تعداد نشریات | 418 |
تعداد شمارهها | 10,005 |
تعداد مقالات | 83,623 |
تعداد مشاهده مقاله | 78,416,474 |
تعداد دریافت فایل اصل مقاله | 55,445,021 |
Conformational behaviors of trans-2,3-bis(methylthio)-1,4-dioxane, -dithiane and –diselenane. A hybrid-DFT study and NBO interpretations | ||
Journal of the Iranian Chemical Research | ||
مقاله 5، دوره 3، شماره 3، اسفند 2010، صفحه 179-189 اصل مقاله (309.55 K) | ||
نویسندگان | ||
Davood Nori-Shargh* 1؛ Zahra Mahmoodi1؛ Nasrin Masnabadi2؛ Hooriye Yahyaei3؛ Seiedeh Negar Mousavi1 | ||
1Department of Chemistry, Science Faculty, Arak Branch, Islamic Azad University, Arak, Iran | ||
2Department of Chemistry, Roudehen Branch, Islamic Azad University, Roudehen, Iran | ||
3Department of Chemistry, Islamic Azad University, Zanjan Branch, P.O.Box 49195.467,Zanjan, Iran | ||
چکیده | ||
The conformational behaviors of 2,3-bis(methylthio)-1,4-dioxane (1), 2,3-bis(methylthio)- 1,4-dithiane (2) and 2,3-bis(methylthio)-1,4-diselenane (3) have been analyzed by means of hybrid-density functional theory (B3LYP/Def2-TZVPP) based method and NBO interpretation. B3LYP/Def2-TZVPP results showed that the axial conformations of compounds 1-3 are more stable than their equatorial conformations. The calculated Gibbs free energy difference (Geq–Gax) values (i.e. ΔGeq-ax) at 298.15 K and 1 atm between the axial and equatorial conformations decrease from compound 1 to compound 3. The NBO analysis of donor-acceptor (LP→σ*) interactions showed that the anomeric effects (AE) decrease from compound 1 to compound 3. On the other hand, the calculated dipole moment values between the axial and equatorial conformations [Δ(μeq - μax)] increase from compound 1 to compound 2 but decrease from compound 2 to compound 3. However, the variations of the calculated Δ(μeq - μax) values are not in the same trend observed for the corresponding AE and ΔG values. Therefore, the calculated Δμ values do not seem to be sufficient to account for the axial preferences in compounds 1-3. These findings led to the proposal that the AE, due to donor→acceptor hyperconjugation effect, is more significant for the explanation of the axial conformational preferences of compounds 1-3 than the electrostatic effect. | ||
کلیدواژهها | ||
anomeric effects؛ Stereoelectronic interactions؛ Molecular modeling؛ Ab initio؛ NBO؛ 2,3-bis(methylthio)-1,4-dithiane | ||
مراجع | ||
[1] U. Lemieux, S. Koto, Tetrahedron 30 (1974) 1933-1944. [2] T. Edwards, Chem. Ind. (London) (1955) 1102-1111. [3] E. Juaristi, G. Cuevas, The Anomeric Effect, CRC Press. Inc., Florida, 1995. [4] C. Altona, C. Romers, E. Havinga, Tetrahedron Lett. 21 (1959) 16-20. [5] N.D. Epiotis, R.L. Yates, R.J. Larson, C.R. Kirmayer, F. Bernardi, J. Am. Chem. Soc. 99 (1977) 8379-8388. [6] E.L. Eliel, S.H. Wilen, Stereochemistry of Organic Compounds, Wiley, New York, 1994. [7] J.P. Praly, R.U. Lemieux, Can. J. Chem. 65 (1987) 213-223. [8] M.A. Pericás, A. Riera, J. Guilera, Tetrahedron 42 (1986) 2717-2718. [9] N.S. Zefirof, L.G. Gurvich, A.S. Shashkov, M.Z. Krimer, E.A. Vorob’eva, Tetrahedron 32 (1976) 1211-1219. [10] E.L. Eliel, E. Juaristi, J. Am. Chem. Soc. 100 (1978) 6114-6119. [11] E. Juaristi, J. Chem. Edu. 56 (1979) 438-441. [12] M.J. Frisch, G.W. Trucks, H.B. Schlegel, G.E. Scuseria, M.A. Robb, J.R. Cheeseman, J.A. Montgomery, T. Vreven, K.N. Kudin, J.C. Burant, J.M. Millam, S.S. Iyengar, J. Tomasi, V. Barone, B. Mennucci, M. Cossi, G. Scalmani, N. Rega, G.A. Petersson, H. Nakatsuji, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, M. Klene, X. Li, J.E. Knox, H.P. Hratchian, J.B. Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R. E. Stratmann, O. Yazyev, A. J. Austin, R. Cammi, C. Pomelli, J.W. Ochterski, P.Y. Ayala, K. Morokuma, G.A. Voth, P. Salvador, J.J. Dannenberg, V.G. Zakrzewski, S. Dapprich, A.D. Daniels, M.C. Strain, O. Farkas, D.K. Malick, A.D. Rabuck, K. Raghavachari, J.B. Foresman, J.V. Ortiz, Q. Cui, A.G. Baboul, S. Clifford, J. Cioslowski, B.B. Stefanov, G. Liu, A. Liashenko, P. Piskorz, I. Komaromi, R.L. Martin, D.J. Fox, T. Keith, M.A. Al-Laham, C.Y. Peng, A. Nanayakkara, M. Challacombe, P.M.W. Gill, B. Johnson, W. Chen, M.W. Wong, C. Gonzalez, J.A. Pople, Gaussian 03, Revision B.03, Gaussian, Inc., Wallingford CT, 2004. [13] A.D. Becke, J. Chem. Phys. 98 (1993) 5648-5652. [14] C. Lee, W. Yang, R.G. Parr, Phys. Rev. B 37 (1988) 785-789. [15] W.J. Hehre, L. Radom, P.V.R. Schleyer, J.A. Pople, Ab initio Molecular Orbital Theory Wiley, New York, 1986. [16] J.M. Seminario, P. Politzer, (Eds), Modern Density Function Theory, A Tool for Chemistry, Elsevier, Amsterdam, 1995. [17] E.D. Glendening, J.K. Badenhoop, A.E. Reed, J.E. Carpenter, J.A. Bohmann, C.M. Morales, F. Weinhold, Theoretical Chemistry Institute, University of Wisconsin, Madison, WI, 2004. NBO Version 5.G. [18] F. Weigend, R. Ahlrichs, Phys. Chem. Chem. Phys. 7 (2005) 3297-3305. [19] D. Nori-Shargh, F. Roohi, F. Deyhimi, R. Naeem-Abyaneh, J. Mol. Struct. (Theochem) 763 (2006) 21-28. D. Nori-Shargh & et al. / J. Iran. Chem. Res. 3 (2010) 179-189 189 [20] D. Nori-Shargh, M. Malekhosseini, F. Deyhimi, J. Mol. Struct. (Theochem) 763 (2006) 187-198. [21] D. Nori-Shargh, F. Deyhimi, J.E. Boggs, S. Jameh-Bozorghi, R. Shakibazadeh, J. Phys. Org. Chem. 20 (2007) 355-364. [22] D. Nori-Shargh, H. Yahyaei, J. Mol. Struct. (Theochem) 913 (2009) 8-15. [23] D. Nori-Shargh, N. Hassanzadeh, M. Kosari, S. Sharifi, J. Mol. Struct. (Theochem) 940 (2010) 129- 134. [24] A. Zeinalinezhad, D. Nori-Shargh, Z. Abbasi-Bakhtiari, J.E. Boggs, J. Mol. Struct. (Theochem) 947 (2010) 52-57. [25] D. Nori-Shargh, H. Yahyaei, J.E. Boggs, J. Mol. Graph. Model. 28 (2010) 807-813. [26] K.B. Wiberg, M.A. Murcko, J. Phys. Chem. 91 (1987) 3616-3620. [27] F. Freeman, A. Phornvoranunt, W.J. Hehre, J. Phys. Org. Chem. 11 (1998) 831-835. [28] T.M. Gilbert, Tetrahedron Lett. 39 (1998) 9147-9150. [29] M. Remko, P.D. Lyne, W.G. Richards, Phys. Chem. Chem. Phys. 1 (1999) 5353-5357. [30] D. Strickland, R.A. Caldwell, J. Phys. Chem. 97 (1993) 13394-13402. [31] I. Arnason, G.K. Thorarinson, E. Matern, J. Mol. Struct. (Theochem) 545 (1998) 91-102. | ||
آمار تعداد مشاهده مقاله: 648 تعداد دریافت فایل اصل مقاله: 431 |