A solution and solid state study of niobium complexes University of ...

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O O Cl Nb Cl OMe OMe Chapter 4 3a 3b Figure 4.1: Graphical representation of the niobium(V) crystal structures obtained: 1) [NbCl(acac-κ 2 -O,O’)(OMe)3], 2) [Nb(acac-κ 2 -O,O’)(OEt)2(µ 2 -O)]4, 3a) [NbCl2(phacac-κ 2 - O,O’)(OMe)2] and 3b) [NbCl(phacac-κ 2 -O,O’)(OMe)3]. (phacac = 1-phenyl-1,3-butane- 4.2 Experimental 1 2 dionate) The X-ray intensity data was collected on a Bruker X8 ApexII 4K Kappa CCD area detector diffractometer, equipped with a graphite monochromator and MoKα fine- focus sealed tube (λ = 0.71073 Å, T = 100(2) K) operated at 2.0 kW (50 kV, 40 mA). The initial unit cell determinations and data collections were done by the SMART 1 software package. The collected frames were integrated using a narrow-frame integration algorithm and reduced with the Bruker SAINT-Plus and XPREP software 1 Bruker SMART-NT Version 5.050. Bruker AXS Inc. Area-Detector Software Package; Madison, WI, USA, 1998. 59
Chapter 4 packages 2 respectively. Analysis of the data showed no significant decay during the data collection. Data was corrected for absorption effects using the multi-scan technique SADABS 3 , and the structure was solved by the direct methods package SIR97 4 and refined using the WinGX 5 software incorporating SHELXL. 6 The final anisotropic full-matrix least-squares refinement was done on F 2 . The methine, methylene and aromatic protons were placed in geometrically idealized positions (C– H = 0.93 – 0.98 Å) and constrained to ride on their parent atoms with Uiso(H) = 1.2 Ueq(C). Non-hydrogen atoms were refined with anisotropic displacement parameters. The graphics were done using the DIAMOND 7 program with 50% probability ellipsoids for all non-hydrogen atoms. 2 Bruker SAINT-Plus Version 6.02 (including XPREP), Bruker AXS Inc. Area-Detector Integration Software, Madison, WI, USA, 1999. 3 Bruker SADABS Version 2004/1. Bruker AXS Inc. Area Detector Absorption Correction Software, Madison, WI, USA, 1998. 4 A. Altomare, M.C. Burla, M. Camalli, G.L. Cascarano, C. Giacovazzo, A. Guagliardi, A.G.G. Moliterni, G. Polidori, R. Spagna, J. Appl. Cryst., 1999, 32, 115. 5 L.J. Farrugia, J. Appl. Cryst., 1999, 32, 837. 6 G.M. Sheldrick, SHELXL97. Program for crystal structure refinement, University of Göttingen, Germany, 1997. 7 K. Brandenburg & H. Putz; DIAMOND, Release 3.0e, Crystal Impact GbR, Bonn, Germany, 2006. 60
Page 1 and 2:
A solution and solid state study of
Page 3 and 4:
Table of contents Abbreviations and
Page 5 and 6:
3.4 Infrared Spectroscopy (IR) ....
Page 7 and 8:
Abbreviations and Symbols Abbreviat
Page 9 and 10:
Abstract 93 Nb NMR was successfully
Page 11 and 12:
Opsomming 93 Nb KMR is met sukses g
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Chapter 1 metals. 3 Due to Wollasto
Page 15 and 16:
Synopsis... 2. Literature Review of
Page 17 and 18:
Chapter 2 Niobium resembles tantalu
Page 19 and 20: 2.1.2 Uses Chapter 2 Niobium has a
Page 21 and 22: 2.2 Separation of Nb and Ta 2.2.1 M
Page 23 and 24: Chapter 2 Buachuang et al. 16 repor
Page 25 and 26: Chapter 2 Niobium oxide surfaces ex
Page 27 and 28: 2.4.6 Water absorption Chapter 2 Th
Page 29 and 30: Chapter 2 been reported in literatu
Page 31 and 32: Chapter 2 containing niobium as the
Page 33 and 34: Chapter 2 conclusions, with regard
Page 35 and 36: Chapter 2 Figure 2.5: Structure of
Page 37 and 38: 2.6.3.3 [NbCl3O(ttbd) - ] Chapter 2
Page 39 and 40: Chapter 2 (a) (b) Figure 2.10: Stru
Page 41 and 42: 2.7 Alkoxides Chapter 2 Specific kn
Page 43 and 44: Chapter 2 Reactions of dialkylamid
Page 45 and 46: Chapter 2 other NbCl5-x(OMe)x produ
Page 47 and 48: Chapter 2 In 1991 Lee et al. 83 pub
Page 49 and 50: EtO EtO EtO EtO Cl Nb Cl Cl Nb Cl R
Page 51 and 52: Chapter 2 The hemicarbonate formed
Page 53 and 54: Synopsis... 3. Synthesis and Charac
Page 55 and 56: Chapter 3 with γ = magnetogyric ra
Page 57 and 58: Chapter 3 electromagnetic spectrum
Page 59 and 60: 3.5.1 Bragg’s law Chapter 3 Bragg
Page 61 and 62: 3.5.3 ‘Phase problem’ Chapter 3
Page 63 and 64: Chapter 3 A = ∑ ε cl (3.14) In
Page 65 and 66: Chapter 3 t1/2 = 54 = . 3.7 Sy
Page 67 and 68: 3.7.2.4 Synthesis of [NbCl4(acac)]:
Page 69: 4. Crystallographic Synopsis... Cha
Page 73 and 74: Chapter 4 4.3 Crystal Structure of
Page 75 and 76: Chapter 4 longer bonds (C1-C2, C2-C
Page 77 and 78: Chapter 4 Figure 4.5: Packing of [N
Page 79 and 80: Chapter 4 Figure 4.7: Molecular str
Page 81 and 82: Chapter 4 Table 4.5: Selected bond
Page 83 and 84: Chapter 4 Figure 4.11: Molecular st
Page 85 and 86: Chapter 4 Figure 4.12: The phacac p
Page 87 and 88: Chapter 4 Table 4.9: Hydrogen bonds
Page 89 and 90: Chapter 4 According to our knowledg
Page 91 and 92: 5.2 Experimental procedures 5.2.1 K
Page 93 and 94: Chapter 5 corresponds to one specie
Page 95 and 96: 5.3 Results and Discussion 5.3.1 Pr
Page 97 and 98: Chapter 5 Figure 5.5: Typical UV/Vi
Page 99 and 100: 5.3.3 Derivation of the rate law Ch
Page 101 and 102: Chapter 5 The Stopped-flow data (fa
Page 103 and 104: Chapter 5 Figure 5.9: Eyring plot,
Page 105 and 106: Chapter 5 However, more information
Page 107 and 108: Chapter 6 second reaction entailed
Page 109 and 110: Appendix A Table 1.3: Bond angles (
Page 111 and 112: Appendix A A 2 Supplementary Data f
Page 113 and 114: Appendix A C(16)-H(16B) 0.96 C(16)-
Page 115 and 116: Appendix A O(7)-C(10)-C(11) 123.6 (
Page 117 and 118: Appendix A H(18E)-C(18B)-H(18F) 109
Page 119 and 120: Appendix A H(18F) 6243 6605 575 75
Page 121 and 122:
Appendix A Table 3.3: Bond angles (
Page 123 and 124:
Appendix A Table 3.4: Anisotropic d
Page 125:
Appendix B Appendix B B 1 Supplemen
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