Luminescent Anionic Cyclometalated Organoplatinum (II) Complexes with Terminal and Bridging Cyanide Ligand: Structural and Photophysical Properties.

We present the synthesis and characterization of two series of mononuclear heteroleptic anionic cycloplatinated(II) complexes featuring terminal cyanide ligand Q[Pt(C^N)(-MeCH)(CN)] [C^N = benzoquinolate (bzq), Q = K and NBu ; 2-phenylpyridinate (ppy), Q = K and NBu and 2-(2,4- difluorophenyl)pyridinate (dfppy), Q = K and NBu ] and a series of symmetrical binuclear complexes (NBu)[Pt(C^N)(-MeCH)(μ-CN)] (C^N = bzq , ppy , dfppy ). Compounds , , and - were further determined by single-crystal X-ray diffraction. There are no apparent intermolecular Pt···Pt interactions owing to the presence of bulky NBu counterion. Slow crystallization of K[Pt(ppy)(-MeCH)(CN)] in acetone/hexane evolves with formation of yellow crystals, which were identified by single-crystal X-ray diffraction methods as the salt complex {[Pt(ppy)(-MeCH)(CN)]K(OCMe)(μ-OCMe)}[Pt(ppy)(-MeCH)(μ-CN)Pt(ppy)(-MeCH)]·2acetone (), featuring the binuclear anionic unit neutralized by an hybrid inorganic-organometallic coordination polymer {[Pt(ppy)(-MeCH)(CN)]K(OCMe)(μ-OCMe)}. The photophysical properties of all compounds were recorded in powder, polystyrene film, and solution states with a quantum yield up to 21% for in the solid state. All complexes displayed bright emission in rigid media, and for the interpretation of their absorption and emission properties, density functional theory (DFT) and time-dependent DFT calculations were applied.