Addition of alcohols to phenyldicyandiamides metal complexes of 1-phenylamidino-o-alkylurea and related ligands

Abstract

Abstract Copper(II), nickel(II), cobalt(II) and palladium(II) promote addition of alcohols to phenyldicyandiamide, o-chloro- and p-chlorophenyldicyandiamide. 1-Phenylamidino-O-alkylurea (1-PhAAUH), 1-o-chlorophenylamidino-O-alkylurea (1-o-ClPhAAUH) and 1-p-chlorophenylamidino-O-alkylurea (1-p-ClPhAAUH) metal complexes are thereby formed. Copper(II) gives two series of complexes: (1) [Cu(1-PhAAUH)2]X2 (X = univalent anion). These complexes are red-violet (η = 18.8 kK), bi-univalent electrolytes and paramagnetic with a square planar [CuN4]chromophore. (2) Cu(1-PhAAUH)X2 (X = Cl, 1 2 SO 4 or NO3). These are blue to green and absorb about 15.2 kK for X = Cl, at 14.4 kK for X = 1 2 SO 4 and at 14.5 kK for X = NO3. The sulfato complexes are obtained only in methanol while the only nitrato complex has been obtained in ethanol medium. The sulfato complex is considered to contain a bridging sulphate group while the nitrate complex has both coordinated and ionic nitrate. Nickel(II) forms orange yellow coloured bis(ligand) complexes. They are diamagnetic, absorb around 22.7 kK and hence possess square planar[NiN4] geometry. Both copper(II) and nickel(II) bis(ligand) complexes show tetragonality in donor solvents. No bis(ligand) copper(II) and nickel(II) complexes were obtained with higher alcohols than ethanol. Palladium(II) reacts with the substituted dicyandiamides in different alcohols to provide dichloro-mono(ligand) complexes. They are diamagnetic and show the Pd-Cl stretch around 340 and 350 cm−1. Methanol addition reactions are also initiated by cobalt(II) ultimately giving tris(ligand) cobalt(III) complexes. With p-chlorophenyldicyandiamide a mixed chelate, p-chlorophenyldicyandiamide bis((1-p-chlorophenylamidino-O-methylurea) cobalt(III), is obtained. The compounds show the 1 A 1g → 1 T 1g transitions and are diamagnetic. Characterisation of the above complexes have been made on the basis of elemental analyses, alkoxyl determinations, conductance, electronic absorption spectra, magnetic moments and IR spectra. The free ligands are too unstable to be isolated in the solid crystalline state.