be exact, a Schiff base ligand （HL）, was derived from the condensation of 1-phenyl-3-methyl-4-phenylacetyl-5-pyrazolone （PMPAP） with L-phenylalanine methyl ester. They were characterized by IR and single-crystal X-ray diffraction. Green block crystals of both ligand and its complex were grown at room temperature. The ligand, which consists of two individual fragments, crystalizes in the P1 space group （a = 5.6268（5）, b = 10.6892（11） and c = 19.4869（18） A）. The complex crystalizes in the P21 space group （a -- 21.4076（18）, b = 9.4792（8） and c = 25.287（2） A）, which consists of a nickel six-coordinated compound. Every fragment is a distorted octahedron with four oxygen and two nitrogen atoms. The Schiff base ligand （HL） and its complex have been tested in vitro to evaluate their antibacterial activity against bacteria Escherichia Coli and Bacillus subtilis. It is found that the complex has higher activity than the corresponding free Schiff base ligand （HL） against the same bacterial.

Syntheses, Characterizations, Crystal Structures and Antibacterial Activities of Two Zinc(II) Complexes with a Schiff Base Derived from o-Vanillin and p-Toluidine

Two new zinc（Ⅱ） complexes, [Zn2L2Ch].2[ZnL（CH3OH）Cl2] 1 and [ZnL2（NO3）2] 2, were synthesized by reacting ZnX2.nH2O （X = Cl^-, NO3^-） and a Schiff base ligand 2-[（4-methylphenylimino）methyl]-6-methoxyphenol （C15HIsNO2, L） which was obtained by the condensation of o-vanillin （2-hydroxy-3-methoxybenzaldehyde） with p-toluidine. Both 1 and 2 were characterized by single-crystal X-ray diffraction technique, elemental analysis, molar conductance, FT-IR, UV-Vis, IH-NMR spectra and thermogravimetrie analysis. The Schiff base ligand and its zinc（Ⅱ） complexes have been tested in vitro to evaluate their antibacterial activity against bacteria, viz., Escherichia Coli, Staphylococcus aureus and Bacillus Subtilis. The results show that these complexes have higher activity than the corresponding free Schiff base ligand against the same bacteria.

Syntheses, Crystal Structures and Antibacterial Activities of Two Heterocyclic Schiff Base Compounds

Two heterocyclic Schiff bases were synthesized via the condensation reactions of primary amines with carbonyl compounds. 2-[（4-pyridylmethylene）-amino] phenol （compound 1） was synthesized by the interaction of 4-pyridinecarboxaldehyde with o-aminophenol in ethanol solvent; N,N＇-bis（3-（furan-2-yl）allylidene）benzene-1,4-diamin （compound 2） was synthesized by the interaction of 3-（2-furyl）acrolein with p-phenylenediamine in ethanol medium. The compounds were characterized by elemental analysis, IR, MS and single-crystal X-ray diffraction. Compound 1 （C12H10N2O） crystallizes in the monoclinic system, space group P21/c with α = 7.0771（7）, b = 7.2820（7）, c = 19.849（2）, b = 96.3390（10）°, V = 1016.66（17） ？3, Z = 4, Mr = 198.22, Dc = 1.295 g/cm3, F（000） = 416, GOOF = 1.060, m = 0.085 mm-1, the final R = 0.0371 and wR = 0.0929 for 1497 observed reflections with I 〉 2σ（I）. Compound 2 （C20H16N2O2） crystallizes in the orthorhombic system, space group Fdd2 with α = 26.344（15）, b = 48.50（3）, c = 5.293（3）, V = 6764（7） ？3, Z = 16, Mr = 316.35, Dc = 1.243 g/cm3, F（000） = 2656, GOOF = 1.043, m = 0.081 mm-1, the final R = 0.0526 and wR = 0.1267 for 2059 observed reflections with I 〉 2σ（I）. 1 and 2 molecules are connected through hydrogen bonds to generate a 2D network and a 1D chain structure, respectively. The preliminary antibacterial activity results showed that the title compounds display excellent antibacterial activities to Escherichia coli, Staphylococcus aureus and Bacillus subtilis.

Synthesis,Crystal Structure,and Antioxidant and Antibacterial Activities of3,5-Dihydroxy-N'-(4-nitrobenzylidene)benzohydrazide

A new compound, 3,5-dihydroxy-N＇-（4-nitrobenzylidene）benzohydrazide （I）, has been synthesized and characterized by single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group P21/c with a = 9.632（12）, b = 12.256（15）, c = 11.425（14） A, β = 105.306（11）°, Z = 4, V = 1301（3） A3, Dc = 1.538 g/cm3, F（000） = 704,μ = 0.276 and S = 1.011. The final R = 0.0444 and wR = 0.1186 for 3808 observed reflections with I〉 20（I）. We used methods such as ABTS, DPPH assays and in vitro hydroxyl radical scavenging experiment to assess the in vitro antioxidant activity of the new compound, and found that its IC50 value was 48.59 μg/mL for scavenging ABTS radicals, 48.04 μg/mL for scavenging DPPH radicals, and 1.03 mg/mL for scavenging hydroxyl radicals, indicating that it had a good in vitro antioxidant activity. We also test the antibacterial activities of this compound against three bacteria, and it showed considerable antibacterial activity against S.aureus. The MIC values of S.aureus, K.pneumoniae and P. aeruginosa are respectively 0.156, 0.625 and 1.25 mg/mL.

Synthesis, Crystal Structure and Antibacterial Activity of Two Hydrazones Derived from 2-Fluorobenzhydrazide

Two new Schiff base benzoyl hydrazone compounds, C14H10FN3O3 （Ⅰ） and C14H10F2N2O （Ⅱ）, have been synthesized and characterized by elemental analysis, IR, UV and X-ray single-crystal diffraction. Both compounds crystallize in monoclinic, space group P21/c with a = 7.0514（14）, b = 25.928（5）, c = 7.7099（15）, β = 111.823（2）°, V = 1308.6（4）3, Z = 4, C14H10FN3O3, Mr = 287.25, Dc = 1.458 g/cm3, μ（MoKα） = 0.115 mm-1, F（000） = 592, the final R = 0.0841 and wR = 0.2489 for 1901 observed reflections （I 2σ（I）） for I; a = 11.232（3）, b =12.735（4）, c = 8.612（2） , β = 90.869（3）°, V = 1231.7（6）3, Z = 4, C14H10F2N2O, Mr = 260.24, Dc = 1.403 g/cm3, μ（MoKα） = 0.111 mm-1, F（000） = 536, the final R = 0.0453 and wR = 0.1085 for 1317 observed reflections （I 2σ（I）） for Ⅱ. The antibacterial activities of both compounds against two bacteria were first studied and one compound showed considerable antibacterial activity against K. Pneumonia and S. aureus.

Synthesis, Crystal Structure and Antibacterial Activity of 4,4'-Hydrazine-1,2- diylidenebis(methanylylidene)bis(2-ethoxyphenol)

A new Schiff base compound, 4,4′-hydrazine-1,2-diylidenebis（methanylylidene）- bis（2- ethoxyphenol） （C18H20N2O4）, has been synthesized by the condensation of 3-ethoxy-4- hydroxybenzaldehyde and 80% hydrazine hydrate in an ethanol solution. The compound was characterized by 1H NMR, MS and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/n with a = 5.2421（5）, b = 10.3700（8）, c = 14.9906（11）A, β = 97.6030（10）°, Z = 2, V= 807.73（12） A, Dc = 1.350 g/cm3, Mr = 328.36, λ（MoKa） = 0.71073 A,μ = 0.096 mm-1, F（000） = 348, R = 0.041 and wR = 0.0136. The two benzene rings are coplanar. The molecule adopts an E,E configuration about the central C=N functional bonds. A total of 3938 unique reflections were collected, of which 1440 with I 〉 2σ（I） were observed. A different type of intermolecular hydrogen bond, O-H…N, exists in the crystal. The title complex molecules are connected through hydrogen bonds to generate a two-dimensional network. The preliminary antibacterial activity results showed that the title compound exhibits antibacterial activity against Staphylococcus aureus.

Synthesis and Crystal Structure of Isonicotinic Acid [1-(3,5-Dibromo-2- hydroxyphenyl)methylidene]hydrazide Methanol

A new Schiff base compound, C13H9Br2N3O2CH3OH, isonicotinic acid [1-（3,5- dibromo-2-hydroxyphenyl）methylidene]hydrazide methanol, has been synthesized and characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. The compound comprises a Schiff base moiety isonicotinic acid [1-（3,5-dibromo-2-hydroxyphenyl） methylidene]hydrazide and a methanol molecule. The crystal belongs to the triclinic system, space group P1 with a = 8.464（1）, b = 9.511（2）, c = 10.901（2）A, a = 92.940（2）, β = 110.456（2）, y = 96.040（2）°, Z= 2, V= 814.0（2）A^3, Dc = 1.759 g/cm^3, Mr = 431.09, λ（MoKa） = 0.71073A, μ = 4.994 mm^-1, F（000） = 424, R = 0.0440 and wR = 0.1061. A total of 3284 unique reflections were collected, of which 2197 with I 〉 20（I） were observed. The molecule adopts a trans configuration about the C=N double bond. The dihedral angle between the benzene and pyridine rings is 22.0（4）°. The crystal structure is stabilized by intermolecular O-H…N and C-H…O hydrogen bonds, forming layers parallel to the ac plane. The preliminary biological tests show that the compound has potential antibacterial activities.

Synthesis and Crystal Structure of 4-[(1E)-(4-Hydroxy-3,5-dimethoxybenzylidene)-amino]-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-one

The title compound （C20H21N3O4, Mr = 367.40） has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is of orthorhombic, space group P212121 with a = 7.5143（15）, b = 13.901（3）, c = 18.545（4）A , V = 1937.1（7） A^3, Z = 4, Dc = 1.260 g/cm^3, μ = 0.089 mm^-1, F（000） = 776, the final R = 0.0616 and wR = 0.0912. X-ray diffraction reveals that the molecule adopts an E configuration about the central C=N double bond. The intermolecular O-H…O hydrogen bond stabilizes the crystal structure by causing the formation of a supramolecular architecture.

Synthesis and Crystal Structure of 2-Hydroxybenzoic Acid [1-(3,5-Dibromo-2-hydroxyphenyl)methylidene]hydrazide Methanol

A new Schiff base compound, 2-hydroxybenzoic acid [1-（3,5-dibromo-2-hydroxyphenyl） methylidene]hydrazide methanol （C14H10Br2N2O3·CH3OH）, has been synthesized by the condensation of equimolar 3,5-dibromosalicylaldehyde and 2-hydroxybenzoic acid hydrazide in a methanol solution. The compound was characterized by elemental analysis, IR spectra, and singlecrystal X-ray diffraction. The compound consists of a Schiff base moiety 2-hydroxybenzoic acid [1-（3,5-dibromo-2-hydroxyphenyl）methylidene]hydrazide and a lattice methanol molecule. The crystal belongs to the monoclinic system, space group P21/n with a = 7.183（1）, b = 15.673（2）, c = 15.001（2） A, β = 98.345（2）°, Z = 4, V = 1670.9（4） A^3, Dc = 1.773 g/cm^3, Mr = 446.10, λ（MoKα） = 0.71073 , μ = 4.872 mm^-1, F（000） = 880, R = 0.0458 and wR = 0.0963. A total of 3445 unique reflections were collected, of which 2236 with I 〉 2σ（Ⅰ） were observed. As expected, the molecule adopts a trans configuration about the C=N double bond. The two benzene rings are nearly coplanar （mean deviation from the combined plane is 0.061（4） ）, with the dihedral angle of 7.9（3）°. The preliminary biological tests show that the compound has moderate antibacterial activities.

Synthesis and Crystal Structure of 4-{[(1E)1-(2-Hydroxy-3-methoxyphenyl)methylidene]amino}-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-one

The title Schiff base compound, C19H19N3O3, a derivative of antipyrine, has been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group C2/c, with α = 27.935（5）, b = 7.553（1）, c = 16.692（3） A, β = 105.810（3）°, Z = 8, V= 3388.7（10） A^3, Dc = 1.323 g/cm^3, Mr = 337.37, λ（MoKα） = 0.71073 A,μ= 0.091 mm^-1, F（000） = 1424, R = 0.0630 and wR = 0.1273. A total of 3513 unique reflections were collected, of which 2112 with I 〉 2σ（I） were observed. The molecular structure adopts a trans configuration about the C=N double bond. The pyrazoline and C（1）-C（6） phenyl ring are approximately coplanar （mean deviation from the combined plane is 0.069（3） A）, with the dihedral angle of 9.7（2）°. The preliminary biological tests show that the compound has high antibacterial activities.

Synthesis and Crystal Structure of (E)2-(3′-Bromo-5′-chloro-salicylidene amino)-4-methyl Pyridine

A new Schiff base compound, 2-bromo-4-chloro-6-[（4-methylpyridin-2-ylimino）methyl]phenol （C13H10BrClN20）, has been synthesized by the condensation of equimolar 3-bromo-5- chlorosalicylaldehyde and 4-methylpyridin-2-ylamine in a methanol solution. The compound was characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21 with a = 6.048（3）, b = 14.063（7）, c = 7.623（4） A,β = 97.703（7）°, Z = 2, V = 642.5（6）A3, Dc = 1.683 g/cm3, Mr=325.59, 2（MoKa） = 0.71073A,μ = 3.395 mm^-1, F（000） = 324, R = 0.0370 and wR = 0.0662. A total of 3879 reflections were collected, of which 1970 with I 〉 2σ（I） were observed. As expected, the molecule adopts a trans configuration about the C=N double bond. The benzene and pyridine rings are nearly coplanar （mean deviation from the combined plane is 0.031（3）A）, with their dihedral angle of 3.3（3）°. The preliminary biological tests show that the compound has excellent antibacterial activities.

Synthesis and Crystal Structure of 3-{[(1E)1-(2-Hydroxyphenyl) methylidene]amino}-4-cyanopyrazole

The title Schiff base compound （C11H8N4O）, a derivative of pyrazole, has been synthesized by the reaction of salicylaldehyde and 3-amino-4-cyanopyrazole in absolute ethanol and characterized by elemental analyses, IR, ^1H NMR and X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P21/n, with a = 7.5594（7）, b = 18.3342（19）, c = 22.461（2） A^°, β = 98.419（2）°, V = 3079.5（5） A^°3, Mr = 212.21, Z = 12, F（000） = 1320, Dc = 1.373 g/cm^3, T = 298（2） K, 2 = 0.71073 A^°, the final R = 0.0571 and wR = 0.0493. A total of 5412 unique reflections were collected, of which 1612 with I 〉 2σ（I） were observed. The molecular structure adopts a trans configuration about the C=N double bond. The preliminary biological tests show that the compound has high antibacterial activities.

Synthesis,structural characterization and antibacterial activity of diorganotin(Ⅳ) complexes with ONO tridentate Schiff bases containing pyridine ring

Five organotin（IV） complexes, were obtained by reaction of SnR2C12 （R = Ph, Me, Bu） with ONO donor Schiff bases. The synthesized complexes have been investigated by elemental analysis and IR, 1H NMR, and ll9Sn NMR spectroscopy. These data show that the Schiff base acts as a tridentate dianionic ligand and coordinates via the imine nitrogen and two oxygen atoms. The X- ray crystallography of complex 4 shows a dimeric structure for this molecule. The in vitro antibacterial activities of the Schiff bases and their complexes have been evaluated against Gram-positive （Bacillus subtilis and Staphylococcus aureus） and Gram-negative （Escherichia coli and Pseudomonas aeruginosa） bacteria and compared with the standard antibacterial drugs.

Synthesis, Molecular Structure and Antibacterial Activity of 1-(4-Methoxybenzaldehyde)-4-Methylthiosemicarbazone

A novel ligand, 1-(4-methoxybenzylidene)-4-methylthiosemicarbazone (MBT) derived from 4-methoxybenzaldehyde was synthesized and characterized by spectroscopic methods (IR, 1H NMR, 13C NMR), single crystal X-ray diffraction technique and physical means. MBT showed antibacterial activity in vitro with MICs of 64 μg/mL (a strain of Salmonella typhi (ATCC 6539)), 128 μg/mL (Salmonella typhi), 64 μg/mL (Salmonella paratyphi A), 128 μg/mL (Salmonella paratyphi B) and 64 μg/mL (Salmonella typhimurium). The results showed that MBT demonstrated moderate in vitro antibacterial activity against a strain of Salmonella typhi (ATCC 6539), Salmonella paratyphi A, and Salmonella typhimurium, indicating its promise as a possible lead for the discovery of antibacterial drugs.

邻香兰素缩对甲苯胺Schiff碱过渡金属配合物的合成、表征、晶体结构及抗菌活性研究(英文)

合成了邻香兰素缩对甲苯胺Schiff碱HL(C15H15NO2)与锰(Ⅱ),锌(Ⅱ)的配合物[Mn(HL)3(CH3OH)](ClO4)2(1)和[Zn(HL)2(H2O)2](ClO4)2(2)。用元素分析、红外光谱、紫外-可见光谱、1HNMR核磁共振、摩尔电导等手段进行表征;用单晶X-射线衍射方法测定了配合物的晶体结构,配合物的中心金属离子与Schiff碱配体中的酚羟基氧及甲氧基氧发生配位,锰(Ⅱ)的配位数为7,而锌(Ⅱ)的配位数为6。测定了配体和配合物对大肠杆菌、金黄色葡萄球菌、枯草杆菌的抗菌活性。

六种乙酰甲喹衍生物的合成及抗菌活性研究

以乙酰甲喹和取代伯胺为原料,设计、合成了一系列含有席夫碱片段的衍生物,其中四种为新化合物,结构经^(1)H-NMR、^(13)C-NMR和高分辨率质谱表征。首次通过单晶结构证明了选择性还原产生副产物3-乙酰基-2-甲基喹喔啉-1-氧化物的结构。体外抗菌活性结果表明,目标化合物对金黄色葡萄球菌、枯草芽孢杆菌、大肠埃希菌、铜绿假单胞菌等抗菌活性较差,但部分目标化合物在人工胃液中的水解物抗菌活性明显优于乙酰甲喹。

氨基酸席夫碱镍、钴配合物的合成、晶体结构与抑菌活性

合成了1-苯基-3-甲基-4-对氯苯甲酰基-5-吡唑啉酮缩L-苯丙氨酸甲酯Schiff碱Ni(Ⅱ)、Co(Ⅱ)配合物[NiL_2](CH_3OH)(1)和[CoL_2](CH_3OH)(2)。用元素分析、红外光谱和X-射线单晶结构进行了表征,配合物1和2的晶体结构都同时含有两个独立子单元及一个游离的甲醇分子,各子单元都形成六配位的八面体结构。采用琼脂扩散法测定了配体和配合物对大肠杆菌、金黄色葡萄球菌抗菌活性,结果表明配合物2对大肠杆菌的抑制作用最强。

钾的配合物C_9H_(10)KNO_4S的合成、晶体结构及生物活性

The title complex was synthesized by the reaction of taurine 、salicylic and potassium hydrate in water ethanol solution. The crystal structure was determined by X ray diffraction method and the chemical formula weight of the complex is 267.34. and the crystal belongs to monoclinic system with space group P21/c and cell parameters: a=2.0292(8)nm, b=0.7283(4)nm, c=0.7540(4)nm; β=94.15(1)°, V=1.1115(9)nm3, Z=4, Dc=1.598 g·cm-3, μ=0.0663mm-1, F(000)=552. Thecomplex is a lamellar compound of infinite expansion. In addition, the complex has been tested for its antibacterial active. The average diameter of complex antibacterial activing cycle: colibacillus is 9mm, pseudomonas aeruginosa is 8mm. CCDC: 194630.

一个新希夫碱的合成、晶体结构及抑菌活性

合成了一个新型希夫碱 ,测定了该化合物的晶体结构 :单斜晶系 ,空间群P2 1/n ,a =13 32 56 ,b =6 9775 ,c=13 94 0 2 ,α =90° ,β =113 881° ,γ =90° ,V =1185 18( ) 3 ,Z =4 ,Dc =1 5 2 4g/cm3 ,R =0 0 73。抑菌试验表明 :该希夫碱对金黄色葡萄球菌有深度的抑制作用。