Zn/Cd/Cu- frameworks constructed by 3,3′-diphenyldicarboxylate and 1,4-bis(1,2,4-triazol-1-yl)butane: Syntheses, structure, luminescence and luminescence sensing for metal ion in aqueous medium

Abstract Three metal-organic frameworks (MOFs), [M(dpdc)(btb) 0.5 ] n (M = Zn 1 , Cd 2 ; dpdc = 3,3′-diphenyldicarboxylate and btb = 1,4-bis(1,2,4-triazol-1-yl)butane) and [Cu 3 (dpdc) 3 (btb) 2 ] n ( 3 ) were prepared and structurally determined. 1 is a 2D structure with the topology of {3 3 ·4 7 ·5 4 ·6}, while 2 possesses a 3D framework with the {3 12 ·4 29 ·5 14 } topology. Complex 3 displays a 3D framework with the topology of {3 15 .4 35 .5 5 }2{3 6 .4 8 .5 12 .6.7}. 1 – 2 exhibit intense blue luminescence and high stability in water, which make them highly promising candidates as sensors using in aqueous medium. Complex 1 is a potential bi-functional chemosensor for Fe 3+ and Al 3+ ions while 2 displays a selective sensing ability to Fe 3+ ion. Quenching mechanism of Fe 3+ on the luminescence of 1 – 2 is attributed to the charge transfer process LMCT. 1 and 2 have same compositions but have different structures, thermally stabilities and different luminescence sensing functions. The relationship between MOF structures and luminescence sensing toward metal ions are further discussed.