The π-Electron Delocalization in 2-Oxazolines Revisited: Quantification and Comparison with Its Analogue in Esters †
Abstract
:1. Introduction
2. Experimental Section
2.1. Materials
2.2. Instrumentation
2.3. Single Crystal X-ray Diffraction Analyses
Crystal Structure Analysis | Methyl 3-(4,5-dihydrooxazol-2-yl) Propanoate, EstOx | 4-(2-Aminoethoxy)-4-oxo-butanoic Acid, EstAA |
---|---|---|
Crystal data | ||
CCDC No. | 1418758 | 1418759 |
Crystal form | block | block |
Crystal colour | colorless | colorless |
Empirical formula | C7H11NO3 | C6H11NO4 |
Formula weight | 157.17 | 161.16 |
Crystal system | monoclinic | monoclinic |
Space group | P21 | P21/c |
a (Å) | 5.547 (2) | 10.3132 (8) |
b (Å) | 6.765 (3) | 9.0304 (7) |
c (Å) | 9.993 (4) | 8.0012 (7) |
α (°) | 90 | 90 |
β (°) | 91.583 (13) | 96.688 (5) |
γ (°) | 90 | 90 |
V (Å3) | 374.9 (3) | 740.10 (10) |
ρcalc (g·cm−3) | 1.268 | 1.446 |
Z | 2 | 4 |
F(0 0 0) | 152 | 344 |
µ (Mo-Kα) (cm−1) | 0.102 | 0.122 |
Data Collection | ||
Measured reflections | 4559 | 1786 |
Unique reflections | 1278 | 1786 |
Rint | 0.0659 | 0.000 |
Absorption | ||
Tmin/Tmax | 0.9690/0.9808 | 0.9574/0.9855 |
Refinement Results | ||
Refined parameters | 101 | 101 |
R1 a,b, wR2 a;c | 0.0530; 0.1352 | 0.0630; 0.1432 |
a, b | 0.0887; 0.0457 | 0,000; 2.2816 |
ρ (e·Å−3) | 0.306; −0.219 | 0.362; −0.325 |
2.4. Preparation of Methyl 3-(4,5-Dihydrooxazol-2-yl)propanoate EstOx
2.5. Preparation of 4-(2-Aminoethoxy)-4-oxobutanoic Acid EstAA
3. Results and Discussion
3.1. Synthesis of the Compounds EstOx and EstAA
3.2. Crystal Structure of EstOx
3.3. Crystal Structure of EstAA
Atom Names | Bond Length N–H | Distance H···O | Distance N···O | Angle NHO |
---|---|---|---|---|
N1–H1A···O2 A | 0.91 Å | 1.84 Å | 2.739(3) Å | 171.1° |
N1–H1B··O2 B | 0.91 Å | 1.86 Å | 2.741(3) Å | 162.7° |
N1–H1C··O1 C | 0.91 Å | 1.84 Å | 2.747(3) Å | 172.2° |
3.4. Quantum Chemical Calculations of EstOx
4. Conclusions
Supplementary Materials
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Fimberger, M.; Luef, K.P.; Payerl, C.; Fischer, R.C.; Stelzer, F.; Kállay, M.; Wiesbrock, F. The π-Electron Delocalization in 2-Oxazolines Revisited: Quantification and Comparison with Its Analogue in Esters. Materials 2015, 8, 5385-5397. https://doi.org/10.3390/ma8085249
Fimberger M, Luef KP, Payerl C, Fischer RC, Stelzer F, Kállay M, Wiesbrock F. The π-Electron Delocalization in 2-Oxazolines Revisited: Quantification and Comparison with Its Analogue in Esters. Materials. 2015; 8(8):5385-5397. https://doi.org/10.3390/ma8085249
Chicago/Turabian StyleFimberger, Martin, Klaus P. Luef, Claudia Payerl, Roland C. Fischer, Franz Stelzer, Mihály Kállay, and Frank Wiesbrock. 2015. "The π-Electron Delocalization in 2-Oxazolines Revisited: Quantification and Comparison with Its Analogue in Esters" Materials 8, no. 8: 5385-5397. https://doi.org/10.3390/ma8085249