HYDROGEN INTERACTION WITH METAL HALIDES: THE NUCLEAR QUADRUPOLE COUPLING CONSTANT OF GOLD IN THE $\mathit{p}${-H}$_2${-AuCl} COMPLEX AND TRENDS IN THE OTHER HYDROGEN-COINAGE METAL HALIDE INTERACTIONS

Abstract

The rotational spectrum of \textit{p}-H$_2$-AuCl has been measured using a laser ablation equipped FTMW cavity spectrometer. The predicted structure, using a 60 electron core potential and an aug-cc-pVQZ \textbf{311}(2005) 227.} \textbf{114} (2005) 283.} at the MP2 level of theory, shows that H$_2$ has an $r_e = 0.91$\AA. A predicted value for the \textit{eQq}($\chi_{aa}$) of gold required a semi-empirical method using the results of previous AuCl complexes in the gas phase. Transitions have been measured across multiple J levels, and have been used to determine the rotational constants, centrifugal distortion constants, and nuclear quadrupole coupling constants of multiple isotopologues. The \textit{o}-H$_2$-AuCl has also been observed. While the monomer value of the \textit{eQq} of $^{197}$Au was determined to be 9.63112(13) MHz in $^{197}$Au$^{35}$Cl \textbf{203} (2000) 105.}, we observed a significant change in the \textit{eQq} of $^{197}$Au in \textit{p}-H$_2$-$^{197}$Au$^{35}$Cl to a value of -817.9983(36) MHz [0.02728556(12) cm$^{-1}$], giving rise to a Au hyperfine component splittings of approximately 220 MHz [0.007 cm$^{-1}$] and suggesting a change in electronic structure with the interaction of H$_2$. We will present a summary of the hydrogen-coinage metal halide talks given at this conference, including trends in \textit{eQq} and hydrogen metal halide dissociation energies.