Hydrolysis of aliphatic naphthalene diimides: effect of charge placement in the side chains

Abstract

Water‐soluble naphthalene diimides (NDIs) have found uses in a wide variety of applications including as electron acceptors in electron transfer reactions and as molecules that undergo spontaneous organization in aqueous solution. Many studies have looked at their interaction with nucleic acids including work with DNA duplexes, triplexes, quadruplexes, hairpins, and DNA–RNA heteroduplexes. In many of these interactions the NDIs serve as threading intercalators. Herein we describe the reversible hydroxide‐catalyzed hydrolysis of NDIs bearing aliphatic side chains, with ring opening first to the monoimide and then to the diamide. Examples with N‐methylpyrrolidinium groups placed two (1) and three (5) atoms from the central core were studied. The Ka values for the first and second hydrolyses for 1 were 2.5 ± 0.2 × 105 and 2.0 ± 0.1 × 102 M−1, respectively; for 5 they were 1.4 ± 0.1 × 105 and 44 ± 2 M−1, respectively. NDI 1 hydrolyzed 6.8 times faster than 5. The rates for the first and second ring opening of 1 in 100 mM hydroxide measured by stopped‐flow were 17.0 ± 0.2 and 0.53 ± 0.01 s−1, respectively. Capillary electrophoresis in borate buffer showed separation of the diimide and monoimide with the former eluting first. Nuclear magnetic resonance (NMR) showed both the syn and anti isomers of the diamide species. Overall, the rate of hydrolysis of the NDI is increased when the cationic charge is moved closer to the NDI core. Copyright © 2008 John Wiley & Sons, Ltd.

Single‐Molecule Redox‐Targeting Reactions for a pH‐Neutral Aqueous Organic Redox Flow Battery

“…The long-term cycling along with the unchanged FTIR spectra of cycled PI granules (Supporting Information, Figure S14) show that the redox-targeting reaction and active material are reasonably stable. The capacity drops ( Figure 4 b; Supporting Information, Figure S13) were presumably caused by the hydrolysis degradation of PI, [44,45] as well as the potential shift of 2,7-AQDS with pH variation.…”

Electrochemical Evaluation of a Napthalene Diimide Derivative for Potential Application in Aqueous Organic Redox Flow Batteries

“…www.advancedsciencenews.com www.entechnol.de avoiding hydrolysis of NDI. However, as the NDI hydrolysis is reversible, [41,52] cycling at a higher pH might be beneficial to further avoid the HER.…”

Estudo das propriedades eletrônicas e espectroscópicas de uma série de diimidas naftálicas com substituintes aromáticos com potencial aplicação em dispositivos de armazenamento e conversão de energia

“…10. Nestes espectros é facilmente detectável a diferença no deslocamento da carbonila de espécies como a NMI-py dicarboxílico, NDA e NMA (1,4,5,8-naftalenomonoanidrido dicarboxílico): os estiramentos simétrico e assimétrico da C=O aparecem por volta de 1778 cm −1 para os anidridos presentes na NDA e NMA, e não aparecem na NMI-py que possui uma mistura de modos vibracionais das carbonilas dos grupos carboxila (por volta de 1700 cm −1 ) e diimida (geralmente duas bandas bem 167 ; e (b) Barros (2006 Os estiramentos do grupo amina estão caracterizados nos modos vibracionais em 3411 cm −1 , 3320 cm −1 , e 3218 cm −1 (gura 3.19).…”

“…Espectro de 1 H-RMN da hidrólise de uma diimida (esquerda); espectros de 1 H-RMN de uma mistura de monoimidas (direita) Fonte:Kim (2007) 167 e Tambara (2011) 166. A recristalização em DMF mostrou-se eciente na puricação da NDI-py como pode ser visto no novo espectro com os picos dos três tipos de hidrogênio para esta espécie (gura 3.6): dois dubletos para os dois tipos de hidrogênio da piridina em 7.594-7.609 ppm e 8.824-8.839 ppm, e um singleto em 8.764 ppm para os hidrogênios simétricos do naftaleno.…”