| Abstract: Two rare earth complexes based on enoxacin (HEx), [Ce(Ex)4]·39H2O (1) and [Sm2(Ex)4(HEx)2(ox)]·24H2O (2) (HEx=enoxacin; ox=oxalate), have been synthesized and characterized by IR, EA and X-ray diffraction. The analyses of the single X-ray diffraction results indicate that 1 is a mononuclear Ce(Ⅳ) complex and crystallizes in tetragonal system, space group I41/a with a=1.551 74(12) nm, c=4.066 6(4) nm, V=9.791 9(14) nm3, Z=4, μ=0.574 mm-1, F(000)=4 480, Dc=1.441 g·cm-3, R1=0.074 3, wR2=0.180 0; 2 is an oxalate-bridged binuclear Sm(Ⅲ) complex and crystallizes in triclinic system, space group P1 with a=1.505 72(19) nm, b=1.511 98(10) nm, c=1.610 58(10) nm, α=116.723(2)°, β=107.987(2)°, γ=98.020(2)°, V=2.943 0(5) nm3, Z=1, μ=1.095 mm-1, F(000)=1 412, Dc=1.545 g·cm-3, R1=0.039 4, wR2=0.121 7. The bindings of 1 and 2 with calf thymus DNA (CT-DNA) have been investigated by electronic absorption spectroscopy and emission spectroscopy. The results indicate that both complexes bind with double-stranded CT-DNA mostly via intercalative mode, with the intrinsic binding constants (Kb) of 4.45×104 and 6.56×104 mol-1·L, respectively. Antibacterial tests show both complexes have better antibacterial activities against Gram and fungi microbial than the free ligand HEx. CCDC: 751128, 1; 751129, 2. |
