Structure-Property correlation studies of N-donor ligand based Metal Organic Frameworks

Abstract

Ligand L (L= 1, 4-bis (4-pyridyl)-2, 3-diaza-1, 3-butadiene) belonging to an interesting family of nitrogen-donors has been utilised with Cd(II) salt in constructing two 2D MOFs. Crystallographic characterisations reveal that the two polymeric frameworks contain counter anions which are coordinated to the metal centres. Through a novel anion exchange process, the coordinated anions can be exchanged without destructing the framework. Both the compounds undergo structural changes upon replacement of the coordinated anions by foreign anions, which is evident from the slight variations in the PXRD patterns with respect to the corresponding parent compounds. Such phenomenon gives an indication of dynamism in the framework. This anion exchange process is highly selective, N3¯ being the most preferred by the framework. Interestingly, both the compounds exhibit anion-responsive tunable luminescence.