Expanded Helicenes: A General Synthetic Strategy and Remarkable Supramolecular and Solid-State Behavior was written by Kiel, Gavin R.;Patel, Sajan C.;Smith, Patrick W.;Levine, Daniel S.;Tilley, T. Don. And the article was included in Journal of the American Chemical Society in 2017.Safety of 1,4-Dimethoxy-2-butyne This article mentions the following:
A divergent synthetic strategy allowed access to several members of a new class of helicenes, the “expanded helicenes”, which are composed of alternating linearly and angularly fused rings. The strategy is based on a three-fold, partially intermol. [2+2+n] (n = 1 or 2) cycloaddition with substrates containing three diyne units. Investigation of aggregation behavior, both in solution and in the solid state, revealed that one of these compounds forms an unusual homochiral, π-stacked dimer via an equilibrium that is slow on the NMR time scale. The versatility of the method was harnessed to access a selenophene-annulated expanded helicene that, in contrast to its benzannulated analog, exhibits long-range π-stacking in the solid state. The new helicenes possess low racemization barriers, as demonstrated by dynamic 1H NMR spectroscopy. In the experiment, the researchers used many compounds, for example, 1,4-Dimethoxy-2-butyne (cas: 16356-02-8Safety of 1,4-Dimethoxy-2-butyne).
1,4-Dimethoxy-2-butyne (cas: 16356-02-8) belongs to ethers. The oxygen atom in ethers are more electronegative than carbon, thus the hydrogens which are alpha to the ethers are more acidic than the simple hydrocarbons. Ethers can form hydrogen bonds with other molecules (alcohols, amines, etc.) that have O―H or N―H bonds. The ability to form hydrogen bonds with other compounds makes ethers particularly good solvents for a wide variety of organic compounds and a surprisingly large number of inorganic compounds.Safety of 1,4-Dimethoxy-2-butyne
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem