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.
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.
