Cluster-based CaII, MgII and Cdn coordination polymers based on amino-functionalized tri-phenyl tetra-carboxylate: Bi-functional photo-luminescent sensing for Fe3+ and antibiotics

Excess and deficiency of iron(III) and antibiotics from normal permissible limits will induce serious disorders, so their detection is important but challenging. In this work, the asymmetric amino-functionalized tetra-carboxylate H4L (2'-amino-1,1':4',1"-terphenyl-3,3",5,5"-tetracarboxylic acid) containing large conjugated ter -phenyl aromatic backbones have been synthesized and employed. Through a one -pot powerful solvo-thermal synthetic strategy, a series of unique tri-nuclear cluster -based Ca, Mg and CcIll coordination polymers, namely [Cal.s(14HL)(DMF)]. (1), {(Mg1.5( 7-HL).(H20)213H2Oln (2) and {[Cdi.sUlio-L)o.7sln.H20"DMF}n (3) have been successfully prepared. 1-3 exhibit excellent photo -luminescent properties and good fluorescence stability. Structural analyses reveal that tti-nuclear Can secondary building blocks (SBUS) are linked via HO-, forming the 2D clustered -based micro -porous coordination polymer 1. As for 2, three carboxylate groups of partly depronated HO- also link these neighboring tri-nuclear Mg SBUS, which constructs the 2D Mg coordination framework 2. As for 3, fully de-pronated L4- also links these neighboring tri-nuclear SBUS, which ultimately constructs the 3D micro -porous coordination framework 3. Experimental powder x-ray diffraction (PXRD) patterns coincide well with the theoretical patterns, which indicate that we have successfully synthesized the pure phase material 1-3. Photo -luminescent experiments demonstrate that coordination polymers 1-3 can be successfully applied towards bi-functional sensing for sensitive detection. of Fe3+ and the antibiotics NZF (Nitrofurazone). To the best of our knowledge, this is the first example of the application of amino-functionalized tri-phenyl tetra-carboxylate based MOFs towards bi-functional discrimination of Fe3+ and NZF antibiotics with high efficiency Ks values (For Fe3+: 7.28 x 104M-1 for 1; 3.38 x 104M(-1) for 2 and 3.29 x 104 M-1 for 3 and for NZF antibiotics: 4.47 x 10(3)M(-1) for 1; 4 x 10(3)M(-1) for 2 and 5.6 x 10(3)M(-1) for 3).