Self-assembly of organometallic Pd(II) complexes via CH3⋯π interactions: The first example of a cyclopalladated compound with herringbone stacking pattern

Two binuclear cyclometallated compounds [Pd(C2,N-dmba)(μ-N3)]2 (1) and [Pd2(C2,N-dmba)2(μ-N3)(μ-Cl)] (2) (dmba = N,N-dimethylbenzylamine) have been synthesized and characterized by elemental analysis, IR and NMR spectroscopies and single crystal X-ray diffraction crystallography. The ability of CH3 groups to form C(sp3)single bondH⋯π hydrogen bonds with phenyl rings is responsible for the molecular self-assembly within the crystals of 1 and 2. Compound 1 crystallizes as one-dimensional supramolecular chains whereas the crystal packing of 2 consists of a herringbone of sandwiches composed by two inversely related [Pd2(C2,N-dmba)2(μ-N3)(μ-Cl)] molecules.