scholarly journals 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

2012 ◽  
Vol 116 (13) ◽  
pp. 3359-3365 ◽  
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

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

2014 ◽  
Vol 70 (a1) ◽  
pp. C775-C775 ◽  
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.

scholarly journals Direct observation of the excited state structure of a Ag(I)-Cu(I) complex

2014 ◽  
Vol 70 (a1) ◽  
pp. C774-C774 ◽  
Author(s):  
Katarzyna Jarzembska ◽  
Radoslaw Kaminski ◽  
Bertrand Fournier ◽  
Elzbieta Trzop ◽  
Jesse Sokolow ◽  
...  
Keyword(s):  
Excited State ◽  
Solid State ◽  
Structural Changes ◽  
Luminescent Properties ◽  
Crystal Form ◽  
Data Sets ◽  
Time Resolved ◽  
Model Complex ◽  
Metal Metal ◽  
Molecular Excited State

Heterodentate coordination complexes have been extensively studied because of their rich electronic and luminescent properties, which are of importance in the design of molecular devices. The short metal-metal contacts found in such complexes determine the nature of the lowest lying emissive states, and must be explored in order to understand their physical properties. Recent advances in time-resolved (TR) synchrotron techniques supported by specific data collection strategies and data processing procedures [1] allow for elucidation of molecular excited state geometries in the solid state. The approach has been so far successfully applied to several high-quality Laue-data sets collected at the 14-ID BioCars beamline at the Advanced Photon Source.[2] In this contribution we present synchrotron TR experiment results obtained for a new solvent-free crystal form of a model complex containing Ag(I) and Cu(I) (Ag2Cu2L4, L = 2-diphenylphosphino-3-methylindole).[3] This system exhibits red solid-state luminescence with a lifetime of about 1 µs. This is one of the shortest-lived excited states we have studied so far with the Laue technique. The relatively short lifetime goes along with significant structural changes observed upon irradiation, such as, the Ag...Ag distance shortening of about 0.2 Å in the excited state. The results clearly show strengthening of the Ag...Ag interactions suggesting a bond formation upon excitation. The photocrystallographic findings are supported by spectroscopic measurements and quantum computations. The results confirm the triplet nature of the emissive state originating mainly from a ligand-to-metal charge transfer. Research funded by the NSF (CHE1213223). BioCARS Sector 14 is supported by NIH, National Center for Research Resources (RR007707). APS is funded by the U.S. DOE, Office of Basic Energy Sciences (W-31-109-ENG-38). KNJ is supported by the Polish Ministry of Science and Higher Education through the "Mobility Plus" program.

Spin mixed charge transfer states of iridium complex Ir(ppy)3: transient absorption and time-resolved photoluminescence

RSC Advances ◽  
2015 ◽  
Vol 5 (43) ◽  
pp. 34094-34099 ◽  
Author(s):  
Mohan Singh Mehata ◽  
Yang Yang ◽  
Zong-Jing Qu ◽  
Jun-Sheng Chen ◽  
Feng-Jiao Zhao ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Quantum Chemistry ◽  
Transient Absorption ◽  
Iridium Complex ◽  
Time Resolved ◽  
Ligand Charge Transfer ◽  
Quantum Chemistry Calculations ◽  
Time Resolved Photoluminescence

Transient absorption and time-resolved PL together with quantum chemistry calculations demonstrated the existence of multiple low-lying metal-to-ligand charge transfer states of Ir(ppy)3.

Isolation of a metal-to-ligand charge-transfer (MLCT) state of a tris 1,4-diimine complex of iron in the solid state: X-ray crystal structure and EPR

2017 ◽  
Vol 41 (2) ◽  
pp. 452-456 ◽  
Author(s):  
Nirmal K. Shee ◽  
Michael G. B. Drew ◽  
Dipankar Datta
Keyword(s):  
Crystal Structure ◽  
Charge Transfer ◽  
Solid State ◽  
X Ray ◽  
Ligand Charge Transfer ◽  
Mlct State

Using 5,6-dihydro-5,6-epoxy-1,10-phenanthroline as the ligand L, the X-ray crystal structure of [FeL3](ClO4)2·2H2O is determined.

scholarly journals Time-Resolved Dehydration-Induced Structural Changes in an Intact Bovine Cortical Bone Revealed by Solid-State NMR Spectroscopy

2009 ◽  
Vol 131 (47) ◽  
pp. 17064-17065 ◽  
Author(s):  
Peizhi Zhu ◽  
Jiadi Xu ◽  
Nadder Sahar ◽  
Michael D. Morris ◽  
David H. Kohn ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Cortical Bone ◽  
Solid State Nmr ◽  
Structural Changes ◽  
Time Resolved ◽  
Solid State Nmr Spectroscopy

Synthesis, Electronic Spectra and Solvent-Induced Reversible Dissociation of Diphosphine(hexafluoroacetylacetonato)copper(I) Complexes

2003 ◽  
Vol 58 (10) ◽  
pp. 950-954 ◽  
Author(s):  
Valeri Pawlowski ◽  
Andreas Strasser ◽  
Arnd Vogler
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
Electronic Spectra ◽  
Ion Pairs ◽  
Excitation Spectra ◽  
Polar Solvents ◽  
Long Wavelength ◽  
Reversible Dissociation ◽  
Ligand Charge Transfer

The complexes CuI(P-P)(hfac) with P-P = 1,2-bis(diphenylphosphino)ethane (diphos), 1,3-bis-(diphenylphosphino)propane (prophos), 2,2’-bis(diphenylphosphino)-1,1’-binaphthyl (binap) and hfac = hexafluoroacetylacetonate were synthesized and spectroscopically characterized. In the solid state or in solutions of non-polar solvents these compounds are yellow owing to a long-wavelength (hfac− →P-P) ligand-to-ligand charge transfer absorption. In coordinating solvents such as CH3CN the complexes undergo a reversible dissociation according to the equation: Cu(P-P)(hfac) + n CH3CN ⇌ [Cu(P-P)(CH3CN)n]+hfac−.While the complexes are not luminescent the ion pairs [Cu(P-P)(CH3CN)n]+hfac− are emissive at 77 K. The cations and the anions show separate emissions as indicated by the excitation spectra.

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