Synthesis, Structure and Spectral, and Electrochemical Properties of New Mononuclear Ruthenium(III) Complexes of Tris[(benzimidazol‐2‐yl)methyl]amine: Role of Steric Hindrance in Tuning the Catalytic Oxidation Activity

Abstract

The new mononuclear Ru III complexes [Ru(ntb)Cl 2 ]Cl (1), [Ru(ntb)Cl 2 ]ClO 4 (1a), and [Ru(mntb)Cl 2 ]Cl (2) (ntb = tris-(benzimidazol-2-ylmethyl)amine, mntb = tris(N-methylbenzimidazol-2-ylmethyl)amine) have been synthesized and characterized. The X-ray crystal structure of 1 reveals that the coordination geometry around the Ru III center is distorted octahedral in which four sites are occupied by the tetradentate ligand ntb and the remaining cis positions by two chloride ions. The stronger Ru-N bzim bonds elongate the Ru-Cl bonds thereby labilizing the coordinated chloride ions. In the electronic absorption spectra the Ru III complexes show two bands corresponding to π(bzim) Ǟ t 2g (Ru) and pπ(Cl -) Ǟ t 2g (Ru) ligand-to-metal charge transfer (LMCT) transitions along with intraligand transitions in the UV region. Complex

Synthesis, structure, catalytic and calculated non-linear optical properties of cis- and trans-, mer-chlorobis(triphenyl phosphine/triphenyl arsine)-dipicolinato rutheniumIII complexes

“…The nature of the spectra revealed the absence of any hyperfine splitting due to interaction with any other nuclei present in the complexes. Complexes 1, and 2 showed three lines with three different 'g' values (g x -g y -g z ) indicating rhombic distortion [26,46,47], while complexes 3 and 4 showed two lines with two different 'g' values (g x = g y -g z ) similar to previously reported by Natarajan et al [26]. The 'g' values are in the range 2.32-1.87.…”

Synthesis, Characterization, and Catalytic Activities of A Nickel(II) Monoamido‐Tetradentate Complex: Evidence For NiIII–Oxo and NiIV–Oxo Species

“…Although iron and manganese complexes are considered as promising catalysts for various organic reactions and biomimetic oxidation reactions, various metal‐based catalysts for oxidation reactions have been recently reported, in which iron and manganese metals are replaced with different transition metals . Among them, nickel complexes have come up as attractive transition‐metal catalysts for oxidation reactions, because they are involved in enzymatic catalysis, have shown to be efficient in oxidation reactions, and have been relatively less‐well explored compared to the corresponding Fe– and Mn–oxo intermediates.…”

Transition metal‐catalyzed oxidative transformations of methylarenes

“…Palaniandavar and co‐workers synthesized and characterized several mononuclear Ru(III) complexes such as [Ru(ntb)Cl 2 ]Cl, [Ru(ntb)Cl 2 ]ClO 4 and [Ru(mntb)Cl 2 ]Cl (ntb = tris‐benzimidazol‐2‐ylmethyl)amine; mntb = tris( N ‐methylbenzimidazol‐2‐ylmethyl)amine) that were used as efficient catalysts in the oxidation of organic compounds under the condition that TBHP and m ‐CPBA were applied as co‐oxidants . Cyclohexene oxidation, cyclooctene oxidation and alkane oxidation were investigated.…”