Tetracyanomethane under Pressure: Extended CN Polymers from Precursors with Built-in sp³ Centers

Abstract

Tetracyanomethane, C(CN), is a tetrahedral molecule containing a central sp carbon that is coordinated by reactive nitrile groups that could potentially transform to an extended CN network with a significant fraction of sp carbon. High-purity C(CN) was synthesized, and its physiochemical behavior was studied using in situ synchrotron angle-dispersive powder X-ray diffraction (PXRD) and Raman and infrared (IR) spectroscopies in a diamond anvil cell (DAC) up to 21 GPa. The pressure dependence of the fundamental vibrational modes associated with the molecular solid was determined, and some low-frequency Raman modes are reported for the first time. Crystalline molecular C(CN) starts to polymerize above ∼7 GPa and transforms into an interconnected disordered network, which is recoverable to ambient conditions. The results demonstrate feasibility for the pressure-induced polymerization of molecules with premeditated functionality.

Evidence for Functionalized Carbon Nanothreads from π-Stacked, para-Disubstituted Benzenes

“…, irradiation) to initiate reactivity. , Recently, much interest has been shown to various organic molecules subjected to high pressures, where solid-state reactions readily take place. Here, novel reaction pathways become accessible and previously unrealized metastable materials may be synthesized simply through compression. − …”

From Molecules to Carbon Materials—High Pressure Induced Polymerization and Bonding Mechanisms of Unsaturated Compounds

“…The structure containing the amino groups is ready to eliminate ammonia gas at appropriate conditions. Besides HCN and CH 3 CN, other nitriles like cyanogen [120], tetracyanoethylene (TCNE) [121], phosphorous tricyanide (P(CN) 3 ) [122], tetracyanomethane (C(CN) 4 ) [123] and dicyanoacetylene [124] also polymerize under high pressure.…”

A new chemical compound with an unusual ratio of number of carbon and nitrogen atoms – C(N12): quantum-chemical modelling

“…Carbon and nitrogen form among themselves a very signicant number of chemical compoundsboth neutral and cations and anions. 1 Among neutral compounds containing atoms of only these two elements, cyanogens C 2 N 2 (dicyan N^C-C^N, isocyanogen C]N-C^N), diisocyanogen C]N-N]C), paracyanogena cyanogen polymer (NCCN) n , paraisocyanogenan isocyanogen polymer, (CNCN) n , 2-4 percyanoalkynes, -alkenes and -alkanes, [5][6][7][8][9][10][11][12][13][14][15] dinitrilopolyynes, perazidoalkynes, -alkenes and -alkanes, 16,17 percyanoheterocycles, 18 of which in total there are at least several dozen. 1 At the end of the 20thbeginning of the 21st centuries, in connection with the discovery of fullerenes, numerous derivatives of them were added to this list, which can be subdivided into two categoriescyanofullerens that are a class of modied fullerenes in which cyano-groups are attached to a fullerene skeleton with the C 60 (CN) 2n formula (n ¼ 1-9), and azafullerenes that are a class of heterofullerenes in which the element substituting for carbon is nitrogen, f.e.…”