Significant differences between solid state and solution photochemistry and photophysics of mesogenic organometallic gold complexes

Five new gold complexes 4-ROC6H4C≡CAuN≡CC6H4-4-OR′ (R/R′ = CH3/C9H19 (C1N9 ), C15H31/C9H19 (C15N9 ), C6H13/C15H31 (C6N15 ), C9H19/C15H31 (C9N15 ), C12H25/C15H31 (C12N15 )) were synthesized and characterized (1H and 13C NMR, IR, Raman spectroscopy, and high resolution mass spectrometry). Their organized smectic phases were investigated by TGA, DSC, powder XRD, and polarized light optical microscopy, and the solids are found to have crystalline and amorphous domains. No evidence for Au•••Au interactions was observed. The steady state and time-resolved absorption and emission properties at 298 and 77 K were examined, and surprisingly, the excited lifetime of the triplet excited state in the solid state is extremely short-lived (<100 ps) in comparison with the microsecond time scale recorded for the solution and at 77 K. The photosensitization of 1O2 was observed in solution but not in the solid state. The nature of the singlet (ligand-to-ligand charge transfer) and triplet (ethynyl/intraligand ππ*) excited states were assessed using DFT and TD-DFT computations. The thermal and UV-photochemical formation of gold nanoparticles were performed in solution (slow) and in the solid state (faster). The thermally generated nanoparticles are found to be larger (2–20 nm; TEM) and exhibit well-defined shapes, whereas the photochemically generated ones are smaller (1–10 nm) and show ill-defined shapes.

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Restricted Photochemistry in the Molecular Solid State: Structural Changes on Photoexcitation of Cu(I) Phenanthroline Metal-to-Ligand Charge Transfer (MLCT) Complexes by Time-Resolved Diffraction

The Journal of Physical Chemistry A ◽

10.1021/jp300313s ◽

2012 ◽

Vol 116 (13) ◽

pp. 3359-3365 ◽

Cited By ~ 47

Author(s):

Anna Makal ◽

Jason Benedict ◽

Elzbieta Trzop ◽

Jesse Sokolow ◽

Bertrand Fournier ◽

...

Keyword(s):

Charge Transfer ◽

Solid State ◽

Structural Changes ◽

Time Resolved ◽

Ligand Charge Transfer ◽

Molecular Solid

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Visualization and Manipulation of Molecular Motion in Solid State through Photo-Induced Clusteroluminescence

10.26434/chemrxiv.8280464 ◽

2019 ◽

Author(s):

Haoke Zhang ◽

Lili Du ◽

Lin Wang ◽

Junkai Liu ◽

Qing Wan ◽

...

Keyword(s):

Quantum Mechanics ◽

Excited State ◽

Solid State ◽

Light Source ◽

Molecular Motion ◽

Molecular Machine ◽

Conjugated Molecules ◽

Time Resolved ◽

Packing Structure ◽

New Strategy

Building molecular machine has long been a dream of scientists as it is expected to revolutionize many aspects of technology and medicine. Implementing the solid-state molecular motion is the prerequisite for a practical molecular machine. However, few works on solid-state molecular motion have been reported and it is almost impossible to “see” the motion even if it happens. Here the light-driven molecular motion in solid state is discovered in two non-conjugated molecules s-DPE and s-DPE-TM, resulting in the formation of excited-state though-space complex (ESTSC). Meanwhile, the newly formed ESTSC generates an abnormal visible emission which is termed as clusteroluminescence. Notably, the original packing structure can recover from ESTSC when the light source is removed. These processes have been confirmed by time-resolved spectroscopy and quantum mechanics calculation. This work provides a new strategy to manipulate and “see” solid-state molecular motion and gains new insights into the mechanistic picture of clusteroluminescence.

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The Character of Low-Lying Excited States of Mixed-Ligand Metal Carbonyls. TD-DFT and CASSCF/CASPT2 Study of [W(CO)4L] (L = ethylenediamine, N,N'-dialkyl-1,4-diazabutadiene) and [W(CO)5L] (L = pyridine, 4-cyanopyridine)

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20030089 ◽

2003 ◽

Vol 68 (1) ◽

pp. 89-104 ◽

Cited By ~ 6

Author(s):

Stanislav Záliš ◽

Antonín Vlček ◽

Chantal Daniel

Keyword(s):

Excited States ◽

Substitution Effect ◽

Electronic Transitions ◽

Ligand Field ◽

Metal Carbonyls ◽

Electron Density Redistribution ◽

Time Resolved ◽

Model Complex ◽

Td Dft ◽

Time Resolved Infrared Spectroscopy

This contribution presents the results of the TD-DFT and CASSCF/CASPT2 calculations on [W(CO)4(MeDAB)] (MeDAB = N,N'-dimethyl-1,4-diazabutadiene), [W(CO)4(en)] (en = ethylenediamine), [W(CO)5(py)] (py = pyridine) and [W(CO)5(CNpy)] (CNpy = 4-cyanopyridine) complexes. Contrary to the textbook interpretation, calculations on the model complex [W(CO)4(MeDAB)] and [W(CO)5(CNpy)] show that the lowest W→MeDAB and W→CNpy MLCT excited states are immediately followed in energy by several W→CO MLCT states, instead of ligand-field (LF) states. The lowest-lying excited states of [W(CO)4(en)] system were characterized as W(COeq)2→COax CT excitations, which involve a remarkable electron density redistribution between axial and equatorial CO ligands. [W(CO)5(py)] possesses closely-lying W→CO and W→py MLCT excited states. The calculated energies of these states are sensitive to the computational methodology used and can be easily influenced by a substitution effect. The calculated shifts of [W(CO)4(en)] stretching CO frequencies due to excitation are in agreement with picosecond time-resolved infrared spectroscopy experiments and confirm the occurrence of low-lying M→CO MLCT transitions. No LF electronic transitions were found for either of the complexes studied in the region up to 4 eV.

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Spectroscopic trends in a series of Re(I) α-diimine complexes as a function of the antenna/photoisomerizable ligands: a TD-DFT and MS-CASPT2 study

Canadian Journal of Chemistry ◽

10.1139/cjc-2014-0069 ◽

2014 ◽

Vol 92 (10) ◽

pp. 979-986 ◽

Cited By ~ 11

Author(s):

Megumi Kayanuma ◽

Chantal Daniel ◽

Etienne Gindensperger

Keyword(s):

Excited States ◽

Electronic Structures ◽

Density Functional ◽

Time Dependent ◽

Functional Theory ◽

B3lyp Level ◽

Ligand Charge Transfer ◽

Td Dft ◽

Energy Domain ◽

Diimine Complexes

The absorption spectra of 11 rhenium(I) complexes with photoisomerizable stilbene-like ligands have been investigated by means of density functional theory (DFT). The electronic structures of the ground and excited states were determined for [Re(CO)3(N,N)(L)]+ (N,N = bpy (2,2′-bipyridine), phen (1,10-phenanthroline), Me4phen (3,4,7,8-tetramethyl-1,10-phenanthroline), ph2phen (4,7-diphenyl-1,10-phenanthroline), or Clphen (5-chloro-1,10-phenanthroline); L = bpe (1,2-bis(4-pyrydil)ethylene), stpy (4-styrylpyridine), or CNstpy (4-(4-cyano)styrylpyridine)) at the time–dependent (TD) DFT/CAM-B3LYP level of theory in vacuum and acetonitrile to highlight the effects of both antenna N,N and isomerizable L ligands. The TD-DFT spectra of two representative complexes, namely [Re(CO)3(bpy)(stpy)]+ and [Re(CO)3(phen)(bpe)]+, have been compared with MS-CASPT2 spectra. The TD-DFT spectra obtained in vacuum and acetonitrile agree rather well both with the ab initio and experimental spectra. The absorption spectroscopy of this series of molecules is characterized by the presence of three low-lying metal to ligand charge transfer (MLCT) states absorbing in the visible energy domain. The nature of the isomerizable ligands (bpe, stpy, or CNstpy) and the type of antenna ligands (bpy, phen, and substituted phen) control the degree of mixing between the MLCT and intraligand excited states, their relative energies, as well as their intensities.

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Synthesis and photophysical properties of extended π conjugated naphthalimides

Photochemical & Photobiological Sciences ◽

10.1039/c6pp00372a ◽

2017 ◽

Vol 16 (4) ◽

pp. 539-546 ◽

Cited By ~ 5

Author(s):

C. Rémy ◽

C. Allain ◽

I. Leray

Keyword(s):

Charge Transfer ◽

Dft Calculations ◽

Photophysical Properties ◽

Photoinduced Charge Transfer ◽

Time Resolved ◽

Time Resolved Spectroscopy ◽

Td Dft ◽

Photoinduced Charge

A series of π conjugated naphthalimide derivatives were prepared. Compounds display efficient photoinduced charge transfer in solution which was rationalized by time-resolved spectroscopy and modelled by TD-DFT calculations.

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Towards understanding triiodide photochemistry in the solid state by femtosecond electron diffraction

EPJ Web of Conferences ◽

10.1051/epjconf/201920509007 ◽

2019 ◽

Vol 205 ◽

pp. 09007

Author(s):

Rui Xian ◽

Stuart A. Hayes ◽

Gaston Corthey ◽

Carole A. Morrison ◽

Alexander Marx ◽

...

Keyword(s):

Solid State ◽

Electron Diffraction ◽

Large Amplitude ◽

Atomic Level ◽

Coherent Motion ◽

Reaction Products ◽

Time Resolved ◽

Femtosecond Electron Diffraction

The photochemistry of the triiodide anion has been investigated by femtosecond electron diffraction. The time-resolved signal indicates the presence of reaction products and large-amplitude coherent motion produced by participating species. To reconstruct the atomic detail of the reaction and identify the major contributors to the detected signal, we outline the approach for atomic-level reconstruction.

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Time-resolved photoluminescence of solid state fullerenes

Chemical Physics Letters ◽

10.1016/0009-2614(93)89187-m ◽

1993 ◽

Vol 204 (5-6) ◽

pp. 461-466 ◽

Cited By ~ 28

Author(s):

H.J. Byrne ◽

W. Maser ◽

W.W. Rühle ◽

A. Mittelbach ◽

W. Hönle ◽

...

Keyword(s):

Solid State ◽

Time Resolved ◽

Time Resolved Photoluminescence

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First steps towards time-resolved 'in-house' X-ray diffraction experiments

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314092249 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C775-C775 ◽

Cited By ~ 1

Author(s):

Radoslaw Kaminski ◽

Jason Benedict ◽

Elzbieta Trzop ◽

Katarzyna Jarzembska ◽

Bertrand Fournier ◽

...

Keyword(s):

Excited State ◽

Time Resolution ◽

Structural Changes ◽

Laser Pulses ◽

High Repetition Rate ◽

X Ray Diffraction ◽

Laboratory Equipment ◽

Time Resolved ◽

X Ray ◽

Ligand Charge Transfer

High-intensity X-ray sources, such as synchrotrons or X-ray free electron lasers, providing up to 100 ps time-resolution allow for studying very short-lived excited electronic states in molecular crystals. Some recent examples constitute investigations of Rh...Rh bond shortening,[1] or metal-to-ligand charge transfer processes in CuI complexes.[2] Nevertheless, in cases in which the lifetime of excited state species exceeds 10 μs it is now possible, due to the dramatic increase in the brightness of X-ray sources and the sensitivity of detectors, to use laboratory equipment to explore structural changes upon excitation. Consequently, in this contribution we present detailed technical description of the 'in-house' X-ray diffraction setup allowing for the laser-pump X-ray-probe experiments within the time-resolution at the order of 10 μs or larger. The experimental setup consists of a modified Bruker Mo-rotating-anode diffractometer, coupled with the high-frequency Nd:YAG laser (λ = 355 nm). The required synchronization of the laser pulses and the X-ray beam is realized via the optical chopper mounted across the beam-path. Chopper and laser capabilities enable high-repetition-rate experiments reaching up to 100 kHz. In addition, the laser shutter is being directly controlled though the original diffractometer software, allowing for collection of the data in a similar manner as done at the synchrotron (alternating light-ON & light-OFF frames). The laser beam itself is split into two allowing for improved uniform light delivery onto the crystal specimen. The designed setup was tested on the chosen set of crystals exhibiting rather long-lived excited state, such as, the Cu2Br2L2 (L = C5H4N-NMe2) complex, for which the determined lifetime is about 100 μs at 90 K. The results shall be presented. Research is funded by the National Science Foundation (CHE1213223). KNJ is supported by the Polish Ministry of Science and Higher Education through the "Mobility Plus" program.

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