Substituent effects on the light-induced C–C and C–Br bond activation in (bisphosphine)(η2-tolane)Pt0 complexes. A TD-DFT study

Escudero, Daniel; Aßmann, Mariana; Pospiech, Anne; Weigand, Wolfgang; González, Leticia

doi:10.1039/b903603b

Cited by 12 publications

(20 citation statements)

References 18 publications

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“…In general, it is only the experimental UV absorption spectrum or emission energies that are compared with the theory. Our work on Ru, [197][198][199][200] Ir, [201,202] Pt [203,204] and Zn [205] complexes, and that of many other groups, see for example refs. [206][207][208][209], have found that, astonishingly, TD-DFT can be in reasonable agreement with the experiment as long as a judicious selection of functionals/basis is done and solvent effects are included.…”

Section: Excited-state Description Of Transition Metal Complexesmentioning

confidence: 97%

Progress and Challenges in the Calculation of Electronic Excited States

2011

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A detailed understanding of the properties of electronic excited states and the reaction mechanisms that molecules undergo after light irradiation is a fundamental ingredient for following light-driven natural processes and for designing novel photonic materials. The aim of this review is to present an overview of the ab initio quantum chemical and time-dependent density functional theory methods that can be used to model spectroscopy and photochemistry in molecular systems. The applicability and limitations of the different methods as well as the main frontiers are discussed. To illustrate the progress achieved by excited-state chemistry in the recent years as well as the main challenges facing computational chemistry, three main applications that reflect the authors' experience are addressed: the UV/Vis spectroscopy of organic molecules, the assignment of absorption and emission bands of organometallic complexes, and finally, the obtainment of non-adiabatic photoinduced pathways mediated by conical intersections. In the latter case, special emphasis is put on the photochemistry of DNA. These applications show that the description of electronically excited states is a rewarding but challenging area of research.

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Section: Excited-state Description Of Transition Metal Complexesmentioning

confidence: 97%

Progress and Challenges in the Calculation of Electronic Excited States

2011

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“…In the limit f στ xc = 0 and b = 1, the equations above reduce to the TD-HF case. [56][57][58][59][60][61][62][63] Admittedly, the charge-transfer is not long range inter-molecular but intra-molecular in these systems, but questions remain how general these findings are. The singlet-triplet splitting therefore tends to zero and excitation energies reduce to the Kohn-Sham gap.…”

Section: Introductionmentioning

confidence: 99%

Charge-transfer excited states in phosphorescent organo-transition metal compounds: a difficult case for time dependent density functional theory?

2015

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Figure 0: TOC Entry -Synopsis: A series of 17 platinum (II) and iridium (III) complexes have been investigated theoretically and experimentally to elucidate the charge-transfer character in emission from the lowest triplet state. Time-dependent density functional theory is found to be surprisingly accurate for metal-to-ligand transitions. ABSTRACTLight emitting organo-transition metal complexes have found widespread use in the past. The computational modelling of such compounds is often based on time-dependent density functional theory (TDDFT), which enjoys popularity due to its numerical efficiency and simple black-box character. It is well known, however, that TDDFT notoriously underestimates energies of charge-transfer excited states which are prominent in phosphorescent metal-organic compounds. In this study, we investigate whether TDDFT is providing a reliable description of the electronic properties in these systems. To this end, we compute 0-0 triplet state energies for a series of 17 pseudo-square planar platinum (II) and pseudo-octahedral iridium (III) complexes that are known to feature quite different localization * characteristics ranging from ligand-centered (LC) to metal-to-ligand charge transfer (MLCT) transitions. The calculations are performed with conventional semi-local and hybrid functionals as well as with optimally tuned range-separated functionals that were recently shown to overcome the charge transfer problem in TDDFT. We compare our results against low temperature experimental data and propose a criterion to classify excited states based on wave function localization. In addition, singlet absorption energies and singlet-triplet splittings are evaluated for a subset of the compounds and are also validated against experimental data. Our results indicate that for the investigated complexes charge-transfer is much less pronounced than previously believed.

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“…Conventional organic substituents are extensively investigated due to their importance in tuning the chemical, physicochemical, and biochemical properties of chemical species . Various substituent groups on catalysts ligands result in different catalytic effects, while multiple substituent groups on substrates can also change their reactivities .…”

Section: Introductionmentioning

confidence: 99%

Electronic effect of ionic‐pair substituents

Chen

Liu

et al. 2013

J of Physical Organic Chem

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For conventional organic substituents, an almost linear relationship can be established between the para Hammett constants in aqueous solutions and chemical shifts or natural population analysis charges (NPA charges). Based on these correlations, the Hammett constants of six synthesized ionic-pair substituents were estimated via the chemical shifts, which were well in agreement with the results calculated by NPA charges. The para Hammett constants of 89 different ionic-pair substituents (77 anion-cationic and 12 cation-anionic) were therefore calculated in the gas phase based on the density functional theory method. The results show that both the anion-cationic and cation-anionic substituents are electron-withdrawing groups and the different cation-anion combinations could tune the Hammett constants of the ionic-pair substituents in a range from 0.03 to 0.77.

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Substituent effects on the light-induced C–C and C–Br bond activation in (bisphosphine)(η2-tolane)Pt0 complexes. A TD-DFT study

Cited by 12 publications

References 18 publications

Progress and Challenges in the Calculation of Electronic Excited States

Progress and Challenges in the Calculation of Electronic Excited States

Charge-transfer excited states in phosphorescent organo-transition metal compounds: a difficult case for time dependent density functional theory?

Electronic effect of ionic‐pair substituents

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