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)

Abstract

Three polymorphs of pyrene-2,7-bis­(Bpin)₂ (<b>1</b>) and two of pyrene-2-(Bpin) (<b>2</b>), where Bpin = 4,4,5,5-tetramethyl-[1,3,2]­dioxaborolane, two different 1:1 co-crystals of <b>1</b> with toluene, and co-crystals of hexafluorobenzene (HFB) with <b>1</b> (of highly unusual 2:1 composition) and <b>2</b> (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-<b>1</b> have densities respectively lower and higher than the chiral α-<b>1</b>; α- and β-<b>2</b> have different packing modes, both with <i>Z</i>′ = 3. Compound <b>1</b> is prone to form channel host–guest structures, for example, α- and β-<b>1·</b>PhMe and <b>1</b>·2HFB. The drastically different stabilities of α- and β-<b>1·</b>PhMe are discussed. The complex <b>2·</b>HFB has a mixed-stack packing motif. The structural versatility of <b>1</b> and <b>2</b> is explained by synthon frustration between structurally incongruent pyrene and Bpin moieties