1,3-Dicyclo-hexyl-imidazolidine-2,4,5-trione: a second polymorph

Area of Science:

• Crystallography
• Organic Chemistry
• Solid-State Chemistry

Background:

• The title compound, C(15)H(22)N(2)O(3), was initially identified as a byproduct during the oxidative cleavage of a specific imidazolidinedione derivative.
• Previous research documented the crystal structure of a non-centrosymmetric polymorph (space group P2(1)2(1)2(1)).

Purpose of the Study:

• To report the crystal structure of a second polymorph of the title compound.
• To compare the crystallographic features and intermolecular interactions of the two polymorphs.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the crystal structure.
• Crystallization from an ethanol solution at a reduced temperature (253 K) yielded the second polymorph.

Main Results:

• The second polymorph crystallizes in the centrosymmetric space group P2(1)/n.
• Unlike the first polymorph, the second polymorph lacks C=O⋯C=O interactions (C⋯O distance > 3.15 Å).
• Close packing in the second polymorph is primarily facilitated by C-H⋯π and weak C-H⋯O intermolecular interactions.

Conclusions:

• The study reveals the existence of a second polymorph of C(15)H(22)N(2)O(3) with distinct crystallographic properties.
• The difference in space group and intermolecular interactions highlights the sensitivity of crystal packing to crystallization conditions.