Ultrafast Structural Rearrangements in the MLCT Excited State for Copper(I) bis-Phenanthrolines in Solution

PDF Version Also Available for Download.

Description

Ultrafast excited state structural dynamics of [Cu{sup I}(dmp){sub 2}]{sup +} (dmp = 2,9-dimethyl-1,10-phenanthroline) have been studied to identify structural origins of transient spectroscopic changes during the photoinduced metal-to-ligand-charge-transfer (MLCT) transition that induces an electronic configuration change from Cu(I) (3d{sup 10}) to Cu(II) (3d{sup 9}). This study has important connections with the flattening of the Franck-Condon state tetrahedral geometry and the ligation of Cu(II)* with the solvent observed in the thermally equilibrated MLCT state by our previous laser-initiated time-resolved x-ray absorption spectroscopy (LITR-XAS) results. To better understand the structural photodynamics of Cu(I) complexes, we have studied both [Cu{sup I}(dmp){sub 2}]{sup +} ... continued below

Physical Description

PDF-file: 51 pages; size: 1.2 Mbytes

Creation Information

Shaw, G B; Grant, C D; Shirota, H; Castner Jr., E W; Meyer, G J & Chen, L X October 5, 2006.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

Ultrafast excited state structural dynamics of [Cu{sup I}(dmp){sub 2}]{sup +} (dmp = 2,9-dimethyl-1,10-phenanthroline) have been studied to identify structural origins of transient spectroscopic changes during the photoinduced metal-to-ligand-charge-transfer (MLCT) transition that induces an electronic configuration change from Cu(I) (3d{sup 10}) to Cu(II) (3d{sup 9}). This study has important connections with the flattening of the Franck-Condon state tetrahedral geometry and the ligation of Cu(II)* with the solvent observed in the thermally equilibrated MLCT state by our previous laser-initiated time-resolved x-ray absorption spectroscopy (LITR-XAS) results. To better understand the structural photodynamics of Cu(I) complexes, we have studied both [Cu{sup I}(dmp){sub 2}]{sup +} and [Cu{sup I}(dpp){sub 2}]{sup +} (dpp = 2,9-diphenyl-1,10-phenanthroline) in solvents with different dielectric constants, viscosities and thermal diffusivities by transient absorption spectroscopy. The observed spectral dynamics suggest that a solvent-independent inner-sphere relaxation process is occurring despite the large amplitude motions due to the flattening of the tetrahedral coordinated geometry. The singlet fluorescence dynamics of photoexcited [Cu{sup I}(dmp){sub 2}]{sup +} were measured in the coordinating solvent acetonitrile, using the fluorescence upconversion method at different emission wavelengths. At the bluest emission wavelengths, a prompt fluorescence lifetime of 66 fs is attributed to the excited state deactivation processes due to the internal conversion and intersystem crossing at the Franck-Condon state geometry. The differentiation between the prompt fluorescence lifetime with the tetrahedral Franck-Condon geometry and that with the flattened tetrahedral geometry uncovers an unexpected ultrafast flattening process in the MLCT state of [Cu{sup I}(dmp){sub 2}]{sup +}. These results provide guidance for future x-ray structural studies on ultrafast time scale, as well as for synthesis towards its applications in solar energy conversion.

Physical Description

PDF-file: 51 pages; size: 1.2 Mbytes

Source

  • Journal Name: Journal of the American Chemical Society, vol. 129, no. 7, February 21, 2007, pp. 2147-2160; Journal Volume: 129; Journal Issue: 7

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Report No.: UCRL-JRNL-225105
  • Grant Number: W-7405-ENG-48
  • Office of Scientific & Technical Information Report Number: 902226
  • Archival Resource Key: ark:/67531/metadc888843

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • October 5, 2006

Added to The UNT Digital Library

  • Sept. 22, 2016, 2:13 a.m.

Description Last Updated

  • Dec. 2, 2016, 4:39 p.m.

Usage Statistics

When was this article last used?

Yesterday: 0
Past 30 days: 1
Total Uses: 2

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Shaw, G B; Grant, C D; Shirota, H; Castner Jr., E W; Meyer, G J & Chen, L X. Ultrafast Structural Rearrangements in the MLCT Excited State for Copper(I) bis-Phenanthrolines in Solution, article, October 5, 2006; Livermore, California. (digital.library.unt.edu/ark:/67531/metadc888843/: accessed September 22, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.