Knowledge Bank

Vanadium carbonyls were produced by trapping vaporized vanadium metal in neon and argon matrices doped with small amounts of $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CO$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}CO$. Analyses of the X-band ESR spectra indicate that VCO has a $\mathrm{<mrow\; data-mjx-texclass="ORD">6</mrow>}\Sigma$ ground state with a broad, relatively flat, potential. This is evidenced by two distinctly different sets of $\mathrm{<mrow\; data-mjx-texclass="ORD">51</mrow>}V$ hyperfine splittings (hfs) and zero-field splittings $(|D|)$ in argon matrices. Only one of these molecules is trapped in neon. $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}C$ hfs is 6 G in both matrices. $V(CD)2$ has a $\mathrm{<mrow\; data-mjx-texclass="ORD">4</mrow>}\Sigma$ ground state with $|D|=0.30cm-1$; the $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}C$ hfs is unresolved. A signal near $g=2(S=12)$ is assigned to $V(CD)3$ with $D3h$ or $C3v$ symmetry. The trend among the three carbonyls is for $Aiso(51V),$ i.e., the unpaired s character, to decrease as n increases.