Structure of the monoclinic form of 2,6-di-tert-butyl-4-methylphenol (DBMP), C15H24O

Crystal structure and Hirshfeld surface analysis of 5-(3,5-di-tert-butyl-4-hy-droxy-phen-yl)-3-phenyl-4,5-di-hydro-1H-pyrazole-1-carboxamide

In the title compound, C24H31N3O2, the mean plane of the central pyrazole ring [r.m.s. deviation = 0.095 Å] makes dihedral angles of 11.93 (9) and 84.53 (8)°, respectively, with the phenyl and benzene rings. There is a short intra-molecular N-H⋯N contact, which generates an S(5) ring motif. In the crystal, pairs of N-H⋯O hydrogen bonds link inversion-related mol-ecules into dimers, generating an R 2 2(8) ring motif. The Hirshfeld surface analysis indicates that the most significant contribution involves H⋯H contacts of 68.6.

The antioxidant methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

The title compound, C18H28O3, was prepared by the reaction of 2,6-di-tert-butylphenol with methyl acrylate under basic conditions using dimethyl sulfoxide as the promoter. The structure of this antioxidant indicates significant strain between theortho tert-butyl substituents and the phenolic OH group. In spite of the steric crowding of the OH group, it participates in intermolecular hydrogen bonding with the ester carbonyl O atom.

The first crystal structure of a monomeric phenoxyl radical: 2,4,6-tri-tert-butylphenoxyl radical

Crystals of the 2,4,6-tri-tert-butylphenoxyl radical have been isolated and characterized by X-ray diffraction, and calculations have been performed that give the distribution of spin density in the radical.