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

Chao LIU Jun-Feng NIU Yang LI Ji-Gui XU Xin-Hua LIU

Citation:  LIU Chao, NIU Jun-Feng, LI Yang, XU Ji-Gui, LIU Xin-Hua. Syntheses, Crystal Structures and Antibacterial Activities of Cobalt(Ⅱ) and Manganese(Ⅱ) Complexes with Schiff Base Ligand Derived from Tryptamine[J]. Chinese Journal of Structural Chemistry, 2016, 35(7): 1002-1010. doi: 10.14102/j.cnki.0254-5861.2011-1049 shu

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

English

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    1   INTRODUCTION

    Schiff bases are very important compounds containing N=C functional groups, which can react with a range of metal ions forming stable complexes as bi-, tri-, and poly-dentate ligands[1-4]. Some transition metal complexes with Schiff base ligands show excellent biological properties, such as antibacterial[5], anticancer[6], antifungal[7] and antiviral activities[8], so the biological behavior of the complexes has drawn scientists' considerable attention during the past decades[9, 10]. Manganese and cobalt are two kinds of trace elements essential for normal human development and the studies on their complexes have great meanings in the field of medicine chemistry[11, 12]. Recently, some Co(II) and Mn(II) Schiff base complexes have been widely designed and synthesized, and their potential applications in medicine chemistry field was tested as biological agents[13-15].

    As a continuation of work on the exploration of novel antibacterial complexes, we have synthesized two new metal complexes [Co(L)2] (1) and [Mn(L)2] (2) based on Schiff base ligand derived from tryptamine. The crystal structures of 1 and 2 were determined by IR, X-ray diffraction analysis, and elemental analysis. Furthermore, their antibacterial activities against Escherichia coli, Salmonella typhi, Staphylococcus aureus, and Bacillus subtilis were tested using the agar diffusion assay.

    2   EXPERIMENTAL

    2.1   Reagents and instruments

    All chemicals and solvents were commercially purchased and used without further purification except the Schiff base ligand which was synthesized according to the literature[16]. 1H NMR and 13C NMR spectra were recorded in CDCl3 solution on a Bruker AV-400 spectrometer. Infrared spectra were obtained on a FTS-40 spectrophotometer with KBr pellets in the 4000~400 cm-1 region. Elemental analyses (C, H and N) were performed on a Vario EL Ⅲ elemental analyzer. Power X-ray diffractions (PXRD) were measured on a DX-2600 diffractometer with Cu-Kα radiation.

    2.2   Synthesis of the ligand

    Synthetic route of the ligand is shown in Scheme 1. According to the literature[16], 3-methyl-2-hydroxybenzaldehyde (2 mL, 16.66 mmol) was added to a solution of tryptamine (2.67 g, 16.66 mmol) in 45 mL of methanol and the resulting mixture was refluxed with stirring for 24 h. The solution was concentrated to 15 mL and placed in the refrigerator overnight, then dark yellow crystals were obtained in 89.0% yield. m.p.: 89~90 ℃. 1H NMR (400 MHz, CDCl3, ppm): δ 14.01 (br, 1H, NH), 8.19 (s, 1H, N=CH), 7.96~7.68 (m, 2H, 4, 7-indol-H), 7.37 (m, 1H, 2-Indol-H), 7.28 (m, 1H, 6-Ar-H), 7.20~ 7.11 (m, 2H, 5, 6-indol-H), 7.06 ~ 6.77 (m, 2H, 4, 5-Ar-H), 3.93 (t, J = 3.6 Hz, 2H, CH2N), 3.20 (t, J = 6.9 Hz, 2H, indol-CH2), 2.31 (s, 3H, CH3). 13C NMR (100 MHz, CDCl3, ppm): δ 164.8, 159.5, 136.0, 132.8, 132.7, 128.6, 126.9, 125.7, 122.0, 121.7, 118.9, 118.3, 117.6, 112.9, 110.9, 59.1, 26.6, 15.2.

    Figure Scheme1.  Synthetic route of the ligand

    2.3   Synthesis of complex 1

    To an ethanol solution (45 mL) of Co(OAc)2·4H2O (0.44 g, 1.75 mmol), 2 equiv of the ligand (0.97 g, 3.50 mmol) was added and the resulting mixture was refluxed with stirring for 24 h. After cooling to room temperature, the solvent was removed by a rotary evaporator to give the purple powder. The residue was dissolved in a co-solvent of CH3OH and CH2Cl2 (v(CH3OH):v(CH2Cl2) = 1:1), and single-shaped crystals of 1 suitable for X-ray diffraction study were obtained after about two days in 84.7% yield. m.p.: 162~163 ℃. Anal. Calcd. for C36H34N4CoO2 (%): C, 70.47; H, 5.58; N, 9.13. Found (%): C, 70.55; H, 5.78; N, 8.86. IR (KBr, cm-1): 3415 (vs), 3049 (w), 2906 (w), 2912 (m), 1662 (m), 1613 (s), 1547 (s), 1449 (s), 1416 (s), 1318 (s), 1214 (m), 1088 (m), 1006 (w), 859 (w), 733 (s), 580 (w), 493 (w).

    2.4   Synthesis of complex 2

    To an ethanol solution (45 mL) of Mn(OAc)2·4H2O (0.43 g, 1.75 mmol), 2 equiv of the ligand (0.97 g, 3.50 mmol) was added and the resulting mixture was refluxed with stirring for 24 h. After cooling to room temperature, the solvent was removed by a rotary evaporator to give the brown powder. The residue was dissolved in 15 mL of DMF, and single-shaped crystals of 2 suitable for X-ray diffraction study were obtained after about one day in 75.5% yield. m.p.: 147~149 ℃. Anal. Calcd. for C36H34N4MnO2 (%): C, 70.93; H, 5.62; N, 9.19. Found (%): C, 70.89; H, 5.44; N, 9.41. IR (KBr, cm-1): 3399 (vs), 3028 (m), 2940 (s), 2907 (m), 2836 (m), 1618 (s), 1591 (s), 1553 (s), 1460 (m), 1432 (s), 1312 (s), 1236 (m), 1083 (s), 1023 (m), 859 (m), 744 (s), 711 (w), 629 (m), 580 (w), 498 (m).

    2.5   Crystal structure determination

    Two single crystals of the title complexes with dimensions of 0.22mm × 0.25mm × 0.26mm for 1 and 0.22mm × 0.26mm × 0.28mm for 2 were selected for X-ray single-crystal diffraction analysis on a Bruker APEX-II CCD diffractometer. Crystallographic data were collected with a graphitemonochromatic MoKα radiation (λ = 0.71073 Å) at 296(2) K using an ω-scan mode. Empirical absorption corrections were applied by using the SADABS program[17]. The structures of complexes 1 and 2 were solved by direct methods using SHELXS-97[18] and refined by full-matrix least-squares on F2 with SHELXL-97[19]. All non-hydrogen atoms were refined anisotropically and all hydrogen atoms attached to C, N and O atoms were generated geometrically and refined isotropically with a riding model.

    For complex 1, a total of 6911 reflections were collected in the range of 1.81≤θ≤25.00º, of which 2615 were independent with Rint = 0.028 and 2093 were observed with I > 2σ(I). The final R = 0.0363, wR = 0.1007 (w = 1/[σ2(Fo 2) + (0.0379P)2 + 3.2241P], where P = (Fo 2 + 2Fc 2)/3), (Δρ)max = 0.27, (Δρ)min = -0.25 e/Å3, (Δ/σ)max = 0.000 and S = 1.05. For complex 2, a total of 16524 reflections were collected in the range of 2.03≤θ≤25.01º, of which 5318 were independent with Rint = 0.073 and 3089 were observed with I > 2σ(I). The final R = 0.0525, wR = 0.1543 (w = 1/[σ2(Fo 2) + (0.0741P)2 + 0.0000P], where P = (Fo 2 + 2Fc 2)/3, (Δρ)max = 0.52, (Δρ)min = -0.26 e/Å3, (Δ/σ)max = 0.000 and S = 1.01. The selected bond lengths and bond angles for the complexes are given in Table 1, the structural parameters of D-H···π and C-H···O bonds are summarized in Table 2, and the π···π stacking interactions for complex 1 are listed in Table 3.

    Table 1.  Selected Bond Lengths (Å) and Bond Angles (º) for Complexes 1 and 2
    1 Bond Dist. Bond Dist. Bond Dist. Co(1)-O(1) 1.899 (2) Co(1)-N(2) 1.998(2) Co(1)-O(1A) 1.899(2) Angle (°) Angle (°) Angle (°) O(1)-Co(1)-N(2) 95.23(8) O(1)-Co(1)-O(1A) 136.46(8) O(1)-Co(1)-N(2A) 104.69(8) 2 Bond Dist. Bond Dist. Bond Dist. Mn(1)-O(1) 1.838(3) Mn(1)-O(2) 1.847(3) Mn(1)-N(1) 1.906(4) Angle (°) Angle (°) Angle (°) O(1)-Mn(1)-O(2) 175.13(13) O(1)-Mn(1)-N(1) 92.28(16) O(1)-Mn(1)-N(3) 87.46(14) O(2)-Mn(1)-N(1) 88.81(16) O(2)-Mn(1)-N(3) 91.84(13) N(1)-Mn(1)-N(3) 175.48(16)
    Co(1)-N(2A) 1.998(2) N(2)-C(11) 1.284(3) O(1)-C(17) 1.316(3)
    O(1A)-Co(1)-N(2) 104.69(8) N(2)-Co(1)-N(2A) 124.61(8) O(1A)-Co(1)-N(2A) 95.23(8)
    Mn(1)-N(3) 1.905(4) N(1)-C(7) 1.305(7) O(1)-C(1) 1.321(6)
    Symmetry code for complex 1: A: –x, y, 1.5–z
    Table 1.  Selected Bond Lengths (Å) and Bond Angles (º) for Complexes 1 and 2
    Table 2.  Structural Parameters of D-H···π and C-H···O Bonds for Complexes 1 and 2 (Å, °)
    1
    D-H …A d(D-H) d(H …A) d(D …A) Z(DHA)
    N(1)-H(1)…Cg(4)#1 0.97 2.66 3.515(2) 148
    To be continued
    2
    C(9)—H(9B)…O(2) 0.97 2.38 2.760(6) 103
    C(10)—H(10A)…O(2) 0.97 2.52 3.099(6) 118
    C(27)-H(27B)…O(l) 0.97 233 2.762(6) 106
    C(14)—H(14)…Cg(2)#1 0.93 3.00 3.663(7) 130
    C(26)—H(26)…Cg(5) #2 0.93 2.94 3.834(6) 161
    N(4)-H(4A)…Cg(6) #2 0.86 2.47 3.243(6) 151
    N(2)—H(2)…Cg(7) #3 0.86 2.53 3.245(6) 141
    C(15)-H(15)…Cg(8)#1 0.93 2.90 3.725(7) 149
    Symmetry codes: #1: 1/2–x, –1/2+y, 3/2–z; Cg(4): C(1)~C(6), respectively for complex 1; #1: 3/2–x, –1/2+y, 5/2–z; #2: –1/2+x, 1/2–y, –1/2+z; #3: 1/2+x, 1/2–y, 1/2+z; Cg(2): N(4), C(29), C(30), C(35), C(36); Cg(5): C(1)~C(6); Cg(6): C(12)~C(16); Cg(7): C(19)~C(24); Cg(8): C(30)~C(35), respectively for complex 2
    Table 2.  Structural Parameters of D-H···π and C-H···O Bonds for Complexes 1 and 2 (Å, °)
    Table 3.  ππ Stacking Interactions for Complex 1 (Å, °)
    Cg(I) Res(I) Cg(J) Cg—Cg Alpha CcI Perp CoT Perp Slippage
    Cg(5) [1] —> Cg(2) #2 3.7017(13) 3.70 3.428 3.331
    Cg(2) [1] -> Cg(5) #2 3.7017(13) 3.70 3.331 3.428
    Cg(5) [1] —> Cg(5) #2 3.5293(16) 0.02 3.394 3.394 0.969
    Symmetry code: #2: –x, 1 –y, 2–z. Cg(2): Co(1), O(1), N(2), C(11), C(12), C(17); Cg(5): C(12)~C(17)
    Table 3.  ππ Stacking Interactions for Complex 1 (Å, °)

    3   RESULTS AND DISCUSSION

    3.1   Crystal structural description

    3.2   Powder XRD

    In order to check the phase purity of complexes 1 and 2, powder X-ray diffraction (PXRD) technology has been carried out for the bulk samples at room temperature, as shown in Figs. 5 and 6. The main peak widths of the experimental PXRD patterns are in good agreement with their simulated ones, indicating good phase purity of the complexes. There are a few minor dissimilarities in some peak positions and intensities between the simulated and experimental patterns, which may be due to the superior orientation of the crystalline powder samples.

    Figure 5.  Analysis of the simulated and experimental PXRD patterns of complex 1
    Figure 6.  Analysis of the simulated and experimental PXRD patterns of complex 2

    3.3   Antibacterial activity

    The antibacterial activities of the ligand and the complexes were studied using the agar diffusion assay. The test strains were used as follows: Escherichia coli, Salmonella typhi, Staphylococcus aureus, and Bacillus subtilis. The experimental apparatus, filter paper and nutrient agar medium were placed in an autoclave and sterilized at 120 ℃ for 30 min. The ligand and the complexes were dissolved in DMSO with the concentration of 0.01 g/mL and were stocked after sterilization. After they were soaked in the solution for 2 h, the filter papers with 6 mm diameter were placed on the culture medium and incubated at 37 ℃ for 24 h. Antibacterial activities of the above compounds were evaluated by measuring the diameters of inhibition rings.

    The antibacterial activities of the Schiff base ligand and the complexes are presented in Table 4. The results of the bacterial growth inhibition study showed that the ligand and the complexes exhibited different antibacterial activities to the test strains, and that DMSO had no inhibitory effect on the test strains. The ligand showed excellent antibacterial activities against Escherichia coli, Staphylococcus aureus and Bacillus subtilis while week activities against Salmonella typhi. Compared to the free ligand, complexes 1 and 2 had stronger antibacterial activities against the strains quoted above, which is related to the biological function of cobalt and manganese elements. Moreover, complex 1 exhibited the best activities against Escherichia coli with inhibition ring for 16.8 mm and complex 2 exhibited the best activities to Bacillus subtilis with inhibition ring for 15.5 mm. The experimental results showed that, owing to the synergistic effect of the ligand and the metal ions, the antibacterial activities of complexes 1 and 2 increased significantly.

    Table 4.  Antibacterial Data for the Ligand and the Complexes (mm)
    Compound Inhibition zone diameter in mm
    Escherichia coli Salmonella typhi Staphylococcus aureus Bacillus subtilis
    DMSO - - - -
    Ligand 8.7 - 6.4 7.2
    Complex 1 16.8 11.4 10.5 11.7
    Complex 2 13.1 11.5 11.3 15.5
    Table 4.  Antibacterial Data for the Ligand and the Complexes (mm)

    3.1.2   Crystal structural description of complex 2

    The coordination environment of Mn(II) ion in complex 2 is shown in Fig. 3. X-ray single-crystal diffraction analysis reveals that complex 2 exhibits a distorted square-planar geometry with two Mn-N and two Mn-O bonds which are in opposite positions of the central Mn(Ⅱ) ion. The Mn(II) ion is four-coordinated by two hydroxyl oxygen atoms (O(1) and O(2)) from two Schiff base ligands and two imino nitrogen atoms (N(1) and N(3)) from the same two ligands, forming two six-membered chelate rings. The averaged bond distances of Mn-O and Mn-N are 1.843(3) and 1.906(4) Ǻ, respectively, in agreement with the values reported in the literatures[22, 23]. The bond angles of O(1)- Mn(1)-N(1) (92.28(16)º), N(1)-Mn(1)-O(2) (88.81(16)º), O(2)-Mn(1)-N(3) (91.84(13)º) and N(3)-Mn(1)-O(1) (87.46(14)º) are added up to 360.39º, approximately equal to 360º, indicating that Mn(1) and the four coordination atoms are nearly coplanar. Furthermore, the bond angles O(1)- Mn(1)-O(2) and N(1)-Mn(1)-N(3) are respectively 175.13(13)º and 175.48(16)º, which deviate from 180º, so the Mn(Ⅱ) ion is in a distorted square squareplanar environment. The aromatic ring composed of atoms C(1) to C(6) and the chelating ring constructed by atoms Mn(1), O(1), C(1), C(6), C(7) and N(1) are nearly coplanar with a dihedral angle of 8.4(2)°. This is also indicated by the torsion angles of O(1)-C(1)-C(2)-C(3) being 178.5(5)° and C(5)-C(6)-C(7)-N(1) being 172.6(5)°.

    Figure 3.  Molecular structure of complex 2

    In complex 2, there also exist week intramolecular hydrogen bonds between two ligands coordinated to the same Mn(II) ion. The hydroxyl oxygen atom from one ligand acts as H-acceptor to the methylene carbon atom from another ligand, forming three types of C-H···O hydrogen bonds: C(9)- H(9B)···O(2) (2.760(6) Å), C(10)-H(10A)···O(2) (3.099(6) Å) and C(27)-H(27B)···O(1) (2.762(6) Å). Meanwhile, the units of complex 2 are linked by two types of N-H···π hydrogen bonds (N(2)-H(2)···Cg(7) and N(4)-H(4A)···Cg(6)) and three types of C-H···π hydrogen bonds (C(14)-H(14)···Cg(2), C(15)- H(15)···Cg(8) and C(26)-H(26)···Cg(5)) into an infinite 3D supramolecular structure. By all weak interactions quoted above, the crystal structure of complex 2 is further stabilized. The crystal packing diagram in the unit cell is shown in Fig. 4.

    Figure 4.  Crystal packing diagram of complex 1 along the b axis

    3.1.1   Crystal structural description of complex 1

    The coordination environment of Co(II) ion in complex 1 is shown in Fig. 1. X-ray single-crystal diffraction analysis reveals that complex 1 exhibits a distorted tetrahedral geometry with two Co-N and two Co-O bonds. The central Co(II) ion is fourcoordinated by two hydroxyl oxygen atoms (O(1) and O(1A)) from two Schiff base ligands and two imino nitrogen atoms (N(2) and N(2A)) from the same two ligands, forming two six-membered chelate rings. The four atoms of O(1), O(1A), N(2) and N(2A) are on the four vertices of the tetrahedron, and Co(1) occupies the centre of the tetrahedron. The two Co-O bond distances are 1.899(2) Å and two Co-N 1.998(2) Å. The six bond angles formed by Co(1) and four coordination atoms are O(1)- Co(1)-N(2) (95.23(8)°), O(1)-Co(1)-O(1A) (136.46(8)°), O(1)-Co(1)-N(2A) (104.69(8)°), O(1A)-Co(1)-N(2) (104.69(8)°), N(2)-Co(1)-N(2A) (124.61(8)°) and O(1A)-Co(1)-N(2A) (95.23(8)°), which deviate from that of the tetrahedral angle (109.47°), so the Co(Ⅱ) ion is in a distorted tetrahedral environment. The aromatic ring composed of atoms C(12) to C(17) and the chelating ring consisting of atoms Co(1), O(1), C(17), C(12), C(11) and N(2) are nearly coplanar with a dihedral angle of 3.70(10)°. This is also indicated by the torsion angles of O(1)-C(17)-C(16)-C(15) being 179.5(2)° and C(13)-C(12)-C(11)-N(2) being 177.9(2)°.

    Figure 1.  Molecular structure of complex 1

    The nonclassical hydrogen bonding plays a very important role in the construction of supramolecular architecture[20, 21]. The units of complex 1 are linked by N-H···π hydrogen bonds (N(1)-H(1)···Cg(4)) into an infinite 1D supramolecular structure. Meanwhile, a series of face-to-face π···π stacking interactions with centroid···centroid distances ranging from 3.7017(13) to 3.5293(16) Å also exist between the adjacent benzene rings of the neighboring ligands and the coordination rings of the adjacent cobalt ions, extending the 1D framework into a 3D supramolecular structure. The crystal packing diagram in the unit cell is shown in Fig. 2.

    Figure 2.  Crystal packing diagram of complex 1 along the b axis

    4   CONCLUSION

    In summary, complexes [Co(L)2] (1) and [Mn(L)2] (2) have been synthesized and structurally characterized by solvothermal method. Two complexes are both mononuclear and belong to the monoclinic system with space groups C2/c and P21/n, respectively. Structural analyses reveal that complex 1 exhibits an infinite 1D chain structure by intermolecular N-H···π hydrogen bonds, which is further extended into a 3D supramolecular structure by π···π stacking interactions, and that complex 2 exhibits an infinite 3D supramolecular structure by intermolecular N-H···π and C-H···π hydrogen bonds. Additionally, the study on the antibacterial activities shows that complexes 1 and 2 possess stronger inhibiting effects on four kinds of bacteria than the free Schiff base ligand.

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  • Scheme1  Synthetic route of the ligand

    Figure 1  Molecular structure of complex 1

    Figure 2  Crystal packing diagram of complex 1 along the b axis

    Figure 3  Molecular structure of complex 2

    Figure 4  Crystal packing diagram of complex 1 along the b axis

    Figure 5  Analysis of the simulated and experimental PXRD patterns of complex 1

    Figure 6  Analysis of the simulated and experimental PXRD patterns of complex 2

    Table 1.  Selected Bond Lengths (Å) and Bond Angles (º) for Complexes 1 and 2

    1 Bond Dist. Bond Dist. Bond Dist. Co(1)-O(1) 1.899 (2) Co(1)-N(2) 1.998(2) Co(1)-O(1A) 1.899(2) Angle (°) Angle (°) Angle (°) O(1)-Co(1)-N(2) 95.23(8) O(1)-Co(1)-O(1A) 136.46(8) O(1)-Co(1)-N(2A) 104.69(8) 2 Bond Dist. Bond Dist. Bond Dist. Mn(1)-O(1) 1.838(3) Mn(1)-O(2) 1.847(3) Mn(1)-N(1) 1.906(4) Angle (°) Angle (°) Angle (°) O(1)-Mn(1)-O(2) 175.13(13) O(1)-Mn(1)-N(1) 92.28(16) O(1)-Mn(1)-N(3) 87.46(14) O(2)-Mn(1)-N(1) 88.81(16) O(2)-Mn(1)-N(3) 91.84(13) N(1)-Mn(1)-N(3) 175.48(16)
    Co(1)-N(2A) 1.998(2) N(2)-C(11) 1.284(3) O(1)-C(17) 1.316(3)
    O(1A)-Co(1)-N(2) 104.69(8) N(2)-Co(1)-N(2A) 124.61(8) O(1A)-Co(1)-N(2A) 95.23(8)
    Mn(1)-N(3) 1.905(4) N(1)-C(7) 1.305(7) O(1)-C(1) 1.321(6)
    Symmetry code for complex 1: A: –x, y, 1.5–z
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    Table 2.  Structural Parameters of D-H···π and C-H···O Bonds for Complexes 1 and 2 (Å, °)

    1
    D-H …A d(D-H) d(H …A) d(D …A) Z(DHA)
    N(1)-H(1)…Cg(4)#1 0.97 2.66 3.515(2) 148
    To be continued
    2
    C(9)—H(9B)…O(2) 0.97 2.38 2.760(6) 103
    C(10)—H(10A)…O(2) 0.97 2.52 3.099(6) 118
    C(27)-H(27B)…O(l) 0.97 233 2.762(6) 106
    C(14)—H(14)…Cg(2)#1 0.93 3.00 3.663(7) 130
    C(26)—H(26)…Cg(5) #2 0.93 2.94 3.834(6) 161
    N(4)-H(4A)…Cg(6) #2 0.86 2.47 3.243(6) 151
    N(2)—H(2)…Cg(7) #3 0.86 2.53 3.245(6) 141
    C(15)-H(15)…Cg(8)#1 0.93 2.90 3.725(7) 149
    Symmetry codes: #1: 1/2–x, –1/2+y, 3/2–z; Cg(4): C(1)~C(6), respectively for complex 1; #1: 3/2–x, –1/2+y, 5/2–z; #2: –1/2+x, 1/2–y, –1/2+z; #3: 1/2+x, 1/2–y, 1/2+z; Cg(2): N(4), C(29), C(30), C(35), C(36); Cg(5): C(1)~C(6); Cg(6): C(12)~C(16); Cg(7): C(19)~C(24); Cg(8): C(30)~C(35), respectively for complex 2
    下载: 导出CSV

    Table 3.  ππ Stacking Interactions for Complex 1 (Å, °)

    Cg(I) Res(I) Cg(J) Cg—Cg Alpha CcI Perp CoT Perp Slippage
    Cg(5) [1] —> Cg(2) #2 3.7017(13) 3.70 3.428 3.331
    Cg(2) [1] -> Cg(5) #2 3.7017(13) 3.70 3.331 3.428
    Cg(5) [1] —> Cg(5) #2 3.5293(16) 0.02 3.394 3.394 0.969
    Symmetry code: #2: –x, 1 –y, 2–z. Cg(2): Co(1), O(1), N(2), C(11), C(12), C(17); Cg(5): C(12)~C(17)
    下载: 导出CSV

    Table 4.  Antibacterial Data for the Ligand and the Complexes (mm)

    Compound Inhibition zone diameter in mm
    Escherichia coli Salmonella typhi Staphylococcus aureus Bacillus subtilis
    DMSO - - - -
    Ligand 8.7 - 6.4 7.2
    Complex 1 16.8 11.4 10.5 11.7
    Complex 2 13.1 11.5 11.3 15.5
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  • 收稿日期:  2015-11-11
  • 接受日期:  2016-05-25
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