CHEM01200604005 A. K. Pathak - Homi Bhabha National Institute

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Different minimum energy structures obtained on full geometry optimization of − each size hydrated cluster of nitrate anion, NO 3 .nH2 O (n=1-8) are displayed in Fig. 2.2. Two stable minimum energy structures are obtained on full geometry optimization of the − monohydrate cluster, NO 3 -H2 O as shown in Fig. 2.2-I(A-B). In contrast to the earlier reported structure, 15 the most stable structure has a symmetric double-hydrogen-bonding − (DHB) arrangement where two O atoms from NO 3 group and two H-atoms of the solvent H 2 O molecule are connected by H-bonding of length 2.06 Å. Calculated NO bond distances are 1.25 and 1.27 Å, respectively, for the spectator and H-bonded bonds. Structure I-B having one single hydrogen bonding (SHB) between one oxygen atom of the nitrate anion and H atom of the solvent H 2 O molecule is less stable than the structure I-A by 2.78 kcal/mol. The calculated H-bond distance is 1.83 Å and so this SHB should be stronger than each DHB of structure I-A. Again, NO bond distances are 1.25 and 1.27 Å, respectively for the spectator and H-bonded bonds. Three minimum energy structures are predicted for the di-hydrate cluster, − NO 3 .2H2 O and displayed in Fig. 2.2-II(A-C). The structures are very close in energy with a difference in relative stability of < 2 kcal/mol. Structures II-A and II-C have two double-hydrogen-bonding (DHB) arrangements and both the solvent H 2 O units are − attached to the same two O atoms of NO 3 in case of the less stable structure II-C. In case of II-C, none of the solvent H 2 O units is in the NO 3 − plane, structure II-A is planar though. Structure II-B has two single hydrogen bonding (SHB) and one inter water hydrogen bonding (WHB) arrangements. 34
Five minimum energy structures displayed in Fig. 2.2-III(A-E) are predicted for tri-hydrate cluster, NO 3 − .3H2 O. Structure III-A is the most stable one having a cyclic − three-member water network attached to two oxygen atoms of NO 3 moiety. This particular structure consisting of three SHB and three WHB arrangements is more stable than the least stable structure III-E having two SHB, one DHB and one WHB arrangements by only ~1 kcal/mol. Structure III-B consisting of a cyclic three-member water network attached to all the three oxygen atoms is less stable than the structure III-A by 0.26 kcal/mol. Symmetric structure III-C having three DHB arrangements is 0.39 kcal/mol less stable compared to the most stable one. Structure III-D consisting of three SHB and two WHB arrangements is less stable by 0.66 kcal/mol compared to the − structure III-A. Based on the optimized structures up to NO 3 .nH2 O (n=1-3), it is observed that the average energy of a single SHB and WHB arrangements are 7-11 − kcal/mol and 5-8 kcal/mol, respectively. So, a balance between water-NO 3 and water- − water interactions decides the structure of hydrated anion clusters, NO 3 .nH2 O. As the number of solvent water molecules increases, a large number of minimum energy configurations are expected for a particular size of hydrated cluster. The initial structures for larger hydrated clusters are considered with a bottom-up approach based on the predicted stable structures from the smaller size hydrated clusters. Thus the initial − guess structures for NO 3 .4H2 O cluster are considered based on the predicted minimum − energy structures of NO 3 .nH2 O clusters (n=1-3), keeping a different number of symmetrical DHB, SHB and WHB arrangements. Six stable minimum energy structures − are obtained for NO 3 .4H2 O cluster. The optimized structures are displayed in Fig. 2.2- 35
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MICROSOLVATION OF CHARGED AND NEUTR
Page 3 and 4:
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
Page 9 and 10:
CHAPTER 4 Solubility of Halogen Gas
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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 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: To see the effect of hydration on t
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
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adical ( • OH) reacts with HCO 3
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most stable conformer for each size
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The structures of the hydrated clus
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Table 5.1. Calculated absorption ma
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molar extinction coefficient value
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ammonia. 61-62 Hydrogen bonded wate
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stable minimum energy structure is
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IV-A IV-B V-A V-B V-C VI-A VI-B VI-
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6.3.3. Vertical Ionization Potentia
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311++G(2d,2p) level, the scaling fa
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K(NH 3 ) 4 K(NH 3 ) 5 IR Intensity
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CHAPTER 7 Structure, Energetics and
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Thus Monte Carlo based simulated an
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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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