Accurate prediction of emission energies with TD-DFT methods for platinum and iridium OLED materials.

Title Accurate prediction of emission energies with TD-DFT methods for platinum and iridium OLED materials.
Authors G.R. Morello
Journal J Mol Model
DOI 10.1007/s00894-017-3348-2
Abstract

Accurate prediction of triplet excitation energies for transition metal complexes has proven to be a difficult task when confronted with a variety of metal centers and ligand types. Specifically, phosphorescent transition metal light emitters, typically based on iridium or platinum, often give calculated results of varying accuracy when compared to experimentally determined T1 emission values. Developing a computational protocol for reliably calculating OLED emission energies will allow for the prediction of a complex's color prior to synthesis, saving time and resources in the laboratory. A comprehensive investigation into the dependence of the DFT functional, basis set, and solvent model is presented here, with the aim of identifying an accurate method while remaining computationally cost-effective. A protocol that uses TD-DFT excitation energies on ground-state geometries was used to predict triplet emission values of 34 experimentally characterized complexes, using a combination of gas phase B3LYP/LANL2dz for optimization and B3LYP/CEP-31G/PCM(THF) for excitation energies. Results show excellent correlation with experimental emission values of iridium and platinum complexes for a wide range of emission energies. The set of complexes tested includes neutral and charged complexes, as well as a variety of different ligand types.

Citation G.R. Morello.Accurate prediction of emission energies with TD-DFT methods for platinum and iridium OLED materials.. J Mol Model. 2017;23(6):174. doi:10.1007/s00894-017-3348-2

Related Elements

Iridium

See more Iridium products. Iridium (atomic symbol: Ir, atomic number: 77) is a Block D, Group 9, Period 6 element with an atomic weight of 192.217. The number of electrons in each of iridium's shells is [2, 8, 18, 32, 15, 2] and its electron configuration is [Xe] 4f14 5d7 6s2. Iridium Bohr ModelThe iridium atom has a radius of 136 pm and a Van der Waals radius of 202 pm. Iridium was discovered and first isolated by Smithson Tennant in 1803. In its elemental form, Iridium has a silvery white appearance. Iridium is a member of the platinum group of metals.Elemental Iridium It is the most corrosion resistant metal known and is the second-densest element (after osmium). It will not react with any acid and can only be attacked by certain molten salts, such as molten sodium chloride. Iridium is found as an uncombined element and in iridium-osmium alloys. Iridium's name is derived from the Greek goddess Iris, personification of the rainbow, on account of the striking and diverse colors of its salts.

Platinum

See more Platinum products. Platinum (atomic symbol: Pt, atomic number: 78) is a Block D, Group 10, Period 6 element with an atomic weight of 195.084. The number of electrons in each of platinum's shells is [2, 8, 18, 32, 17, 1] and its electron configuration is [Xe] 4f14 5d9 6s1. The platinum atom has a radius of 139 pm and a Van der Waals radius of 175 pm. Platinum Bohr ModelElemental PlatinumPlatinum was discovered and first isolated by Antonio de Ulloa in 1735. It is one of the rarest elements in the earth's crust, occurring at a concentration of only 0.005 ppm. Platinum is found uncombined as a free element and alloyed with iridium as platiniridium. In its elemental form, platinum has a grayish white appearance. It is highly resistant to corrosion: the metal does not oxidize in air at any temperature. It is generally non-reactive, even at high temperatures. The origin of the name "platinum" comes from the Spanish word platina, meaning silver.