Research Output per year
Control over vibrational frequency modes is important in optimising the performance and behaviour of conjugated organic materials employed as charge transfer mediators and optical components in optoelectronic devices. Raman spectroscopy represents a powerful technique that can be employed to determine the structural implications of molecular substitution on photophysical properties in such conjugated organic environments. Herein, we report for the first time, the optimised geometries for a series of eight systematically varied N-substituted diketopyrrolopyrroles as well as their experimental and computed Raman spectra, with special emphasis placed upon their spectral band assignments. Clear out-of-plane structural re-arrangements, including pyramidalisation of the lactam nitrogens arising from intramolecular H-bonding interactions were observed upon N-substitution in the reported systems, leading to significant vibrational frequency shifts for ν(N-C) and ν(C=O) modes. In addition, mode scaling factors were determined and found to be comparable with those reported previously, employed using the same density functional. The following study addresses the implications of structural variation on the progression of those intense Raman modes which play a key role in tuning the photophysical properties of N-substituted diketopyrrolopyrrole systems and as such should be of broad interest to those developing functional materials based upon this molecular motif.
- density functional theory
- scaling factors
Intermolecular interactions and energetics in the crystalline π-π stacks and associated model dimer systems of asymmetric halogenated diketopyrrolopyrrolesCalvo-Castro, J., Warzecha, M., Oswald, I. D. H., Kennedy, A. R., Morris, G., McLean, A. J. & McHugh, C. J., 13 Jan 2016, In : Crystal Growth and Design. 16, 3, p. 1531-1542 12 p.
Research output: Contribution to journal › Article