Charge-transfer complexes of pyrimidine Schiff bases with aromatic nitro compounds

Charge-transfer (CT) complexes of pyrimidine Schiff bases, derived from condensation of 2-aminopyrimidine and substituted benzaldehydes, with some aromatic polynitro compounds were prepared and investigated using IR, UV, visible and H-1 NMR spectroscopy. For all solid complexes, the main interaction between the donor and acceptor molecules takes place through the pi-pi* interaction. Strong and some weak acidic acceptors, in addition interact through proton transfer from the acceptor molecule to the basic centre of the electron donor. Also, an pi-pi* transition was detected in some complexes. (C) 2011 Elsevier B.V. All rights reserved.