title: Odd-Even Alternation in Tautomeric Porous Organic Cages with Exceptional Chemical Stability.
abstract: Amine-linked (C-NH) porous organic cages (POCs) are preferred over the imine-linked (C=N) POCs owing to their enhanced chemical stability. In general, amine-linked cages, obtained by the reduction of corresponding imines, are not shape-persistent in the crystalline form. Moreover, they require multistep synthesis. Herein, a one-pot synthesis of four new amine-linked organic cages by the reaction of 1,3,5-triformylphloroglucinol (Tp) with different analogues of alkanediamine is reported. The POCs resulting from the odd diamine (having an odd number of -CH2groups) is conformationally eclipsed, while the POCs constructed from even diamines adopt a gauche conformation. This odd-even alternation in the conformation of POCs has been supported by computational calculations. The synthetic strategy hinges on the concept of Schiff base condensation reaction followed by keto-enol tautomerization. This mechanism is the key for the exceptional chemical stability of cages and facilitates their resistance towards acids and bases.
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR)Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr.HomiBhabha Road, Pune-, 411008, India.
authors.forename: Saibal
authors.initials: S
authors.lastname: Bera
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR)Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr.HomiBhabha Road, Pune-, 411008, India.
authors.forename: Arghya
authors.initials: A
authors.lastname: Basu
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR)Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr.HomiBhabha Road, Pune-, 411008, India.
authors.forename: Srinu
authors.initials: S
authors.lastname: Tothadi
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR)Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr.HomiBhabha Road, Pune-, 411008, India.
authors.forename: Bikash
authors.initials: B
authors.lastname: Garai
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR)Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr.HomiBhabha Road, Pune-, 411008, India.
authors.forename: Subhrashis
authors.initials: S
authors.lastname: Banerjee
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR)Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr.HomiBhabha Road, Pune-, 411008, India.
authors.forename: Kumar
authors.initials: K
authors.lastname: Vanka
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR)Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr.HomiBhabha Road, Pune-, 411008, India.
authors.forename: Rahul
authors.identifier: 0000-0002-3547-4746
authors.initials: R
authors.lastname: Banerjee
keywords: chemical stability; keto-enol tautomerism; odd-even effect; porous organic cages