CHEM01200604005 A. K. Pathak - Homi Bhabha National Institute

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40 K (NH3 ) n (n=1-6) 4.0 K (NH3 ) n (n=1-6) E w solv (kcal/mol) 30 20 10 VIP w (eV) 3.5 3.0 0 0 1 2 3 4 5 6 7 n 2.5 1 2 3 4 5 6 n A B solv Fig. 6.2. Plot of calculated weighted average (A) solvent stabilization energy ( E w ) in kcal/mol and (B) vertical ionization potential (VIP w ) in eV vs. number of ammonia molecules (n) in K.nNH 3 (n=1-6) solv cluster at BHHLYP/6-311++G(2d,2p) level of theory. To estimate E w and VIP w the weight factor is calculated based on the statistical population of all the minimum energy structures of each size cluster at 150 K. 6.3.4. IR Spectra As discussed in the previous sections, K.nNH 3 clusters are stabilized by the interaction between K and N (from NH 3 ) atoms as well as inter ammonia H-bonding interaction. Due to these interactions it is expected that bands due to stretching (N-H), bending and inversion modes of NH 3 in the ammoniated clusters K.nNH 3 (n=1-6) get shifted compared to that of free ammonia molecule. IR spectra for all the conformers of K.nNH 3 cluster (n ≤ 6) and free NH 3 are calculated. Lorentzian line shape has been applied with peak half-width of 20 cm -1 for all the IR spectra plots. Based on the literature data on the vibrational frequency of NH 3 (ν sym = 3337 cm -1 , ν asym = 3444 cm -1 , ν bend = 1627 cm -1 and ν inversion = 950 cm -1 ) and the present calculated values (ν sym = 3596 cm -1 , ν asym = 3720 cm -1 , ν bend = 1732 cm -1 and ν inversion = 1061cm -1 ) at BHHLYP/6- 102
311++G(2d,2p) level, the scaling factor is taken as 0.93 to account the anharmonic nature of vibration. The same scaling factor has been used for predicting IR spectrum in all these clusters. Calculated scaled frequencies for free NH 3 are 986, 1611, 3345 and 3460 cm -1 , respectively for inversion (ν inversion ), bending (ν bend ), symmetrical stretching (ν sym ) and asymmetrical stretching (ν asym ) at BHHLYP/6-311++G(2d,2p) level of theory and the theoretical IR spectra is displayed in Fig.6.3-A. It is worth to mention that the peak in the N-H stretching region is due to asymmetric mode, and the symmetric mode is too weak to observe. Scaled IR spectra for mono ammoniated cluster, K.NH 3 with a strong sharp peak in the N-H stretching region is shown in Fig.6.3-B. It is interesting to observe that all the mode of ammonia compare to free molecule get red shifted (Δν bend = - 20 cm -1 , Δν sym = - 48 cm -1 and Δν asym = -59 cm -1 ) except the inversion mode which is blue shifted compare to the same (Δν inversion = 100 cm -1 ) in K.NH 3 cluster. It is also worth to mention that in the N-H stretching region the major contribution to the peak is from symmetric mode. The IR bands below 1000 cm -1 are due to librations of NH 3 in this cluster. Scaled IR spectra for di-ammoniated cluster, K.2NH 3 with a strong sharp peak in the N-H stretching region is shown in Fig.6.3-C. It is clear from the figure that the inversion mode gets blue shifted (Δν inversion = 105 cm -1 ) compare to that free ammonia molecule, and the bending mode is vanished. The scaled IR spectra of K.3NH 3 cluster is displayed in Fig.6.3-D and similar in nature to that of K.2NH 3 cluster. From tetra-ammoniated cluster onwards (n>3) more than one conformer is found, so weighted average scaled IR spectra is generated based on the statistical population at 150 K. Weighted average scaled IR spectra of K.4NH 3 cluster with strong sharp peak in the N-H stretching region is displayed in Fig.6.3-E. It is clearly seen from the Fig.6.3-D, that the inversion band is vanished and the bending mode is 103
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MICROSOLVATION OF CHARGED AND NEUTR
Page 3 and 4:
STATEMENT BY AUTHOR This dissertati
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Dedicated to my Daughter, Wife and
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CONTENTS Page No. SYNOPSIS LIST OF
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CHAPTER 4 Solubility of Halogen Gas
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7.3.4. IR and Raman Spectra 117-121
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S Macroscopic Microscopic Dual leve
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molecular level interaction during
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Chapter 3: This chapter describes I
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In this system the conformers of a
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LIST OF FIGURES Page No. Fig. 1.1 2
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Fig. 2.6 54 (I) Plot of calculated
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(IIIA) Cl 2 .3H 2 O; (IIIB) Br 2 .3
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Fig. 6.3 104-105 Calculated scaled
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LIST OF TABLES Page No. Table. 2.1
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CHAPTER 1 Introduction 1.1. Microso
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1.2. Motivation 1.2.1. Macrosolvati
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ulk water and pure neutral water cl
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insight about the electronic struct
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Newton -Raphson (NR) method expand
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potential energy surface for these
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terms, the energy can be written in
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Boyd proposed the use of Gaussian t
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eported experimental findings. Theo
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hydrated halide series, X¯.nH 2 O,
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anions (Cl •− 2 , Br •− 2 &
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geometrical parameters close to MP2
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symmetrical DHB, SHB or WHB arrange
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of I-I axis and having the least I-
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Br •− 2 .nH 2 O hydrated cluste
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VI-F VI-G VII-A VII-B VII-C VII-D V
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To see the effect of hydration on t
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Five minimum energy structures disp
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arrangements. In total, it has one
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NO 3 − .nH2 O (n ≥ 6), a few eq
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V-E V-F V-G V-H V-I VI-A VI-B VI-C
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VII-D VII-E VII-F VII-G VII-H VII-I
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VIII-K VIII-L Fig.2.2. Fully optimi
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clusters. Hydrated cluster having c
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However, these calculations do not
Page 81 and 82: Table 2.1. Weighted average energy
Page 83 and 84: Where, E[I •− 2 .nH 2 O] is the
Page 85 and 86: The variation of the weighted avera
Page 87 and 88: CHAPTER 3 IR Spectra of Water Embed
Page 89 and 90: ecome more meaningful. At present,
Page 91 and 92: I-A II-A II-B III-A III-B III-C III
Page 93 and 94: Cluster experiments are carried out
Page 95 and 96: 3350-3500 cm -1 (scaling factor ~0.
Page 97 and 98: these systems, X. nH 2 O (X= Br 2
Page 99 and 100: CHAPTER 4 Solubility of Halogen Gas
Page 101 and 102: including polarized and diffuse fun
Page 103 and 104: and I 2 systems. The most stable st
Page 105 and 106: Cl Cl Br Br I I VA VB VC Cl Cl Br B
Page 107 and 108: (Br δ+ -Br δ- ) in the studied hy
Page 109 and 110: stabilization energy does not follo
Page 111 and 112: 80 Cl 2 .nH 2 O (n=1-8) 80 Br 2 .nH
Page 113 and 114: separated ion pair in presence of s
Page 115 and 116: adical ( • OH) reacts with HCO 3
Page 117 and 118: most stable conformer for each size
Page 119 and 120: The structures of the hydrated clus
Page 121 and 122: Table 5.1. Calculated absorption ma
Page 123 and 124: molar extinction coefficient value
Page 125 and 126: ammonia. 61-62 Hydrogen bonded wate
Page 127 and 128: stable minimum energy structure is
Page 129 and 130: IV-A IV-B V-A V-B V-C VI-A VI-B VI-
Page 131: 6.3.3. Vertical Ionization Potentia
Page 135 and 136: K(NH 3 ) 4 K(NH 3 ) 5 IR Intensity
Page 137 and 138: CHAPTER 7 Structure, Energetics and
Page 139 and 140: Thus Monte Carlo based simulated an
Page 141 and 142: I I I I I I I I A B C D I I I I I I
Page 143 and 144: interaction as well as solvent-solv
Page 145 and 146: Table 7.1. Various energy parameter
Page 147 and 148: change in VDE is observed. This is
Page 149 and 150: symmetric C-O stretching mode of CO
Page 151 and 152: to the maximum charge transfer of t
Page 153 and 154: CHAPTER 8 A Generalized Microscopic
Page 155 and 156: possible breakdown of these laws ma
Page 157 and 158: P 7 P , , P , ,, 1 ∂ 2
Page 159 and 160: M DE = (r, ω)C DE , (r,
Page 161 and 162: known. However, for most of the com
Page 163 and 164: The calculated bulk detachment ener
Page 165 and 166: espect to experimentally measured v
Page 167 and 168: References 1. Ohtaki, H.; Radani, T
Page 169 and 170: 29. Turi, L.; Sheu, W.; Rossky,P.J.
Page 171 and 172: 61. (a) Ehrler, O. T.; Neumark, D.
Page 173 and 174: LIST OF PUBLICATIONS *1. “σ/σ
Page 175 and 176: 13. “Vibrational analysis of I
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CHEM01200604005 A. K. Pathak - Homi Bhabha National Institute

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