ISMSC 2007 - Università degli Studi di Pavia

N,N-bis(2-aminoethyl)-2,2-bipyridine-3,3-dicarboxamide: A Novel
Fluorescent Chemosensor For Divalent Nickel and Copper
Rati Kanta Bera, B. K. Kanungo and Minati Baral*
Department of Chemistry, Sant Longowal Institute of Engineering & Technology, Longowal,
Punjab-148106, India
PSB 87
A novel bipyridyl based fluorescent system, N,N-bis(2-aminoethyl)-2,2-bipyridine-3,3dicarboxamide
(BABD) for sensing divalent nickel and copper has been synthesized and
characterized through elemental analyses and spectral (UV-VIS, IR, 1 H NMR and 13 C NMR)
data. The lowest energy molecular geometry of BABD was obtained through empirical and
quantum mechanical method. Theoretical UV–VIS, IR and 1 H NMR spectral data were
calculated from the energy-minimized structure (Fig. 1) by applying semi-empirical ZINDO, PM3
and TNDO/2 method, respectively and were compared with the experimental data. The
fluorescence behavior of this system has been studied in the absence and in the presence of
the salt of several transition metal ions. On excitation at 289 nm the system gives a maximum
emission band at ~379 nm and two shoulders at 410 and 442 nm. It was observed that BABD is
highly specific and selective towards divalent nickel and copper and gives sensitive response of
fluorescence enhancement in aqueous solution. The emitting behavior of the BABD over the pH
range 2 to 11 was investigated through a spectrofluorimetric titration experiment.
Fig 1. Energy minimized structure of BABD
The fluorescence band of BABD at ~379 nm showed dramatic enhancement with increase in pH
whereas in low pH (