N. R. WALKER, School of Chemistry, Bedson Building, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, U.K.; S. L. STEPHENS, W. MIZUKAMI, D. P. TEW AND A. C. LEGON, School of Chemistry, University of Bristol, Bristol, BS8 1TS, U.K..
An experiment to probe species generated within a supersonically-expanding jet consisting of SF6, Ag, C2H2 and argon by broadband rotational spectroscopy revealed the existence of a T-shaped complex of hitherto unknown origin. Empirical tests revealed that this complex requires the presence of C2H2 and Ag within the gas sample. While the intensity of the associated transitions are enhanced by the presence of SF6, theoretical calculations and empirical tests implied that the identified complex is H2C2 AgCCH rather than the original target of the experiment, H2C2 AgF. This deduction is now supported by evidence acquired through experiments exploiting 13C-enriched isotopic samples. Transitions have been assigned for the H213C2 Ag13C13CH isotopologue. Data acquired from each isotopologue allows determination of the rotational constants ( B 0, C 0) and centrifugal distortion constant, _ J . The data are consistent with a T-shaped complex in which the Ag atom of AgCCH binds to electrons within the -orbitals of ethyne. Preliminary determinations of bond lengths will be presented. Experiments are in progress to measure the spectra of deuterated isotopologues.