Nitrogenous chelate complexes of transition metals. VII. Complexes of silver(I) and silver(II) with tridentate chelating ligands

Silver(1) complexes of 2,2',2"-terpyridine and a related Schiff base chelate 8-(or-pyridylmethyleneamino)quinoline have been prepared. They are of the type Ag(chelate)X, where X = NO3, ClO4, and PF6. Both Ag(terpy)+ and Ag(pmq)+ are stable in solution and conductance measurements have been obtained. Ag(terpy)PF6 is monomeric in nitrobenzene. Reaction of the above complex ions with pyridine or triphenylphosphine affords stable species of the form [Ag(chelate)(py)]+ and [Ag(chelate)(Ph3P)]+ which have been isolated as their perchlorate salts. Both Ag(chelate)+ and [Ag(ohelate)L]+ involve unusual stereochemistry for AgI. The known paramagnetic AgII complexes Ag(terpy)X2 (X = NO3, ClO4, ½S2O8) have been reprepared. They are unstable in solution and reduce readily to AgI. They all show magnetic moments in the range 1.7-1.9 B.M. Ag(terpy)2+ in an aqueous solution of CeIv shows a strong absorption band at 470 mμ (880).