HIGH SPIN MOLECULES: S = 3 MANGANESE MONOHALIDES AND $S - 5/2$ DIHALIDES

Abstract

Previous ESR studies of the manganese $hydrides^{1}$ and $fluorides^{2}$ have been extended to the chlorides, bromides, and iodides trapped in solid argon at $4^{\circ} K$. The linear dihalides exhibit no $^{55}$Mn hyperfine splitting, but the fine structure for these $^{6}\sum$ 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 $MnCl_{2}$ and $MnBr_{2}$, respectively.] The $^{7}\Sigma$ monohalides also show increases in D as anion size increases with D varying from + 0.070(1) to $\tilde + 0.5 \mbox{cm}^{-1}$ from MnCl to Mnl. $All_{2}$ three monohalides exhibit $|A\bot(^{55}Mn)|$ close to that of MnF (418 MHz)$^{2}$. No halogen hyperfine structure was observed in any of these spectra.