We have presented spectrally resolved femtosecond three-pulse photon echo measurements on Zn(II)–OEP, Ni(II)–OEP and Co(II)–OEP. Increased degree of freedom in scans of time delays allows one to separate and extract specific type of spectroscopic information in complex molecules by studying spectral and temporal evolution of the photon echo signals. By varying the population times, population relaxation dynamics and inhomogeneous broadening is revealed in the photon echo spectra. Time-integrated photon echo signals show two different timescales. The electronic relaxation timescale is found to be sub 50fs whereas the timescale for intramolecular vibrational relaxation, occurring in Q00 band, was found to be over a picosecond for Co(II)–OEP and Ni(II)–OEP and within a picosecond for Zn(II)–OEP.
