High-pressure polymorphism in L-serine monohydrate: identification of driving forces in high pressure phase transitions and possible implications for pressure-induced protein denaturation

Crystal structures of amino acids: from bond lengths in glycine to metal complexes and high-pressure polymorphs

“…[166] l-Ser monohydrate has a single high-pressure transition, where particularly the hydrogen bonding role of the water molecular changes between the phases. [113] As for the racemates of these two amino acids, no phase transitions were observed for dl-Ser up to pressure of 8.6 GPa. [167] dl-Cys, on the other hand, undergoes a phase transition at only 0.1 GPa, the lowest pressure reported for a phase transition in a crystalline amino acid, yielding dl-Cys (II), which is also obtained by cooling at ambient pressure.…”

“…The shortest crystallographic axis of any amino acid is 4.418 Å, found in the high-pressure (5.2 GPa) polymorph II of l-Ser monohydrate (LSERMH16). [113] The shortest axis associated with hydrogen bonding between molecules related by translation is 4.616 Å for 5-methyl l-Glu (GAVRAX, L3-L3 layer), [114] while the upper limit is 6.238 Å for diammonium O-phospho-dl-threoninate (GEJKUC, no 2D layer), [66] corresponding to the distances labelled A and B in Figure 12, respectively. The vast majority of amino acid structures have an axis in this range.…”

Multicomponent organic crystals at high pressure

“…Though the water molecules become coordinatively saturated with respect to H-bonding, and interlayer serine-serine Coulombic interactions are strengthened, model calculations suggested that overall the intermolecular interactions are weaker in phase-II than phase-I. According to the authors of the work, the lattice enthalpy becomes more negative through the transition as a result of the smaller PV term applying to the more efficiently packed phase-II structure [80].…”

“…Such an example is provided by a comparison of the effect of pressure on L-and DLserine [15,[74][75][76][77][78][79], L-serine monohydrate [80,81], and on bis-DL-serinium oxalate dihydrate [82].…”

Polymorphism Solvatomorphism 2008

“…The 2008 literature also contained a number of additional reports that summarized investigations of phase transitions among polymorphs and solvatomorphs of various organic compounds, and aspects of these159–170 have been summarized in Table 3.…”