Ionic [Cu(NN)(PP)] ⁺ TAD9727 F Complexes with Pyridine‐based Diimine Chelating Ligands and Their Use in OLEDs

Dinuclear Cu(I) Complex with Combined Bright TADF and Phosphorescence. Zero-Field Splitting and Spin–Lattice Relaxation Effects of the Triplet State

“…With this excitation, substantial structural changes between the electronic ground state and the emitting excited state occur. Similar structural changes were reported for other Cu­(I) and Ag­(I) complexes with CT character of the lowest excited states. ,− ,− ,,,− ,,− Such geometry changes usually favor extensive nonradiative relaxations that are connected with small emission quantum yields. ,,,, However, a rigid environment will frequently reduce the extent of geometry change and, thus, can lead to high emission quantum yields. ,− ,,,− ,,,,,,,, …”

“…1,3−6,9−16,18,19,33−36,83,88−94 Such geometry changes usually favor extensive nonradiative relaxations that are connected with small emission quantum yields. 5,6,12,33,95 However, a rigid environment will frequently reduce the extent of geometry change and, thus, can lead to high emission quantum yields. 1,[4][5][6]11,12,[14][15][16]18,33,34,36,88,89,91,96 In the context of this study, we are mainly interested in emission properties.…”

“…5,6,12,33,95 However, a rigid environment will frequently reduce the extent of geometry change and, thus, can lead to high emission quantum yields. 1,[4][5][6]11,12,[14][15][16]18,33,34,36,88,89,91,96 In the context of this study, we are mainly interested in emission properties. Therefore, the TD-DFT calculations are carried out in the optimized T 1 state geometry.…”

“…Within the past decade, scientific interest in organo Cu­(I) compounds has grown drastically due to their ability to exhibit efficient thermally activated delayed fluorescence (TADF). − The TADF effect can be applied, for example, in OLEDs (organic light-emitting diodes) ,,,− ,,,,− or light-emitting electrochemical cells (LEECs) ,− to harvest all generated singlet and triplet excitons through emission from the lowest excited singlet state S 1 . Hence, this mechanism is called the singlet harvesting effect. ,, By this mechanism, 100% internal OLED quantum efficiency can be achieved, similarly as is obtainable using the triplet harvesting effect. ,− This latter mechanism, however, is based on high-cost third-row organo-transition metal compounds, such as Ir­(III) ,,,− or Pt­(II) ,,<...…”

P∩N Bridged Cu(I) Dimers Featuring Both TADF and Phosphorescence. From Overview towards Detailed Case Study of the Excited Singlet and Triplet States

“…While for singlet harvesting, the molecules have to show efficient thermally activated delayed fluorescence (TADF) at ambient temperature. Examples are found among Cu(I), Ag(I), Au(III), W(VI) and Zn(II) complexes [ 7 , 9 , 10 , 11 , 12 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 ] or specifically designed organic molecules [ 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 ,…”