Structure of cycloguanil hydrochloride by neutron diffraction

Area of Science:

• Crystallography
• Chemical Physics
• Materials Science

Background:

• The s-triazine scaffold is a core structure in various biologically active compounds and materials.
• Understanding the precise three-dimensional arrangement of atoms in crystalline solids is crucial for predicting their properties and designing new molecules.

Purpose of the Study:

• To elucidate the detailed crystal structure of 4,6-Diamino-1-(p-chlorophenyl)-1,2-dihydro-2,2-dimethyl-s-triazine hydrochloride.
• To investigate the intermolecular interactions, including hydrogen bonding, that stabilize the crystal lattice.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the unit-cell parameters and collect intensity data.
• The crystal structure was solved and refined using standard crystallographic techniques, yielding R(F2) = 0.050 and wR(F2) = 0.063.

Main Results:

• The compound crystallizes in the monoclinic system (space group P21/c) with determined unit-cell dimensions.
• The triazine ring displays a non-planar conformation, with the quaternary carbon atom displaced from the plane of the other five ring atoms.
• Intermolecular hydrogen bonding forms cyclic dimers between the 6-amino groups and N(5) atoms of adjacent molecules, while other N-H groups interact with the chloride counterion.

Conclusions:

• The study provides a precise structural description of 4,6-Diamino-1-(p-chlorophenyl)-1,2-dihydro-2,2-dimethyl-s-triazine hydrochloride at the molecular and crystalline levels.
• The observed hydrogen bonding network and non-planar ring conformation are key features influencing the compound's solid-state properties.