CHEM01200604005 A. K. Pathak - Homi Bhabha National Institute

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CO 3 2¯ or HCO3¯ anion to form a transient species, which has a broad and moderately strong absorption in the visible region. This absorption maximum is assigned to the carbonate radical anion species, CO • 3 ⎯, again a specific one electron oxidising species. Nitrate anion (NO 3¯) is one of the most abundant species in acidic wastes as well as in the atmosphere. 40 It is known as the so-called terminal anion in the series of atmospheric reactions involving nitrogen and thus its study is of particular importance. The process of hydration involving nitrate anion in the atmosphere is very important, as water is present in the atmosphere in relatively large concentrations. Structure and energetics of Cl 2•¯.nH 2 O (n=1-5), NO 3¯.nH 2 O (n=1-5) and CO • 3 ⎯.H 2 O cluster is reported in literature. 24,32,41 But no report is available on higher clusters and on other systems in this series. In what follows, structural (growth motif) and energetics aspects of X. nH 2 O (X= Cl •− 2 , Br •− 2 , I •− 2 , CO •− − 3 , NO 3 and CO 2− 3 ) clusters are presented in a systematic manner in this chapter. 2.2. Theoretical Approach All the calculations have been carried out applying hybrid density functional, namely, Becke’s half-and-half (BHH) non-local exchange and Lee-Yang-Parr (LYP) non-local correlation functionals (BHHLYP) and Becke’s three parameter non-local exchange (B3) and Lee-Yang-Parr (LYP) non-local correlation functionals (B3LYP) with triple split valence, 6-311++G(d,p) set of basis function. This BHHLYP hybrid functional includes 50% Hartree-Fock exchange, 50% Slater exchange and the additional correlation effects of the LYP functional. 42 It is reported in the literature that BHHLYP functional performs well to describe such open shell doublet systems like halogen dimer radical 20
anions (Cl •− 2 , Br •− 2 & I •− 2 ). 43-44 Quasi Newton Raphson based algorithm has been applied to carry out geometry optimization for each of these molecular clusters with various initial thought structures to find out the most stable one. This procedure involves the calculation of a multi-dimensional potential energy surface for the anionic molecular cluster and finding a minimum on the surface. The key issue in this search procedure is to guess a good starting geometry of the cluster, which might converge during the calculation to a local or the global minimum. In the present calculation, several possible starting geometries are generated systematically based on different possible threedimensional structures. In the first case, initial structures are considered where all the solvent water molecules are at a distance of ionic hydrogen bonding with either of the two I atoms and far from another solvent molecule to have any inter solvent hydrogen bonding interaction. In the second case, guess structures are considered where all the solvent molecules are at a distance of ionic hydrogen bonding with either of the two I atoms and also at a distance to have an inter water hydrogen bonding interaction. In the third case, a few solvent water molecules are considered at a distance of ionic hydrogen bonding with either of the two iodine atoms and far from another solvent water molecule to have any inter water hydrogen bonding interaction. Rest of the solvent water molecules are considered at a distance of ionic hydrogen bonding with either of the two I atoms and also at a distance where inter water hydrogen bonding interaction can exist. No symmetry restriction has been imposed in the adopted optimization procedure. However, it is to be noted that the adopted procedure for geometry optimization cannot guarantee to locate the global minimum energy structure especially for the higher hydrated clusters. Hessian calculations have been performed for all the optimized minimum energy structures to 21
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 and 14: S Macroscopic Microscopic Dual leve
Page 15 and 16: molecular level interaction during
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: hydrated halide series, X¯.nH 2 O,
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 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 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
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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