The Jahn–Teller Effect in Binary Transition Metal Carbonyl Complexes

McKinlay, Russell G.; Paterson, Martin J.

doi:10.1007/978-3-642-03432-9_11

Cited by 10 publications

(25 citation statements)

References 106 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[21] This transition involves nuclear distortions and would occur within a few periods of a JT active vibrational mode, that is, on a sub-picosecond timescale. [22] Such a rapid decay of a JT excitation is, however, in contrast with our findings for Pr 0.65 Ca 0.35 MnO 3 reported below. It furthermore seems to contradict the observed long lifetimes of polaron excitations of up to 1 ns in the semiconducting phase of La 0.7 Ca 0.3 MnO 3 [23,24] and several nanoseconds in Nd 0.5 Sr 0.5 MnO 3 , [25] all measured at pump energies of E = 1.55 eV ≈ 4 E 0 .…”

Section: Introductioncontrasting

confidence: 99%

Evolution of Hot Polaron States with a Nanosecond Lifetime in a Manganite Perovskite

Raiser

Mildner

Ifland

et al. 2017

Advanced Energy Materials

View full text Add to dashboard Cite

Understanding and controlling the relaxation process of optically excited charge carriers in solids with strong correlations is of great interest in the quest for new strategies to exploit solar energy. Usually, optically excited electrons in a solid thermalize rapidly on a femtosecond to picosecond timescale due to interactions with other electrons and phonons. New mechanisms to slow down thermalization will thus be of great significance for efficient light energy conversion, e.g., in photovoltaic devices. Ultrafast optical pump–probe experiments in the manganite Pr0.65Ca0.35MnO3, a photovoltaic, thermoelectric, and electrocatalytic material with strong polaronic correlations, reveal an ultraslow recombination dynamics on a nanosecond‐time scale. The nature of long living excitations is further elucidated by photovoltaic measurements, showing the presence of photodiffusion of excited electron–hole polaron pairs. Theoretical considerations suggest that the excited charge carriers are trapped in a hot polaron state. Escape from this state is possible via a slow dipole‐forbidden recombination process or via rare thermal fluctuations toward a conical intersection followed by a radiation‐less decay. The strong correlation between the excited polaron and the octahedral dynamics of its environment appears to be substantial for stabilizing the hot polaron.

show abstract

Section: Introductioncontrasting

confidence: 99%

Evolution of Hot Polaron States with a Nanosecond Lifetime in a Manganite Perovskite

Raiser

Mildner

Ifland

et al. 2017

Advanced Energy Materials

View full text Add to dashboard Cite

show abstract

“…[30] This problem, sometimes observed for CC2, for transition metal systems has been attributed to the large T 1 amplitudes which are used as similarity transform operators to ensure that the singles are treated at zeroth order both with and without the external field perturbation. [30,44] !eq π*)/ (3d x 2 À y 2 � !eq π*) 4.775 0.0000…”

Section: Resultsmentioning

confidence: 99%

“…Following dissociation, the ground and 1E' states converge to a tetrahedral geometry through bending to fill in the coordination hole. [14,44] Our results for the two-photon absorption spectrum of Fe (CO) 5 are presented in Table 3. As already discussed above, the two-photon absorption spectrum has never been investigated theoretically.…”

Section: E'mentioning

confidence: 99%

“…After proceeding through a tetrahedral triply-degenerate conical intersection (T ⊗ t ⊕ e type) Fe(CO) 4 in principle will attain one of eight equivalent structures of C 2v symmetry (see Figure 6). [14,44] However given the vibrationally hot nature of the Fe(CO) 4 it could easily pseudo-rotate around the Jahn-Teller moat. It may then undergo thermalized dissociation to Fe(CO) 3 .…”

Section: E'mentioning

confidence: 99%

See 1 more Smart Citation

One‐ and Two‐Photon‐Induced Photochemistry of Iron Pentacarbonyl [Fe(CO)₅]: Insights from Coupled Cluster Response Theory

2019

Self Cite

View full text Add to dashboard Cite

We present herein the first comprehensive study of the oneand two-photon absorption of Fe(CO) 5 utilising a hierarchy of linear-and quadratic-response coupled cluster (LR-and QR-CC) methodologies to provide an in-depth characterisation, as well as potential energy curves for axial and equatorial bond dissociations, highlighting the state crossings leading from the bright 1A 2 '' state through to the dissociative 1E' state. We have characterised a range of metal-to-ligand charge transfer (MLCT) and ligand field (LF) states that are in agreement with both previous studies and experiment, including the identification of a series of E' states that present Rydberg character in the 5.9-7.2 eV region. Due to the rapid excited state dissociation of Fe (CO) 5 through the low lying 1E' and 2E'' ligand-field states, we have also included an LR-CCSD analysis of the major dissociative product, Fe(CO) 4 . Analysis of the C 2v geometry of Fe(CO) 4 reveals four accessible ligand field states at 1.085, 1.684, 1.958, and 2.504 eV respectively, reinforcing the highly unstable nature of Fe(CO) 4 along with a strong MLCT band between 4.300 and 5.573 eV. This band overlaps with one in the spectra of Fe(CO) 5 suggesting that full fragmentation could proceed by two paths: two-photon excitation leading to dissociation, or through sequential one-photon absorption events, the first causing dissociation to and the second initiating further fragmentation of the complex.[a] T.

show abstract

“…This feature is rather common to the electronic excited states of many transition metal complexes and it is the http://dx.doi.org/10.1016/j.chemphys.2014.11.011 0301-0104/Ó 2014 Elsevier B.V. All rights reserved. ability of their excited states to mix in different ways that allows some of the most varied and rich photochemistry to take place, see for example [32][33][34][35].…”

Section: Introductionmentioning

confidence: 99%

Excited electronic states of MnO4−: Challenges for wavefunction and density functional response theories

Almeida¹,

McKinlay²,

Paterson³

2015

Chemical Physics

Self Cite

View full text Add to dashboard Cite

a b s t r a c tThe lowest excited electronic states of the permanganate ion MnO 4 À are calculated using a hierarchy of coupled cluster response approaches, as well as time-dependent density functional theory. It is shown that while full linear response coupled cluster with singles and doubles (or higher) performs well, that permanganate represents a stern test for approximate coupled cluster response models, and that problems can be traced to very large orbital relaxation effects. TD-DFT is reasonably robust although errors around 0.6 eV are still observed. In order to further investigate the strong correlations prevalent in the electronic ground state large-scale RASSCF calculations were also performed. Again very large orbital relaxation in the correlated wavefunction is observed. Although the system can qualitatively be described by a single configuration, multi-reference diagnostic values show that care must be taken in this and similar metal complexes.

show abstract

The Jahn–Teller Effect in Binary Transition Metal Carbonyl Complexes

Cited by 10 publications

References 106 publications

Evolution of Hot Polaron States with a Nanosecond Lifetime in a Manganite Perovskite

Evolution of Hot Polaron States with a Nanosecond Lifetime in a Manganite Perovskite

One‐ and Two‐Photon‐Induced Photochemistry of Iron Pentacarbonyl [Fe(CO)₅]: Insights from Coupled Cluster Response Theory

Excited electronic states of MnO4−: Challenges for wavefunction and density functional response theories

Contact Info

Product

Resources

About

The Jahn–Teller Effect in Binary Transition Metal Carbonyl Complexes

Cited by 10 publications

References 106 publications

Evolution of Hot Polaron States with a Nanosecond Lifetime in a Manganite Perovskite

Evolution of Hot Polaron States with a Nanosecond Lifetime in a Manganite Perovskite

One‐ and Two‐Photon‐Induced Photochemistry of Iron Pentacarbonyl [Fe(CO)5]: Insights from Coupled Cluster Response Theory

Excited electronic states of MnO4−: Challenges for wavefunction and density functional response theories

Contact Info

Product

Resources

About

One‐ and Two‐Photon‐Induced Photochemistry of Iron Pentacarbonyl [Fe(CO)₅]: Insights from Coupled Cluster Response Theory