Knowledge Bank

Previous ESR studies of the manganese $hydrides1$ and $fluorides2$ have been extended to the chlorides, bromides, and iodides trapped in solid argon at $4\circ K$. The linear dihalides exhibit no $\mathrm{<mrow\; data-mjx-texclass="ORD">55</mrow>}$Mn hyperfine splitting, but the fine structure for these $\mathrm{<mrow\; data-mjx-texclass="ORD">6</mrow>}\sum$ molecules yields zero-field-splitting (zfs) and 9 values. The zfs increases with increasing anion [$|D|$ = 0.433(1) and 1.247(1) $cm-2$ for $MnCl2$ and $MnBr2$, respectively.] The $\mathrm{<mrow\; data-mjx-texclass="ORD">7</mrow>}\Sigma$ monohalides also show increases in D as anion size increases with D varying from + 0.070(1) to $+~0.5cm-1$ from MnCl to Mnl. $All2$ three monohalides exhibit $|A\perp (55Mn)|$ close to that of MnF (418 MHz)$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$. No halogen hyperfine structure was observed in any of these spectra.