CHEM01200604005 A. K. Pathak - Homi Bhabha National Institute

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V-A V-B V-C V-D V-E V-F V-G V-H V-I V-J V-K V-L Fig. 3.2. Fully optimized minimum energy structures at BHHLYP/6-311++G(d,p) level of theory for (I) Cl 2•¯.H 2 O, (II) Cl 2•¯.2H 2 O, (III) Cl 2•¯.3H 2 O, (IV) Cl 2•¯.4H 2 O and (V) Cl 2•¯.5H 2 O clusters. Marked alphabets in the upper case are used to refer different minimum energy conformers for each size of the hydrated cluster arranged in order of stability showing ‘A’ as the most stable one. Cl atoms are shown by the largest green color spheres, the smallest spheres refer to H atoms and the rest (red in color) corresponds to O atoms in each structure shown in the figure. In each case, the distance between the two Cl atoms is ~ 2.6 Å, the distance between Cl and H-bonded H atoms is 2.3-2.8 Å and the distance between O and H atoms in inter water network is ~ 2.0 Å. 62
Cluster experiments are carried out under NVE ensemble condition and the precise value of the low temperature is not known. However, as these molecular clusters are stable only in the low temperature, the experimental condition is such that the temperature is kept below 200K. To choose a suitable method for the calculation of IR spectra of Cl • 2 ⎯.nH 2 O clusters, weighted average IR spectra is generated at MP2, B3LYP and BHHLYP level of theory at various temperature (T= 75 K to 200 K) with 6- 311++G(d,p) basis set. It is observed that the calculated IR spectrum at BHHLYP level of theory at 100K is very close to the experimentally recorded spectrum. So, BHHLYP functional is used to generate IR spectra for all the Cl • 2 ⎯.nH 2 O clusters. The minimum energy structures (including the second hydration shell) of Cl • 2 ⎯.nH 2 O (n=1-5) clusters are displayed in Fig. 3.2. Cl •− 2 .nH 2 O clusters are stabilized by double hydrogen bonding (DHB), single hydrogen bonding (SHB) and inter water hydrogen bonding (WHB) as discussed in Chapter 2. Due to these interactions, it is expected that IR bands due to stretching (O-H) and bending modes of H 2 O in the hydrated clusters get shifted compared to that of the free water molecule. For mono- and di-hydrated cluster, one and two minimum energy structures have been found, respectively. The calculated scaled IR spectra of Cl •− 2 .nH 2 O (n=1 and 2) cluster is also shown in Fig. 3.3. It is reported that for mono- and di-hydrate cluster (n=1 and 2), the experimental IR spectra 24 corresponding to the symmetric structure having one and two DHB, respectively (see Fig.3.2-1A and II-B). First principles CPMD simulations are also carried out for 1.2 ps at 100K to generate the dipole autocorrelation function (DACF) for Cl •− 2 .3H 2 O. The Fourier transform to DACF (FT-DACF) is carried out to generate IR spectra. The IR spectrum for Cl •− 2 .3H 2 O cluster based on FT-DACF is displayed in Fig.3.4 (I). It is clear from the 63
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MICROSOLVATION OF CHARGED AND NEUTR
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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
Page 41 and 42: potential energy surface for these
Page 43 and 44: terms, the energy can be written in
Page 45 and 46: Boyd proposed the use of Gaussian t
Page 47 and 48: eported experimental findings. Theo
Page 49 and 50: hydrated halide series, X¯.nH 2 O,
Page 51 and 52: anions (Cl •− 2 , Br •− 2 &
Page 53 and 54: geometrical parameters close to MP2
Page 55 and 56: symmetrical DHB, SHB or WHB arrange
Page 57 and 58: of I-I axis and having the least I-
Page 59 and 60: Br •− 2 .nH 2 O hydrated cluste
Page 61 and 62: VI-F VI-G VII-A VII-B VII-C VII-D V
Page 63 and 64: To see the effect of hydration on t
Page 65 and 66: Five minimum energy structures disp
Page 67 and 68: arrangements. In total, it has one
Page 69 and 70: NO 3 − .nH2 O (n ≥ 6), a few eq
Page 71 and 72: V-E V-F V-G V-H V-I VI-A VI-B VI-C
Page 73 and 74: VII-D VII-E VII-F VII-G VII-H VII-I
Page 75 and 76: VIII-K VIII-L Fig.2.2. Fully optimi
Page 77 and 78: clusters. Hydrated cluster having c
Page 79 and 80: 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: I-A II-A II-B III-A III-B III-C III
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 and 132: 6.3.3. Vertical Ionization Potentia
Page 133 and 134: 311++G(2d,2p) level, the scaling fa
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
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interaction as well as solvent-solv
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Table 7.1. Various energy parameter
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change in VDE is observed. This is
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symmetric C-O stretching mode of CO
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to the maximum charge transfer of t
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CHAPTER 8 A Generalized Microscopic
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possible breakdown of these laws ma
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P 7 P , , P , ,, 1 ∂ 2
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M DE = (r, ω)C DE , (r,
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known. However, for most of the com
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The calculated bulk detachment ener
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espect to experimentally measured v
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References 1. Ohtaki, H.; Radani, T
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29. Turi, L.; Sheu, W.; Rossky,P.J.
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61. (a) Ehrler, O. T.; Neumark, D.
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LIST OF PUBLICATIONS *1. “σ/σ
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13. “Vibrational analysis of I
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CHEM01200604005 A. K. Pathak - Homi Bhabha National Institute

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