Method for differentiating two mechanisms by nonradiative deactivation in inhomogeneous luminescing systems

A study on enhancing the quantum yield and antimicrobial activity of Pr(iii) by varying the coordination environment

“…These emissions can be attributed to the radiative transition from the upper 3 P 0 level to the lower energy states. 77,78 These radiative transition peaks at 465 and 389 nm were also seen in complex 1. The Pr complexes also emit UV 5d-4f luminescence.…”

“…These complexes emitted luminescence from two excited states, i.e., 3 P 0 and 1 D 2 in solution. 77,78 But because the energy gap for the 1 D 2 state is much larger than that for the other levels, it might, therefore, be expected that the emission of Pr will occur only from the 1 D 2 state. 79 A very high intensity peak at 604 nm in complex 6 which resembles the transition, originates from the 1 D 2 level, whereas in complex 10 this transition occurs at 603 nm in the form of a broad peak.…”

“…89,90 The vibrational relaxation process of excited states in the Pr complexes 1 and 10 was justied by the small Stoke's shi, high quantum yield and a long life time shown by these complexes which was facilitated by the ligand behavior. 78 The high K nr was caused by the lower emission energy and this high K nr decreases the life time which is rationalized by the ligand oscillator. 80,[91][92][93][94][95][96] All these luminescence characteristics of Pr complexes are given in Table 5.…”