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

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using instead of a pyridyl substituent on the DTDA ring a pyramidal substituent (I-32). This was first reported in 2006 along with a coordination complex, bridging two manganese ions stabilized by hfac ligands once again (I-33). 151 To model the magnetic I-32 I-33 data, the complex was treated as a spin-trimer and both the coupling constants for the Mn-Mn interaction as well as the Mn-radical were found to be negative, indicating antiferromagnetic coupling. But since the latter interaction was a factor of 20 stronger there was not substantial evidence of spin frustration. The magnetic data was actually quite remarkable for this compound since as the temperature was lowered there was a dramatic increase in the χT product indicating the onset of very strong ferromagnetic interactions which, at the time that the communication in which it was reported was published, were unknown. There was some further work conducted using this radical ligand in which the generation of monomeric complexes was investigated. While this was successful for Co 2+ and Ni 2+ , attempts to isolate the manganese complex were unsuccessful and repeatedly 48
gave a combination of 2 mononuclear units and a binuclear unit. 152 This will be revisited briefly in chapter 2 for comparison purposes with the compounds discussed therein. There has also been limited work put towards the coordination of DSDA radical ligands. The only other reports prior to the DSDA complexes discussed in chapter 2 were obtained using the phenyl substituted DSDA in reactions similar to those carried out for I-24 and I-25. The radical was reacted with excess Pt(dppe) 2 to give a green compound which exhibited a broad singlet EPR spectrum with satellites from the phosphorus atoms and was found to be compound I-34. This green colour quickly dissipated however, giving a yellow solution with a precipitate. There was still an EPR signal; however the g value and coupling parameters confirmed that it was the uncoordinated radical. The I-34 I-35 precipitate was found to contain two different platinum species. One was analogous to the trinuclear I-25, however a different compound I-35 was also observed in which one of the selenium atoms had been lost to give a 5 membered ring with platinum. Both nitrogen atoms were protonated and the cationic charge was stabilized by a chlorine atom. 153 The nature of this counter-ion and the source of protonation were not 49
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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
Page 23 and 24:
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
Page 27 and 28: III-2 III-1 III-3 III-4 III-5 III-6
Page 29 and 30: V-7 V-8 V-9 V-10 V-11 V-12 V-13 V-1
Page 31 and 32: Chapter 1 - General Introduction 1.
Page 33 and 34: linear relationship shown in Figure
Page 35 and 36: A plot of χT vs. T is an important
Page 37 and 38: examination of phenyl methylene. In
Page 39 and 40: different atomic nuclei. Qualitativ
Page 41 and 42: 3) 14 and a variety of thiazyl base
Page 43 and 44: with one another with an energy bar
Page 45 and 46: 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: I-28 I-29 I-30 The metals manganese
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 and 98: 2.2.2 pymDSDA Coordination Complexe
Page 99 and 100: 2.2.3 DTDA Coordination Complexes o
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
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The work presented in this chapter
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736(s), 723(s), 646(s), 632(s), 469
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(0.2023 g, 1.104 mmol) in 30 mL of
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(6) Chattoraj, S. C.; Cupka Jr, A.
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Chapter 3 - 5-oxo-5H-naphtho[1,2-d]
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triethylammonium chloride which was
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3.3.2 Mass Spectrometry A sample of
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3.3.4 X-ray Crystallography Crystal
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a 2-fold screw axis across half of
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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
Page 247 and 248:
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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