Syntheses, structures, and solid-state phosphorescence characteristics of trans -bis(salicylaldiminato)Pt(II) complexes bearing perpendicular N -aryl functionalities

The syntheses, structures, and solid-state emission characteristics of trans -bis(salicylaldiminato)Pt(II) complexes bearing N -aromatic functionalities are described herein. A series of Pt complexes bearing various N -phenyl ( 1 ) and N -(1-naphthyl) ( 2 ) groups on the salicylaldiminato ligands were prepared by reacting PtCl 2 (CH 3 CN) 2 with the corresponding N -salicylidene aromatic amines, and the trans -coordination and crystal packing of these complexes were unequivocally established based on X-ray diffraction (XRD). Complexes with 2,6-dimethylphenyl ( 1c ), 2,6-diisopropylphenyl ( 1d ), 1-naphthyl ( 2a ), and 1-(2-methylnaphthyl) ( 2b ) groups on the N atoms exhibited intense phosphorescent emission at ambient temperature in the crystalline state, while those with phenyl ( 1a ), 2,6-dibromophenyl ( 1b ), and 2,6-bis( N , N -dimethylamino)phenyl ( 1e ) functionalities were either less emissive or non-emissive under the same conditions. XRD analyses identified significant intramolecular interactions between Pt and H atoms of the N -aryl functionalities in the emissive crystals of 1c , 1d , and 2a . These interactions were evidently an important factor associated with intense emission at ambient temperature.