Solvo-thermal synthesis of a unique alkaline earth-transition Ba-Cd micro-porous coordination framework as hetero-metallic luminescent sensor for Cu2+ and real-time detection of benzaldehyde.

In this work a unique hetero-metallic alkaline earth-transition Ba-Cd luminescent micro-porous metal-organic framework {[BaCd(µ6-tp)1.5(µ2-Cl)(H2O) (DMF)2]·0.75H2O}n (H2tp=terephthalic acid) (1) has been prepared under solvo-thermal conditions. In 1 infinite 1D {Ba-X-Cd} (X=O, Cl) inorganic chains are linked via these full de-pronated tp2- ligands forming a unique 3D I1O2 type micro-porous coordination framework. PXRD patterns of 1 have been determined confirming pure phases of 1. Luminescence investigations suggested that 1 exhibits highly selective and sensitive sensing for trace amounts of benzaldehyde in ethanol, which provides a facile method for real-time detection of benzaldehyde. Meanwhile 1 also exhibits highly selective and sensitive sensing for Cu2+ over other cations with high quenching efficiency Ksv value 1.15×104L·mol-1. As far as we know, 1 represents the first example of alkaline earth-transition hetero-metallic Ba-Cd micro-porous coordination framework as bi-functional luminescent probes for Cu2+ and benzaldehyde.