1,2,3-Dithiazolyl and 1,2,35-Dithiadiazolyl Radicals as Spin-Bearing ...

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atom from the 1,2,3-DTA ring which should bear the majority of the spin density as will be explained in section 5.2.5 with comparison to the calculations. The carbon and sulfur atoms will not couple with the unpaired electron as the most abundant isotopes have no net, nuclear spin. However the other two nitrogen atoms as well as the hydrogen and chlorine atom can potentially couple. Figure 5-7. EPR spectrum (above) in CH 2 Cl 2 and simulation (below) of V-1. Coupling parameters: a N = 6.35G, a N = 0.653, a Cl = 0.705, a H = 0.473, g = 2.00796, LW = 0.22. A simulation using WinSim2002 was run to provide coupling constants for the different atoms; the primary splitting from the nitrogen atom with the greatest amount of spin density was found to be 6.35 G. Only one of the other two nitrogen atoms was 149
equired to obtain a decent agreement with the experimental spectrum. This nitrogen atom was found to have a coupling constant a factor of 10 lower than the primary splitting factor at 0.653 G. 1 H has a nuclear spin I = 1/2 and was assigned a coupling constant with the value 0.473 G and the chlorine atom, the two major isotopes for which have a spin of I = 3/2, was assigned with a value of 0.705 G. The g value was found to be 2.00796, higher than the measured value for a free electron at 2.0032. 7 An agreement factor of 93.3% was obtained using a line width of 0.22. There are yet features that are not present in the simulation such as a shoulder on the central peak of each of the first two multiplets, but it may be impossible to simulate these given the anisotropy of the spectrum. It should be noted that the substantial anisotropy seen in the experimental spectrum implies slow tumbling which is characteristic of a molecule much larger than the expected structure of V-1. 5.2.6 Conclusions and Future Work Calculations were carried out for the radical V-1 and the SOMO is shown in Figure 5-8. There are substantial coefficients on the chlorine atom as well as the halide-bearing carbon and the Mulliken atomic spin densities of 2% and 23% respectively confirm that there is a substantial amount of the radical character at these atoms. No evidence has been found suggesting that a carbon-carbon bond is being formed between two of these molecules to destroy the radical, however the calculations suggest that it may be a possibility. While there is a small amount of spin density expected to be on the chlorinebearing carbon atom, the steric bulkiness of the halogen may be enough to prevent the 150
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1,2,3-Dithiazolyl and 1,2,35-Dithia
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an individual binuclear coordinatio
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weren’t sure about something our
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2.1 General........................
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5.3 Reverse oDTANQ.................
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LIST OF FIGURES AND SCHEMES Figure
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Figure 2-12. Magnetic susceptibilit
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GLOSSARY OF ABBREVIATIONS ° Degree
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K k k B LMCT ls LUMO Kelvin Exchang
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LIST OF STRUCTURES I-1 I-2 I-3 I-4
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I-16a I-16b I-16c I-16d I-16e I-16f
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I-22 I-23 I-24 I-25 exo I-26 endo x
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I-34 I-35 II-3 II-4 II-1 xxv
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III-2 III-1 III-3 III-4 III-5 III-6
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V-7 V-8 V-9 V-10 V-11 V-12 V-13 V-1
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Chapter 1 - General Introduction 1.
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linear relationship shown in Figure
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A plot of χT vs. T is an important
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examination of phenyl methylene. In
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different atomic nuclei. Qualitativ
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3) 14 and a variety of thiazyl base
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with one another with an energy bar
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magnetic properties and undergoes a
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heteroatoms which could facilitate
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Figure 1-5. Qualitative molecular o
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temperature. 64 This was a very imp
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dimerization and therefore a quench
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e enough to overcome the energetica
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eaches the lower end of the investi
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DTDAs has been to exploit the rearr
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1.3.4 1,2,3-Dithiazolyl Radicals (I
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aromatic ring not only protects the
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is quite similar to the spin-polari
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compound there are many competing m
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a b c d e Figure 1-16. a) Nonorthog
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would result in non-orthogonal over
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platinum center as well as the phos
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substantial amount of unpaired elec
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I-28 I-29 I-30 The metals manganese
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gave a combination of 2 mononuclear
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changes related to geometric, chemi
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Finally, the last chapter reviews t
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(23) Rajca, A. Chem. Rev. 1994, 94,
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(53) Azuma, N.; Tsutsui, K.; Miura,
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(79) Decken, A.; Cameron, T. S.; Pa
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(102) Herz, R.; Leopold Cassella &
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(128) Aliaga-Alcalde, N., 2003. (12
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Chapter 2 - Structural and Magnetic
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2.2.2 pymDSDA Coordination Complexe
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2.2.3 DTDA Coordination Complexes o
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indicators tend to be very weak str
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In Figure 2-1a, the nickel complex
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2.2.3 Cyclic Voltametry The cyclic
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propensity for intermolecular Se-N
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dimerization motif. One possible ex
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the bridging ligand such that the D
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contacts into four different intera
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e acting as a closed-shell, S = 0,
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2.3.4 [Zn(hfac) 2 ] 2·pymDTDA (II-
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ancillary ligands and the nearly oc
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single molecular unit. Upon closer
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across the entire temperature regim
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2.5 Conclusions and Future Work It
Page 127 and 128: therefore chain formation. However
Page 129 and 130: The work presented in this chapter
Page 131 and 132: 736(s), 723(s), 646(s), 632(s), 469
Page 133 and 134: (0.2023 g, 1.104 mmol) in 30 mL of
Page 135 and 136: (6) Chattoraj, S. C.; Cupka Jr, A.
Page 137 and 138: Chapter 3 - 5-oxo-5H-naphtho[1,2-d]
Page 139 and 140: triethylammonium chloride which was
Page 141 and 142: 3.3.2 Mass Spectrometry A sample of
Page 143 and 144: 3.3.4 X-ray Crystallography Crystal
Page 145 and 146: a 2-fold screw axis across half of
Page 147 and 148: number of electrons that this compo
Page 149 and 150: often generated in situ although wa
Page 151 and 152: similar to compounds II-1 and II-2,
Page 153 and 154: 3.6 Experimental General All reacti
Page 155 and 156: Chapter 4 - The Polymorphism of Tri
Page 157 and 158: 4.3 Discussion Prior to the discove
Page 159 and 160: (derived from angles ranging from 4
Page 161 and 162: a b c Figure 4-2. Packing diagrams
Page 163 and 164: polymorphs observed and are therefo
Page 165 and 166: Chapter 5 5.1 Overview There are se
Page 167 and 168: success and so a Herz ring closure
Page 169 and 170: did not immediately precipitate, bu
Page 171 and 172: Figure 5-2 shows the IR spectra for
Page 173 and 174: comparison of the infrared data obt
Page 175 and 176: discussed in section 5.2.2. As the
Page 177: ing was formed. One of the nitrogen
Page 181 and 182: Considerations have been put toward
Page 183 and 184: chelation pocket is similar to that
Page 185 and 186: the mixture was filtered to remove
Page 187 and 188: good spectroscopic handle for this
Page 189 and 190: spectrum from about 1900 to 400 cm
Page 191 and 192: doublets of triplets associated wit
Page 193 and 194: adical, followed by the closed-shel
Page 195 and 196: completely dry after being under va
Page 197 and 198: changed substantially after the tra
Page 199 and 200: The reaction to produce V-15 was qu
Page 201 and 202: the proton two carbons away next to
Page 203 and 204: which is parallel to the mean plane
Page 205 and 206: of the 1,2,3-DTA rings could act as
Page 207 and 208: mixture was refluxed for 20 h yield
Page 209 and 210: the heat source was removed and the
Page 211 and 212: 1085(w), 1059(w), 1008(w), 917(w),
Page 213 and 214: ___________________________________
Page 215 and 216: Crystallography P 2 1 /c a = 9.1678
Page 217 and 218: Compound Name: 4-(2′-pyrimidyl)-1
Page 219 and 220: Compound Name: [μ-4-(2′-pyrimidy
Page 221 and 222: Magnetometry 192
Page 223 and 224: Crystallography P-1 a = 8.9576, b =
Page 225 and 226: Compound Name: [μ-4-(2′-pyrimidy
Page 227 and 228: Magnetometry: 198
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Crystallography: P2 1 /n a = 19.884
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Compound Name: 5-oxo-5H-naphtho[1,2
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204
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206
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MS (EI + ): 208
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Compound Name: 5-chloro-1H-[1,2,5]t
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Compound Name: 3-nitro-1,2-naphthaq
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Compound Name: 3,4-dioxo-3,4-dihydr
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Compound Name: 4,5-dioxo-4,5-dihydr
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Compound Name: 6,6′-dinitro-1,1
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220
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1,2,3-Dithiazolyl and 1,2,35-Dithiadiazolyl Radicals as Spin-Bearing ...

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