Blue Shifted emission from a Pt complex with an expanded pi-system

Luminescent square planar platinum complexes have been extensively studied in medicinal chemistry, photosensitizers and optoelectronic devices. The research in organic light-emitting display (OLED) has attracted much attention because of their high internal efficiency allowing the use of all of the electrogenerated singlet and triplet excitons. In this comunication we report the synthesis of a cyclometallated Pt(II)dibenzoquinoline, (DBQ)Pt(dpm), which has an expanded ligand's pi-system. The comparison of the series of complexes (ppy)Pt(dpm), (BZQ)Pt(dpm),(DBQ)Pt(dpm) and the corresponding free corresponding cyclometallated ligands will be discussed in terms of: X-ray crystallography, electrochemical and photophisical properties and DFT calculations. The unexpected blue shifted emission of (DBQ)Pt(dpm) qualifies it as an interesting phosphorescent dopant for OLEDs. Standard OLED devices were therefore fabricated and studied as well.