Encapsulating ruthenium and osmium with tris(2-aminoethyl)amine based tripodal ligands
作者:Soumik Mandal、Dipravath K. Seth、Parna Gupta
DOI:10.1016/j.poly.2011.09.010
日期:2012.1
The reaction of a series of tripodal ligands, H3L1.2 and L3-6, with [M(PPh3)(2)Cl-2[(M = Ru, Os) affords a family of coordination cage compounds of the type [(ML1.2)-L-III] (1-4) or [(ML3-6)-L-II](BPh4)(2) (5-12). The Schiff base ligands (H3L1, L-3, L-5) have been synthesized by condensation of tris(2-aminoethyl)amine with salicylaldehyde, pyridine-2-aldehyde and 1-methy1-2-imidazolecarboxaldehyde. These ligands were further reduced and subsequently methylated to form the new ligands (H3L2, L-4, L-6). Single crystal X-ray diffraction studies of 1 and 2 show that the tripodal ligand wraps around the metal center as a hexadentate ligand to form a cage. All the synthesized compounds have been thoroughly characterized by ESI-MS, FT-IR, UV-Vis and NMR spectroscopic methods. To the best of our knowledge, this is the first ever report of osmium complexes with tris(2-aminoethyl)amine based tripodal ligands. DFT calculations were performed to obtain geometry optimized structures of all the other complexes (3-12). (C) 2011 Elsevier Ltd. All rights reserved.