CHEM01200604005 A. K. Pathak - Homi Bhabha National Institute

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water H-bonding network among solvent H 2 O molecules and ionic hydrogen bond formation between solvent H 2 O molecule and I atom. Four minimum energy structures predicted for tri-hydrate cluster, I •− 2 .3H 2 O are displayed in Fig. 2.1-III(A-D). Initial guess structures are considered based on the optimized minimum energy structures observed in case of di-hydrate cluster, I •− 2 .2H 2 O. Geometry optimization leads to two different minimum energy structures when the initial guess structure is designed based on structure II-A adding the third H 2 O forming symmetrical DHB with two I atoms. When the third H 2 O is kept at a close distance from one of the H 2 O molecules (r OO ~ 3.5 Å), structure III-A is obtained. On the other hand when the said distance, r OO is more than 3.5 Å in the initial geometry, structure III-B is obtained. The initial guess for structure III-C consists of three symmetrical DHB arrangements. In this particular optimized structure, all the three H 2 O molecules are directly connected to I atoms without any inter H 2 O interaction. Structure III-D, having two DHB and one SHB arrangements from axial side of I •− 2 moiety is the least stable conformer for the tri-hydrate cluster. The surface structure III-A having three H 2 O molecules connected by inter H 2 O H-bonding network (WHB arrangements) is the most stable one and has the shortest I-I bond distance among the different conformers of I •− 2 .3H 2 O cluster. The calculated dihedral angle, δ(O-I-I-O) in the structure III-C is 120 o . As expected, the number of possible conformers increases with the increase in the number of solvent water molecules. Initial guess structures are considered with a bottomup approach based on the predicted stable structures from the smaller size hydrated clusters. Thus the initial guess structures for I •− 2 .4H 2 O cluster is designed based on the predicted minimum energy structures of I •− 2 . nH 2 O (n=1-3), keeping different numbers of 24
symmetrical DHB, SHB or WHB arrangements. Seven different structures having no imaginary frequency are obtained for I •− 2 .4H 2 O cluster and are displayed in Fig. 2.1- IV(A-G). Once again, the surface structure, IV-A where four H 2 O molecules form a H- bond cyclic network using one of its H atoms and the other H atoms are connected to I atoms is the most stable one. Structure IV-A consists of four WHB and four SHB arrangements. The least stable structure, IV-G, has two symmetrical double H-bonding (DHB) and two axial single H-bonding (SHB) arrangements with no inter water H- bonding (WHB). Structure IV-E has four symmetrical DHB keeping the angle between two successive O-I-I planes as 90 o . Structure IV-F with three DHB and one axial SHB arrangement is less stable than IV-A by 15.18 kcal/mol. Rest of the conformers have at least one DHB arrangement with different number of H 2 O systems in inter water H- bonding networks. It is clearly observed that the most stable structure has the maximum number of WHB arrangements and the relative stability of the conformers decreases with the decrease in the number of WHB arrangements. Similarly, the initial guess structures for penta-hydrate (I •− 2 .5H 2 O) cluster is designed based on the predicted minimum energy structures of I •− 2 .nH 2 O (n=1-4), keeping different numbers of symmetrical DHB, SHB or WHB arrangements. Geometry optimization with various initial guess structures for the penta-hydrate cluster, I •− 2 .5H 2 O yields seven minimum energy structures, having no imaginary frequency and the structures are displayed in Fig. 2.1-V(A-G). The most stable structure, V-A is the one where one solvent H 2 O molecule adds to the most stable structure of the tetra-hydrate cluster, I •− 2 .4H 2 O (IV-A) from the other side of H-bond network forming double hydrogen bonding between two I atoms and two H-atoms of H 2 O. Structure V-B is 4.47 25
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 and 50: hydrated halide series, X¯.nH 2 O,
Page 51 and 52: anions (Cl •− 2 , Br •− 2 &
Page 53: geometrical parameters close to MP2
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
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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.
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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