Synthesis and Interlayer Assembly of a Graphenic Bowl with Peripheral Selenium Annulation

Abstract

Pentagonal cyclization at the bay positions of armchair-edged graphenic cores can build molecular bowls without the destruction of hexagonal lattices. However, this synthesis remains challenging due to unfavorable strain and the multiple reactions required. Here, we show that a new type of graphenic molecular bowl with a depth of 1.7 Å and a diameter of 1.2 nm is constructed by sextuple Se annulation at the bay positions of armchair-edged hexa-peri-hexabenzocoronene. This graphenic bowl is functionalized with phenylseleno groups that stack into a discrete bilayer dimer in solution. Such a dimer exhibits high stability and survives in the gas phase after laser ablation. Strikingly, the asymmetric one-dimensional supramolecular columns of graphenic bowl with coherent stacking configuration are observed in the solid state, which results in a strong second harmonic generation with prominent polarization dependence. Our findings present a concise synthesis of a giant molecular bowl with a graphenic core and demonstrate the unique supramolecular assembly of extended graphenic bowls.

Axially Chiral Nonbenzenoid Nanographene with Second Harmonic Generation Property

“…Furthermore, the damage threshold power for the crystal of 2, when subjected to the 800 nm femtosecond pulselaser, was measured to be 62 mW, which is comparable to that of WS 2 (Figures 5c and S28). 70 The crystals of enantiopure R-2 and S-2 were successfully obtained, enabling us to investigate their SHG-circular dichroism (SHG-CD) properties. To conduct the SHG-CD measurement, we separately deposited crystals of R-2 and S-2 onto a quartz substrate.…”

Trichalcogenasupersumanenes and its concave-convex supramolecular assembly with fullerenes

“…Müllen and Feng et al have disclosed an elegant synthesis of tri -sulfur annulated p -HBC derivatives (TSHBC) 44 in which only three five-membered rings formed in bay regions, further full S annulation were not observed due to the high strain. Fortunately, during this paper was being reviewed, Tan group reported the synthesis of hexa -selenium annulated p -HBC derivatives (HSHBC) 43 by using a similar strategy to TSHBC. The success of HSHBC can be attributed to the bigger atomic radius of selenium atom and smaller strain.…”

“…Hitherto the most literature-known hydrocarbon buckybowls were related to C 60 [11][12][13][14][15][16][17][18][19] or C 70 [20][21][22][23][24][25][26] fullerene fragments and their π-extended derivatives [27][28][29][30] . In addition, some heteroatoms-embedded buckybowls involving B 31 , N [32][33][34][35][36][37][38] , P 39 , S 40 , Se [41][42][43] , etc. have also been synthesized and sought as model compounds and partial structures for higher heterofullerenes.…”