Solid-State Reactivity and Single-Crystal Structure Studies. The Case of <i>diag</i><i>−</i><i>lat</i> Isomerization in [Re(η⁵-C₅H₄Me)(CO)(P(OPh₃)Br₂] and [Re(η⁵-C₅H₄^tBu)(CO)₂Br₂]

Abstract

The complex [Re(η 5 -C 5 H 4 Me)(CO)(P(OPh 3 )Br 2 ] ( 1 ) isomerizes from the diag → lat ( trans → cis ) isomer in the solid state, while [Re(η 5 -C 5 H 4 t Bu)(CO) 2 Br 2 ] ( 2 ) does not isomerize, although 2 is found to isomerize in the melt. Both complexes isomerize from the lat → diag isomer in solution. The crystal structures of both isomers of 1 and 2 have been determined by single-crystal X-ray diffraction. The crystal structures of 1 are analyzed to determine the structural forces driving the solid-state isomerization. For 2, the crystal structures are analyzed and compared with those of [Re(η 5 -C 5 H 4 Me)(CO) 2 Br 2 ] ( 3 ), which does isomerize in the solid state.