p-Toluenethiolate manganese(II) porphyrin complexes: Structure and spectroscopic properties

Abstract

Utilizing tetraphenylporphyrin (TPP), tetratolylporphyrin (TTP), tetramesitylporphyrin (TMP), and tetra-[Formula: see text]-chlorophenylporphyrin (T[Formula: see text]ClPP) as ligands, several five-coordinate high-spin [Formula: see text]-toluenethiolate Manganese(II) complexes are isolated and studied by UV-vis, single-crystal X-ray and EPR spectroscopies. The crystal structures show noteworthy features including flexible axial [Formula: see text]-toluenethiolate ligands and intramolecular C−H[Formula: see text][Formula: see text] and [Formula: see text]-[Formula: see text] interactions between ligands and porphyrin planes. All four products are further studied by X-band EPR on both solid and solution states at 4 K which confirmed the [Formula: see text] = 2/5 high-spin states. Temperature-dependent EPR and measurements with different equivalents of ligands are also reported for comparison. The work provides new references for the study of the active center of P450s and the biochemical reaction between cysteine residues and heme.