Solid State Self-Assembly of an Extended Curved-Arm Nickel(II) Macrocycle with Fullerene C60.

Abstract

Three new co-crystalline structures are reported that contain fullerene C₆₀ with the under-represented Ni(II)-dibenzotetraaza[14]annulene derivative, (5,14-dihydro-6,8,15,17-tetrabenzyl-2,3,11,12-tetramethyldibenzo[b,i][1,4,8,11]tetraazacyclo-tetradecine)nickel(II), [Ni(Bz₄TMTAA)]. The single-crystal X-ray analysis shows that the three studied compounds crystallize in the monoclinic C2/c, Pnma orthorhombic and triclinic P $1,char/0x00AFnotimplemented$ space groups, with the two former compounds being polymorphs that are isostructural but differ in their symmetries. From the crystallographic results, a common packing arrangement is established, with C₆₀ and [Ni(Bz4TMTAA)] molecules organised around one-dimensional hollow channels, associated 1 : 1 and 1 : 2 complexation of the macrocycle and the fullerene molecules, the latter being organised into hexagonal arrays. Interestingly, one of the structures showed a skewed hexagonal channel arrangement with the introduction of water molecules. Hirshfeld surface analyses have been used to investigate non-covalent interactions and cumulative π…π, C-H…π, H…H, and N…C₆₀ interactions between fullerene C₆₀ and [Ni(Bz₄TMTAA)] host molecule which are deemed the stabilizing factors for forming the sophisticated arrangements in the solid-state. differences.