This work focuses on characterization of chiral organic systems with partial solid solutions. Particularly, behavior the (R)- and (S)-ethanolammonium 3-chloromandelates (E3ClMA) has been investigated experimentally. Partial solutions series (R)-E3ClMA–(Rac)-E3ClMA (S)-E3ClMA–(Rac)-E3ClMA were discovered at eutectic type binary phase diagram by means systematic differential scanning calorimetry X-ray powder diffraction measurements. Solubility metastable zone width measured for (R)-E3ClMA,...

Two model compounds—valine C5H11NO2 (l-Val) and isoleucine C6H13NO2 (l-Ile)—were chosen to study isomorphism of the compounds formed by enantiomeric molecules having similar shapes, but differing in number chiral centers. The X-ray powder diffraction method was applied investigate samples with various ratios valine crystallized from aqueous solutions cooling isothermal methods. Limited solid state miscibility between established. A non-equimolar discrete compound molecular ratio Val:Ile =...

1 : 3 and 2 discrete compounds are verified in two chiral systems discussed with respect to known cases the literature.

Solubility equilibria of threonine, allo-threonine, and their mixtures in water were measured a temperature range between 10 80 °C. In comparison with the threonine species exhibit higher solubility water. The phase diagram ternary system l-allo-threonine/l-threonine/water shows maximum solubilities at l-threonine contents 56–66%, while tie lines clearly indicate presence solid solutions. X-ray powder diffraction (XRPD) studies various prove complete miscibility l-allo-threonine molecules...

Features of crystal structures and their thermal deformations in the l-threonine/l-allo-threonine system were investigated by means single-crystal X-ray diffraction temperature-resolved powder diffraction. The belongs to systems with continuous solid solutions. comparative analysis l-threonine (l-Thr), l-allo-threonine (l-aThr), mixed crystals was conducted based on literature our own data. It found that distances between methyl groups are more sensitive composition than lengths hydrogen...

Equimolar and non-equimolar heterocompounds of amino acids are examined with a common approach considering their molecular dimers, side chain structures conformations.

The limits of solid solutions and thermal deformations in the L-alanine–L-serine (L-ala–L-ser) amino acid system have been determined. Thirteen mixtures with various proportions components L-ser/L-ala were studied using powder X-ray diffraction techniques. It was found that regions are rather limited cover less than 10 mol. % from each component side. behavior L-ser L-ala composition = 90/10 by temperature-resolved diffraction. heating only causes deformations, while two-phase ratio form at...

X-Ray diffractometry was employed to investigate the possibility of formation non-equimolar discrete compounds in chiral system malic acid S- and R-enantiomers. Samples studied were mixtures single enantiomers or an enantiomer various polymorphs racemic compound. From samples prepared via recrystallization melt grinding initial reactants, it is demonstrated that can form stable stoichiometric S:R ratios 3:1 1:3. Compared known pure phases, corresponding S3R/SR3 are characterized by a proper...

Thermal deformations, polymorphic transformations and melting of normal paraffins CnH2n+2 with odd numbers n = 17, 19, 21 23 have been studied by the thermoroentgenographic method. Common traits corresponding to four stages distinguished in thermal deformations all paraffins. A quantitative structural interpretation deformation nature is given based on principle rotation aliphatic chains about their axes. Odd ≤ melt before reaching hexagonal state, paraffin at heating first undergoes an...

The anisotropy of thermal deformations in seven studied chiral crystal structures is attributed to the different numbers and organizations intermolecular contacts.

The method of temperature-resolved powder X-ray diffraction (TRPXRD) was used to determine the elevated temperature behavior L-aspartic acid (L-asp), DL-aspartic (DL-asp), L-glutamic (L-glu), and an L-asp0.25,L-glu0.75 solid solution. These amino acids were not found undergo any solid-phase (polymorph) transformations. When heated, they all experienced only thermal deformations. corresponding parameters monoclinic cells L-asp DL-asp, orthorhombic L-glu L-asp0.25,L-glu0.75, calculated for...

Abstract In weathering crusts, sedimentary rocks and zones of hydrothermal transformation frequently mixed‐layer illite‐montmorillonite will occur. Based upon new experimental transformations montmorillonite beidellite under conditions in the presence potassium chloride it is shown that illite‐montmorillonite, with decreasing expandable proportion, occurs form transitional stages → illite transformation. Besides increase reaction temperature or concentration, first all an increased charge...