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ResearchMolecular Inorganic Chemistry - Browne group

Spectroscopy

Raman spectroscopy

Facilities available

The Raman systems available in the Browne group include:

Raman fibre probe/station (with polarizers) and microscope at an excitation wavelength of 785 nm (Perkin Elmer).

Additional microscope facilities are available - 633 nm on request, 488 nm (inverted microscope) and 532 nm (van Wees group) - as well as a cryostat (77 K -300 K) and heating stage (298K to 600 K) and attachment for macro-sampling (e.g. solutions in cuvettes, solids etc)

Additional fibre/probe based systems are available at 532, 785 and 1064 nm (all dispersive)

Open bench Raman systems are available equipped with lasers at (CW) 244, 266, 355, 405.1, 473, 532, 561, 691 nm and (ns-pulsed) 213, 266, 355, 532, 1064 nm (other pulsed wavelengths available using a Raman shifting cell) with 77 K to 390 K temperature control of samples. All systems use SOLIS from Andor Technology except for the 785 nm systems. Time resolve Raman spectroscopy is available using either CCD or iCCD detection.

Handling data

Data collected using the Perkin Elmer systems can be processed using the PE software. For data colelcted using Andor SOLIS, export the data (use the batch conversion option) in Grams .spc format and then open the files in Spekwin32 (available for free for academic users at http://www.effemm2.de/spekwin/index_en.html). The data can be processed using this software or alternatively you can save the files as jcamp .dx files and open them in the perkin elmer software. This latter option is especially useful if you want to subtract spectra recorded on different days for which the spectrograph was aligned slightly differently.

Typical processing involves 'cosmic' spike removal (spekwin32 is useful but can remove peaks sometimes as well so use it carefully!) and a multipoint baseline correction (the PE software is the handiest for this). In general the y-axis is meaningless except in special cricumstances so in general use an internal reference when doing quantitative work.

Resonance Raman spectroscopy:

CW, transient and time resolved Raman spectroscopy is a core competency of the Browne group. The primary aim is to use resonant enhancement to allow us to probe the behaviour of photo and/or catalytically active species in real time under reaction conditions where the catalyst present in concentrations that are too low to allow for detection by normal Raman spectroscopy.

As an example the resonance Raman spectra of [Ru(bpy)3]2+ in acetonitrile at 355 nm with (lower) continuous (5 mW) and pulsed (6 ns, 0.3 mJ per pulse). The lower spectrum shows  the complex in the ground electronic state only while the upper spectrum shows essentially only features of the complex in the lowest emissive electronic state (single colour pump/probe).

UV Resonance Raman spectroscopy

One of the focus areas of development of the group is in the use of UV Resonance and time resolved resonance Raman spectroscopy. For a recent application note see UVRAMAN

NIR spectroscopy

The group operates a NIR spectroscopy system for 1064 nm Raman spectroscopy, NIR absorption spectroscopy (900-2500 nm) and NIR emission spectroscopy e.g. singlet oxygen emission.

CW and ns-TR resonantly enhanced Raman spectra of [Ru(bpy)3]2+
CW and ns-TR resonantly enhanced Raman spectra of [Ru(bpy)3]2+
Last modified:28 July 2017 11.12 a.m.