Ph. D. THESIS 2009

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These investigations revealed the obtaining of associations of molecules which form spectacular supramolecular aggregates. The anti isomer gives a cyclic dimer by four hydrogen bonds (Figure 31). a b Figure 31. ORTEP diagram for the cyclic dimer of 5-anti (a : aRaR – aRaR ; b : aSaS – aSaS associations) The association of the molecules is homochiral and involves either aRaR (a) or aSaS (b) structures (the dimers are built up by highly selective enantiomeric recognition processes). The crystal is more or less a homogenous solution of the two enantiomeric dimers (it is a racemate). Syn isomer forms a supramolecular wheel via a cyclic trimer built up by six hydrogen bonds (Figure 32). Both analyzed structures exhibit a chain-chain conformation, according to the torsion angles values. 39
Figure 32. ORTEP diagram for the cyclic trimer of achiral 5-syn isomer. The distances from the hydrogen atoms of OH groups to the N atoms are d = 1.842-1.974 Å in the dimer and d’ = 1.676 – 1.848 Å in the trimer, respectively. These low values suggest strong interactions by hydrogen bonds and a high stability of the cyclic structures. The investigations of the lattice for 2-syn revealed a layered structure with transversal (along the crystallographic axis a) and longitudinal (along the crystallographic axis b) channels (Figure 33). Figure 33. View of the lattice (along the c crystallographic axis) of 5-syn. 40
Page 1 and 2: “BABES-BOLYAI” UNIVERSITY CLUJ-
Page 3 and 4: General Introduction OUTLINE Part A
Page 5 and 6: 3.6.1. Dots 188 3.6.2. 3D structure
Page 7 and 8: Part A: Synthesis and Structural An
Page 9 and 10: H 3C H 3C O O O C C O O 1a O O C C
Page 11 and 12: The two forms are in equilibrium an
Page 13 and 14: Figu re 4 . Th e 13 C-NMR APT (CDCl
Page 15 and 16: set used , the anarmonicities that
Page 17 and 18: Figure 9. ORTEP diagram for the bic
Page 19 and 20: 1.5.1. Tetramethyl 3,7-dihydroxybic
Page 21 and 22: Table 7. The selected molecular par
Page 23 and 24: a b Figure 14. 1 H NMR spectrum (CD
Page 25 and 26: Figure 16. 13 C NMR spectrum APT (C
Page 27 and 28: Absorbance (a. u.) Absorbance (a.u.
Page 29 and 30: icyclo[3.3.1]nonane-3,7-dione solut
Page 31 and 32: m u lt ip let a t a t δ ==1 .7 6 p
Page 33 and 34: Figure 22. 13 C NMR APT spectrum of
Page 35 and 36: Figure 24. NMR investigation of the
Page 37 and 38: (mol·l -1 ) syn 8.8 x10 -3 1.4373
Page 39: a b Figure 29. 3D FTIR spectra in s
Page 43 and 44: H2 … N3 = 1.839 Å H5 … N6 = 1.
Page 45 and 46: 2. Conclusions of the part A Differ
Page 47: 20. L. J. Bellamy, “Advanced in I
Page 50 and 51: 2. Experimental part: fabrication a
Page 52 and 53: 3 m 30 m a b Figure 4. Optical imag
Page 54 and 55: (NA 1.25) in phase-contrast (a) and
Page 56 and 57: was chosen instead of an aqueous on
Page 58 and 59: Our goal is to develope a lasser as
Page 60 and 61: Figure 15. a Optical image of gold
Page 62 and 63: the power as parameter exhibits a m
Page 64 and 65: a b Figure 21 a) Optical image of g
Page 66: 4.5.3. 3D structures The 3D structu
Page 69 and 70: Selected References 1. E. S. Wu, J.
Page 71: VIII. J. Bosson-Ehoomann, A. Mihut,

Ph. D. THESIS 2009

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