Fast estimation of the internal conversion rate constant in photophysical applications

Abstract

A fast method for estimating nonadiabatic coupling matrix elements (NACME) and rate constants for internal conversion (kIC) is presented. The method based on Plotnikov’s theory requires only calculations of the...

Photo- and Electroluminescent Neutral Iridium(III) Complexes Bearing Imidoylamidinate Ligands

“…In addition, the presence of the Me group in Ir4 could provide an additional channel for the phosphorescence and fluorescence quenching because of the high anharmonicity of C−H bonds of the methyl group. 55 All these can result in the reduction of QY for Ir4. Inspection of the data from Table 6 also shows that the calculated radiative phosphorescence lifetimes are close to those determined experimentally.…”

“…The difference in k­(T∼ 1 ⇝S 0 ) values can arise because of the structural differences of the triplet excited state from the singlet ground state for Ir4 as compared to Ir1 – 3 . In addition, the presence of the Me group in Ir4 could provide an additional channel for the phosphorescence and fluorescence quenching because of the high anharmonicity of C–H bonds of the methyl group . All these can result in the reduction of QY for Ir4 .…”

Internal conversion rate constant calculations considering Duschinsky, anharmonic and Herzberg–Teller effects

“…Considering only the XH stretching modes, the NACME ( 〈ϕ i |Λ|ϕ f 〉) is calculated aswhere N XH is the number of accepting X–H modes of the molecule. 33 A i ia and A f jb are configuration interaction (CI) coefficients obtained in ab initio correlated calculations of excited states or in similar calculations at the time-dependent density functional theory (TDDFT) level. The a and b indices denote virtual molecular orbitals (MOs), whereas i and j are indices of the occupied MOs.…”

The combination of skeleton-engineering and periphery-engineering: a design strategy for organic doublet emitters

“…In this study, k IC values can be calculated by Plotnikov's expression: 31,32 k IC (i → f) = 〈 Ψ i | Λ | Ψ f 〉 2 V if where Ψ i and Ψ f are the Born–Oppenheimer (BO) adiabatic states, 33 and 〈 Ψ i | Λ | Ψ f 〉 is nonadiabatic coupling matrix elements (NACMEs) between Ψ i and Ψ f states for the j th normal mode based on the TD-DFT framework. 34–36 V if is the vibrational effect factor, 37 which is determined according to formula (6): 38,39 where Δ if is the energy difference between the initial and final vibrational states, and it is generally believed that the Δ if value of polyatomic molecules is not greater than 100 cm −1 .…”

“…2.3.2 Internal conversion process. In this study, k IC values can be calculated by Plotnikov's expression: 31,32 k…”