Orthorhombic and monoclinic polymorphs of 1,3,5-triphenylperhydro-1,3,5-triazine-2,4,6-trione at 120 K: chains and sheets formed by C—H...π(arene) hydrogen bonds

Abstract

The title compound, C21H15N3O3, crystallizes in two polymorphic forms. In the orthorhombic polymorph, (I), in space group Fdd2 with Z' = 1, the molecules lie in general positions, while in the monoclinic polymorph, (II), in space group C2/c with Z' = 1/2, the molecules lie across twofold rotation axes. In each polymorph, the molecules are linked by a single C-H.pi(arene) hydrogen bond, forming chains in polymorph (I) and sheets in (II).

Isocyanurates with Planar Chirality: Design, Optical Resolution, and Isomerization

“…The two phenyl groups (Ph 1 and Ph 2 ) covalently bonded to the imide N atoms were orthogonally distorted to the isocynanurate planes in the ranges of 74.9–95.7° for ϕ and 77.2–81.9° for χ because of steric repulsions between the phenyl rings and the oxygens on the isocyanurate ring. These values were comparable with torsion angles (60–80°) between benzene rings and heterocyclic rings of N,N ′, N ″‐triphenylisocyanurates in crystal . The dihedral angles ( ψ ) between Ph 2 and Ph 3 were 56.4–74.5° which are larger than those (~ 50°) between two benzene rings of ortho‐terphenyl in crystal .…”

“…These values were comparable with torsion angles between benzene rings and heterocyclic rings of N,N 0 , N 00 -triphenylisocyanurates in crystal. 76,77 The dihedral angles (c) between Ph 2 and Ph 3 were 56.4-74.5 which are larger than those (~50 ) between two benzene rings of ortho-terphenyl in crystal. [106][107][108] Furthermore, the spatial distances (ds) between the carbons of Ph 3 s and the hydrogens at ortho positions of Ph 1 s were 3.10-3.32 Å, being longer than those between hydrogens and aromatic rings in molecular structures formed by C-HÁÁÁp-arene interactions.…”

“…Cyclic N ‐phenylimides adopt the orthogonal conformation due to steric repulsion between the ortho H atoms of the phenyl group and the O atoms (Fig. C) …”

“…2C). [75][76][77] We have focused our interests on isocyanurate [78][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95] for the purpose of the synthesis and utility of novel enzyme models because the isocyanurate framework is a rigid six-membered ring and has three O atoms with electron-donating properties and three N atoms to which a variety of functional groups is connected. Optically active isocyanurates having three flexible amino acid units were previously reported to distinguish between enantiomers of guest molecules.…”

Microporous Polyisocyanurate and Its Application in Heterogeneous Catalysis

“…The interlayer distance was estimated by TEM to be ∼3.57 Å. This value was slightly larger than graphite (3.35 Å), and Yaghi’s COF‐1 (3.33 Å) and COF‐5 (3.46 Å); it might be the result of twisting between phenyl rings and C 3 N 3 six‐membered rings 14. This new material represents a nice bridge between PIMs and COFs.…”