We report the detection of lowest energy conformer $E$-1-cyano-1,3-butadiene ($E$-1-C$_4$H$_5$CN), a linear isomer pyridine, using fourth data reduction GOTHAM deep spectral survey toward TMC-1 with 100 m Green Bank Telescope. performed velocity stacking and matched filter analyses Markov chain Monte Carlo simulations find evidence for presence this molecule at 5.1$\sigma$ level. derive total c...

The title compound, C28H40N2, was obtained from the condensation reaction of 4-tert-butyl-2,6-di-methyl-aniline and butane-2,3-dione. The mol-ecule lies on an inversion centre. The C=N bond has an E conformation. The plane of the benzene ring is almost perpendicular to the 1,4-di-aza-butadiene mean plane [dihedral angle = 89.8 (9)°].

The highly unsaturated binuclear butadiene iron carbonyls (C(4)H(6))(2)Fe(2)(CO)(n) (n = 2, 1) have been examined using density functional theory. For (C(4)H(6))(2)Fe(2)(CO)(n) (n = 2, 1), both coaxial and perpendicular structures are found. The global minima of (C(4)H(6))(2)Fe(2)(CO)(n) (n = 2, 1) are the perpendicular structures 2Q-1 and 1Q-1, respectively, with 17- and 15-electron configurat...

The complex (η(5)-C(5)H(5))Ir(η(4)-C(6)H(6)) reacts with Grubbs' catalyst to give a novel polyacetylene consisting of cyclopentadienyliridium bound s-cis butadiene moieties separated by C=C linkages. A crystal structure of the pentamethylcyclopentadienyl analog establishes a strong structural analogy with norbornadiene, a classical ROMP monomer.

The thermal [4+2] cycloadditions of 3-acetyl-, 3-carbamoyl, and 3-ethoxycarbonylcoumarins with 2,3-dimethyl-1,3-butadiene under solvent free conditions are reported, as well as the epoxidation reactions of some adducts. Discussion is focused on the structural features of the Diels-Alder adducts and their epoxides, based upon NMR, X-ray, and mass spectral data, and supported by ab initio theoret...

The rational design of a mercury(II) ligand consisting in a 1-(4'-oxyphenyl)-4(1'-pyrenyl)-2,3-diaza-1,3-butadiene receptor unit, optimizes the sensitivity and reliability of a SPR sensor by the formation of a well packed SAM over the gold surface. SPR analysis allows detecting mercury(II) concentrations in aqueous systems in the picomolar range, meliorating on three orders of magnitude the EU ...

A sequential Diels-Alder reaction/silicon-directed [4 + 2]-annulation was developed to assemble hydroisochromene-type ring systems from menadione 2. In the first step, a Diels-Alder of the 1-silyl-substituted butadiene 1 with 2 furnished an intermediate cyclic allylsilane. Subsequently, TMSOTf promoted a [4 + 2]-annulation through trapping of an oxonium, generated by condensation between an ald...

The cycloaddition of 4-methoxycarbonyl-2(1H)-pyridones to silyloxydienes gave isoquinolone derivatives in reasonable yields. Furthermore, the cycloaddition of 6-methoxycarbonyl-2(1H)-pyridones to 2,3-dimethyl-1,3-butadiene produced cycloadducts (isoquinolone and quinolone derivatives) and double cycloadducts (phenanthridone derivatives). The activation energies using Gaussian 98 with RHF/3-21G ...

A series of studies to further evaluate the developmental and reproductive toxicity of inhaled 1,3-butadiene was sponsored by the National Toxicology Program. Pregnant Sprague-Dawley rats (24-28/group) and Swiss (CD-1) mice (18-22/group) were exposed to atmospheric concentrations of 0, 40, 200, or 1000 ppm 1,3-butadiene for 6 hr/day on days 6 through 15 of gestation (dg) and killed on dg 18 (mi...