S1 Organic-Inorganic Hybrids Composed of Keggin- Type [PMo 10 V 2 O 40 ] 5- Anion and Porphyrins: Synthesis, Characterization and Influence of Porphyrin Substituents on Optical Nonlinearities Farooq Khurum Shehzad, †,฀ Arshad Iqbal, † Yunshan Zhou, †,* Lijuan Zhang, †,* Ting Wang † and Xiaoyu Ren † † State Key Laboratory of Chemical Resource Engineering, Institute of Science, Beijing University of Chemical Technology, Beijing 100029, P. R. China ฀ Department of Chemistry, COMSATS University Islamabad, Park Road, Tarlai Kalan, Islamabad, 45550, Pakistan Synthesis of 5,10,15,20-tetrakis(4-hydroxy phenyl)porphyrin (compound 5): The compound 5 was prepared by the modified literature method. S1 In the first step 4-hydroxybenzaldehyde (4.0 g, 32.8 mmol, 6.0 eq.) was dissolved in 100 mL propionic acid and methyl-4-formylbenzoate (1.8 g, 11 mmol, 2.0 eq.) was also added to it. Upon the refluxing, the pyrrole (C 4 H 4 NH, 2.94 g, 42.6 mmol, 8.0 eq.) mixed with 20 mL of propionic acid was added dropwise to the reaction mixture. The reaction was refluxed for 1.5 hour and then cooled to room temperature. A mixture of six porphyrins were obtained after filtration by suction which were isolated by silica gel column chromatography (88 mg, 6.8% yield of required compound). Elemental analysis for C 44 H 30 N 4 O 4 (F W : 678.75) Calc: C, 77.86; H, 4.46; N, 8.25. found: C, 77.83; H, 4.456; N, 8.27. Synthesis of 5,10,15,20-tetrakis(3,4-Dimethoxy phenyl)porphyrin (compound 6): The compound 6 was prepared by modified Alan D. Adler’s method. S2 In 375 mL propionic acid, 3,4-dimethoxybenzaldehyde (16.6 g, 0.1 mole) was dissolved. Upon refluxing, pyrrole (6.96 mL,