Structural Isomers of a Potential Linking Ligand Containing a Pyridyl and a Carboxylate Terminals: (n-py)-CH=N-C6H4-CH2-COOH} (n = 3, 4)

Zhen Nu Zheng, Soon W. Lee
2014 Bulletin of the Korean Chemical Society (Print)  
Coordination polymers currently receive much attention due to their desirable properties applicable to a wide variety of fields, such as ion exchange, host-guest chemistry, adsorption-desorption, luminescence, magnetism, biomedicine, catalysis, and gas storage. 1-9 Many factors influence the topology of such polymers, including the preferred geometry of a metal, coordination modes of linking ligands, the nature of solvents used, the acidity of a reaction mixture, and synthetic methods adopted
more » ... c methods adopted (layer-diffusion, hydrothermal, solvothermal, hydro(solvo)thermal, or microwave heating method). In particular, the judicious choice of appropriate linking ligands is crucial to the successful preparation of desired polymers, and bis(pyridy)-or multicarboxylate-type linking ligands have been commonly used. [10] [11] [12] Recently, several asymmetric linking ligands possessing a carboxylate and a pyridyl or an imidazole were employed to prepare coordination polymers, in which both d-and f-block metals coexist as nodes within their frameworks. [13] [14] [15] [16] [17] [18] [19] [20] [21] We also recently prepared several pyridyl-carboxylate-type linking ligands (L1-L6 in Chart 1) and their coordination polymers. 22-31 Ligands L1 and L2 contain an amide (-C(O)-NH-) fragment, whereas ligands L3-L6 possess an imine (-C=N-) fragment. In particular, the  conjugation is interrupted in ligands L1-L4. As a continuation of our research, we prepared two relatively long potential linking ligands by Schiff-base condensation. They contain pyridyl-carboxylate terminals and are structural isomers due to the different positions of the nitrogen
doi:10.5012/bkcs.2014.35.2.647 fatcat:lpr2tbj4uzcy7g42mzpxhpbil4