Main Factors Governing Chemical Shifts of Carbon and Nitrogen in Cyano Group. An Experimental and Theoretical Study

• Autorzy: Molchanov S. , Gryff-Keller A.
• Konferencja: 1st Symp. on NMR in Chemistry, Biology and Medicine; 8-10 Semptember, Warsaw, Poland. Issue dedicated to honour Prof. Witanowski
• Języki publikacji: EN

Abstrakty

EN

The feasibility of a description of magnetic shielding of carbon and nitrogen nuclei of cyano group in various cyano compounds as a net result of the interplay of different structural factors is discussed. Analysis of experimental data and DFT GIAO calculations of shielding constants have shown that the main factors governing the carbon chemical shifts are the heavy-atom and inductive effects, although the resonance and steric properties of a substituent are also of some importance. On the other hand, the shielding of the cyano nitrogen is connected mainly with the redistribution of _-electrons within the cyano group, which is the result of mesomeric interaction, and, to a lesser extent, with the inductive properties of the substituent. The steric and heavy-atom effects of the substituent seem to be irrelevant for the shielding of cyano nitrogen.

Słowa kluczowe

EN

NMR; magnetic shielding; cyano compounds; DFT GIAO calculations; substituent effect

• Wydawca: Polskie Towarzystwo Chemiczne
• Czasopismo: Polish Journal of Chemistry
• Rocznik: 2006
• Tom: Vol. 80, nr 7
• Strony: 1031--1038
• Opis fizyczny: Bibliogr. 17 poz., rys.

Twórcy

autor

Molchanov S.

autor

Gryff-Keller A.

• Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warszawa, Poland

Bibliografia

• 1. Hansch C., Leo A. and Taft R.W., Chem. Rev., 91, 165 (1991).
• 2. Swain C.G. and Lupton E.C. Jr., J. Am. Chem. Soc., 90, 4328 (1968).
• 3. Unger S.H. and Hansch C., Progr. Phys. Org. Chem., 12, 91 (1976).
• 4. Velde G.T., Bickelhaupt F.M., Baerends E.J., Guerra C.F., Van Gisbergen S.J.A., Snijders J.G. and Ziegler T., J. Comput. Chem., 22(9), 931 (2001).
• 5. Frisch M.J., Trucks G.W., Schlegel H.B., ScuseriaG.E., Robb M.A., Cheeseman J.R., Montgomery Jr., J. A., Vreven T., Kudin K.N., Burant J.C., Millam J.M., Iyengar S.S., Tomasi J., Barone V., Mennucci B., Cossi M., Scalmani G., Rega N., Petersson G.A., Nakatsuji H., Hada M., Ehara M., Toyota K., Fukuda R., Hasegawa J., Ishida M., Nakajima T., Honda Y., Kitao O., Nakai H., Klene M., Li X., Knox J.E., Hratchian H.P., Cross J.B., Bakken V., Adamo C., Jaramillo J., Gomperts R., Stratmann R.E., Yazyev O., Austin A.J., Cammi R., Pomeili C., Ochterski J.W., Ayala P.Y., Morokuma K., Voth G.A., Salvador R, Dannenberg J.J., Zakrzewski V.G., Dapprich S., Daniels A.D., Strain M.C., Farkas O., Malick D.K.,Rabuck A.D., Raghavachari K., Foresman J.B., Ortiz J.Y., Cui Q., Baboul A.G., Ciifford S., Cioslowski J., Stefanov B.B., Liu G., Liashenko A., Piskorz R, Komaromi L, Martin R.L., Fox D.J., Keith T., Al-Laham M.A., Peng C.Y., Nanayakkara A., Chailacombe M., Gili P.M.W., Johnson B., Chen W., Wong M.W., Gonzalez C. and Pople J.A., Gaussian 03, Revision C.02, Gaussian, Inc., Wallingford CT, (2004).
• 6. DALTON, a molecular electronic structure program, Release 2.0 (2005), http://www.kjemi.uio.no/software/dalton/dalton .html
• 7. TURBOMOLE, Program Package for ab initio Electronic Structure Calculations, V5.8 (2005), http://www.cosmologic.de/turbomole.html
• 8. Witanowski M., Stefaniak L. and Webb G.A., Annu. Rep. NMR Spectrosc., 11B, l (1981); 18, l (1986);25, l (1993).
• 9. (a) Witanowski M., Sicinska W. and Webb G.A., Magn. Reson. Chem., 27(4), 380 (1989); (b) Witanowski M., Sicinska W., Biedrzycka Z. and Webb G.A., J. Mol. Struct., 380(1-2), 133 (1996); © Jackowski K., Bematowicz P. and Wielogorska E., Z Phys. Chem., 216(12), 1401 (2002); (d) Witanowski M., Biedrzycka Z., Sicinska W. and Grabowski Z., J. Magn. Reson., 164(2), 212 (2003).
• 10. (a) Barszczewicz A., Helgaker T., Jaszuński M., Jorgensen P. and Ruud K., J. Magn. Reson., 114(A), 212 (l999) andreferencescitedtherein; (b) OlahG.A. and KiovskyT.E., J. Am. Chem. Soc., 90,4666 (l968); (c) Becker W, Beck E. and Rieck R., Z Naturforsch., 25(B), 1332 (1970); (d) Gryff-Keller A. and Molchanov S., Bull. Acad. Pol. Sci., Chemistry, 47(1), 83 (1999).
• 11. Helgaker T., Jaszuński M. and Ruud K., Chem. Rev., 99, 293 (1999).
• 12. Autschbach J. and Ziegler T., in Encyclopedia of NMR, edited by Grant D.M, Harris R.K. (Chichester: Wiley), 9, 306 (2002).
• 13. Molchanov S. and Gryff-Keller A., Mol. Phys., 100, 3349 (2002).
• 14. Molchanov S. and Gryff-Keller A., Magn. Reson. Chem., 41(10), 788 (2003).
• 15. (a) Buckingham A.D. and Malm S.M., Mol. Phys., 22, 1127 (1971); (b) Mason J., Adv. Inorg. Chem. Radiochem., 18, 197(1976).
• 16. Sardashti M. and Maciel G.E., J. Phys. Chem., 92, 4620 (1988).
• 17. Bergmann D. and Hinze J., Angew. Chem. Int. Ed. Engl., 35, 150 (1996).