Abstract
This paper presents the evolution of views on methyl internal rotation potential barrier. Various mechanisms proposed for the origin of torsional barrier in ethane have been reviewed. Inadequacy of one dimensional description of internal rotation has been highlighted in small methyl conjugated molecules in the light of its multidimensional nature. The effect of skeletal flexing on the picture of barrier formation by dissecting the barrier energy into potential type, virial type and symmetry type is described. The role of π and σ electrons at different stages of molecular flexing is discussed. The analysis identifies the dominant contributions to barrier origin as π-bonding changes during rigid rotation and σ-bonding changes resulting from bond lengthening during methyl group rotation. The contribution of lone pair electrons in determining the preferred structure of the methyl group in imine compounds such as 1-methyl 2-(1H)-pyridinimine is presented.
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References
Nielson H H 1932Phys. Rev. 40 445
Philis J G, Berman J M and Goodman L 1990Chem. Phys. Lett. 167 16
Kundu T, Thakur S N and Goodman L 1992J. Chem. Phys. 97 5410
Gu H, Kundu T and Goodman L 1993J. Phys. Chem. 97 7194
Lister D G, MacDonald J N and Owen N L 1978Internal rotation and inversion: An introduction to large amplitude motions in molecules (New York: Academic Press)
Reed A E and Weinhold F 1991Isr. J. Chem. 31 277
Payne W P and Allen L C 1977 InApplication of electronic structure theory (ed.) H F Shaefer (New York: Plenum) p. 29
Villard A 1974 InInternal rotation in molecules (ed.) W J Orville-Thomas (New York: John Wiley) p. 385
Ito M 1994 Large-amplitude motions of aromatic molecules as studied by supersonic jet spectroscopy.Dynamics of excited molecules (ed.) K Kuchitsu (Amsterdam: Elsevier Science) ch 5, p. 97
Spangler L H and Pratt D W 1995 InJet spectroscopy and molecular dynamics (eds) J M Hollas and D Phillips (London: Chapman and Hall) p. 369
Swalen J D and Costein C C 1959J. Chem. Phys. 31 1562
Brant D M, Pugmire R J, Livingston R C, Strong K A, McMurry H L and Brugger R M 1970J. Chem. Phys. 52 4424;
Ozkabak A and Goodman L 1992J. Chem. Phys. 96 5958
Kemp D and Pitzer K S 1936J. Chem. Phys. 4 749
Kemp D and Pitzer K S 1937J. Am. Chem. Soc. 59 276
Pitzer K S 1937J. Chem. Phys. 5 466, 473
Pitzer R M 1951Discuss. Faraday Soc. 10 66
Sovers O J, Kern C W, Pitzer R M and Karplus M 1968J. Chem. Phys. 49 2592
Gavezzotti A and Bertell I S 1979J. Am. Chem. Soc. 101 5142
Brunk T K and Weinhold F 1979J. Am. Chem. Soc. 101 1700
Bader R W F, Cheeseman J K, Laidig K E, Wiberg K B and Breneman C 1990J. Am. Chem. Soc. 112 6530
Goodman L, Gu H and Prophristic V 1999J. Chem. Phys. 110 4266
Prophristic V and Goodman L 2001Nature (London) 411 565
Belov S P, Yu Tretyakov M, Kleiner I and Hougan J T 1993J. Mol. Spectrosc. 160 61
Kleiner I, Hougan J T, Suenram R D, Lovas F J and Godefroid M 1991J. Mol. Spectrosc. 148 38
Kleiner I, Hougan J T, Suenram R D and Lovas F J 1992J. Mol. Spectrosc. 153 578
Hollenstein H and Winther F 1978J. Mol. Spectrosc. 71 118
Durig J R, Guirgis G and Bell S J 1989J. Phys. Chem. 93 348
Hadad C M, Foresman J B and Wiberg K B 1993J. Phys. Chem. 97 4293
Jorgensen W L and Allen L C 1971J. Am. Chem. Soc. 93 567
Munoz-Caro, C, Nino A and Moule D C 1994Theor. Chim. Acta 88 299
Goodman L, Kundu T and Leszczynski J 1995J. Am. Chem. Soc. 117 2082
Wiberg K B and Martini E 1985J. Am. Chem. Soc. 107 5035
Hehre W J, Pople J A and Devaquet J P 1976J. Am. Chem. Soc. 98 664
Hoffman R 1970Pure Appl. Chem. 24 567
Darigo A E, Pratt D W and Houk K N 1987J. Am. Chem. Soc. 109 6591
Kundu T, Goodman L and Leszczynski J 1995J. Chem. Phys. 103 1523
Goodman L, Kundu T and Leszczynski J 1996J. Phys. Chem. 100 2770
Goodman L, Leszczynski J and Kundu T 1994J. Chem. Phys. 100 1274;
Nino A, Munoz-Caro C and Moule D C 1994J. Phys. Chem. 98 1519
Goodman L, Leszczynski J and Kundu T 1993J. Am. Chem. Soc. 115 11991
Slater J C 1933J. Chem. Phys. 1 687
Nelander B 1969J. Chem. Phys. 51 469
Mitra A 1995Study of methyl torsional potential surface in acetaldehyde M Sc dissertation, Indian Inst. Technol., Bombay, Mumbai
Walker R, Richard E C and Weisshaar J C 1996J. Phys. Chem. 100 7333
Eas ALL, Liu H, LimE C, Jensen P, Dechene I, Zgierski M Z, Siebrand Wand Bunker PR 2000J. Chem. Phys. 112 167
Breen P J, Warren J A, Bernstein E R and Selmen J I 1987J. Chem. Phys. 87 1917
Kreiner W A, Rudolph H D and Tan B T 1973J. Mol. Spectrosc. 48 86
Amir-EbrahimV, Choplin A, Domaison J and Roussy G L 1981J. Mol. Spectrosc. 66 281
Liljefors T and Allinger N L 1985J. Comput. Chem. 6 478
George P, Bock C W, Stezowski J J, Hildenbrand T and Glusker J P 1988J. Phys. Chem. 92 5656
Lu K T, Weinhold F and Weisshaar J C 1995J. Chem. Phys. 102 6787
Yam S and Spangler L H 1995J. Chem. Phys. 99 3047
Siewert S S and Spangler L H 1995J. Phys. Chem. 99 9316
Takazawa K, Fuzzi M and Ito M 1993J. Chem. Phys. 95 3205
Okuyama K, Mikami N and Ito M 1985J. Phys. Chem. 89 5617
Breen P J, Warren J A and Bernstein E R 1987J. Am. Chem. Soc. 109 3453
Walker R A, Richard E C, Lu K T and Weisshaar J C 1995J. Phys. Chem. 99 12422
Breen P J, Warren J, Bernstein E and Seeman J 1987J. Chem. Phys. 87 1927
Sammeth D M, Siewert S S, Callis P R and Spangler L H 1992J. Phys. Chem. 96 5771
Yam S and Spangler L H 1992J. Chem. Phys. 96 4106
Disselkamp R, Lim H S and Bernstein E R 1992J. Chem. Phys. 97 7889
Tomer J L, Spangeler L H and Pratt D N 1988J. Am. Chem. Soc. 110 1615
Metzger B S and Spangler L H 1997J. Phys. Chem. 101 5431
Mizuno H, Okuyama K, Ebata T and Ito M 1987J. Phys. Chem. 91 5589
Bandy R, Nash J and Zwier T 1991J. Chem. Phys. 95 2317
Nakai H and Kawai M 2000J. Chem. Phys. 113 2168
Pradhan B, Singh B P and Kundu T 2001Proceedings of National laser symposium (Indore, CAT) p. 309
Pradhan B, Singh B P and Kundu T (in preparation)
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Kundu, T., Pradhan, B. & Singh, B.P. Origin of methyl torsional potential barrier — An overview. J Chem Sci 114, 623–638 (2002). https://doi.org/10.1007/BF02708856
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DOI: https://doi.org/10.1007/BF02708856