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located the heaviest atoms and remaining atoms were found in subsequent Fourier difference syntheses. Refinements were full-matrix least-squares on F 2 for structures having not more than 1200 parameters, and were block-diagonal least-squares on F 2 for structures having more than 1200 parameters. Routine Lorentz and polarization corrections were applied and absorption corrections were performed using the SADABS program. a R = ∑ ||Fo |-|F c ||/ ∑ |F o |. b R w = [ ∑ w(F 2 o-F 2 c) 2 / ∑ w(F 2 o) 2 ] 1/2 2.1.3 Multinuclear magnetic resonance spectroscopy NMR spectra were recorded on a JEOL 400 ECX spectrometer operating at 9.39 T (400 MHz for proton) magnetic field. The resonance frequencies were 161.834 MHz for 31 P, 149.081 MHz for 119 Sn and 16.656 MHz for 183 W. Chemical shifts are given with respect to external standard 85% H 3 PO 4 for 31 P, (C 2 H 5 ) 4 Sn for 119 Sn, 2 M Na 2 WO 4 for 183 W. All aqueous 183 W NMR spectra were collected on highly concentrated solution. 2.1.4 Cyclic voltametry All cyclic voltammogramms (CV) were recorded on a EG & G 273 A voltameter driven by a PC with the M270 software. Potentials are coated against a saturated calomel electrode (SCE). The counter electrode was a platinum gauze of large surface area. All experiments were performed at room temperature. 2.1.5 Elemental analyses and thermogravimetric analysis All elemental analyses were performed by Kanti Labs Ltd. in Missisunga, Canada. Thermogravimetric analysis (TGA): Water contents were determined using a TGA Thermalgravimetric Analyzer with 15-20 mg samples in 100 µL alumina pans, under a 100 mL min −1 N 2 flow and with heating rates of 5 ◦ C min −1 . 19
2.2 Preparation of starting materials 2.2.1 Synthesis of Na 9 [AsW 9 O 33 ]·27H 2 O To a hot (∼95 ◦ C) solution of 110g of Na 2 WO 4·2H 2 O in 117 mL of distilled water, 3.67 g of As 2 O 3 were added. Then 27.7 mL concentrated HCl were added dropwise with in 2 minutes with continuous stirring for a period of 10 minutes. The solution was cooled for a while and than filtered into a beaker and covered with parafilm. The formation of crystals starts when the solution cools in the period of time. The filtrate was left in an open beaker until the solution reached the mark of crystals. The crystals were collected in a bruchner funnel and dried at ∼50 ◦ C in an air oven overnight. The final compound was characterized by FTIR spectroscopy and compared to the reported spectrum [69]. 2.2.2 Synthesis of Na 9 [SbW 9 O 33 ]·27H 2 O Solution A : 1.96 g of Sb 2 O 3 were dissolved in 10 mL conc. HCl (may or may not dissolve completely). Solution B : 40g of Na 2 WO 4·2H 2 O were dissolved in 80 mL of distilled water (∼90 ◦ C). Solution A was transferred into the beaker containing Solution B. including the non dissolved Sb 2 O 3 drop wise and then, the whole reaction mixture was refluxed for approximately an hour. The solution was cooled and filtered, crystals start forming immediately. Solution was left open until the it reached the level of crystals. The final compound was characterized by FTIR spectroscopy and compared to the reported spectrum [70]. 2.2.3 Synthesis of K 14 [As 2 W 19 O 67·(H 2 O)] To a solution of 94g (285 mmol) of Na 2 WO 4·2H 2 O in 250 mL of distilled water. 4.45g (22.5 mmol) of As 2 O 3 were added subsequently. The solution was stirred for few minutes and pH was adjusted to 6.3 by addition of 12 M HCl (37%).The solution was heated to ∼80 ◦ C for 10 mins, and after cooling 35g (45 mmol) of KCl was added to the solution at room temperature. The solution was stirred again for 15 mins and the formed precipitate was filtered off and dried at ∼80 ◦ C in an air oven overnight. It was characterized by FTIR spectroscopy and compared to the reported spectrum [71]. 20
Page 1 and 2: Hybrid Organic-Inorganic Polyoxomet
Page 3 and 4: Abstract Polyoxometalates (POMs) ar
Page 5 and 6: the cubic system (space group I m¯
Page 7 and 8: AsW 9 O 32 OH) 2 ]·36H 2 O (RbNa-1
Page 9 and 10: Paris-Sud, Orsay Cedex, France) for
Page 11 and 12: 2.2.9 Synthesis of K 12 [H 2 P 2 W
Page 13 and 14: Bibliography . . . . . . . . . . .
Page 15 and 16: 3.5 Left: combined polyhedral and b
Page 17 and 18: 3.33 Combined polyhedron and ball/s
Page 19 and 20: List of Tables 1.1 Selected M-M dis
Page 21 and 22: MO 6 octahedra surrounding a centra
Page 23 and 24: 1.1.1 The clathrate-like structure
Page 25 and 26: 7(MoO 4 ) 2− + 8H + → [Mo 7 O 2
Page 27 and 28: Fig. 1.4: Combined polyhedral/ball
Page 29 and 30: This planar structure was originall
Page 31 and 32: [X 2 M 18 O 62 ] 6− , the D 3h We
Page 33 and 34: [P 2 W 19 O 68 (HO)] 14− , [P 2 W
Page 35 and 36: Fig. 1.11: Monomeric (left) and dim
Page 37: Chapter 2 Experimental 2.0.1 Reagen
Page 41 and 42: as Cs 6 [P 2 W 5 O 23 ]·7H 2 O by
Page 43 and 44: was adjusted between 5-6 by additio
Page 45 and 46: Chapter 3 Results 3.1 The hybrid or
Page 47 and 48: Fig. 3.2: FTIR spectra of compound
Page 49 and 50: Fig. 3.3: W 183 NMR spectra of (CsN
Page 51 and 52: Fig. 3.5: Left: combined polyhedral
Page 53 and 54: formed upon crystallization and bot
Page 55 and 56: X-ray Crystallography A crystal of
Page 57 and 58: the presence of the four (CH 3 ) 2
Page 59 and 60: Fig. 3.10: Cyclic voltammogram of 2
Page 61 and 62: as a function of electrolyte compos
Page 63 and 64: was observed that could be traced t
Page 65 and 66: electrochemical set-up was an EG &
Page 67 and 68: Fig. 3.14: The central core of Sn(C
Page 69 and 70: of these fragments [88, 90]. For co
Page 71 and 72: diffractometer using Mo K α radiat
Page 73 and 74: Fig. 3.18: Side view of [{Sn(CH 3 )
Page 75 and 76: host−guest systems with large cav
Page 77 and 78: X-ray Crystallography Single crysta
Page 79 and 80: 3.5.2 Results and discussions Polya
Page 81 and 82: Fig. 3.26: Ball and stick represent
Page 83 and 84: can distinguish between different m
Page 85 and 86: Fig. 3.28: STM pictures of {Sn(CH 3
Page 87 and 88: Fig. 3.31: Size distribution by int
Page 89 and 90:
3.6 The bis-phenyltin substituted,
Page 91 and 92:
Table 3.7: Crystal Data and Structu
Page 93 and 94:
tral belt in-between the two tin at
Page 95 and 96:
Fig. 3.35: 183 W NMR spectra of com
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whereas they are five-coordinated (
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investigated by scanning tunneling
Page 101 and 102:
3.8 The di-titanium substituted, lo
Page 103 and 104:
Fig. 3.37: Ball/stick (left), polyh
Page 105 and 106:
[As 2 W 19 O 67 (H 2 O)] 14− , [A
Page 107 and 108:
3.9 The cyclic trimeric-titanium su
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Table 3.9: Crystal Data and Structu
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Fig. 3.40: FTIR spectra of compound
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Fig. 3.42: Side-view of compound 11
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11 by 183 W-NMR (at 16.66 MHz on a
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3.11 Structure and solution propert
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472(w), 444(w) cm −1 . This proce
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MHz in 10 mm tubes and the 111 Cd N
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Fig. 3.47: 111 Cd NMR spectra of [C
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in aqueous solution, so that the nu
Page 127 and 128:
of cadmium ions in 12 and 13 and it
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doubtedly 183 W-NMR, but the parama
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K): (relative intensities in parent
Page 133 and 134:
Fig. 3.49: Combined polyhedral/ball
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Fig. 3.50: 183 W NMR spectrum of [I
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(17) are isostructural. They consis
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Fig. 3.53: 183 W NMR spectrum of [I
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3.12.4 Conclusion We have synthesiz
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[37] D. Gatteschi, O. Kahn, J. Mill
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94:226403, 2005. [123] R. J. Hamers
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[206] I. Loose, E. Droste, M. Bösi
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NMR Spectra Fig. 3.54: 13 C NMR spe
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Fig. 3.56: 31 P NMR spectrum of pol
Page 153 and 154:
Fig. 3.58: 13 C NMR spectrum of pol
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Fig. 3.60: 1 H NMR spectrum of poly
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Fig. 3.62: 119 Sn NMR spectrum of p
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Fig. 3.66: 1 H NMR spectrum of poly
Page 161 and 162:
Fig. 3.70: 13 C NMR spectrum of pol
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were applied and an absorption corr
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Fig. 3.75: Size distribution by num
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Table 3.16: Crystal Data and Struct
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Fig. 3.80: FTIR spectra of compound
Page 171 and 172:
FIRASAT HUSSAIN International Unive
Page 173 and 174:
Publications 1. Observation of a Ha
Page 175 and 176:
PAPERS IN CONFERENCE/ SYMPOSIA / WO
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