SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF A TETRACOPPER(I) COMPLEXOF HYLAMINO)-PROPYLIMINOMETHYL)-4-METHYLTHIOPHENOLATE

The compound 2,6-diformyl-4-methylphenyl disulfide (1) has been made b y hydrolysis of (2,6-diformyl-4-methylphenyl)dimethylthiocarbamate fol lowed by oxidation with I-2 Condensation of 1 with 4 equiv. of 3-dimet hylaminopropylamine and subsequent reduction with Na/benzophenone resu lts in the sodium salt of the Schiff base binucleating ligand -(bis(3- dimethylamino)-propyliminomethyl)-4-methyl thiophenolate (2, NaL). The ligand (L) binds 2 eq of Cu(I) and crystallizes from MeCN solution to give an air sensitive tetracopper(I) complex with the formula [Cu4L2( MeCN)](PF6)(2) (3).0.5 MeCN.0.25 MeOH as determined bu X-ray crystallo graphy. The complex contains three distorted trigonal planar and one d istorted tetrahedral Cu-1 centers with Cu-S bond lengths short for the ir respective coordination geometries. In DMSO solution, H-1 NMR spect ra of 3 reflect free ligand symmetry suggesting dissociation into dime rs. Cyclic voltammetry of 3 in MeCN reveals one irreversible oxidation at 110 mV (cs SCE). (C) 1991 Elsevier Science Ltd.