Research

Highly efficient visible-light driven photochromism: developments towards a solid-state molecular switch operating through a triplet-sensitised pathway


Reference:

Brayshaw, S. K., Schiffers, S., Stevenson, A. J., Teat, S. J., Warren, M. R., Bennett, R. D., Sazanovich, I. V., Buckley, A. R., Weinstein, J. A. and Raithby, P. R., 2011. Highly efficient visible-light driven photochromism: developments towards a solid-state molecular switch operating through a triplet-sensitised pathway. Chemistry - A European Journal, 17 (16), pp. 4385-4395.

Related documents:

This repository does not currently have the full-text of this item.
You may be able to access a copy if URLs are provided below. (Contact Author)

Official URL:

http://dx.doi.org/10.1002/chem.201003487

Abstract

We introduce a new highly efficient photochromic organometallic dithienylethene (DTE) complex, the first instance of a DTE core symmetrically modified by two PtII chromophores [Pt(PEt3)(2)(C C)(DTE)(C C)Pt(PEt3)(2)Ph] (1), which undergoes ring-closure when activated by visible light in solvents of different polarity, in thin films and even in the solid state. Complex 1 has been synthesised and fully photophysically characterised by (resonance) Raman and transient absorption spectroscopy complemented by calculations. The ring-closing photo-conversion in a single crystal of 1 has been followed by X-ray crystallography. This process occurs with the extremely high yield of 80%-considerably outperforming the other DTE derivatives. Remarkably, the photocyclisation of 1 occurs even under visible light (> 400 nm), which is not absorbed by the non-metallated DTE core HC C(DTE)C CH (2) itself. This unusual behaviour and the high photocyclisation yields in solution are attributed to the presence of a heavy atom in 1 that enables a triplet-sensitised photocyclisation pathway, elucidated by transient absorption spectroscopy and DFT calculations. The results of resonance Raman investigation confirm the involvement of the alkynyl unit in the frontier orbitals of both closed and open forms of 1 in the photocyclisation process. The changes in the Raman spectra upon cyclisation have permitted the identification of Raman marker bands, which include the acetylide stretching vibration. Importantly, these bands occur in the spectral region unobstructed by other vibrations and can be used for non-destructive monitoring of photocyclisation/photoreversion processes and for optical readout in this type of efficiently photochromic thermally stable systems. This study indicates a strategy for generating efficient solid-state photoswitches in which modification of the PtII units has the potential to tune absorption properties and hence operational wavelength across the visible range.

Details

Item Type Articles
CreatorsBrayshaw, S. K., Schiffers, S., Stevenson, A. J., Teat, S. J., Warren, M. R., Bennett, R. D., Sazanovich, I. V., Buckley, A. R., Weinstein, J. A. and Raithby, P. R.
DOI10.1002/chem.201003487
Uncontrolled Keywordsdithienylethene, platinum, structure elucidation, photocyclisation, photochromism, transient absorption spectroscopy
DepartmentsFaculty of Science > Chemistry
RefereedYes
StatusPublished
ID Code23892

Export

Actions (login required)

View Item