Imidazolium 3-nitro-benzoate.

In the title compound, C(3)H(5)N(2) (+)·C(7)H(4)NO(4) (-), the benzene ring forms a dihedral angle of 40.60 (5)° with the imidizolium ring. The nitro-benzoate anion is approximately planar: the benzene ring makes dihedral angles of 3.8 (3) and 3.2 (1)° with the nitro and carboxyl-ate groups, respectively. In the crystal structure, the cations and anions are linked by inter-molecular N-H⋯O hydrogen bonds, forming a zigzag chain along the b axis.

Bis(1-methyl-1-phenyl-ethyl) peroxide.

In the crystal structure, the title compound (also called dicumyl peroxide), C(18)H(22)O(2), lies on a center of symmetry. The COOC plane including the di-oxy group makes a dihedral angle of 79.10 (5)° with the phenyl ring. An inter-molecular C-H⋯π inter-action is observed between the phenyl groups.