The design, synthesis, characterization, and application of phosphorescent metal complexes

New phosphorescent complexes based on ruthenium, osmium, and iridium have been designed, synthesized, and characterized. A series of twenty-one new divalent osmium complexes of the form [Os(II)(N-N)₂L-L] 2+ and [ClOs(II)(CO)(N-N)(L-L)]+, where N-N is a polypyridyl ligand and L-L is either a phosphine or arsine ligand, were designed and synthesized. The reaction of 3-chloropropio-4-bromophenone with o-nitroanaline yielded 4,7-bis(p-bromophenyl)-1,10-phenanthroline. The resulting 4,7-bis(p-bromophenyl)-1,10-phenanthroline was then reacted with aryl boronic acids in a Susuki coupling reaction catalyzed by tetrakis(triphenylphosphine) palladium(0) to yield new phenanthroline ligands. Complexes of Os(II) were made from two equivalents of the phenanthroline ligand and one equivalent of an arsine or phosphine ligand. Crystal structures of many of the complexes will be provided. These complexes feature metal to ligand charge transfer phosphorescence that has been tuned to the green, yellow, orange and red regions (522 nm to 651 nm) of the visible spectrum. The emission quantum yields range 19–45% and the lifetime range from 400–2000 nanoseconds. The complexes were incorporated into both pressure sensing paints (PSP) and organic light emitting diodes (OLED). The osmium based PSPs featured very low rates of photodegradation and very low loss in emission quantum yield with increasing temperature. OLEDs exhibited saturated red electrophosphorescence. The OLEDs were fabricated from either a poly(vinylcarbizole) or poly(2-vinylnapthalene) matrix with 3% by weight doping of the osmium complex. Brightness over 1,600 cd m−2 and efficiency of 2.2% for double layer devices has been achieved. Iridium complexes synthesized were incorporated into pressure sensing paint (PSP). The luminophores may be excited in the ultraviolet or blue visible wavelengths and give narrow emission bands at the yellow and orange wavelengths. The iridium based PSPs gave dynamic range up to 75% (as defined by I_vac-I_atm/I_vac), temperature dependence as low as 0.37% °C−1, and low rates of photodegradation.