dc.creator Halfen, D. T. en_US dc.creator Clouthier, D. J. en_US dc.creator Ziurys, L. M. en_US dc.date.accessioned 2008-07-15T13:38:50Z dc.date.available 2008-07-15T13:38:50Z dc.date.issued 2008 en_US dc.identifier 2008-FC-02 en_US dc.identifier.uri http://hdl.handle.net/1811/33365 dc.description Author Institution: Steward Observatory, University of Arizona, Tucson, AZ, 85721; Department of Chemistry, University of Kentucky, Lexington, KY, 40506; Department of Chemistry, Department of Astronomy, and Steward Observatory, University of Arizona, Tucson, AZ, 85721 en_US dc.description.abstract The pure rotational spectrum of the CCP radical (X$^{2}\Pi_{r}$) has been measured using millimeter-wave direct absorption techniques. This work is the first high-resolution data for this radical. This species was created by the reaction of gas-phase phosphorus and acetylene in the presence of argon carrier gas and an AC glow discharge. Twenty-four rotational transitions were measured in the frequency range of 120 to 413 GHz. Each transition is separated into two spin-orbit components; however, only the $\Omega$ = 1/2 component has been observed to date. This spin component is additionally split into lambda-doublets. Below 209 GHz, hyperfine interactions due to the phosphorus nuclear spin of I = 1/2 are evident, spitting each lambda-doublet into two lines. The data were fit with a case (c) Hamiltonian, and effective rotational, lambda-doubling, and phosphorus hyperfine constants were determined. Additional searches are being conducted for the $\Omega$ = 3/2 component. These data prove that CCP has a linear geometry in its ground state. This structure is similar to other MC$_2$ species, such as CCS and CCCl, in contrast to NaC$_2$, MgC$_2$, AlC$_2$, and SiC$_2$. The change in structure from T-shaped to linear is caused by a increase in the covalent bonding interactions between the C$_2$ moiety and the heteroatom. en_US dc.language.iso English en_US dc.publisher Ohio State University en_US dc.title MILLIMETER/SUBMILLIMETER SPECTRUM OF THE CCP (X$^{2}\Pi_{r}$) RADICAL en_US dc.type Article en_US
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