Figure 1. 1H NMR spectra of free H2TPP in CDCl3 at 298 K

From

An Undergraduate Experiment Using Microwave-Assisted Synthesis of Metalloporphyrins: Characterization and Spectroscopic Investigations

Shaikha S. Al Neyadi, Ahmed Alzamly, Abdullah Al-Hemyari, Ibrahim M. Tahir, Saeed Al-Meqbali, M. A. Ali Ahmad, Muna Bufaroosha

World Journal of Chemical Education. 2019, 7(1), 26-32 doi:10.12691/wjce-7-1-4