Pentaaza macrocyclic ytterbium(III)complex and solvent controlled supramolecular self-assembly of its dimeric mu-eta~2:eta~2 peroxo-bridged derivatives

摘要

The unprecedented template action of ytterbium ion in the synthesis of pentaaza macrocyclic Schiff bases is exemplified by isolation and definitive identification of the seven-coordinate pentagonal bipyramidal complex with the formula of [YbLCl_2]ClO_4(1),where L is 2,14-dimethyl-3,6,10,13,19-pentaazabicyclo[13.3.1]nonadeca-l(19),2,13,15,17-pentaene,providing the first example of crystallographically characterized pentaaza macrocyclic ytterbium complex.For the first time the spectrum of the ~2F_(7/2)->~2F_(5/2)transition has been obtained for a molecular complex of ytterbium with organic ligands in which all ligand-field components of the ground and excited state are well displayed at room temperature.This complex is capable of forming a dimeric peroxo Yb_2(mu-eta~2:eta~2-O_2)L_2~4+(2)derivative containing the biologically significant planar side-on doubly bidentate coordination mode of the peroxide.Inclusion of the appropriate solvent molecule into the crystal structure generates supramolecular architectures(2a-d)in which the solvent controlled self-assembly is observed.Spectral properties of these complexes were found to be very important and promising in the area of ytterbium physicochemistry.