Physical Properties of cis-1-Cyano-1,3-butadiene

Synthesis and Characterization of Cyanobutadiene Isomers—Molecules of Astrochemical Significance

“…A selective route to produce ( Z )-1-cyano-1,3-butadiene ( Z -1 ) has been reported, although details of the experimental procedure and spectroscopic properties are not readily available. Multiple studies describe the separation, isolation, and physical properties of Z -1 . , As a counterpart to our development of a selective process for the preparation of E -1 from Z -1,4-dibromo-2-butene ( Z -10 ), we observed that subjecting E -10 to the reaction conditions shown in Scheme resulted in a mildly selective formation of Z -1 . Although this procedure utilizes acetonitrile as the solvent, which was problematic in the isolation and purification of E -1 , the slightly higher volatility of Z -1 enables its separation from E -1 and acetonitrile in a straightforward fashion.…”

“…1-Cyano-1,3-butadiene (2,4-pentadienenitrile) ( 1 ; mixture of E and Z isomers) was originally isolated and studied at DuPont as a potential monomer unit by Carothers and co-workers (Scheme a). − Snyder et al prepared 1 by flash vacuum pyrolysis (Scheme b), separated the E and Z isomers by careful fractional distillation, and investigated the reactivity of 1 in trapping, dimerization, and polymerization reactions. − These early investigations contain a wealth of useful data describing the synthesis and physical properties of E -1 and Z -1 , but the experimental procedures for synthesis, purification, and isolation were designed for a relatively large scale, and these reports predate modern methods for spectroscopic characterization. − …”