Pt(II) Phosphors Featuring Both Dicarbene and Functional Biazolate Chelates: Synthesis, Luminescent Properties, and Applications in Organic Light-Emitting Diodes.

Pt(II) metal complexes [Pt(C^C)(X^X)] comprising three functional dianionic azolate chelates (X^XH2: bipzH2 = 5,5'-di(trifluoromethyl)-3,3'-bipyrazole, bitzH2 = 5,5'-di(trifluoromethyl)-3,3'-bi-1,2,4-triazole, and phpzH2 = 3-(trifluoromethyl)-5-(4-(trifluoromethyl)phenyl)-1H-pyrazole), together with three different charge-neutral dicarbene chelates (i.e., C^C = 1,1'-methylene bis(3-methyl-imidazol-2-ylidene), 1,1'-methylene bis(3-isopropyl-imidazol-2-ylidene), and 1,1'-(propane-1,3-diyl) bis(3-isopropyl-imidazol-2-ylidene), were synthesized and found to show bright solid-state emission depending on the associated X^X and C^C chelates.

Ambipolar Phosphine Derivatives to Attain True Blue OLEDs with 6.5% EQE.

A family of new branched phosphine derivatives {Ph2N-(C6H4)n-}3P → E (E = O 1-3, n = 1-3; E = S 4-6, n = 1-3; E = Se 7-9, n = 1-3; E = AuC6F5 4-6, n = 1-3), which are the donor-acceptor type molecules, exhibit efficient deep blue room temperature fluorescence (λem = 403-483 nm in CH2Cl2 solution, λem = 400-469 nm in the solid state). Fine tuning the emission characteristics can be achieved varying the length of aromatic oligophenylene bridge -(C6H4)n-. The pyramidal geometry of central R3P → E fragment on the one hand disrupts π-conjugation between the branches to preserve blue luminescence and high triplet energy, while on the other hand provides amorphous materials to prevent excimer formation and fluorescence self-quenching.