The interaction of three free-basemeso-tris(p-X-phenyl)corroles H3[TpXPC]
(X = H, CH3, OCH3) with Re2(CO)10at 235 °C in the presence of K2CO3ino-dichlorobenzene has led to putative rhenium
biscorrole sandwich compounds with the formula ReH[TpXPC]2. Density functional theory calculations and Re L3-edge extended X-ray absorption fine structure measurements
suggest a seven-coordinate metal center, with the “extra”
hydrogen located on one of the corrole nitrogens. The complexes can
be deprotonated by a base such as 1,8-diazabicyclo[5.4.0]undec-7-ene,
resulting in a substantial sharpening of the UV–vis spectra
and split Soret bands, consistent with the generation ofC2-symmetric anions. Both the seven-coordinate neutral
and eight-coordinate anionic forms of the complexes represent a new
coordination motif in the field of rhenium–porphyrinoid interactions.