1H-Benzo[g]pteridine-2,4-dione

Area of Science:

• Crystallography
• Solid-state chemistry
• Organic chemistry

Background:

• Previous structural determination of C10H6N4O2 by Smalley et al. (2021) utilized powder diffraction and 15N NMR spectroscopy.
• Understanding tautomeric forms and solid-state structures is crucial for predicting chemical properties and reactivity.

Purpose of the Study:

• To confirm the solid-state structure of C10H6N4O2 using low-temperature crystallographic data.
• To elucidate the tautomeric form (alloxazine vs. isoalloxazine) in the solid state.
• To analyze the intermolecular interactions and crystal packing.

Main Methods:

• Single-crystal X-ray diffraction at low temperature.
• Analysis of crystallographic data from a non-merohedral twin crystal.
• Identification of hydrogen bonding patterns (N-H...O and N-H...N).

Main Results:

• The alloxazine tautomer (1H-benzo[g]pteridine-2,4-dione) is confirmed as the dominant form in the solid state.
• Molecules self-assemble into hydrogen-bonded chains propagating along the [01] direction.
• Alternating R2(8) rings formed by N-H...O and N-H...N interactions dictate the crystal structure.
• The crystal was identified as a non-merohedral twin with a specific domain ratio.

Conclusions:

• The crystallographic confirmation solidifies the understanding of C10H6N4O2's solid-state structure and tautomeric preference.
• The identified hydrogen-bonding network provides insights into crystal engineering and material properties.
• Detailed structural analysis aids in differentiating between alloxazine and isoalloxazine forms in related compounds.