Deep eutectic solvents comprising creatine and citric acid and their hydrated mixtures

Abstract

We report the phase diagram for the binary creatine–citric acid mixture which features a stable and broad eutectic region.

Empirical Hydrogen Bonding Donor (HBD) Parameters of Organic Solvents Using Solvatochromic Probes – A Critical Evaluation

“…[12d,47b,87] In addition, the investigation of deep eutectic solvent mixtures with B30 and other solvatochromic indicators has become a popular subject of investigation. [80,81,128,129] The application of the pKa rule to assess proton transfer or hydrogen bond formation is an essential prerequisite for the correct analysis of solvatochromism in these solvent systems. For example, dubious (too large) E T (30) values for solvent systems containing citric acid are reported without critical discussion.…”

“…[128] However, other authors have carefully checked and found that this solvent system cannot be measured with B30. [129] The central aspect of the density of the solvent mixture in relation to the involved, proportionate molar masses of constituents is a decisive factor. Precise density measurements as a function of composition in mixtures of organic solvents and with ILs are an essential basis for arriving at physically correct statements in connection with solvatochromic measurements.…”

“…For example, dubious (too large) E T (30) values for solvent systems containing citric acid are reported without critical discussion [128] . However, other authors have carefully checked and found that this solvent system cannot be measured with B30 [129] …”

“…[1b,c] It was also shown that the E T (30) parameter of various alcohols, including monohydric and polyhydric alcohols, correlates significantly with D HBD . [1c] Furthermore, both the solvent dependent 129 Xe NMR shift and the rate constant k 1 of S N 1 solvolysis reaction of 2-chloro-2-methylpropane (tertiary butyl chloride) partially correlate with D HBD . [1b] In the context of the influence of OH group density on the UV/Vis absorption energy, we want to evaluate further empirical polarity scales in relation to the D HBD quantity.…”

Rapid dissolution of high concentration poly(3-hydroxybutyrate) using neoteric biosolvents: experiment and molecular dynamics simulation

“…18 In line with green chemistry principles and sustainability requirements, the search for ‘truly’ green solvents for the dissolution of biopolymers such as PHAs is essential. 19 To provide such green dissolution media, Abbott et al 20 discovered deep eutectic solvents (DESs) in 2003 and their applications have grown by leaps and bounds in about two decades. 21 A DES is a eutectic mixture of a hydrogen-bond donor (HBD) and a quaternary ammonium or phosphonium salt resulting in a liquid with a melting point below that of its individual components.…”