Giant strain geared to transformable H-bonded network in compressed β-D-mannose

Area of Science:

• Crystallography
• Materials Science
• Supramolecular Chemistry

Background:

• Hydrogen bonds in sugars and ices are stable with temperature but sensitive to pressure.
• Previous studies investigated pressure-induced transitions in other sugars like glucose and sucrose.

Purpose of the Study:

• To investigate the effects of high pressure on the crystal structure and hydrogen bonding network of beta-D-mannose.
• To determine the pressure-induced transition point and its impact on molecular and crystal structure.

Main Methods:

• Single-crystal X-ray diffraction under high pressure.
• Analysis of crystal deformation and strain propagation.
• Comparison with pressure-induced transitions in other sugars.

Main Results:

• Beta-D-mannose undergoes a structural transition at 1.95 GPa, the lowest observed pressure for sugars.
• The transition induces significant, non-destructive strain and visible shape deformation in the crystal.
• The 3D hydrogen bond network and molecular conformation are reconstructed, preserving space-group symmetry.
• New repulsive O...O contacts are formed in beta-D-mannose under pressure.

Conclusions:

• Beta-D-mannose exhibits a unique pressure-induced transition at a lower threshold than other sugars.
• The observed strain and structural changes highlight the sensitivity of sugar crystal structures to pressure.
• Understanding these transitions is crucial for materials science and predicting sugar behavior under extreme conditions.