Journal article

A sting in the tail of flexible molecules: spectroscopic and energetic challenges in the case of p-aminophenethylamine

Isabella A Lobo, David JD Wilson, Evan Bieske, Evan G Robertson



The neurotransmitter analogue p-aminophenethylamine (APEA) illustrates many of the pitfalls and challenges associated with spectroscopic and conformational analysis of flexible molecules. The combined experimental-theoretical study presented here resolves a long-standing controversy over its conformational energetic preferences. Jet-cooled resonance enhanced two-photon ionisation (R2PI) and IR-UV ion depletion techniques enabled conformer-specific IR spectra in the NH-CH stretch region to be measured for four distinct conformers of APEA. Comparison of spectra with theoretical calculations (including MP2, M06-2X and B3LYP with aug-cc-pVTZ basis sets) allows the two most populated conformers t..

View full abstract

University of Melbourne Researchers


Awarded by Australian Research Council

Funding Acknowledgements

Sincere thanks to Professor Ilana Bar for sending us the stimulated Raman data for PEA and kindly agreeing to its inclusion in this paper. Thanks also to Chris Thompson for earlier efforts with R2PI spectroscopy of APEA. This research was supported under the Australian Research Council's Discovery Project funding scheme (Project Number DP0986980). Financial support from La Trobe University is gratefully acknowledged. Quantum chemistry calculations were carried out using facilities at La Trobe University, the Victorian Partnership for Advanced Computing (VPAC) and at Australia's National Computational Infrastructure National Facility (NCI-NF).