Syntheses, and structural, magnetic, and redox properties of multinuclear copper catecholates

Synthesis, Structure, and Magnetic and Redox Properties of Linear Bis-Dinuclear Complexes Afforded by Schiff Base Ligands Containing Catecholate and Pyridine or Imidazole Groups

“…The analytical results indicate that the reaction of H 2 L 1 , H 2 L 2 , and H 3 L 3 with manganese(II) acetate tetrahydrate under anaerobic conditions leads to complexes characterized by the same empirical composition: Mn 2 L(CH 3 CO 2 ) 2 (CH 3 OH). This composition which is analogous to that obtained from the reaction of H 2 L 1 and H 2 L 2 with copper acetate,8b i.e. Cu 2 L(CH 3 CO 2 ) 2 , clearly shows that H 2 L 1 , H 2 L 2 , and H 3 L 3 are prone to act as dinucleating ligands provided the resulting structure is stabilized by bridging exogenous anions of the carboxylate type.…”

“…The molecular crystal structure of the related [Cu 2 (L 2 ) 2 (CH 3 CO 2 ) 2 ] 2 ·H 2 O complex involving L 2 has been previously described, and it is interesting to compare the main features of the two structures. The pyridine ring and the imine nitrogen of the ligand are linked by a methylene bridge in L 1 and an ethylene bridge in L 2 , thus affording a five-membered − Mn(1) − N(1) − C(8) − C(9) − N(2) − ring in the manganese compound and a six-membered − Cu(1) − N(1) − C(8) − C(9) − C(10) − N(2) − ring in the copper complex.…”

“…3-[(((2 ‘ -Pyridyl)methyl)imino)methyl]benzene-1,2-diol (H 2 L 1 ) and 3-[((2-(2 ‘ - Pyridyl)ethyl)imino)methyl]benzene-1,2-diol (H 2 L 2 ). Both Schiff bases were prepared according to the method reported by Gojon et al,8b i.e. condensation of 2,3-dihydroxybenzaldehyde (0.69 g, 5 × 10 -3 mol) with 2-(aminomethyl)pyridine (0.55 g, 5 × 10 -3 mol) and 2-(2-aminoethyl)pyridine (0.62 g, 5 × 10 -3 mol) for H 2 L 1 and H 2 L 2 , respectively.…”

“…The tetranuclear manganese complexes including catecholate or related ligands have cubane structures involving four Mn(II) ions. 3d,e,m On the other hand, catechol-based ligands with N 2 O 2 donor sets resulting from the Schiff base condensation of 2,3-dihydroxybenzaldehyde with 2-H 2 NR-pyridine (R = methyl, ethyl) allow formation of tetranuclear copper(II) complexes with either bis-dinuclear or cubane 8b structures depending on R and on the bridging ability of the anions. These results prompted us to explore the ability of such ligands to afford tetranuclear manganese complexes of the bis-dinuclear type.…”

Preparation and Structural Characterization of a Platinum Catecholate Complex Containing Two 3-Ethynylthiophene Groups

“…The catechol group can coordinate to a variety of transition and main group metals in a wide range of oxidation states . Catechols and metal catecholates have been intensively studied for their unique structural, electronic, magnetic, and catalytic activity . The incorporation of metal catecholates into a conducting polymer matrix provides the opportunity for the construction of modified electrodes that may have interesting electrocatalytic behavior.…”