Dinuclear europium(3+), terbium(3+) and gadolinium(3+) complexes of a branched hexaazacyclooctadecane ligand containing six 2,2'-bipyridine pendant units

摘要: The dinuclear Eu[sup 3+], Tb[sup and Gd[sup 3+] complexes of a branched hexaazacyclooctadecane ligand containing six 2,2[prime]-bipyridine (bpy) pendant units (1) have been prepared characterized as chloride salts. Elemental analysis FAB[sup +] mass spectrometry show unambiguously that in the solid state two lanthanide ions are by one molecule 1. In CH[sub 3]CN alcohol (ethanol/methanol, 5:1 v/v) solution, 1 exhibits bpy-centered absorption band at 285 nm phosphorescence (77 K, [lambda] = 435 nm, [tau] s). [Gd[sub 2](1)]Cl[sub 6] complex shows an 305 455 with 1.8 ms (at 77 K) whereas solution it displays 286 bands ([lambda] 1.2 s; 3.9 ms). [Eu[sub [Tb[sub 306 H[sub 2]O. all solvents used metal-centered luminescence, characteristic metal ions, can be observed. excitation spectramore » (recorded wavelength centered emission) maximum solvents, which coincides but not 2]O solution. results obtained indicate average almost five bpy per coordinated to [M[sub (M 3+]), water most branches coordinated. 29 refs., 5 figs., 2 tabs.« less