A hindered subphthalocyanine that forms crystals with included aromatic solvent but will not play ball with C₆₀

Abstract

A novel subphthalocyanine containing bulky substituents placed at its peripheral sites (i.e. 2,3,9,10,16,17-hexa(2′,6′-di-iso-propylphenoxy)boron subphthalocyanine) was prepared and assessed for supramolecular binding with C[Formula: see text], through crystallisation and fluorescence studies. Three different crystal polymorphs of the subphthalocyanine were obtained that showed inclusion of a single aromatic solvent molecule within the well-defined cavity of the molecule but complete exclusion of C[Formula: see text]. Analysis of the crystal structures indicated that the bowl-shaped cavity of the subphthalocyanine molecule was only accessible to small molecules due to the steric congestion surrounding the macrocycle, which results in hindered rotation of the substituents on the NMR timescale. Enhanced solubility, up to 42.0 g/L in common organic solvents, was demonstrated consistent with the crystal structures which are dominated by relatively weak intermolecular interactions, which allow solvent molecules to play a role in crystallisation.

Recent advances in subphthalocyanines and related subporphyrinoids

“…20 A similar effect was detected in the low-temperature NMR spectrum of a SubPc peripherally substituted with six 2′,6′-di-iso-propylphenoxy moieties. 19 In the case of SubPc π-complexes featuring a Cp*Ru + unit coordinated to either the concave or the convex face of the macrocycle ( 63–66 , Fig. 12), a notable diatropic effect on the Cp* moiety was observed in the case of the endo -coordinated compound, while an exceptionally small shift was detected for the exo -coordinated complex.…”

“…chlorobenzene, 13 o -dichlorobenzene, 14,15 or 1-chloronaphthalene 16 ). 11 SubPcs synthesis has also been carried out by addition of a 1 M solution of BCl 3 in heptanes 17–19 or dichloromethane 20–27 to a solution of the starting phthalonitrile in a high-boiling solvent such as p -xylene, 22,24 1-chloronaphthalene, 18 o -dichlorobenzene, 17,19,21,23,25,26 1,2,4-trichlorobenzene 20 or dimethyl sulfoxide. 11,27 Microwave irradiation has also been employed for SubPc preparation.…”

“…1 Several novel crystal structures of SubPc derivatives have been published since then, which are reported in ref. 17, 19, 30, 32, 43, 56, 57, 79, 85–88, 91, 96, 97, 108, 111, 114, 121, 130, 132, 141, 143, 145, 165, 172, 180 and 182–185. Selected data from X-ray diffraction analysis of some of these crystal structures are reported in Table 1.…”

Trifluoroethoxy‐Coated Subphthalocyanines Attract Small Arenes in Their π‐Concave Cavity

“…The concave π‐surface space in SubPcs should be useful for trapping small arene compounds and the resulting clathrates should be suitable for X‐ray crystallographic analysis. During our research in this direction, McKeown and co‐workers observed that hexa(2′,6′‐diisopropylphenoxy)boron SubPc forms crystals that included an aromatic solvent . We herein disclose the X‐ray crystallographic analysis of a series of clathrates of trifluoroethoxy‐coated SubPcs; we found that they routinely contain one small arene at the center of the concave cavity.…”

Trifluoroethoxy‐Coated Subphthalocyanines Attract Small Arenes in Their π‐Concave Cavity

“…[a] S. Mori, J. Wang, E. Tokunaga, Prof. N. Shibata Department of Nanopharmaceutical Sciences NagoyaInstitute of Technology Gokiso, Showa-ku, Nagoya4 66-8555 (Japan) E-mail:nozshiba@nitech.ac.jp SubPc forms crystalst hat included an aromatic solvent. [7] We herein disclose the X-ray crystallographic analysis of as eries of clathrates of trifluoroethoxy-coated SubPcs;w ef ound that they routinely contain one small arene at the center of the concavec avity. The trifluoroethoxy moiety plays an important role in the formation of arene clathrates, as revealed by ac omparative study using nonsubstituted SubPc.…”