Abstract
Eight new solid complexes of pipemidic acid (PPA) with trichlorizated rare earth metals LaCl3, CeCl3, PrCl3, NdCl3, SmCl3, TbCl3, DyCl3, and YCl3 have been synthesized. The complexes were characterized by elemental analyses, IR, NMR, and molar conductance measurements. The general formulas of the complexes are [M(PPA)4]Cl3 (M=Ce(III), Pr(III), Nd(III), Sm(III), Tb(III), Dy(III), Y(III)), and [La(PPA)4Cl]Cl2. At the same time, the antibacterial activities of PPA and four of its complexes were tested. The results show that PPA and its complexes all have inhibitory action against bacteria of Escherichia coli, Bacillus subtilis, Streptococcus pneumoniae, and Pseudomonas aeruginosa but not Staphylococcus aureus. We compared their antibacterial activities and found that the antibacterial activity of [La(PPA)4Cl]Cl2 against S. pneumoniae is much stronger than that of PPA and the other complexes.
