Structural Versatility of Pyrene-2-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane) and Pyrene-2,7-bis(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane)

Three polymorphs of pyrene-2,7-bis­(Bpin)2 (1) and two of pyrene-2-(Bpin) (2), where Bpin
= 4,4,5,5-tetramethyl-[1,3,2]­dioxaborolane,
two different 1:1 co-crystals of 1 with toluene, and
co-crystals of hexafluorobenzene (HFB) with 1 (of highly
unusual 2:1 composition) and 2 (of usual 1:1 composition)
were isolated, studied by X-ray diffraction and differential scanning
calorimetry, and described using Hirshfeld surfaces and two-dimensional
fingerprint plots. Centrosymmetric phases β- and γ-1 have densities respectively lower and higher than the chiral
α-1; α- and β-2 have different
packing modes, both with Z′ = 3. Compound 1 is prone to form channel host–guest structures, for
example, α- and β-1·PhMe and 1·2HFB. The drastically different stabilities of α- and
β-1·PhMe are discussed. The complex 2·HFB has a mixed-stack packing motif. The structural
versatility of 1 and 2 is explained by synthon
frustration between structurally incongruent pyrene and Bpin moieties.