CHEM01200604005 A. K. Pathak - Homi Bhabha National Institute

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studies carried out in bulk solution (macroscopic solvation) during the process of solvation. To understand different molecular level interactions responsible for solvation, one has to apply microsolvation model by adding solvent molecules one by one. The study on microsolvation of neutral and charged chemical species has been a subject of intense research both from experimental and theoretical points of view. This is not only because of the strong dependency of the properties on size and geometry of the solvated clusters of these species but also due to development of sophisticated experimental and theoretical techniques. These experiments are based on supersonic expansion and nozzle beam technique to produce finite size hetero clusters consisting of both solute and finite number solvent molecules. A number of solvent molecules is added to encapsulate the solute by bottom up approach. The hetero clusters are then monitored by various spectroscopic techniques (infrared, photoelectron etc). Molecular dynamics simulation based on model potential studies are also applied to understand microsolvation. But lack of accurate description on solute-solvent and solvent-solvent interaction, model Hamiltonian based studies are rarely used to study microsolvation. First principles based quantum chemical investigation is thus applied as major theoretical technique to study microsolvation. Experimental and theoretical investigations are carried out to study microsolvation both in hydrogen bonding solvent (water, ammonia etc) 5-13 and in nonhydrogen bonding solvent (carbon dioxide, argon etc). 14-15 Positively charged ions have simple solvated structures compared to a negatively charged system as cation binds strongly with solvent molecules. 1 As anions are mass selectable, size selected gas-phase infrared (IR) cluster spectroscopy combined with first principle based theoretical studies have been successfully applied to explore the xiv
molecular level interaction during the process of microhydration. 16-18 Indirect assignment on structure and growth motif is done based on IR spectra analysis of finite size clusters. Molecular cluster acts as an intermediate state between isolated gaseous molecule and condensed phase bulk system. Several efforts are being made to connect molecular cluster properties of a chemical species to its bulk properties. Size selected cluster study has been used to extract the bulk properties like detachment energies of an excess electron using simple extrapolation model based on the continuum model. 6,19 But this model fails to reproduce the bulk detachment energy in most of the cases. 6,20 To understand the process of microsolvation, a detail study on structure and energetics of finite size cluster of various species in water, ammonia and carbon di oxide have been carried out. Solubility, IR, Photoelctron and UV-Vis spectral properties have also been predicted and compared with experimental findings whenever available. When only one solvent molecule is added to solvent, a few minimum energy structures are expected. With the increase in number of solvent molecules in solvated clusters, the number of minimum energy configurations with close in energy for each size solvated clusters are expected to increase. Thus weighted average properties are calculated for better predictability. It is well known that bromine gas is more soluble than chlorine gas in water but no theoretical understanding is available in literature. UV-Vis spectra of various species in aqueous solution are measured by experimental technique but no theoretical study is available. Bulk properties like solubility, bulk detachment energy of excess electron and aqueous UV-Vis spectra are also measured and compared with reported experimental values. Theoretical results on structures, energetics, spectral properties (vibrational, photoelectron) of clusters consisting of various solutes (both xv
Page 1 and 2: MICROSOLVATION OF CHARGED AND NEUTR
Page 3 and 4: STATEMENT BY AUTHOR This dissertati
Page 5 and 6: Dedicated to my Daughter, Wife and
Page 7 and 8: CONTENTS Page No. SYNOPSIS LIST OF
Page 9 and 10: CHAPTER 4 Solubility of Halogen Gas
Page 11 and 12: 7.3.4. IR and Raman Spectra 117-121
Page 13: S Macroscopic Microscopic Dual leve
Page 17 and 18: Chapter 3: This chapter describes I
Page 19 and 20: In this system the conformers of a
Page 21 and 22: LIST OF FIGURES Page No. Fig. 1.1 2
Page 23 and 24: Fig. 2.6 54 (I) Plot of calculated
Page 25 and 26: (IIIA) Cl 2 .3H 2 O; (IIIB) Br 2 .3
Page 27 and 28: Fig. 6.3 104-105 Calculated scaled
Page 29 and 30: LIST OF TABLES Page No. Table. 2.1
Page 31 and 32: CHAPTER 1 Introduction 1.1. Microso
Page 33 and 34: 1.2. Motivation 1.2.1. Macrosolvati
Page 35 and 36: ulk water and pure neutral water cl
Page 37 and 38: insight about the electronic struct
Page 39 and 40: 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
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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 and 92:
I-A II-A II-B III-A III-B III-C III
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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
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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
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.
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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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