Photochromic alkynylplatinum(II) diimine complexes containing a versatile dithienylethene-functionalized 2-(2′-pyridyl)imidazole ligand

• Drastic UV–vis absorption spectral changes suggest the metal-assisted planarization of ligand framework.
• The complexes exhibit phosphorescence in fluid, solid and glass states at room temperature and 77 K.
• Tunable photophysical properties by proper choice of diimine and alkynyl ligands.

The synthesis and incorporation of a versatile photochromic dithienylethene-containing diimine ligand, 2-(2′-pyridyl)imidazole, into platinum(II) bis-alkynyl system have been described. All the platinum(II) complexes have been successfully characterized by 1H NMR spectroscopy, ESI mass spectrometry as well as elemental analysis. One of the complexes has been characterized by X-ray crystallography. Their photochromic, photophysical and electrochemical properties have been studied. Upon photo-excitation, all the platinum(II) complexes exhibited reversible photochromism. Their photophysical and electrochemical behaviors were found to be tunable by various substituents on the ligands.

The synthesis and incorporation of a versatile photochromic dithienylethene-containing diimine ligand, 2-(2′-pyridyl)imidazole, into platinum(II) bis-alkynyl system have been described. The identity of complex 1 has been confirmed by X-ray crystallography. The electronic absorption, emission, electrochemistry and photo-induced UV–vis absorption spectral changes have been studied.Figure optionsDownload as PowerPoint slide