Self-assembled Pd3L2 cages having flexible tri-imidazole donors

Four new M3L2 molecular cages (CA1-CA4) have been synthesized in excellent yield via coordination driven self -assembly of flexible tri-imidazole donors based on triazine (L1) and tri-phenyl benzene (L2) core with 90 degrees cis-blocked metal acceptors of Pd(II). Two of them CA1 and CA2 are highly soluble in water. All the cages were characterized by spectroscopic studies and ESI-MS; CA3 and CA4 also by X-ray diffraction. Selective formation of two separate cages CA3 and CA4 was noticed instead of a hetero-ligand cage, when the metal acceptor (dppf)Pd(OTf)(2) was treated with a mixture of ligands L1 and L2