Mohammadi Ziarani, Ghodsi published the artcileSpiroindeno-pyridineindoles (SIPIs) as new visible colorimetric pH indicators, Quality Control of 13822-56-5, the publication is Chemosphere (2022), 135630, database is CAplus and MEDLINE.
Some new, highly selective, and sensitive colorimetric pH indicators, spiro[4H-indeno-[1,2-b]pyridine-4,3′-[3H]indoles] I (R1 = H, Bn; R2 = Me, Ph; R3 = Et; X = Br, I, F, etc.) (SIPIs) in aqueous solution were developed. SIPIs I were synthesized via a one-pot four-component condensation of isatin derivatives, II β-diketones R2C(O)CH2C(O)OEt, 1,3-indandione, and ammonium acetate using FSi-PrNH-BuSO3H as a nanocatalyst in EtOH. According to the exptl. evaluations, it was found that SIPI derivatives are pH indicators for naked-eye detection of OH ion with intense color changes from orange to purple in the pH range of 10.3-12.
Chemosphere published new progress about 13822-56-5. 13822-56-5 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is 3-(Trimethoxysilyl)propan-1-amine, and the molecular formula is C6H17NO3Si, Quality Control of 13822-56-5.
Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia