Pressure‐Induced Diels–Alder Reactions in C₆H₆‐C₆F₆ Cocrystal towards Graphane Structure

Abstract

Pressure-induced polymerization (PIP) of aromatics is anovel method for constructing sp 3 -carbon frameworks, and nanothreads with diamond-like structures were synthesized by compressing benzene and its derivatives.H ere by compressing abenzene-hexafluorobenzene cocrystal (CHCF), H-F-substituted graphane with al ayered structure in the PIP product was identified. Based on the crystal structure determined from the in situ neutron diffraction and the intermediate products identified by gas chromatography-mass spectrum, we found that at 20 GPaCHCF forms tilted columns with benzene and hexafluorobenzene stackeda lternatively,a nd leads to a[4+ +2] polymer,which then transforms to short-range ordered H-F-substituted graphane.The reaction process involves [4+ +2] Diels-Alder,r etro-Diels-Alder,a nd 1-1' coupling reactions, and the former is the key reaction in the PIP.T hese studies confirm the elemental reactions of PIP of CHCF for the first time,and provide insight into the PIP of aromatics.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Perfect and Defective 13C-Furan-Derived Nanothreads from Modest-Pressure Synthesis Analyzed by 13C NMR

“…Saturated carbon nanothreads, which fill the one-dimension/sp 3 entry in this matrix of dimensionality and hybridization, were first synthesized by high-pressure solid-state polymerization of benzene. 16,17 Since then, a wide variety of nanothreads consisting primarily of sp 3 -hybridized carbon have been synthesized by pressure-induced polymerization of aromatic molecules (e.g., pyridine, thiophene and aniline), [18][19][20][21][22] co-crystals (e.g., naphthalene-octafluoronaphthalene, phenol-pentafluorophenol), [23][24][25][26][27] and a strained saturated hydrocarbon, cubane. 28 Pressure-induced solid-state reaction thus appears to be a general means of obtaining ordered packings of one-dimensional, high-aspect ratio diamond-like backbones decorated with diverse heteroatoms and functional groups, living at the threshold of thickness where framework rigidity first emerges in solids, a regime rife with promise for novel chemical and physical properties.…”

“…28 Pressure-induced solid-state reaction thus appears to be a general means of obtaining ordered packings of one-dimensional, high-aspect ratio diamond-like backbones decorated with diverse heteroatoms and functional groups, living at the threshold of thickness where framework rigidity first emerges in solids, a regime rife with promise for novel chemical and physical properties. [29][30][31][32] Advances in our understanding of nanothread synthesisincluding the roles of temperature, 19,21 aromaticity, 22 molecular stacking geometry, [23][24][25][26] compression rate, 16,17,22,24 and uniaxiality of stress 16,17,20,22 have been accompanied by substantial reductions in synthesis pressure, convincing demonstrations of sp 3 character, 33,[18][19][20][21][22] and initial ascertainments of axial periodicity, 27 but not yet by a clear determination of the precise atomic structure of regular, periodic regions of saturated thread backbone.…”

The neutron scattering platform of China Mianyang Research Reactor (CMRR) and recent applications

“…高压中子衍射谱仪(HPND) [4] (Reprinted with permission from [10] 表 3 CMRR 高分辨中子衍射谱仪主要技术参数 (Reprinted with permission from [11] Copyright © 2019, American Chemical Society) (Reprinted with permission from [5] Copyright © 2016 Elsevier)…”

“…(a) the fitting of the neutron diffraction data, (b) in-situ high pressure neutron diffraction. (Reprinted with permission from[10] © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)…”

Perfect and Defective 13C-Furan-Derived Nanothreads from Modest-Pressure Synthesis Analyzed by 13C NMR

“…27 Pressure-induced solid-state reaction thus appears to be a general means of obtaining ordered packings of one-dimensional, high-aspect ratio diamond-like backbones decorated with diverse heteroatoms and functional groups, living at the threshold of thickness where framework rigidity first emerges in solids, a regime rife with promise for novel chemical and physical properties. [28][29][30][31] Advances in our understanding of nanothread synthesisincluding the roles of temperature, 19,21 aromaticity, 22 molecular stacking geometry, [23][24][25][26] compression rate, 16,17,22,24 and uniaxiality of stress 16,17,20,22 have been accompanied by substantial reductions in synthesis pressure, convincing demonstrations of sp 3 character, and initial ascertainments of axial periodicity, 32 but not yet by a clear determination of the precise atomic structure of regular, periodic regions of saturated thread backbone.…”