Synthesis Of Nitrogen-containing Heterocyclic Ompounds With Metal Salts

Synthesis of nitrogen-containing heterocyclic compounds with metal salts, andstudied their antimicrobial activity. Choose bactericidal agents5-Br-gramine （5-BrG）and1,2-benzoisothiazolin^-3-one （BIT）, which have good bactericidal effect andcoordination-points as ligands, to react with transition metal salts to form complexes,Study the potential antimicrobial properties of complexes after the determination ofthe structures.（1） One single-crystal of5-BrGNO₃and seven complexes of BIT were obtained.The single-crystal C11H14BrN2NO₃was determined by X-ray single-crystal diffractionand X-ray powder diffraction. And the structures of metal-organic complexes werecharacterized by analytical methods, such as element analysis （EA）, infra-reddiffraction （IR）, nuclear magnetic resonance （NMR）, liquid-mass spectrometry（LS-MS）, thermogravimetric （TG）, UV-visible spectra （UV-Vis）, and so on. Thesingle crystal is5-BrGNO₃, the possible structures of complexes are:[Ag（BIT-H）]（1）（4）,[Ag₂（BIT-H）]·NO₃·H₂O （2）,[Ag（BIT）（BIT-H）]（3）,[Cd（BIT）（BIT-H）（CH₃COO）]·7H₂O （5）,[Zn（BIT-H）₂]（6）,[Cu（BIT）（BIT-H）（CH₃COO）]（7）.（2） The fluorescence spectra of complexes have changed compare with BIT. Theexcitation and emission ranges of complex1are increased and its position red-shifted.The fluorescence properties of complex6and7compare with BIT, excitation andemission spectra intensity of complex6are all getting strong and their positionred-shifted, excitation and emission spectra intensity of complex7are all gettingweak, emission spectra’s position of complex7red-shifted.（3） The complexes have antibacterial properties. The antibacterial propertieswere carried out by the experiments of inhibition zone and minimal inhibitoryconcentration. The MIC of BIT and complexes1,2,3to Escherichia coli are: 3.906×10^-4mg/mL、7.812×10^-4mg/mL、1.562×10^-3mg/mL、1.562×10^-3mg/mL; toStaphylococcus aureus are:7.812×10^-4mg/mL、3.125×10^-3mg/mL、7.812×10^-4mg/mL、3.125×10^-3mg/mL. For complexes of silver salts, antibacterial properties toEscherichia coli are: BIT>complex1>complex2=complex3, antibacterial propertiesto Staphylococcus aureus are: BIT=complex2>complex1=complex3.The MIC of BIT and complexes5,6,7to Escherichia coli are:3.906×10^-4mg/mL、2.344×10^-3mg/mL、2.344×10^-3mg/mL、1.172×10^-3mg/mL; toStaphylococcus aureus are:7.812×10^-4mg/mL、2.344×10^-3mg/mL、5.86×10^-4mg/mL、5.86×10^-4mg/mL. Antibacterial properties to Escherichia coli are:BIT>complex7>complex5=complex6, antibacterial properties to Staphylococcusaureus are: complex6=complex7> BIT>complex5.The influence factors of antibacterial activity. Cadmium acetate has goodantibacterial, zinc acetate and copper acetate did not. The MIC of cadmium acetatezinc acetate and copper acetate to Escherichia coli are:1.935×10^-3mg/mL、3.125×10^-2mg/mL、3.125×10^-2mg/mL; to Staphylococcus aureus are:9.766×10^-4mg/mL、3.125×10^-2mg/mL、1.563×10^-2mg/mL. The antimicrobial properties of complex5related with cadmium acetate and ligand, Ligand affects the antimicrobial propertiesof complex6and complex7.