Vibration spectroscopy

M. L. Hair, Vibrational Spectroscopies for Adsorbed Species, ACS Symposium Series No. 137, A. T. Bell and M. L. Hair, eds., American Chemical Society, Washington, DC, 1980. 

Vibrational Spectroscopy. Infrared absorption spectra may be obtained using convention IR or FTIR instrumentation the catalyst may be present as a compressed disk, allowing transmission spectroscopy. If the surface area is high, there can be enough chemisorbed species for their spectra to be recorded. This approach is widely used to follow actual catalyzed reactions see, for example. Refs. 26 (metal oxide catalysts) and 27 (zeolitic catalysts). Diffuse reflectance infrared reflection spectroscopy (DRIFT S) may be used on films [e.g.. Ref. 28—Si02 films on Mo(llO)]. Laser Raman spectroscopy (e.g.. Refs. 29, 30) and infrared emission spectroscopy may give greater detail [31]. 

STM has also been adapted for perfonning single-atom vibrational spectroscopy [73],... 

Stipe B C, Rezaei M A and Flo W 1998 Single-molecule vibrational spectroscopy and microscopy Science 280 1732... 

Raduge C, Pfiumio V and Shen Y R 1997 Surface vibrational spectroscopy of sulfuric acid-water mixtures at the liquid-vapor interface Chem. Phys. Lett. 274 140... 

Shen Y R 1998 Sum frequency generation for vibrational spectroscopy applications to water interfaces and films of water and ice Solid State Commun. 108 399... 

The secondary hydration sheath has also been studied using vibrational spectroscopy. In the presence of... 

Miller R E 1988 The vibrational spectroscopy and dynamics of weakly bound neutral complexes Scianca 240 447-53... 

Vibrational spectroscopy provides detailed infonnation on both structure and dynamics of molecular species. Infrared (IR) and Raman spectroscopy are the most connnonly used methods, and will be covered in detail in this chapter. There exist other methods to obtain vibrational spectra, but those are somewhat more specialized and used less often. They are discussed in other chapters, and include inelastic neutron scattering (INS), helium atom scattering, electron energy loss spectroscopy (EELS), photoelectron spectroscopy, among others. 

Vibrational spectroscopy is an enomiously large subject area spamiing many scientific disciplines. The methodology, both experimental and theoretical, was developed primarily by physical chemists and has branched far and wide over the last 50 years. This chapter will mainly focus on its importance with regard to physical chemistry. 

Raman scattering has been discussed by many authors. As in the case of IR vibrational spectroscopy, the interaction is between the electromagnetic field and a dipole moment, however in this case the dipole moment is induced by the field itself The induced dipole is pj j = a E, where a is the polarizability. It can be expressed in a Taylor series expansion in coordinate isplacement... 

There are thousands of scientists whose work can be classified as vibrational spectroscopy. The following examples are meant to show the breadth of the field, but cannot be expected to constitute a complete representation of all the fields where vibrational spectroscopy is important. 

The temi action spectroscopy refers to those teclmiques that do not directly measure die absorption, but rather the consequence of photoabsorption. That is, there is some measurable change associated with the absorption process. There are several well known examples, such as photoionization spectroscopy [47], multi-photon ionization spectroscopy [48], photoacoustic spectroscopy [49], photoelectron spectroscopy [, 51], vibrational predissociation spectroscopy [ ] and optothemial spectroscopy [53, M]. These teclmiques have all been applied to vibrational spectroscopy, but only the last one will be discussed here. 

Vibrational spectroscopy has been, and will continue to be, one of the most important teclmiques in physical chemistry. In fact, the vibrational absorption of a single acetylene molecule on a Cu(lOO) surface was recently reported [ ]. Its endurance is due to the fact that it provides detailed infonnation on structure, dynamics and enviromnent. It is employed in a wide variety of circumstances, from routine analytical applications, to identifying novel (often transient) species, to providing some of the most important data for advancing the understanding of intramolecular and intemiolecular interactions. 

Mathies R A 1995 Biomolecular vibrational spectroscopy Biochemical Spectroscopy Methods Enzymol. vol 246, ed K Sauer (San Diego, CA Academic) pp 377-89... 

Ayotte P, Bailey C G, Weddle G FI and Johnson M A 1998 Vibrational spectroscopy of small Br (Fl20) and I Fl20) clusters infrared characterization of the ionic hydrogen bond J. Phys. Chem. A 102 3067-71... 

Comprehensive treatment of vibrational spectroscopy, including data for a wide variety of molecules. 

The general task is to trace the evolution of the third order polarization of the material created by each of the above 12 Raman field operators. For brevity, we choose to select only the subset of eight that is based on two colours only—a situation that is connnon to almost all of the Raman spectroscopies. Tliree-coloiir Raman studies are rather rare, but are most interesting, as demonstrated at both third and fifth order by the work in Wright s laboratory [21, 22, 23 and 24]- That work anticipates variations that include infrared resonances and the birth of doubly resonant vibrational spectroscopy (DOVE) and its two-dimensional Fourier transfomi representations analogous to 2D NMR [25]. 

Wright J C, Labuda M J, Zilian A, Chen P C and Hamilton J P 1997 New selective nonlinear vibrational spectroscopies J. Luminesc. 72-74 799-801... 

Labuda M J and Wright J C 1997 Measurement of vibrationally resonant and the feasibility of new vibrational spectroscopies Phys. Rev. Lett. 79 2446-9... 

Khidekel V and Mukamel S 1995 High-order echoes in vibrational spectroscopy of liquids Chem. Phys. Lett. 240 304-14... 

We now present one of the many examples of interfacial vibrational spectroscopy using SFG. Figure Bl.5.15 shows the surface vibrational spectrum of the water/air interface at a temperature of 40 °C [83]. Notice that... 

Dumas P, Weldon M K, Chabal Y J and Williams G P 1999 Molecules at surfaces and interfaces studied using vibrational spectroscopies and related techniques Surf. Rev. Lett. 6 225-55... 

Bain C D 1995 Sum-frequency vibrational spectroscopy of the solid-liquid interface J. Chem. See. Faraday Trans. 91 1281-96... 

Richmond G L 1997 Vibrational spectroscopy of molecules at liquid/liquid interfaces Ana/. Chem. 69 A536-43... 

Zhu X D, Suhr H and Shen Y R 1987 Surface vibrational spectroscopy by infrared-visible sum frequency generation Phys. Rev. B 35 3047-59... 

Du Q, Superfine R, Freysz E and Shen Y R 1993 Vibrational spectroscopy of water at the vapor-water interface Phys. Rev. Lett. 70 2313-16... 

The major role of TOF-SARS and SARIS is as surface structure analysis teclmiques which are capable of probing the positions of all elements with an accuracy of <0.1 A. They are sensitive to short-range order, i.e. individual interatomic spacings that are <10 A. They provide a direct measure of the interatomic distances in the first and subsurface layers and a measure of surface periodicity in real space. One of its most important applications is the direct determination of hydrogen adsorption sites by recoiling spectrometry [12, 4T ]. Most other surface structure teclmiques do not detect hydrogen, with the possible exception of He atom scattering and vibrational spectroscopy. 

Zhu L, Wang W, Sage J T and Champion P M 1995 Femtosecond time-resolved vibrational spectroscopy of heme proteins J. Raman Spectrosc. 26 527-34... 

As with the uncoupled case, one solution involves diagonalizing the Liouville matrix, iL+R+K. If U is the matrix with the eigenvectors as cohmms, and A is the diagonal matrix with the eigenvalues down the diagonal, then (B2.4.32) can be written as (B2.4.33). This is similar to other eigenvalue problems in quantum mechanics, such as the transfonnation to nonnal co-ordinates in vibrational spectroscopy. 

Molecular clusters are weakly bound aggregates of stable molecules. Such clusters can be produced easily using supersonic expansion, and have been extensively studied by both electronic and vibrational spectroscopy [146,... 

Handschuh H, Gantefor G and Eberhardt W 1995 Vibrational spectroscopy of clusters using a magnetic bottle electron spectrometer Rev. Sci. Instnim. 66 3838... 

Cwrutsky J C, Li M, Culver J P, Sarisky M J, Yodh A G and Hoohstrasser R M 1993 Vibrational dynamios of oondensed phase moleoules studied by ultrafast infrared speotrosoopy Time Resolved Vibrational Spectroscopy VI (Springer Proc. in Physics 74) ed A Lau (New York Springer) pp 63-7... 

As mentioned, we also carried out IR studies (a fast vibrational spectroscopy) early in our work on carbocations. In our studies of the norbornyl cation we obtained Raman spectra as well, although at the time it was not possible to theoretically calculate the spectra. Comparison with model compounds (the 2-norbornyl system and nortri-cyclane, respectively) indicated the symmetrical, bridged nature of the ion. In recent years, Sunko and Schleyer were able, using the since-developed Fourier transform-infrared (FT-IR) method, to obtain the spectrum of the norbornyl cation and to compare it with the theoretically calculated one. Again, it was rewarding that their data were in excellent accord with our earlier work. 

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