A lariat crown ether ligand 7,16-bis (2-hydroxy-5-methylbenzyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (L1) has been prepared via one-pot Mannich reaction. Its copper(II) complex Cu-L1 was synthesized and charac-terized by elemental analysis, IR and UV-visible spectroscopy. The crystal structure of the complex has been deter-mined by X-ray diffraction analysis. The result shows that the copper(II) ion is six-coordinated by two nitrogen and four oxygen atoms, two from the crown ether and the other two from the deprotonated phenolate anions, forming an elongated octahedral complex. Electrochemical study indicates that the complex undergoes reversible reduction in DMF solution.
X-ray single crystal analysis of a new paramagnetic manganese(Ⅱ) complex with DTPA-BpABA (a DTPAbisamide derivative), Mn(DTPA-BpABA)·4H2O, shows that four oxygen atoms and three nitrogen atoms from the ligand coordinate to Mn(Ⅱ) cation, forming a seven-coordinate distorted pentagonal bipyramid polyhedron. In the crystal, the carboxyl groups and the nitrogen atoms extensively form hydrogen bonds with the lattice water molecules, building a 3D-network. The relaxometric study indicates that the R1 value of the paramagnetic manganese(Ⅱ)complex is 5.12 mmol·L·s^-1. The higher R1 value means that this complex may find an application in magnetic resonance imaging (MRI) technique.
The X-ray crystallographic structure was reported for a dinuclear copper(Ⅱ) complex with a tetraanionic ligand of p-tert-butylsulfonylcalix[4]arene [Cu2L(CH3OH)6]·4CH3OH (H4L=p-tert-butylsuffonylcalix[4]arene). The complex belongs to triclinic system, P1^-- space group, with a = 1.2303(3) nm, b = 1.2377(3) nm, c = 1.3110(3) nm, a =66.862(4)°, β= 67.206(4)°, γ=61.711(3)°, Z= 1, V= 1.5659(7) nm^3, Dc= 1.371 g/cm^3, F(000) = 682,μ(Mo Kα) = 0.883 mm^-1, R1 =0.0325, wR2=0.0870. In this complex, the calix[4]arene acts as a bis-tridentate chelating ligand with the 1,2-alternate conformation.