A second polymorph of [H3N(CH2)3NH3][V4O10]

Area of Science:

• Inorganic Chemistry
• Crystallography
• Materials Science

Background:

• Polymorphism in inorganic-organic hybrid compounds is crucial for tuning material properties.
• Propane-1,3-diammonium tetravanadate exists in different crystalline forms, influencing its structure and properties.

Purpose of the Study:

• To characterize a novel polymorph of propane-1,3-diammonium tetravanadate, designated as the beta polymorph.
• To elucidate the structural differences between the alpha and beta polymorphs, focusing on the dication conformation and crystal symmetry.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the crystal structure of the new polymorph.
• Comparison of crystallographic data and structural features with the previously reported alpha polymorph.

Main Results:

• The beta polymorph, [C3H12N2][V4O10], crystallizes in the C2/c space group, exhibiting higher symmetry than the alpha polymorph (P2(1)/n).
• The propane-1,3-diammonium dication adopts a syn-syn conformation, lying on a twofold axis, contrasting with the syn-anti conformation in the alpha polymorph.
• Both polymorphs share a similar inorganic layer topology but differ in the stacking arrangement of vanadyl groups ('head-to-head' vs. 'head-to-tail').

Conclusions:

• The conformational difference of the propane-1,3-diammonium dication is responsible for the higher symmetry of the beta polymorph.
• The distinct stacking of vanadyl groups represents a key structural variation between the two polymorphs, potentially impacting material properties.