Sharpless et al. have described, while performing the molybdenum-catalyzed epoxidation reaction of olefins using alkyl hydroperoxides, that the molybdenum-oxo moiety is an active catalytic species. Thus, continuous efforts have been made to synthesize molybdenum-oxo complexes of different ligand environments. While plenty of such works on molybdenum porphyrins are reported in the literature, related molybdenum corroles are very less reported. The synthesis and characterization of two new oxo-molybdenum­(V)-corrolato complexes are described herein. Both the complexes have been fully characterized by several spectroscopic techniques in conjunction with single-crystal X-ray diffraction analysis. The efficacy of the oxo-molybdenum­(V)-corrolato complexes for the catalytic epoxidation reaction of olefins with the help of hydroperoxides has also been explored. The catalytic application of oxo-molybdenum­(V)-corrolato complexes in the epoxidation reaction has not been reported earlier. A mechanism has been proposed to explain the experimental findings.

de Visser et al. have demonstrated theoretically that although vanadium(IV)-oxo complexes are slow oxidants, however in the presence of H2O2, it has generated a side-on vanadium-peroxo complex, which is...

Tetra­(thiocyanato)­corrolato-Ag­(III) complexes presented here constitute a new class of metallo-corrole complexes. The spectroscopic properties of these complexes are quite unusual and interesting. For example, the absorption spectra of these β-substituted corrolato-Ag­(III) complexes are very different from those of the β-unsubstituted corrolato-Ag­(III) derivatives. Single-crystal XRD analysis of a representative tetra­(thiocyanato)­corrolato-Ag­(III) derivative reveals C–H···Ag interactions. The C–H···Ag interactions are rarely demonstrated in the crystal lattice of a discrete coordination/organometallic compound. Optimization of the hydrogen positions of the crystal structure discloses the geometrical parameters of the said interaction as a Ag···H distance of 2.597 Å and ∠C–H···Ag of 109.62°. The natural bond orbital analysis provides information about the donor–acceptor orbitals involved in the interactions and their interaction energies. It was observed that the σC–H orbital overlaps with the vacant d-orbital of Ag with an interaction energy of 17.93 kJ/mol. The filled d-orbital of Ag overlaps with the σ*C–H orbital with an interaction energy of 4.79 kJ/mol. The highlights of this work are that the H···Ag distance is outside of the distance range for the typical agostic interaction but fitted with the weak H-bond distance. However, the ∠C-H···Ag angle is within the range of the agostic interaction. Both crystallographic data and electronic structure calculations reveal that these kinds of intermolecular interactions in square-planar d8 Ag­(III) complexes are intermediate in nature. Thus, they cannot be categorically called either hydrogen bonding or agostic interaction.