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

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provide a dry, dark, free-flowing residue (crude yields tended to be quite greater than 90%) which is then placed on a gradient tube furnace to give a purified crystalline sample of the target species by sublimation in preparative quantities. The purified yields were usually on the order of 35-45%. This is quite remarkable considering that the molecular weight of the species investigated exceed 1000 g/mol. The high volatility of these complexes can be attributed to the nature of the ancillary hfac ligands. Scheme 2-2. Reaction sheme illustrating coordination of II-1 to give II-5; M = Ni and II-6; M = Mn.. This synthesis was successfully achieved for the nickel and manganese ions as outlined in scheme 2-2. An analogous synthesis was attempted using cobalt, however X- ray quality crystals suitable for structural analysis were not obtained. It is believed that the compound thermally decomposed before the temperature for sublimation was achieved at the reduced pressure. While several attempts at sublimation gave very low yields of micro-crystalline material, we were never able to obtain enough for characterization. Solution recrystallization was not considered due to the fact that the high solubility of the metal-hfac species tends to be quite high and do not easily precipitate from solution. 68
2.2.3 DTDA Coordination Complexes of Zinc The synthesis for the pymDTDA radical established by my predecessor 4 was followed to obtain pure, crystalline II-2 for the coordination to the Zn(hfac) 2 fragment. The Zn starting material was prepared from Zn(hfac) 2·2H 2 O 6 and converted to the anhydrous bis-THF adduct in a similar fashion to that used for the other transition metal starting materials. 7 The dimerization of the sulfur species is not nearly as strong as the selenium analogue II-1 and so not nearly as much solvent is required to fully dissolve the radical. In a typical synthesis, II-2 is dissolved in 20-30 mL of distilled methylene chloride to give a dark violet, homogeneous solution while two equivalents of the zinc starting material are dissolved in an equal volume of the same solvent, in a Scheme 2-3. Reaction scheme outlining syntheses of II-7 and II-8 and the different sublimation conditions. separate flask. As a white powder, the zinc containing starting material produces a colourless solution once dissolved. An immediate colour change is induced when the 69
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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
Page 47 and 48: heteroatoms which could facilitate
Page 49 and 50: Figure 1-5. Qualitative molecular o
Page 51 and 52: temperature. 64 This was a very imp
Page 53 and 54: dimerization and therefore a quench
Page 55 and 56: e enough to overcome the energetica
Page 57 and 58: eaches the lower end of the investi
Page 59 and 60: DTDAs has been to exploit the rearr
Page 61 and 62: 1.3.4 1,2,3-Dithiazolyl Radicals (I
Page 63 and 64: aromatic ring not only protects the
Page 65 and 66: is quite similar to the spin-polari
Page 67 and 68: compound there are many competing m
Page 69 and 70: a b c d e Figure 1-16. a) Nonorthog
Page 71 and 72: would result in non-orthogonal over
Page 73 and 74: platinum center as well as the phos
Page 75 and 76: substantial amount of unpaired elec
Page 77 and 78: I-28 I-29 I-30 The metals manganese
Page 79 and 80: gave a combination of 2 mononuclear
Page 81 and 82: changes related to geometric, chemi
Page 83 and 84: Finally, the last chapter reviews t
Page 85 and 86: (23) Rajca, A. Chem. Rev. 1994, 94,
Page 87 and 88: (53) Azuma, N.; Tsutsui, K.; Miura,
Page 89 and 90: (79) Decken, A.; Cameron, T. S.; Pa
Page 91 and 92: (102) Herz, R.; Leopold Cassella &
Page 93 and 94: (128) Aliaga-Alcalde, N., 2003. (12
Page 95 and 96: Chapter 2 - Structural and Magnetic
Page 97: 2.2.2 pymDSDA Coordination Complexe
Page 101 and 102: indicators tend to be very weak str
Page 103 and 104: In Figure 2-1a, the nickel complex
Page 105 and 106: 2.2.3 Cyclic Voltametry The cyclic
Page 107 and 108: propensity for intermolecular Se-N
Page 109 and 110: dimerization motif. One possible ex
Page 111 and 112: the bridging ligand such that the D
Page 113 and 114: contacts into four different intera
Page 115 and 116: e acting as a closed-shell, S = 0,
Page 117 and 118: 2.3.4 [Zn(hfac) 2 ] 2·pymDTDA (II-
Page 119 and 120: ancillary ligands and the nearly oc
Page 121 and 122: single molecular unit. Upon closer
Page 123 and 124: across the entire temperature regim
Page 125 and 126: 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
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often generated in situ although wa
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similar to compounds II-1 and II-2,
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3.6 Experimental General All reacti
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Chapter 4 - The Polymorphism of Tri
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4.3 Discussion Prior to the discove
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(derived from angles ranging from 4
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a b c Figure 4-2. Packing diagrams
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polymorphs observed and are therefo
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Chapter 5 5.1 Overview There are se
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success and so a Herz ring closure
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did not immediately precipitate, bu
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Figure 5-2 shows the IR spectra for
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comparison of the infrared data obt
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discussed in section 5.2.2. As the
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ing was formed. One of the nitrogen
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equired to obtain a decent agreemen
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Considerations have been put toward
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chelation pocket is similar to that
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the mixture was filtered to remove
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good spectroscopic handle for this
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spectrum from about 1900 to 400 cm
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doublets of triplets associated wit
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adical, followed by the closed-shel
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completely dry after being under va
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changed substantially after the tra
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The reaction to produce V-15 was qu
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the proton two carbons away next to
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which is parallel to the mean plane
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of the 1,2,3-DTA rings could act as
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mixture was refluxed for 20 h yield
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the heat source was removed and the
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1085(w), 1059(w), 1008(w), 917(w),
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___________________________________
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Crystallography P 2 1 /c a = 9.1678
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Compound Name: 4-(2′-pyrimidyl)-1
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Compound Name: [μ-4-(2′-pyrimidy
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Magnetometry 192
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Crystallography P-1 a = 8.9576, b =
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Compound Name: [μ-4-(2′-pyrimidy
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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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222
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1,2,3-Dithiazolyl and 1,2,35-Dithiadiazolyl Radicals as Spin-Bearing ...

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