4 Conclusions
The different stable conformations of probe C23 were found through
theoretical method which explained the no fluorescent character of the
probe itself. The extreme points of electrostatic potential of C23
showed the potential reaction sites with the HSA and
SO2. After the Michael addition reaction with
SO2 (HSO3-1), some
rotated C-C bonds in C23 were saturated in CS structure which reduced
the number of the stable conformations and led to the blue fluorescence
generation. The electron excitation analysis indicated the charge
transfer process in the C23 and CS when the molecules were under optical
excitation. These results provided the insights in preparing a wide
range of fluorescent probes and great potential for widespread
industrial applications.