H-Bonded anion–anion complexes in fentanyl citrate polymorphs and solvates. Issue 1 (5th December 2018)

• Record Type: Journal Article
• Authors: Barbas, Rafael; Prohens, Rafel; Bauzá, Antonio; Franconetti, Antonio; Frontera, Antonio
• Is Part Of: Chemical communications. Volume 55:Issue 1(2019)
• Page Start: 115
• Page End: 118
• Publication Date: 2018-12-05
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1039/c8cc09028a
• Languages: English
• ISSNs: 1359-7345

Abstract

Abstract : We report the experimental observation (X-ray characterization) of two types of anion–anion complexes (anion = dihydrogen citrate) stabilized by H-bonds that are observed in fentanyl citrate solvates. Abstract : Herein we report the experimental observation (X-ray characterization) of two different binding modes in H-bonded anion–anion complexes (anion = citrate) in N -(1-(2-phenylethyl)-4-piperidinylium)- N -phenyl-propanamide-citrate (fentanyl citrate). High level DFT calculations indicate that both types of anion–anion complexes (one with two and the other with four H-bonds) are thermodynamically unstable but kinetically stable with respect to the isolated anions with activation barriers as high as 14 kcal mol −1 .