A facile synthesis of trinaphtho[3.3.3]propellane and its π-extension and the formation of a two-dimensional honeycomb molecular assembly

Abstract

The multi-gram-scale synthesis of trinaphtho[3.3.3]propellane (TNP) and its π-extension were achieved. X-ray crystallographic analysis revealed that charge transfer complexes of the π-extended TNP with F4-TCNQ form a two-dimensional honeycomb lattice.

Elucidation of Intramolecular Through‐Space Electronic Communication in a Propeller‐Shaped Molecule

“…Previously we reported af acile methodf or the synthesis of TNPa nd its p-extension. [8] It is notable that mixingo ft he p-extended TNPs (that is, trifluorantheno [3.3.3]propellanes) with organic acceptors gave 2D molecular assemblies with ah oneycomb lattice of charge-transfer complexes.A lthough we werec urious to characterizet he electronic communication among three the fluoranthene moieties of the charged species experimentally,t he poor solubility of the radical cation speciesi no rganic solvents hampered spectroscopic analyses.T oo vercome the solubility problem, we decided to introduce ethoxy groups on the fluoranthene moieties. Here, we report the synthesis of ah exaethoxy derivative( 3)o ft rifluorantheno [3.3.3]propellane and the investigationo fs pin delocalization in its radical cation species (3 · + )b yelectrochemical and spectroscopicmethods.…”

“…Compared with typical p-electron systemsw ith ap lanar scaffold, in propeller-shaped p-electrons ystems such as triptycene [1,2] and trinaphtho [3.3.3]propellane (TNP), [3] in which three aromatic rings are cofacially arranged at an angle of about 1208,t he three aromatic rings are able to interact with each other by spatial overlap of their molecular orbitals. In addition, chemical modification such as p-fusion or the introduction of substituents on triptycene or TNP induces as trong p-stacking interaction that leads to two-dimensional (2D) molecular assemblies, [4][5][6][7][8] and therefore, propeller-shaped p-electron systems are considered as strong candidates of molecular components for novel 2D electronic materials. Previously we reported af acile methodf or the synthesis of TNPa nd its p-extension.…”

“…Bromination of TNP followed by Suzuki-Miyaura coupling and as ubsequenti ntramolecular Heck-type reactionw ith the aid of microwave irradiation afforded the target compound 3,a ss hown in Scheme 1. In the final step, ah igh reaction temperature (180 8C) and the use of distilledD BU were essential for the high yield of the product.The structure of 3 was determined by single-crystal X-ray diffraction study ( Figure S6, Supporting Information).[9] The SQUEEZE subroutine of PLATON [10] was used because the refinementf or the structure of solvent molecule was unsuccessful due to asignificant disordero fethanol used as solvent.The UV/Vis spectra of 3 and 8,9-dimethoxyfluoranthene [8] were measured in dichloromethane (Figure 1). Both compounds showeda ni ntense absorption band around 300 nm and am oderate intensity band, alongw ith progressivev ibronScheme1.Synthesis of 2, 3,10,11,20,21-hexaethoxyfluorantheno[3.3.3] Supporting information(including the synthetic procedure and 1 Ha nd 13 CNMR spectra for all new compounds;X-ray crystal structure of 3;m olecular orbitald iagrams of 8,9-dimethoxyfluoranthene and…”

“…The UV/Vis spectra of 3 and 8,9-dimethoxyfluoranthene [8] were measured in dichloromethane (Figure 1). Both compounds showeda ni ntense absorption band around 300 nm and am oderate intensity band, alongw ith progressivev ibronScheme1.Synthesis of 2, 3,10,11,20,21-hexaethoxyfluorantheno[3.3.3] Supporting information(including the synthetic procedure and 1 Ha nd 13 CNMR spectra for all new compounds;X-ray crystal structure of 3;m olecular orbitald iagrams of 8,9-dimethoxyfluoranthene and…”

“…Here, we report the synthesis of ah exaethoxy derivative( 3)o ft rifluorantheno [3.3.3]propellane and the investigationo fs pin delocalization in its radical cation species (3 · + )b yelectrochemical and spectroscopicmethods. The starting material, TNP, [8] was prepared by am odified procedure in which hot tolueneasawashing solvent in apurification stepw as replacedb ya cetone. Bromination of TNP followed by Suzuki-Miyaura coupling and as ubsequenti ntramolecular Heck-type reactionw ith the aid of microwave irradiation afforded the target compound 3,a ss hown in Scheme 1.…”