A series of trinuclear zinc(II) complexes with reduced Schiff base ligands: turn-off fluorescent chemosensors with high selectivity for nitroaromatics

A facile method for synthesizing trinuclear zinc(ii) complexes with compartmental reduced Schiff bases has been described. Five such complexes, [{(N-3)Zn(L-1)}(2)Zn] (1), [{(SCN)Zn(L-1)}(2)Zn] (2), [{(SCN)Zn(L-2)}(2)Zn] (3), [{(N-3)Zn(L-2)}(2)Zn] (4) and [{(N-3)Zn(L-3)}(2)Zn]center dot CH2CL2 (5) where H2L1 = 2,2 '-[(1,3-propanediyl)bis(iminomethylene)]bis[6-ethoxyphenol], H2L2 = 2,2 '-[(2,2-dimethyl-1,3-propanediyl)bis(iminomethylene)]bis[6-methoxyphenol] and H2L3 = 2,2 '-[(2,2-dimethyl-1,3-propanediyl)bis(iminomethylene)]bis[6-ethoxyphenol], were synthesized and characterized by elemental and spectral analyses. X-ray crystallographic analyses have confirmed their structures. All complexes may be used as sensors for the detection of nitroaromatics in DMF via turn-off fluorescence response.