An optical anion chemosensor based on a europium complex and its molecular logic behavior

In this paper, synthesis and photophysical properties of an organoeuropium complex, Eu(DBM)(3)DPPZ (DBM = dibenzoylmethane, DPPZ = dipyrido [3,2-a:2',3'-c]phenazine), are described and discussed. The europium complex sensor can efficiently recognize AcO- ion over other anions by the increase of luminescence intensity, which is applicable to naked eye detection for AcO- ion. The sensing mechanism is ascribed to the replacement of DPPZ by AcO- ion. Moreover, the Eu3+ emission is also found to be sensitive to molecular oxygen through a back-energy transfer mechanism. Based on these characters, this off-on-type luminescent sensor could successfully mimic an IMP (IMPLICATION) gate at molecular level with AcO- ion and oxygen as inputs. The output of a sharp characteristic Eu3+ emission is read as 0 only in the absence of AcO- ion under oxygen atmosphere. As far as we know, this is the first example of a logic gate corresponding to a two-input IMP function obtained from a europium complex. (c) 2012 Elsevier Ltd. All rights reserved.