Synthesis of binuclear platinum metal N4O2-compartmental complexes: the structures of the protonated metal-free macrocycle [LH4](PF6)2·MeNO2 and of [Pd2(L)](BF4)2·2MeNO2

Abstract

Reaction of [LH₄](PF₆)₂, formed by condensation of 1,3-diaminopropane and 2,6-diformyl-4-methylphenol in the presence of HBr followed by addition of NH₄PF₆, with platinum metal salts in the presence of base affords [M₂(L)]²⁺(M = Pd, Pt) and [M₂Cl₄(L)](M = Rh); the structure of [LH₄](PF₆)₂·MeNO₂ shows a folded conformation incorporating both inter- and intra-molecular π–π interactions between phenyl rings; in contrast, the structure of [Pd₂(L)](BF₄)₂·2MeNO₂ shows the binucleating macrocycle to be planar with intermolecular π-ring stacking.