Structure of the Cumulene Carbene Butatrienylidene: H2CCCC

Experimental Structures of the Carbon Chains HC7N, HC9N, and HC11N by Isotopic Substitution

“…An increase in line intensity by a factor of 2 or more was easily achieved when a small amount (0.12%) of 13 C-acetylene was added to the mixture; for speed and convenience, most of the 13 C measurements were made with this enrichment. Lines of HC 7 15 N and HC 9 15 N, only marginally observed in natural abundance, were enhanced tenfold in intensity using a mixture of diacetylene (0.5%) and nitrogen (0.25%) enriched to over 99.9% in 15 N, again diluted in Ne, a precursor combination found to produce strong lines of HC 11 15 N (8).…”

“…The lines of the single 13 C species of all three cyanopolyynes were readily observed without isotopic enrichment, using for a precursor gas a mixture of diacetylene and cyanoacetylene (0.5% each) heavily diluted in Ne, the blend which gives the strongest lines of the normal species. An increase in line intensity by a factor of 2 or more was easily achieved when a small amount (0.12%) of 13 C-acetylene was added to the mixture; for speed and convenience, most of the 13 C measurements were made with this enrichment.…”

Density functional theoretical (DFT) study for the prediction of spectroscopic parameters of ClCCCN

“…have found considerable amount of interest in recent years 1,2,3,4 . Accurate and efficient calculation of spectroscopic constants for a wide range of molecular systems employs readily available methods and basis sets 5,6 .…”

“…Accurate and efficient calculation of spectroscopic constants for a wide range of molecular systems employs readily available methods and basis sets 5,6 . The DFT method has been demonstrated to have great accuracy in reproducing the experimental values of quadrupole hyperfine coupling constants 7 , molecular structural properties 8 , rotational constants 1,4 , IR frequencies, IR intensities and rotational invariants 9,10,11 etc. to within 8-10%.…”

First Astronomical Detection of the Cumulene Carbon Chain Molecule H[TINF]2[/TINF]C[TINF]6[/TINF] in TMC-1

“…The presence of strong c-C 3 H 2 and H 2 C 3 emission REFERENCES. Pickett, Poynter, & Cohen 1991;Travers et al 1996;Lovas 1992;McCarthy et al 1997. at 5.7 km s Ϫ1 and the apparent absence of H 2 C 6 or H 2 C 4 emission at that velocity indicate that there is a significant chemical inhomogeneity in the hydrocarbon chemistry in TMC-1.…”