A novel S4-symmetric icosanuclear manganese metalladiazamacrocycle was synthesized using a pentadentate ligand, N-3-phenyl-trans-2-propenoylsalicylhydrazide (H3L), that has a rigid and bulky terminal N-acyl group. A 20 cyclic repeat of an--(Mn-N-N)--linkage resulted in a highly puckered diaza-bridged 60-membered icosanuclear metallamacrocycle. The steric interaction between the ligands in the c...

A novel dodecanuclear manganese metalladiazamacrocycle was synthesized employing a new pentadentate ligand N-2-pentenoylsalicylhydrazide (H(3)tpeshz) by supramolecular self-assembly. The backbone of this metal-organic assembly is a repeating unit of an M-N-N-M linkage that extends to complete a 36-membered cyclic structure involving 12 manganese(III) centers. Successive manganese centers are in...

Iron-bispidine complexes are efficient catalysts for the oxidation of thioanisole to phenylmethylsulfoxide with iodosylbenzene as oxidant. With the tetradentate bispidine ligand L(1) (L(1) = 2,4-pyridyl-3,7-diazabicyclo[3.3.1]nonane)) the catalytic efficiency is smaller than with the pentadentate bispidine ligand L(2) (L(2) = 2,4-pyridyl-7-(pyridine-2-ylmethyl)-3,7-diazabicyclo[3.3.1]nonane)). ...

A set of robust molecular cobalt catalysts for the generation of hydrogen from water is reported. The cobalt complex supported by the parent pentadentate polypyridyl ligand PY5Me(2) features high stability and activity and 100% Faradaic efficiency for the electrocatalytic production of hydrogen from neutral water, with a turnover number reaching 5.5 × 10(4) mol of H(2) per mole of catalyst with...

The 4-carboxyphenyl-appended macrocyclic ligand trans-6,13-dimethyl-6-((4-carboxybenzyl)amino)-1,4,8,11-tetraazacyclotetradecane-6-amine (HL10) has been synthesised and complexed with Co(III). The mononuclear complexes [Co(HL10)(CN)]2+ and [CoL10(OH)]+ have been prepared and the crystal structures of their perchlorate salts are presented, where the ligand is bound in a pentadentate mode in each...

Mononuclear metalloenzymes in nature can function in cooperation with precisely positioned redox-active organic cofactors in order to carry out multielectron catalysis. Inspired by the finely tuned redox management of these bioinorganic systems, we present the design, synthesis, and experimental and theoretical characterization of a homologous series of cobalt complexes bearing redox-active pyr...

Mononuclear metalloenzymes in nature can function in cooperation with precisely positioned redox-active organic cofactors in order to carry out multielectron catalysis. Inspired by the finely tuned redox management of these bioinorganic systems, we present the design, synthesis, and experimental and theoretical characterization of a homologous series of cobalt complexes bearing redox-active pyr...