A tripod ligand, 1,1,1 tri [1′ (2′ oxa 5′ oxo 6′ aza 6′ bisphenyl)hexyl] propane(L), and its complexes with Ln(NO 3) 3 · n H 2O(where Ln=La, Ce, Pr, Nd) have been synthesized. These new complexes with the general formula of Ln 2L(NO 3) 6· n H 2O(where Ln=La, n =4; Ln=Pr, n =2; Ln=Ce, Nd, n =1) were characterized by elemental analysis, IR spectra, thermal analysis, 1H NMR spectra and molar conductivity. All the complexes are stable in air and their conductances in acetonitrile solution lie in the 149—158 S·cm 2·mol -1 range, indicating that they are 1∶1 type electrolytes. The IR and 1H NMR spectra of the ligand and its complexes show that all the ether oxygen atoms and the CO groups take part in coordination to the metal ions, and the larger shift for ν CO in the IR spectra of the complexes suggests that the Ln—O(carbonyl) bond is stronger than the Ln—O(ether) one which also was inferred from the 1H NMR spectral data . The thermal behaviour of the complexes are similar. The first loss occurs at 85—100.9 ℃ corresponding to the loss of all the water molecules. The weight losses found in this process compare favourably with the theoretical values. Moreover, the relatively low temperatures of dehydration are consistent with the presence of crystal water.
The crystal structure of the title compound (C27H38N4O7S3, Mr = 626.79) has been determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group Pīwith a = 9.411(1), b = 11.645(2), c = 14.672(2) , a = 91.80(1), b = 95.36(1), g =104.56(1)o, V = 1547.0 3, Z = 2, Dc = 1.346 g/cm3, l = 0.71073 , m(MoKa) = 0.289 mm-1 and F(000) = 664. The structure was refined to R = 0.0406 and wR = 0.1177 for 4103 observed reflections with I > 2s(I). X-ray diffraction analysis reveals that the title compound is a practically distorted tetrahedron and each molecule contains one lattice H2O by hydrogen bond. The antitumor activity of the title compound against HL-60 human leukemia cells has also been studied by MTT method.
A novel La complex with methyl-2-pyridyl ketone benzoyl hydrazone has been synthesized and determined by single crystal X-ray diffraction. The crystal is monoclinic with space group C2/c, a =1 7081(3) nm, b =1 5660(3) nm, c =1 3512(3) nm, α=90 00°, β=94 39(1)°, γ=90 00°, V =3 6037(12) nm 3, Z =4 . The complex is a ten-coordinated one with a lanthanum ion surrounded by a N 4O 6 set. The crystal structure is stabilized by hydrogen bonds between water molecules and NO - 3 anions.
The La(III) complex with a new amide-type tripodal ligand, 2,2,2-nitrilotris{[(2-benzylaminoformyl)- phenoxy]ethyl}amine (L), was synthesized and characterized by X-ray crystallographic analysis. Crystal data: C48H55.50LaN7O18.75, Mr=1169.40, monoclinic, space group, P21/n, a=1.0644(3) nm, b=2.3889(5) nm, c=2.1917(5) nm, b=90.65, V=5.573(2) nm3, Z=1, Dc=1.394 gcm-3, R1=0.0487, wR [I>2s(I)]=0.1266. The results reveal that each La(III) ion binds to 9 oxygen atoms, three of which belong to carbonyl groups from three tripodal ligands and six to three bidentate nitrate groups and a two-dimensional sheet of 4.82 networks is assembled by metal-ligand coordination interaction. L, a heptadentate compound, merely acts as a tridentate bridging spacer due to its steric hindrance and links the La(III) ions as three-connected nodes.
