Photophysical study of dansylamide in heterogeneous polymeric micro-environment

Photophysics of dansylamide investigated in a range of polymers; Large Stokes shift indicate charge transfer process; EERS and decay data point towards heterogeneity; and besides polarity, polymer free volume effect is noticed and analyzed. Derivatives of the 5-amino-1-naphthalenesulfonates, particularly having dansyl (5-N,N-dimethylamino-1-naphthalenesulfonate) group have found extensive use as fluorescence probes for the structural and dynamical studies of biological molecules.Dansylamide is one such biologically important probe molecule which has multifarious applications in the field of luminescence. It'sphoto-physics is a bit complicated due to the attachment of dimethyl group with the amino group and due to possible transitions of the excited state from nearly degenerate ¹L_a and ¹L_b excited states. In a polymer like complex system heterogeneity also influence the ground and excited state processes and there is a complex dependence of photophysical parameters on various factors like polarity, proticity, free volume of site which makes photo physics of dansylamide still more challenging to comprehend. The study demonstrates the effect of heterogeneity and other general and specific microscopic polymer properties on the probe