Mononuclear and Polynuclear Copper(ll) Complexes Derived from Pyridylalkylaminomethyiphenol Polypodal Ligands.

Four mononuclear complexes [Cu(HL¹)CI]PF6·CH3OH (1), [Cu(HSL¹)Cj]PF6-O.75H2O (2), [Cu(HL2)CUPF6.CH3- OH (3), [Cu(HSL2)O]PF6- 1 .5CH3OH (4), and Iwo polynudear complexes [Cu2(SL2)2](PF6)2-2CH3OH (5) and (Cu[Cu(SL2)(Cl))2)(PF6)2 (6) (HL1: 2-[(bis(2-pytidylmethyl)-amino)methyl]-4-methylphenol; HSL¹: 2-[(bis(2-pyridyf- methy[)amino) methylf4-methyl-6-(meth4-thio)phenoI; HL2: 2-((2-pyitddmethy)(2'-pytidyteth4)-aminomethl)]4methyl- phenol; HSL2: 2.[(2-py dmethyl)(2'-pyrtdytethyl)amino-methyl]-4-methyl-6-(methytthio)phenol were obtained and characterized. The crystal structures of the mononuclear complexes 1-4 show the copper centers in a square-base pyramidal environment with the phepolic oxygen coordhiated at the axial position. Dinuclear complex 5 has two copper centers with different geometry and bridged by phenoxo oxygens; one of the copper atoms is square pyramidal while the other can be described with a highly distorted octahedral geometry with a long Cu-S distance (2.867 Å). Density functional theory calculations were used to obtain the reported structure oF6, since single crystals suitable for X-ray diffraction were not isolated. Magnetic studies done for 5 and 6 show an antiferromagnetic behavior for 5 (J = -134 cm-1) and a ferromagnetic behavior for 6 (J = +11.9 cm-1). Redox potentials for the mononuclear complexes were measured by cyclic vohammetty the values show the effectof the chelating ring size (-213 my and -142 mV for Cu-HL¹ and Cu-HL2, respectively) and the presence of the thiomethyl substituent (-213 my and -184 mV for Cu-HL¹ and Cu-HSL¹, respectively). [ABSTRACT FROM AUTHOR]