ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The paper is based on mid-frequency Raman scattering data of neat diamino poly(propylene imine) dendrimer molecule DAB(CN)64; time correlation functions were obtained from a band profile analysis of its fundamental CN mode near 2246 cm−1 at four temperatures between 300 and 123 K; lattice relaxation processes were found to be governed by a stretched exponential modulation function with dispersion parameter α=0.90±0.05 (300 K) and 0.85 (123 K) and corresponding time constant τ0=0.78 and 1.15 ps, respectively. The results suggest that the fast fluctuations of the molecular environment of the CN end groups of the dendrimer system regain equilibrium by independent, parallel pathways with Poisson relaxation times τ that show a broader distribution at lower system temperatures. The results imply that the shape and width of the CN band contour are generated by a vibrational dephasing process in the intermediate modulation regime, under inseparable contributions of intra- and intermolecular oscillator–lattice coupling. © 1999 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.478846
Permalink
