Chromophoric Barbituric Acid Derivatives with Adjustable Hydrogen‐Bonding Patterns as Component for Supramolecular Structures

Abstract

Summary: The barbituric acid moiety of the presented dyes shows multifunctional properties like acidochromism, solvatochromism, and adjustable hydrogen‐bonding pattern for molecular recognition. Hydrogen‐bonding ability, acidity and solvatochromic effects are studied for a series of N‐alkyl substituted 5‐(4‐nitrophenyl)‐barbiturates. Solvatochromism and metal ion complexation are also investigated using chromophoric thiobarbituric acid derivatives.

Interactions of Enolizable Barbiturate Dyes

“…The facts of Table clearly indicate a positive solvatochromism for BA dyes of the merocyanine type, because a , s , d and e coefficients from Equations (4) and (5) altogether show a negative algebraic sign. Likewise, pyridinium‐betaine dyes of the Reichardt‐type, which contain the BA moiety anion as negative part, unambiguously show a negative solvatochromic property because a , s , d and e coefficients from Equations (4) and (5) altogether show a positive algebraic sign …”

“…[3,8] BAs are readily availablea nd can be chemically modified on demand. [9] For this purpose, barbiturate dyes have been constructed in such aw ay that the hydrogen bond formation affects the electron density of one of the substituent of the chromophore.C onceptually, an electron-withdrawing substituent such as the 4-nitrophenyl groupo rt he 4-pyridinium ring is coupled at the five position of the six-membered BA ring. [7] As long as the BA exists in its keto form, those compounds are rarely coloured because the p-conjugation is interruptedb y as p 3 -hybridised carbon atom.…”

Charge density and optical properties of multicomponent crystals containing active pharmaceutical ingredients or their analogues

“…Bis nicotinamidium bis d-tartrate 1.25-hydrate crystals exhibit SHG efficiency of 1.25 compared with KDP (potassium dihydrogen phosphate) (Senthil Murugan et al, 2015). A favorable distribution of hydrogen-bond donors and acceptors as well as the possibility of metal-ion complexation (Bolz et al, 2010) allow the potential for the designed engineering of novel materials based on barbituric acid or its derivatives (Zerkowski et al, 1997;Lehn et al, 1990;Xiong et al, 2003). All of the above facts make pharmaceutical molecules at least worth considering as components for engineering optical devices.…”

Assessing the potential of para-donor and para-acceptor substituted 5-benzylidenebarbituric acid derivatives as push–pull electronic systems: Experimental and quantum chemical study

“…Electron-accepting abilities of barbituric acid moiety are well documented in the literature [7,[27][28][29][30]. However, barbituric acid as electron-donor moiety in the molecules of the pushpull type is not yet confirmed [19,[31][32][33][34].…”

“…Electron-donating substituent (D -push) covalently bonded to electron-accepting substituent (A -pull) via a p-conjugated bridge (linker) represent a class of molecules known as push-pull electronic systems (D-p-A). These compounds have attracted a great attention as organic materials with promising electronic and optical properties applied in non-linear optics (NLO) [11][12][13][14], dyesensitized solar cells (DSSCs) [15,16], organic light-emitting diodes (OLEDs) [17], colorimetric pH sensors, and ions detection [18,19]. The structural motifs, important for the potential application of push-pull barbituric acid derivatives as NLO chromophores, are summarized in a brief article of Ikeda et al [20].…”