Vibrational spectrum and molecular structure of triphenylamine monomer: A combined matrix-isolation FTIR and theoretical studyElectronic supplementary information (ESI) available: Fig. S1 provides atom numbering and Table S1 optimized geometry parameters and rotational constants for the TPA molecule. Table S2 provides a list of calculated frequencies and descriptions for fully symmetrical (A1) vibrations in the TPA monomer. Figs. S2?S4 present changes in the TPA molecule geometry during potential energy scans with different symmetry restrictions.See http://www.rsc.org/suppdata/cp/b3/b306489a/