Thesis (Ph. D.)--University of Wisconsin--Madison, 1932. / Typescript. With this are bound: Chemical aspects of the infrared absorption spectra of the ethyl halides / Paul C. Cross and Farrington Daniels. Reprinted from Journal of chemical physics, vol. 1, no. 1 (Jan. 1933), p. 48-55 -- The calibration of an infrared spectrometer with a rocksalt prism / Paul C. Cross. Reprinted from Review of scientific instruments, vol. 4 (Apr. 1933), p. 197-199. Includes bibliographical references (leaves [46]-[47]).

The atomic spectra of Thallium were excited and photographed in the spectral region from 340 to 9000 Å , using both an electrodeless discharge and a spark-in-Helium as light sources. The single electron Rydberg series have been extended in TI III. The ionization potential of TI III and Pb IV was determined from hydrogenic terms and found to be 240773 ± 5 cm⁻¹ and 342438 ± 5 cm⁻¹ respectively. The dipole polarizability of TI III was found to be 2.53 ± .02 a³₀ and of Pb IV 4.37 ± .04 a³₀. Using a line list previously obtained in this laboratory, terms belonging to three electron configuration were established in TI III and Pb IV. The 5d⁹ ns series was extended in TI IV and an ionization potential of 412500 ± 300 cm⁻¹ arrived at. In TI IV and Pb V the two electron configurations 5d⁹ 6d, 5d⁹ 5f, 5d⁹ 7p and 5d⁸ 6s² were partially established while a number of terms belonging to the complex 5d⁸ 6s6p configuration could be identified as well. The analysis of TI II was extended by completing the 5d¹º 6p² configuration and identifying a number of odd and even parity terms above the first ionization limit. These were tentatively assigned to the 5d¹º 6p7p, 5d⁹ 6s² 7s, 5d⁹ 6s² 6d, 5d⁹6s6p² and the 5d¹º6p7s configurations. The number of classified TI III lines, involved in this extension of the term analysis, has increased from 247 to 579. In the TI IV spectrum the increase in classified lines has been from 35 to 308 lines. In lead spectra the increase in Pb IV has been from 134 lines to 460, and in Pb V the corresponding increase is from 200 to 303 lines. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Currently the formulation of a valid force constant matrix poses the largest problem in the normal coordinate analysis or the mechanical interpretation of vibrational spectra. Usually a preselected set of trial force constants is iteratively corrected by means of first order perturbation theory and the principle of least squares. This thesis breaks that tradition and operates the normal coordinate analysis through an implied force constant matrix, [formula omitted], where LL(t) = G, the familiar Wilson G-matrix. The A-matrix is composed of the experimental vibrational frequencies for a selected basis molecule and the L-matrix is parameterized in a general way. The L-matrix parameters are varied until the implied force constant matrix generates an optimum mechanical picture of the basis molecule and its isotopic homologs. However this thesis emphasizes the vibrational fundamentals of isotopic homologs in specifying the implied force field. In application six L-matrix parameters encompass the sixty-three planar vibrational frequencies of ethylene and its deuterohomologs with slightly less error than traditional calculations using as many as fifteen potential energy parameters. As well, the implied force constants comply with the existing picture of chemical bonding without deliberate a priori reference to it. In particular, aspects of the hybrid orbital force field are confirmed without prior constraints. In more detailed computational studies the implied force field has revealed a systematic trend in anharmonic effects which can he understood in terms of different vibrational amplitudes for different isotopic homologs. The influence of vibrational amplitude has been parameterized and included within the implication method as a simple anharmonicity correction. For example, one L-matrix parameter and three vibrational amplitude parameters encompass the nine observed vibrational frequencies of water and its deuterohomologs with an average frequency error of 0.4 cm(-1) . Without amplitude corrections the average frequency error becomes 10.7 cm(-1) with one L-matrix parameter or 12.8 cm(-1) with four potential energy parameters.. It is particularly significant that this simple picture of anharmonicity employs the observed vibrational frequencies rather that the empirically derived harmonic frequencies. As well, the vibrational amplitude parameters comply with expected features of potential energy surfaces such as the dissociation limit. The principle advantage of the implication method is that there a fewer L-matrix parameters than F-matrix parameters. The principal disadvantage is that approximations and intuitive notations are not easily built into the implication method. However, as experimental information becomes more complete and better understood, the need for improved analytic foundations dominates the need for handy approximations. / Science, Faculty of / Chemistry, Department of / Graduate

The reactions: [formulae omitted] have been studied here in a discharge flow system. Using two temperatures, the rate constant for wall deactivation was found to be 3.8 x 10² exp [fomula omitted] sec⁻¹. It was concluded that the deactivation was not diffusion controlled as previously suggested but controlled by the surface deactivation process on the walls. The rate constant for production of O₂(¹Σg＊) was found to be 6.7 x 10⁴ exp [formula omitted] litres mole⁻¹sec⁻¹, in reasonable agreement with the room temperature value determined by Arnold. An upper limit of 1.6 x 10⁴ litres mole⁻¹sec⁻¹ was obtained for the rate constant of the reaction: N + O₂ (¹Δg ) → NO + 0 showing that the reaction is considerably slower than expected from comparison with the analogous reaction of ground state oxygen. This is rationalized by showing that the two reactions require different transition states. Whilst studying the above reaction several surface catalysed glows from molecular nitrogen and nitric oxide were seen. These glows were found to require O₂ (¹Δg) for their production and not atomic oxygen as previously thought. Several qualitative and spectroscopic experiments were performed and in the light of the information gained various possible mechanisms are discussed. / Science, Faculty of / Chemistry, Department of / Graduate

No description available.

Three gas phase alkaline earth molecules were analyzed using dye laser spectroscopy. The A¹Σ⁺ - X¹Σ⁺ transition of gas phase SrS was studied with high resolution techniques. The 0-0, 0-1, 1-1, 2-1, 3-0, 3-2, 4-1, 5-1, and 5-2 bands were rotationally analyzed and spectroscopic constants were determined. The A¹Σ⁺ state was extensively perturbed. Ground state (X¹Σ⁺) constants derived from the analysis of the nine vibrational levels include: ωₑ = 388.2643 cm⁻¹, Bₑ = 0.1208034(33) cm⁻¹, and rₑ = 2.439687(14) Å. Excited state (A¹Σ⁺) constants determined include: Tₑ = 13932.7068(10) cm⁻¹, ωₑ = 339.1454(20) cm⁻¹, Bₑ = 0.1139895(38) cm⁻¹, and rₑ = 2.511601(17) Å. The spectra of calcium and strontium borohydrides were observed using low resolution laser spectroscopy. The spectra were assigned to the òA₁ - Ẋ²A₁ and Ḃ²E - Ẋ²A₁ transitions of CaBH₄ and SrBH₄. The vibrational frequencies of the metal-ligand stretch determined for CaBH₄ were 457 cm⁻¹ (Ẋ²A₁), 473 cm⁻¹ (Ā²A₁), and 465 cm⁻¹ (Ḃ²E). The corresponding SrBH4 frequencies were 399 cm⁻¹, 420 cm⁻¹, and 421 cm⁻¹.

自由電子雷射器和傅裡葉變換質譜儀的組合使之成為一種研究生物分子和一些水和離子的溶解動力學的有力工具。而理論方法作為實驗的輔助手段常用于判斷一些分子的結構。在本論文中，我運用密度泛函理論和第一性分子動力學方法研究了陽離子化的氨基酸和一些水合陰離子的實驗紅外多光子吸收譜。 / 第二章研究了氫離子和鹼金屬離子化的天冬醯胺酸的紅外多光子吸收譜。以前有文獻用簡諧近似的方法研究過這個團簇，不過這種方法忽略了分子的動力學和非諧效應。我用第一性分子動力學方法重新研究了這個體系，結果顯示這種陽離子化的氨基酸的分子結構非常柔軟，在有限溫度下可以通過二面角的轉動和離子與氨基酸中的氧和氮原子距離的振動可以相互的轉化。而這些構型的相互轉化可以解釋實驗紅外吸收峰的展寬和相對強度變化趨勢。 / 第三章研究了水合碳酸氫根陰離子的紅外多光子吸收譜。以前的文獻指出，對於這種團簇，僅通過對比實驗和簡諧近似的紅外譜圖不能夠判斷是否只有一種異構體存在。應用第一性分子動力學方法，我發現簡諧近似紅外譜和實驗譜的不吻合之處，特別是水分子個數小於等於5時，水分子中氫原子的左右搖擺振動和來回搖擺振動吸收峰在實驗譜中的缺失。通過計算一系列異構體的熱能，我發現一些含量較少的異構體仍然對吸收峰有比較大的貢獻，考慮了這些結構的貢獻我們就可以理解為什麼隨著團簇尺寸的增加，一些吸收峰的強度有一定的變化趨勢。 / 最後兩章研究了水合磷酸二氫根的紅外多光子吸收譜。這是第一次我們和實驗組合作成果。在這個專案裡，我負責分析和全部的理論計算。對於這種團簇，實驗上測量了紅外譜的低頻和高頻區(n=1-4)。有趣的是，特別是體系只包含一個水分子時，兩個穩定的異構體均不能單獨解釋低頻和高頻的實驗結果。基於分子動力學的研究發現，有一個過渡態的吸收峰出現在了高頻區。其原因是氫原子的零點能和隧穿效應。與n=1類似,對於存在多個水分子的體系，實驗譜也揭示了低溫下的異構體效應，而這個效應使得簡諧效應完全失效。 / The combination of the FEL with FTICR makes it a powerful tool in researching the biochemical molecules and solvation dynamics of small hydrated ions. And theoretical methods are often employed in the determination of the molecular structures as auxiliary tools. In this thesis, density functional theory and ab initio molecular dynamics method have been applied to study the experimental infrared multiphoton dissociation (IRMPD) processes for cationized amino acids and hydrated anions. / The second Chapter is the AIMD simulated IR spectra for Asparagine cationized by H⁺, Li⁺, Na⁺, K⁺, and Cs⁺. The previous work simulated these type clusters with harmonic approximation in which the dynamics and anharmonicity effects were missed. My result shows that M⁺(Asn) complexes are very flexible and they could convert into each other at finite temperatures by torsional rotation and stretching the distances between the ion and N, O atoms in Asn. The broaden features and shift of the relative intensities of the vibrational profiles for these conformers are dependent on the structural flexibility of the complexes. / The third Chapter is the IRMPD spectra of the hydrated bicarbonate anion clusters for n=1-7. For some clusters, as mentions in the former harmonic results, comparing the experimental and calculated spectra does not always identify a single isomer as being responsible for the spectrum. By using AIMD technique, I found discrepancies between the harmonic and experimental spectra, especially for the absence of water wagging and rocking mode in the experimental result for n=1-5. By calculating the thermal energies of various isomers of each cluster, I found that the less dominate conformer also shows its large contributions to the vibrational profiles and this could explain the peak intensity trend as the cluster size increase. / The vibrational spectra for (HO)₂PO₂⁻(H₂O)n=1-4, 6, and 8 are presented in the last two chapters. It is the first time we collaborate with experiment group. In these works, I have done all the theoretical simulations. For these clusters, both the low and high (n=1-4) frequency regions of IRMPD spectra are measured. Interestingly for n=1, both the two stable isomer cannot alone represent both the low and high frequency profiles. Base on the AIMD simulations, I found that the existence of an unstable transient state shows it absorption profile in the high frequency region due to the zero point energy and tunneling effect of hydrogen atom. Similar to n=1, the IRMPD spectra of larger clusters (n>1) also show evidence for isomerization at cryogenic temperatures which leads to a complete breakdown of the harmonic approximation. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Sun, Shoutian. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references. / Abstracts also in Chinese. / Sun, Shoutian.

The infrared absorption spectra of single crystals of calcium and sodium formate have been recorded between 4OOO and 500 cm⁻¹. With the aid of polarized radiation it was possible to carry out an analysis of the spectra. Factor group splitting was observed for the molecular modes of calcium formate. It was possible to assign the origin of the components of any given molecular fundamental to one of the two sets of symmetrically non-equivalent formate ions in the Calcium formate unit cell. This assignment was made on the basis of the relative Intensities of the components of the fundamentals. For the sodium formate single crystal spectrum, a combination of factor group and site group analysis was required to satisfactorily interpret the results. The results obtained in this case helped to resolve the controversy surrounding the assignment of the √₂ and √₅ molecular modes for the formate ion. Lattice mode frequencies of 36, 61, 90, 128, 154 and 192 cm⁻¹ for calcium formate and 58, 91, 112, 128 and 231 cm⁻¹ for sodium formate are inferred from combinations with molecular modes. The analysis was completed by the assignment of several modes to formate ion fundamentals and to combination and overtone modes of molecular fundamentals. / Science, Faculty of / Chemistry, Department of / Graduate

published_or_final_version / abstract / Physics / Master / Master of Philosophy

published_or_final_version / Physics / Master / Master of Philosophy