Tunable Far-infrared Laser Spectroscopy of Clusters PDF Download

Author: Charles Albert Schmuttenmaer
Publisher:
ISBN:
Category :
Languages : en
Pages : 532

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Author: Richard J. Saykally
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Two new types of infrared spectrometers have been developed for the study of gas-phase cluster species. A tunable far-infrared (FIR) laser was combined with an apparatus for producing planar supersonic beams of laser vaporized clusters, and used in the measurement of the 64.1 cm-1 bending vibration of c sub 3. A mid-IR diode laser system was constructed with a similar cluster source, and used in studies of the C sub 4, C sub 5, C sub 7, and C sub 9 clusters. Structures and internal dynamics of the clusters were determined. Extensions to metal cluster systems are currently underway. A new type of spectrometer was developed for measuring electronic spectra of supersonic metal clusters. Cavity Ringdown Laser Absorption Spectroscopy (CRLAS) was utilized in a study of the Cu sub 3 cluster in the initial application of the method.

Author: Kerry Lynn Busarow
Publisher:
ISBN:
Category :
Languages : en
Pages : 642

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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 317

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The gas phase high resolution spectroscopic study of weakly bound clusters can provide the information necessary to develop an intermolecular potential energy surface. This surface can then be used to better understand condensed phases. In this work, a tunable far infrared laser spectrometer is used to study weakly bound dimers produced in the newly developed continuous planar supersonic jet expansion apparatus. The water dimer is an extensively studied hydrogen bonded dimer. It undergoes several tunneling motions which result in splittings and perturbations of the rovibrational energy levels. A review is presented of much of the experimental and theoretical work done on water dimer, including a description of the combined fit of all the high resolution spectroscopic results by Coudert and Hougen. Also included is a discussion of the measurement of the K = 1 lower --> K = 2 lower band performed using the tunable far infrared laser/planar jet apparatus. The preliminary results from the study of CH4{center dot}H2O will also be presented. CH4{center dot}H2O is unique in that unlike a strongly anisotropic complex, such as the water dimer, the monomer subunits are nearly free internal rotors. Seven bands are observed which have very similar band origins and rotational constants. Two energy level diagrams are proposed which are strongly influenced by earlier ArH2O studies. A brief qualitative discussion of the CH4{center dot}H2O binding energy compared to that of ArH2O is also included. 152 refs., 54 figs., 20 tabs.

Author: Martina H. Havenith
Publisher: Springer
ISBN: 3540454578
Category : Science
Languages : en
Pages : 124

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This book is intended to give an introduction to intermolecular forces from an experimental point of view. Within the last 10 years the interest has turned more and more into an understanding of the weak, but important, int- molecular forces. New experimental techniques have been developed which have helped to gain more insight into this interesting topic. This book is intended as an introduction for graduate students who are familiar with the main concepts of n~olecular spectroscopy. Special emphasis will be laid on the theoretical concepts. After a detailed description of experimental techniques, the results for two prototype systems which have been the subject of several studies in the literature within recent years will be presented. Ar-CO is becoming the most extensively studied van der Waals complex, theoretically and experimentally. Nevertheless, this example shows that even though the theory has greatly improved and has helped us to improve our knowledge of intermolecular forces, even for relatively simple cases the theory car1 still fall short of an accurate description. For a long time (NH3)2 was considered as a prototype for hydrogen bo- ing. However, subsequent experimental and theoretical studies have revealed the mysteries of the obtained spectra and proved that our previous concept of hydrogen bonds was just too naive.

Author: F. Akif Tezcan
Publisher:
ISBN:
Category : High resolution spectroscopy
Languages : en
Pages : 84

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Author: David Frank Nicoli
Publisher:
ISBN:
Category :
Languages : en
Pages : 257

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A far infrared HCN/DCN laser source and high field superconducting solenoid were used to perform high resolution swept-field spectroscopy of the linear chain magnetic system Co2.2H2O ('CC2'). The field dependent transmission of CC2 was measured at 29.7, 32.2, 51.4 and 52.7/cm over the temperature range 1.3 to 15K in applied fields of from zero to over 100 KOe. The relatively high output power and extreme monochromaticity of the laser source allowed for a qualitative improvement in the resolution of the 'spin-cluster' resonance spectrum and the accurate determination of linewidths and intensities over a substantial temperature range. Spin-cluster excitations corresponding to the creation of 'multimagnons' of effective size up to 14 adjacent flipped spins, with corresponding g-values as large as 95, have been clearly observed. Nearly complete even/odd-cluster manifold separation according to radiation polarization type was obtained. Data taken with the deuterated form of CC2 indirectly verified the existence of an optic phonon at about 29/cm, using its strong coupling to the ordinary 'spin-wave' excitation. A set of new, weak resonances was observed in the middle field region of the spectrum using the HCN laser lines.

Author: Andrew Lloyd Cooksy
Publisher:
ISBN:
Category :
Languages : en
Pages : 516

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Author: Richard Saykally
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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A high resolution infrared cavity ringdown laser absorption spectrometer has been developed to study proposed HEDM molecules and metal containing clusters. Using a novel tunable pulsed Alexandrite ring laser, we are able to generate tunable visible radiation with ca, 40 MHz bandwidth. This tunable visible light is downconverted to the infrared using stimulated Raman scattering in H2 and D2. With this system, tunable radiation from the UV to the far infrared can be generated with ca, 100 MHz bandwidth. We will test this system using our pulsed supersonic laser vaporization source to study both metal and carbon containing species. Infrared Cavity Ringdown Spectroscopy has also been used to study water clusters in both pulsed supersonic beams and pulsed discharged nozzles.

Author: P. Ehrenfreund
Publisher: Springer Science & Business Media
ISBN: 9401147280
Category : Science
Languages : en
Pages : 685

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The book presents the most recent developments of laboratory studies in astrophysics and space research. The individual chapters review laboratory investigations under simulated space conditions, studies for the design of successful space experiments or for supporting the interpretation of astronomical and space mission recorded data. Related theoretical models, numerical simulations and in situ observations demonstrate the necessity of experimental work on the Earth's surface. The expertise of the contributing scientists covers a broad spectrum and is included in general overviews from fundamental science to recent space technology. The book intends to serve as a reference for researchers and graduate students on the most recent activities and results in laboratory astrophysics, and to give reviews of their applications in astronomy, planetology, cosmochemistry, space research and Solar System exploration.