Constructing monocrystalline covalent organic networks by polymerization

Abstract

An emerging strategy for making ordered materials is modular construction, which connects preformed molecular subunits to neighbours through interactions of properly selected reactive sites. This strategy has yielded remarkable materials, including metal-organic frameworks joined by coordinative bonds, supramolecular networks linked by strong non-covalent interactions, and covalent organic frameworks in which atoms of carbon and other light elements are bonded covalently. However, the strategy has not yet produced covalently bonded organic materials in the form of large single crystals. Here we show that such materials can result from reversible self-addition polymerizations of suitably designed monomers. In particular, monomers with four tetrahedrally oriented nitroso groups polymerize to form diamondoid azodioxy networks that can be fully characterized by single-crystal X-ray diffraction. This work forges a strong new link between polymer science and supramolecular chemistry by showing how predictably ordered covalent or non-covalent structures can both be built using a single modular strategy.

Aromatic C-Nitroso Compounds and Their Dimers: A Model for Probing the Reaction Mechanisms in Crystalline Molecular Solids

“…Aromatic dinitroso compounds, e.g., p-dinitrosobenzene, are prone to polymerization which makes them promising candidates for the building blocks of supramolecular architectures [37][38][39]. Hacker reported the first isolation of p-dinitrosobenzene by gas phase deposition on the cold surface at 10 K, and its subsequent spontaneous polymerization upon heating the film of monomer to 170 K [63].…”

“…Aromatic dinitroso compounds, e.g., p-dinitrosobenzene, are prone to polymerization which makes them promising candidates for the building blocks of supramolecular architectures [37][38][39].…”

“…Such a system is simple because it includes the formation and/or breaking of only one chemical bond between two nitrogen atoms during the dimerization of C-nitroso compounds to the Z-or E-azodioxy dimers, or their subsequent dissociation to the starting monomers (Scheme 1) [32][33][34][35][36][37][38][39]. Although most of the aromatic C-nitroso compounds appear as Z-or E-azodioxides in solid state, certain nitrosobenzene derivatives, such as those with strong electron-donating substituents in the para-position (e.g., p-nitrosoanisoles and p-nitrosoanilines), prefer a monomeric form.…”

Studies on Adsorption and Desorption of Ammonia Using Covalent Organic Framework COF-10

“…또, 구리를 기반으로 한 Metal-Organic Framework (MOF)/그래핀 합성물과 CaCl2와 탄소 나노 튜브(MWCNT)을 혼합하는 다공성 물질들을 이용한 암모니아 흡착 및 제거 연구들이 활발히 진행되었다 [4][5][6][7][8][9][10]. 이 중 COFs는 2005년에 처음으로 발표되었다 [11].…”

2D or not 2D?

“…Two-dimensional synthetic polymers arguably have the potential to overcome these limitations, particularly if large crystals can be grown. Single crystals of 3D framework materials -including fully organic ones 6 -have been reported, indicating a free-standing 2D analogue to be a realistic target. Now, two Articles in this issue (page 774 and page 779) describe the formation of 2D polymers -through the photodimerization of rigid anthracene-based monomers -in a single-crystal-to-single-crystal fashion.…”