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

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-pentaazabicyclo13.3.1]nonadeca-1(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 (2)F(7/2) --> (2)F(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.