1 Supporting Information β-Tetracyanobutadiene Appended Porphyrins: Facile Synthesis, Spectral, and Electrochemical Redox Properties and Their Utilization as Excellent Optical Limiters Renu K. Rohal, † Jitendra Nath Acharyya ‡ Mohd Shanu, ‡ G. Vijaya Prakash ‡,* and Muniappan Sankar †,* † Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India ‡ Nanophotonics Lab, Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India Table of Contents Page No Experimental Section and Synthesis of Porphyrins (2-6) 2 Fig. S1 Comparative 1 H NMR of H 2 -TCBD (2) and H 2 -PE 2 (1) in CDCl 3 at 298 K 5 Fig. S2 1 HNMR spectrum of H 2 -TCBD (2) in CDCl 3 at 298 K. 5 Fig. S3 1 HNMR spectrum of Ni-TCBD (4) in CDCl 3 at 298 K. 6 Fig. S4 1 HNMR spectrum of Zn-TCBD (6) in CDCl 3 at 298 K. 6 Fig. S5 13 C NMR spectrum of H 2 -TCBD (2) in CDCl 3 at 298 K 7 Fig. S6 13 C NMR spectrum of Ni-TCBD (4) in CDCl 3 at 298 K. 7 Fig. S7 13 C NMR spectrum of Zn-TCBD (6) in CDCl 3 at 298 K. 8 Fig. S8 MALDI-TOF-MS of H 2 -TCBD (2) using HABA as matrix at 298 K. 8 Fig. S9 MALDI-TOF-MS of Cu-TCBD (3) using HABA as matrix at 298 K. 9 Fig. S10 MALDI-TOF-MS of Ni-TCBD (4) using HABA as matrix at 298 K. 9 Fig. S11 MALDI-TOF-MS of Co-TCBD (5) using HABA as matrix at 298 K. 9 Fig. S12 MALDI-TOF-MS of Zn-TCBD (6) using HABA as matrix at 298 K. 10 Fig. S13 Comparative Cyclic voltammograms of synthesized porphyrins (1-6) in DCM at 298 K. 10