dc.creator Lindsay, C. Michael en_US dc.creator Fajardo, Mario E. en_US dc.date.accessioned 2008-07-15T13:35:52Z dc.date.available 2008-07-15T13:35:52Z dc.date.issued 2008 en_US dc.identifier 2008-WH-05 en_US dc.identifier.uri http://hdl.handle.net/1811/33333 dc.description M. E. Fajardo, 60th Ohio State University International Symposium on Molecular SpectroscopyC. M. Lindsay and M. E. Fajardo, 61st Ohio State University International Symposium on Molecular SpectroscopyA. F. Devonshire, Proc. Roy. Soc. London M. T.Bowers and W. H. Flygare, J. Chem. Phys. en_US dc.description Author Institution: AFRL/MNME, Energetic Materials Branch, Ordnance Division, U. S.; Air Force Research Laboratory, 2306 Perimeter Rd., Eglin AFB, FL 32542-5910 en_US dc.description.abstract Matrix isolation has been used for many decades to study the structure and reactivity of species within an inert matrix. In most cases the infrared spectra of the dopants are fairly simple given that the rotational fine structure is usually frozen out by strong anisotropic interactions with the matrix host. In a few noteable cases, quantized rotation in the solid state has been observed spectroscopically, typically occuring when the rotational energy level spacings of the free rotor are large in comparison to the angle dependent barriers imposed by the host solid. The low angular anisotropy and weak interactions of solid parahydrogen has opened up the possibility to study the rotational motion of larger rotators and recently, we have reported that some molecules containing two second row elements, namely CO}, talk RG04 (2005)} and HCN,}, talk RD10 (2006)} do indeed undergo a hindered rotational motion within the parahydrogen matrix. \vspace{8pt} In this talk, we discuss our efforts to use infrared spectroscopy to study the rotational dynamics of relatively large" rotators embedded in solid parahydrogen, \emph{i.e.}~molecules that do not rotate in other solid matrices. Parahydrogen matrices containing $\sim 5-10$ ppm of CO, NO, HCN, and HCCH are produced using the Rapid Vapor Deposition technique and probed with a high resolution FTIR absorption spectrometer. Analysis of the resulting ro-vibrational spectra show that the crystal field splittings are comparable to the rotational energy level spacings of the free rotor and are sensitive to the vibrational state of the molecule. We analyze this hindered rotational motion using the electrostatic formalism developed by Devonshire} \underline{A153}, 601 (1936).} and Flygare.}, \underline{44}, 1389 (1966).} Additionally, we examine the magnitude of the various crystal field parameters using ab initio H$_2$-dopant pair potential energy surfaces. en_US dc.language.iso English en_US dc.publisher Ohio State University en_US dc.title CRYSTAL FIELD INTERACTIONS OF LARGE" ROTORS EMBEDDED IN SOLID PARAHYDROGEN en_US dc.type Article en_US
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