CHEM01200604005 A. K. Pathak - Homi Bhabha National Institute

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Cl Cl Br Br I I VIIIA VIIIB VIIIC Fig. 4.1. The fully optimized most stable structures calculated applying BHHLYP functional with 6- 311++G(d,p) set of split valence basis function (6-311 basis set is used for iodine) for (IA) Cl 2 .H 2 O; (IB) Br 2 .H 2 O, (IC) I 2 .H 2 O; (IIA) Cl 2 .2H 2 O; (IIB) Br 2 .2H 2 O (IIC) I 2 .2H 2 O; (IIIA) Cl 2 .3H 2 O; (IIIB) Br 2 .3H 2 O, (IIIC) I 2 .3H 2 O; (IVA) Cl 2 .4H 2 O; (IVB) Br 2 .4H 2 O, (IVC) I 2 .4H 2 O; (VA) Cl 2 .5H 2 O; (VB) Br 2 .5H 2 O, (VC) I 2 .5H 2 O; (VIA) Cl 2 .6H 2 O; (VIB) Br 2 .6H 2 O, (VIC) I 2 .6H 2 O; (VIIA) Cl 2 .7H 2 O; (VIIB) Br 2 .7H 2 O, (VIIC) I 2 .7H 2 O; (VIIIA) Cl 2 .8H 2 O, (VIIIB) Br 2 .8H 2 O and (VIIIC) I 2 .8H 2 O. Cl, Br and I atoms are shown by marked spheres, the smallest ‘white’ colour spheres refer to H atoms and the rest (red colour) corresponds to O atoms in each structure. The structures of all these systems are widely different for the larger size clusters (n>6) though they are fairly similar in case of smaller clusters (n=1-6) except for n=2. The structure of Br 2 .nH 2 O (n=7) cluster is quite different from that in the earlier reported work at a lower level of theory. 55 4.3.2. Atomic Charge and Bond Order The calculated Mulliken atomic charges over two Br atoms in Br 2 .H 2 O cluster are about +0.04 and -0.08 a.u. A small variation of atomic charge over two Br atoms is observed for different size hydrated clusters, Br 2 .nH 2 O, and observed to be in the range of 0.04–0.14 a.u. This suggests that Br 2 exists as a charge-separated ion-pair species 76
(Br δ+ -Br δ- ) in the studied hydrated clusters. For I 2 .H 2 O cluster, the calculated Mulliken atomic charges over two I atoms are ~ +0.03 and -0.16 a.u. The variation on atomic charge over two I atoms for different size of hydrated clusters, I 2 .nH 2 O, is observed to be larger than that of Br atoms in Br 2 .nH 2 O cluster. This suggests that I 2 does exist as a charge-separated ion-pair species (I δ+ -I δ- ) in the studied hydrated clusters like Br 2 in Br 2 .nH 2 O systems. However, in contrary to I 2 and Br 2 systems, Cl 2 does not exist as a charge separated species in presence of solvent water molecules. The calculated Mulliken charges over two Cl atoms are fairly close (+0.01 and -0.04 a.u.). This may be due to the high electro negativity of Cl atom compared to Br and I atoms. This observation may be due to the fact that there is a competition between ion the solvation force, which favours a localized charge distribution and the chemical bond interaction, which tends to delocalize a charge. As one moves from Cl 2 to Br 2 to I 2 , the bond gets longer and weaker. As a result, at some stage the charge-separated form becomes more stable than the delocalized form. In other words, the cost to form charge-separated ion pair is large in case of Cl 2 .nH 2 O system compared to Br 2 .nH 2 O or I 2 .nH 2 O systems due to relatively large ionization potential and comparable electron affinity values. It is known that Mulliken charge is sensitive to basis function applied in the calculation. Thus, atomic charges are also calculated applying Atoms in Molecules (AIM) based procedure at BHHLYP/6-311G(d,p) level of theory. The predicted charge-separation between two halogen atoms is +0.09, +0.13 and +0.19 a.u.for Cl 2 .H 2 O, Br 2 .H 2 O and I 2 .H 2 O systems, respectively. The charge-separation values calculated by AIM procedure show a similar trend as calculated Mulliken charges do. Bond orders between the two halogen atoms for all the clusters (X 2 .nH 2 O; X=Cl & I; n=1-8) are also calculated following the definition 77
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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
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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
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: Cl Cl Br Br I I VA VB VC Cl Cl Br B
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
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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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