159394-73-7Relevant articles and documents
Zn(II)-Induced Ground-State π-Deconjugation and Excited-State Electron Transfer in N,N-Bis(2-pyridyl)amino-Substituted Arenes
Yang, Jye-Shane,Lin, Yan-Duo,Lin, Yu-Hsi,Liao, Fen-Ling
, p. 3517 - 3525 (2007/10/03)
The synthesis and X-ray crystal structures of two N,N-bis(2-pyridyl)amino (dpa)-substituted aromatic systems (Ar-dpa) 1 (Ar = 4,4′-disubstituted trans-stilbene) and 2 (Ar = 1,4-disubstituted benzene) and their ZnCl 2 complexes (1/ZnCl2 and 2/ZnCl2) are reported. The fluoroionophoric behavior of 1-2 in response to Zn(II) in acetonitrile also has been investigated. In addition, compound 3DPA has been prepared and served as a π-deconjugated model for 1DPA. The observed crystal structures for 1/ZnCl2 and 2/ZnCl2 could be divided into two distinct types, the planar and the twisted forms, depending on the aryl-dpa (Cph-NC3) dihedral angle. The twisted form is more favorable for these complexes unless the arene has a strong " push-pull" character. Nonetheless, the degree of π-conjugation between the N-pyridyl and the N-aryl group is reduced in both complex forms when compared with the free ligands. Such a Zn(II)-induced π-deconjugation not only directly affects the internal charge transfer (ICT) fluorescence of the dpa-substituted stilbenes but also facilitates the occurrence of photoinduced electron transfer (PET) from the stilbene donor to the dpa/Zn(II) acceptor. The PET process is particularly important in accounting for the observed Zn-(II)-induced fluorescence quenching for 1DPA as well as 3DPA.