A new combination to form a solid solution: a solid solution consisting of a stabilized phenoxyl radical and its methoxy analogue

A new combination of molecules that form a solid solution is reported. The 2,4,6-tris(4-tert-butylphenyl)phenoxyl radical, C₃₆H₄₁O (1_M), formed two solid solutions (α and β) with its methoxy analogue 1,3,5-tris(4-tert-butylphenyl)-2-methoxybenzene, C₃₇H₄₄O (1_OMe). According to single-crystal X-ray analysis, the crystal structure of each solid solution is thought to be dominated by the characters of the main components. The β crystal (1_M:1_OMe = 0.002:0.998) is isomorphic to the crystal composed solely of 1_OMe and the molecules in the β crystal adopt the most preferred conformation for 1_OMe. In contrast, in the α crystal (1_M:1_OMe = 0.80:0.20), the molecules adopt the most preferred conformation for 1_M. However, since a crystal composed solely of 1_M has not been obtained (1_M always precipitates as a σ-dimer formed by a covalent C-O bond between the phenoxyl O atom of one molecule and the para-C atom of the central phenyl ring of another molecule), it is unclear whether it is isomorphic with the α crystal.