Knowledge Bank

\begin{wrapfigure}[11]{R}{3.0CM} \vspace{-0.1cm} \hspace*{-0.4cm} \epsfig{file=FMFA7.eps} \end{wrapfigure} The rotational spectrum of 5 isotopomers of the complex formed between formic acid and formamide have been measured and analyzed using a pulsed beam fourier transform microwave spectrometer. The rotational constants and nitrogen's quadrupole coupling strength for $HC12OOH-H2N14COH$ are A=5889.51(9), B=2148.734(2), 1575.127(1), $eQqaa=1.020(8)$, $eQqbb=1.98(1)$ and $eQqcc=-2.998(9)$ MHz. Using the 15 rotational constants obtained with $HC13OOH$, HCOOD, DCOOH and $H2N15CHO$ isotopologes, key structural information was obtained from a least squares fit. R(CO-HN) distance of $1.77\backslash AA$ and R(OH-OC) distance of $1.81\backslash AA$ and an (COH) angle of formic acid of $121^irc\}$ was obtained that was very different from the monomer value of $106.9^irc\}$. Density functional theory using B3PW91, HCTH407 and TPSS and MP2 calculations were performed using 6-311++G(d,p) and compared to experimentally determined values.