Raman techniques current state

The current detailed understanding of photo-induced electron transfer processes has been advanced dramatically by the development of modern spectroscopic methods. For example, the application of time-resolved optical spectroscopy has developed from modest beginnings (flash-phyotolysis with millisecond resolution) [108,109] to the current state of the art, where laser spectroscopy with nanosecond resolution [110-113] must be considered routine, and where picosecond [114-116] or even femtosecond resolution [117] is no longer uncommon. Other spectroscopic techniques that have been applied to the study of electron transfer processes include time-resolved Raman spectroscopy [118], (time resolved) electron spin... 

Some early applications and potential benefits of the technique were described by Bolton, Prasad, and co-workers [2-5]. Highlighting an area where Raman spectroscopy currently provides valuable data, these workers showed how the lattice vibrations (or phonons) are of considerable value in the characterization of solid states of a drug and especially for the investigation of polymorphism. In addition to examining solid-state stabilities of crystalline modifications to drug crystals, the value of the technique for researching solute-solvent interactions of pharmaceutical materials was also demonstrated. 

The Raman spectroscopy investigation mentioned above (118) showed that the presence of the products is important in controlling the structural transformations occurring during catalyst activation and that a highly disordered structure can be important in selective butane oxidation. The techniques and findings obtained through in situ analysis of the vanadyl pyrophosphate surface have been reviewed by Bluhm et al. (151), who discussed the state of current techniques used to probe the surface... 

Spectroelectrochemistry encompasses a group of techniques that allow simultaneous acquisition of electrochemical and spectroscopic information in situ in an electrochemical cell. A wide range of spectroscopic techniques may be combined with electrochemistry, including electronic (UV-visible) absorption and reflectance spectroscopy, luminescence spectroscopy, infrared and Raman spectroscopies, electron spin resonance spectroscopy and ellipsometry. Molecular properties such as molar absorption coefficients, vibrational absorption frequencies and electronic or magnetic resonance frequencies, in addition to electrical parameters such as current, voltage or charge, are now being used routinely for the study of electron transfer reaction pathways and the fundamental molecular states at interfaces. In this article the principles and practice of electronic spectroelectrochemistry are introduced. 

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