Theoretical insight into a series of cyclometalated platinum(II) complexes with the substituted 2-phenylimidazole ligand

<p>The photophysical properties of a series of platinum(II) complexes have been theoretically investigated. The effect of the electron-withdrawing and electron-donating substituents on charge injection, transport, absorption and phosphorescent properties has been studied. For complexes <b>1</b>–<b>5</b>, the phosphorescence at 474, 453, 451, 524 and 461 nm are assigned to <sup>3</sup>MLCT(triplet metal-to-ligand charge transfer)/<sup>3</sup>ILCT(triplet intraligand charge transfer). In addition, ionization potential (IP), electron affinities (EA) and reorganization energy have also been analyzed to evaluate the charge transfer and balance properties between hole and electron. The calculated results show the complex <b>2</b> possibly possesses the largest radiative decay rate value among these studied complexes.</p>