Ab Initio and DFT Calculations for the Vibrational Frequencies and Barrier to Planarity of Cyclopentene and its Deuterated Isotopomers Abdulaziz Al-Saadi.

Slides:

Advertisements

Similar presentations

Synchrotron-based study of the far infrared spectrum of silacyclobutane: the ν 29 and ν 30 bands Ziqiu Chen, Cody W. van Dijk, Samantha Harder and Jennifer.

Advertisements

CHIRPED-PULSE FOURIER-TRANSFORM MICROWAVE SPECTROSCOPY OF THE PROTOTYPICAL C-H…π INTERACTION: THE BENZENE…ACETYLENE WEAKLY BOUND DIMER Nathan W. Ulrich,

VIBRATIONAL ANHARMONICITY IN ETHYLENE, METHYL FLUORIDE, AND DICHLOROMETHANE: AN EXPLORATION USING GAUSSIAN 03 NORMAN C. CRAIG, Department of Chemistry.

DFT STUDY OF SOLVENT EFFECTS ON CONFORMATIONAL EQUILIBRIA AND

CHEM 515 Spectroscopy Vibrational Spectroscopy III.

Simulating the spectrum of the water dimer in the far infrared and visible Ross E. A. Kelly, Matt J. Barber, Jonathan Tennyson Department of Physics and.

Infrared Spectroscopy of Doubly-Charged Metal-Water Complexes

Infrared spectroscopy of Li(methylamine) n (NH 3 ) m clusters Nitika Bhalla, Luigi Varriale, Nicola Tonge and Andrew Ellis Department of Chemistry University.

Rotational Spectra of Methylene Cyclobutane and Argon-Methylene Cyclobutane Wei Lin, Jovan Gayle Wallace Pringle, Stewart E. Novick Department of Chemistry.

Dispersed Fluorescence Spectroscopy of Jet-Cooled p-Aminotoluene 61 st OSU ISMS 2006 Partha Biswas, a) Montu Kumar Hazra a) and Tapas Chakraborty a,b)

DENNIS J. CLOUTHIER, ROBERT GRIMMINGER, and BING JIN, Department of Chemistry, University.

1 Li Xiao and Lichang Wang Department of Chemistry & Biochemistry Southern Illinois University Carbondale The Structure Effect of Pt Clusters on the Vibrational.

Anion Photoelectron Spectroscopic Studies of NbC 4 H 4 ‾, NbC 6 H 6 ‾ and NbC 6 H 4 ‾ Products of Flow Tube Reactions of Niobium with Butadiene Melissa.

Aloke Das Indian Institute of Science Education and Research, Pune Mimicking trimeric interactions in the aromatic side chains of the proteins: A gas phase.

Laboratory of Molecular Spectroscopy & Nano Materials, Pusan National University, Republic of Korea Spectroscopic Identification of New Aromatic Molecular.

INFRARED-ACTIVE VIBRON BANDS ASSOCIATED WITH RARE GAS SUBSTITUTIONAL IMPURITIES IN SOLID HYDROGEN PAUL L. RASTON and DAVID T. ANDERSON, Department of Chemistry,

Electronic spectroscopy of Li(NH 3 ) 4 Nitika Bhalla, Luigi Varriale, Nicola Tonge and Andrew Ellis Department of Chemistry University of Leicester UK.

1 The Structure and Ring Puckering Barrier of Cyclobutane: A Theoretical Study Sotiris S. Xantheas, Thomas A. Blake Environmental Molecular Sciences Laboratory.

ROTATIONALLY RESOLVED ELECTRONIC SPECTRA OF SECONDARY ALKOXY RADICALS 06/22/10 JINJUN LIU AND TERRY A. MILLER Laser Spectroscopy Facility Department of.

Detection of the H 2 PS free radical by laser spectroscopy Robert Grimminger *, Dennis J. Clouthier *, and Riccardo Tarroni † * Department of Chemistry,

Meng Huang and Anne B. McCoy Department of Chemistry and Biochemistry The Ohio State Univerisity.

Microwave Spectrum of Hydrogen Bonded Hexafluoroisopropanol  water Complex Abhishek Shahi Prof. E. Arunan Group Department of Inorganic and Physical.

1 Fourier transform microwave and infrared study of silacyclobutane Cody van Dijk, Samantha van Nest, Ziqiu Chen and Jennifer van Wijngaarden Department.

Praveenkumar Boopalachandran, 1 Jaan Laane 1 and Norman C. Craig 2 1 Department of Chemistry, Texas A&M University, College Station, Texas Department.

High-resolution threshold photoionization and photoelectron spectroscopy of propene and 2-butyne Julie M. Michaud, Konstantina Vasilatou and Frédéric Merkt.

Andrew Durgan Department of Chemistry & Biochemistry Gonzaga University September 24, 2009.

Infrared Photodissociation Spectroscopy of Aluminum Benzene Cation Complexes Nicki Reishus, Biswajit Bandyopadhyay and Michael A. Duncan Department of.

Important concepts in IR spectroscopy

Vibrational, Electronic, and Fluorescence Spectra and Ab Initio Calculations of 1,4-Benzodioxan (14BZD) Juan Yang, Martin Wagner, Daniel Autrey, and Jaan.

Electronic Spectroscopy of DHPH Revisited: Potential Energy Surfaces along Different Low Frequency Coordinates Leonardo Alvarez-Valtierra and David W.

SPECTROSCOPY OF AND PHOTOINDUCED ELECTRON TRANSFER IN THE COMPLEXES OF C 2 H 4 WITH I AND I 2 Lisa George, Aimable Kalume, and Scott A. Reid Department.

Daniel Weidinger 1, Cassidy Houchins 2 and Jeffrey C. Owrutsky 3 (1)National Research Council Postdoctoral Researcher (2)SRA International (3)Chemistry.

Fundamentals and Torsional Combination Bands of Two Isomers of the OCS-CO 2 Complex J. Norooz Oliaee, M. Dehghany, F. Mivehvar, Mahin Afshari, N. Moazzen-Ahmadi.

DIMETHYL -ETHER THREE DIMENTIONAL SPECTRA M. VILLA U.A.M.-I. (México) and M. L. SENENT C.S.I.C. (Spain)

Rotationally-Resolved Spectroscopy of the Bending Modes of Deuterated Water Dimer JACOB T. STEWART AND BENJAMIN J. MCCALL DEPARTMENT OF CHEMISTRY, UNIVERSITY.

Equilibrium Molecular Structure and Spectroscopic Parameters of Methyl Carbamate J. Demaison, A. G. Császár, V. Szalay, I. Kleiner, H. Møllendal.

THE ANALYSIS OF HIGH RESOLUTION SPECTRA OF ASYMMETRICALLY DEUTERATED METHOXY RADICALS CH 2 DO AND CHD 2 O (RI09) MING-WEI CHEN 1, JINJUN LIU 2, DMITRY.

Int. Symp. Molecular Spectroscopy Ohio State Univ., 2005 The Ground State Four Dimensional Morphed Potentials of HBr and HI Dimers Collaborator: J. W.

E. Gonzalez, C.M.L. Rittby, and W.R.M. Graham

Effective C 2v Symmetry in the Dimethyl Ether–Acetylene Dimer Sean A. Peebles, Josh J. Newby, Michal M. Serafin, and Rebecca A. Peebles Department of Chemistry,

Study of the CH 2 I + O 2 Reaction with a Step-scan Fourier-transform Infrared Absorption Spectrometer: Spectra of the Criegee Intermediate CH 2 OO and.

Sandra C. Balanga, Maria Benavides, PhD Department of Natural Sciences Abstract : This study focuses on determining.

György Tarczay, Gábor Magyarfalvi

Infrared Observation of the ν 1 (  ) and ν 2 (  ) Stretching Modes of Linear GeC 3 E. Gonzalez, C.M.L. Rittby, and W.R.M. Graham Department of Physics.

Infrared Photodissociation Spectroscopy of Aluminum Benzene Cation Complexes Nicki Reishus, Biswajit Bandyopadhyay and Michael A. Duncan Department of.

The ethyl radical in superfluid helium nanodroplets: Rovibrational spectroscopy and ab initio calculations 1 Department of Chemistry, University of Georgia.

Anomalous CH Stretch Intensity Effects in Halomethyl Radicals: “Charge-Sloshing” vs. Bond- Dipole Contributions to IR Transition Moments E.S. Whitney,

Rotational Spectra Of Cyclopropylmethyl Germane And Cyclopropylmethyl Silane: Dipole Moment And Barrier To Methyl Group Rotation Rebecca A. Peebles, Sean.

Itaru KURUSU, Reona YAGI, Yasutoshi KASAHARA, Haruki ISHIKAWA Department of Chemistry, School of Science, Kitasato University ULTRAVIOLET AND INFRARED.

1 The r 0 Structural Parameters of Equatorial Bromocyclobutane, Conformational Stability from Temperature Dependent Infrared Spectra of Xenon Solutions,

O. PIRALI, J. OOMENS, N. POLFER FOM Rijnhuizen, 3439MN Nieuwegein, The Netherlands Y. UENO, R. MABOUDIAN Department of Chemical Engineering, U.C. Berkeley,

Study of Solvent Dependent Excited State Energy Flow in DANS Probed with Ultrafast fs/ps-CARS Mikhail N. Slipchenko, Benjamin D. Prince, Beth M. Prince,

Laser spectroscopy of a halocarbocation: CH 2 I + Chong Tao, Calvin Mukarakate, and Scott A. Reid Department of Chemistry, Marquette University 61 st International.

Actinide Metal Atom (Th and U) Reactions to Form Novel Molecules Metal-Carbon Multiple Bonds Actinide Metal Hydrides Lester Andrews, Chemistry Department,

High Resolution Electronic Spectroscopy of 9-Fluorenemethanol (9FM) in the Gas Phase Diane M. Mitchell, James A.J. Fitzpatrick and David W. Pratt Department.

Microwave Spectroscopic Investigations of the Xe-H 2 O and Xe-(H 2 O) 2 van der Waals Complexes Qing Wen and Wolfgang Jäger Department of Chemistry, University.

CONFORMATION-SPECIFIC ELECTRONIC SPECTROSCOPY OF JET-COOLED 5-PHENYL-1-PENTENE NATHAN R. PILLSBURY, TALITHA M. SELBY, AND TIMOTHY S. ZWIER, Department.

These are at 326 cm -1 and 620 cm -1 which are respectively assigned to the ν(C1N1N2) and imidazole ring deformation mode. The phenyl ring breathing mode.

Infrared Spectroscopy of Protonated Methanol-Water Clusters -Effects of Heteromolecules in Hydrogen Bond Network- Ken-ichiro Suhara, Asuka Fujii and Naohiko.

FTIR and DFT Study of the Vibrational Spectrum of SiC 5 Trapped in Solid Ar T.H. Le, C.M.L. Rittby and W.R.M. Graham Department of Physics and Astronomy.

Rotational spectra of C2D4-H2S, C2D4-D2S, C2D4-HDS and 13CH2CH2-H2S complexes: Molecular symmetry group analysis Mausumi Goswami and E. Arunan Inorganic.

Computational Chemistry:

60th International Symposium on Molecular Spectroscopy

Vibrational spectral investigations of Glyoxime

GOAL: a quantitative interpretation of the vibrational spectra

M. Rezaei, J. George, L. Welbanks, and N. Moazzen-Ahmadi

Single Vibronic Level (SVL) emission spectroscopy of CHBr: Vibrational structure of the X1A and a3A  states.

ADINA INSTITUTE OF SCIENCE AND TECHNOLOGY

Ultraviolet Cavity Ringdown Spectra of 2-Cyclohexen-1-one and its Inversion Potential Energy Function Mohamed Rishard, Emily Giles, Jaeboom Choo, Daniel.

VIBRATIONAL SPECTRA AND ASSIGNMENTS OF FUNDAMENTALS OF 1,1-DIFLUOROCYCLOPROPANE AND ITS d2 AND d4 ISOTOPOMERS and Equilibrium Structure NORMAN C. CRAIG,Department.

Presentation transcript:

Ab Initio and DFT Calculations for the Vibrational Frequencies and Barrier to Planarity of Cyclopentene and its Deuterated Isotopomers Abdulaziz Al-Saadi and Jaan Laane Department of Chemistry Texas A&M University College Station, Texas

2 Cyclopentene-d 0, -d 1, -d 4, and -d 8 We had previously determined the IR and Raman spectra, calculated the 1D and 2D PES, and ran a MM investigation of the four molecules. Cyclopentene exists in the puckered form with a puckering angle of 26º based on spectroscopic determination. Planar Puckered C 2v CsCs CsCs C1C1 Symmetry Species11A 1 + 6A 2 + 9B 1 + 7B 2 20A ’ + 13A ” φ = 26 o C2C2 z x (1) Villarreal, J. R.; Laane, J.; Bush, S. F.; Harris, W. C., Spectrochem. Acta, 1979, 35A, 331. (2) Laane, J., Lord, R. C., J. Chem. Phys., 1967, 47, (3) Rosas, R. L., Cooper, C., and Laane, J., J. Chem. Phys., 1990, 94,

3 Cyclopentene-d 0, -d 1, -d 4, and -d 8 In this work we: Optimized the structure cyclopentene-d 0 in the planar and puckered conformations using the MP2 and DFT theories with the G** and cc-pVTZ basis sets. Predicted the zero-point energy, puckering barrier and puckering angle of cyclopentene-d 0. Calculated the vibrational frequencies of the two structures for cyclopentene-d 0, -d 1, -d 4, and -d 8 molecules from density functional theory and then compared the assignments with the experimental ones. Made several vibrational reassignments for the d 0, d 1, d 4 and d 8 isotopomers. Obtained the liquid IR and Raman spectra for cyclopentene-d 0 to help confirm our reassignments.

4 Calculated Structure of Cyclopentene-d 0 C 2v CsCs

5 Experimental and Calculated Puckering Barrier and Puckering Angle Expt. Calculated MP2/DZ 1 MP2/ G** MP2/ cc-pVTZ DFT-B3LYP/ G** DFT-B3LYP/ cc-pVTZ τ 2.3  3.0  3.1  2.3  2.1  φ 28.8  GED  27.1  26.1  20.0  19.3  22.2  MW 3 26  Far-IR 4 Puckering Barrier (cm -1 ) H τ φ (1) Allen, W. D.; Csaszar, A. G.; Horner, D. A., J. Am. Chem. Soc., 1992, 114, (2) Davis, M. I.; Mueche, T. W.; J. Phys. Chem., 1970, 74, (3) Rathjens, G. W., J. Chem. Phys., 1962, 36, (4) Laane, J., Lord, R. C., J. Chem. Phys., 1967, 47, 4941.

6 Calculated Ring-Puckering & Ring-Twisting Frequencies in Cyclopentene-d 0, -d 1, -d 4, and -d 8 Expt. puck 1 twist 2 Calculated (Scaled) B3LYP/ G**B3LYP/cc-pVTZ IRIR Rampucktwistpucktwist d0d d1d d4d d8d Ring Twisting ( 17 )Ring Puckering ( 33 ) (1) Laane, J., Lord, R. C., J. Chem. Phys., 1967, 47, (2) Villarreal, J. R.; Laane, J.; Bush, S. F.; Harris, W. C., Spectrochem. Acta, 1979, 35A, 331.

7 Assignments Observed * Calculated (Scaled) at DFT-B3LYP Vapor IR 1 Vapor Raman 1 Liquid IR 2 CsCs C 2v G**cc-pVTZ G**cc-pVTZ A1A1 1 CH sym. str s3070 (140)3057(23,187)3068(23,186)3064(23,187)3066(24,187) 2 β-CH 2 sym. str s2900 (7)2897 m2935(55,183)2937(56,173)2939(46,168)2942(44,154) 3 α-CH 2 sym. str. (i.p.) 2860 s2857 (153)2848 vs2879(31,240)2881(31,218)2913(1,282)2896(2,267) 4 C=C str m1617 (91)1610 m1640(3,250)1649(2,143)1650(4,206)1657(3,125) 5 β-CH 2 def vw1473 (16)1479(3,43)1481(2,57)1485(4,41)1486(3,56) 6 α-CH 2 def. (i.p.) 1445 m1448 (23)1463 m1454(2,136)1459(1,143)1459(0,129)1459(0,138) 7 α-CH 2 wag (i.p.) 1290 m1302 (10)1295 m1300(1,21)1303(1,21)1303(1,18)1306(1,19) 8 CH in-plane bend (i.p.) 1101 w1109 (66)1108 vw1107(0,136)1111(0,129)1108(0,118)1112(0,119) 9 Ring str. 962 w 962 (55) 963 m954(1,57)955(1,50)957(1,35)958(1,31) 10 Ring breathing 900 m 896 (100) 903 s885(1,100)885(0,100)875(0,100)875(0,100) 11 Ring def. 608 w 600 (1) 603 m604(14,7)608(12,7)689(0,5)691(0,11) A2A2 12 α-CH 2 antisym. str. (o.p.) 2938 (54)2924(37,121)2924(37,120)2913(0,188)2913(0,184) 13 α-CH 2 twist (o.p.) 1209 (2)1279 w1282(2,7)1287(2,7)1249(0,23)1253(0,25) 14 β-CH 2 twist 1134 (1)1131(2,0)1132(1,0)1139(0,2)1140(0,3) 15 CH out-of-plane bend (o.p.) 1047 (1)955(0,7)961(0,7)958(0,10)965(0,5) 16 α-CH 2 rock (o.p.) 879 (1)872(4,7)875(4,7)889(0,4)893(0,3) 17 Ring twist 390 (2)385(0,14)387(0,21)370(0,8)374(0,11) B1B1 18 CH antisym. str s3062 (18)3055 s3043(8,87)3044(8,87)3040(8,88)3043(8,87) 19 α-CH 2 sym. str. (o.p.) 2873 s2882 (57)2866 s2880(55,82)2883(54,75)2895(97,40)2896(95,33) 20 α-CH 2 def. (o.p.) 1438 vw1444 m1460(3,71)1463(2,71)1464(3,53)1466(2,56) 21 CH in-plane bend (o.p.) 1353 m1354 (2)1350 vw1351(2,0)1358(2,0)1352(2,1)1360(1,3) 22 α-CH 2 wag (o.p.) 1268 m1297 (5)1291(0,7)1296(0,7)1287(2,0)1295(1,0) 23 β-CH 2 wag 1128 w1167 vw1201(0,36)1205(0,29)1246(0,25)1247(1,19) 24 Ring str w1030 (1)1025 w1014(2,36)1015(2,29)1018(2,24)1071(2,18) 25 Ring str. 933 w 933 (2)899(8,0)900(7,0)891(12,7)891(11,5) 26 Ring def. 695 s 690 (1) 770 vw768(0,7)771(0,7)773(1,6)776(1,4) B2B2 27 α-CH 2 antisym. str. (i.p.) 2963 s2973 (39)2949 s2969(44,87)2970(43,84)2972(43,74)2973(43,74) 28 β-CH 2 antisym. str s2929 (30)2925 s2916(5,66)2918(4,61)2910(33,3)2910(35,2) 29 α-CH 2 twist (i.p.) 1207 m1205 m1207(2,50)1209(2,43)1201(2,40)1204(2,38) 30 α-CH 2 rock (i.p.) 1047 s1047 (1)1043 s1047(8,7)1052(7,7)1042(9,2)1048(8,3) 31 CH out-of-plane bend (i.p.) 695 s 696 s699(39,14)702(31,21)660(46,8)663(37,16) 32 β-CH 2 rock 593 m 803 vw802(1,7)803(1,7)766(8,9)770(7,11) 33 Ring puckering (0,14)130(0,7) Experimental and Calculated Frequencies for Cyclopentene (1) Villarreal, J. R.; Laane, J.; Bush, S. F.; Harris, W. C., Spectrochem. Acta, 1979, 35A, 331. (2) This work. * Values shown in italic are from condensed-phase experiments.

8 Vibrational Reassignments for Cyclopentene Assignments Observed * Calculated (Scaled) at DFT-B3LYP Vapor IR 1 Vapor Raman 1 Liquid IR 2 CsCs C 2v G**cc-pVTZ G**cc-pVTZ A1A1 1 CH sym. str s3070 (140)3057(23,187)3068(23,186)3064(23,187)3066(24,187) 2 β-CH 2 sym. str s2900 (7)2897 m2935(55,183)2937(56,173)2939(46,168)2942(44,154) 3 α-CH 2 sym. str. (i.p.) 2860 s2857 (153)2848 vs2879(31,240)2881(31,218)2913(1,282)2896(2,267) 4 C=C str m1617 (91)1610 m1640(3,250)1649(2,143)1650(4,206)1657(3,125) 5 β-CH 2 def vw1473 (16)1479(3,43)1481(2,57)1485(4,41)1486(3,56) 6 α-CH 2 def. (i.p.) 1445 m1448 (23)1463 m1454(2,136)1459(1,143)1459(0,129)1459(0,138) 7 α-CH 2 wag (i.p.) 1290 m1302 (10)1295 m1300(1,21)1303(1,21)1303(1,18)1306(1,19) 8 CH in-plane bend (i.p.) 1101 w1109 (66)1108 vw1107(0,136)1111(0,129)1108(0,118)1112(0,119) 9 Ring str. 962 w 962 (55) 963 m954(1,57)955(1,50)957(1,35)958(1,31) 10 Ring breathing 900 m 896 (100) 903 s885(1,100)885(0,100)875(0,100)875(0,100) 11 Ring def. 593 m 600 (1) 603 m604(14,7)608(12,7)689(0,5)691(0,11) A2A2 12 α-CH 2 antisym. str. (o.p.) 2938 (54)2924(37,121)2924(37,120)2913(0,188)2913(0,184) 13 α-CH 2 twist (o.p.) 1268 m 1279 w1282(2,7)1287(2,7)1249(0,23)1253(0,25) 14 β-CH 2 twist 1128 w 1134 (1)1131(2,0)1132(1,0)1139(0,2)1140(0,3) 15 CH out-of-plane bend (o.p.) 955(0,7)961(0,7)958(0,10)965(0,5) 16 α-CH 2 rock (o.p.) 879 (1)872(4,7)875(4,7)889(0,4)893(0,3) 17 Ring twist 390 (2)385(0,14)387(0,21)370(0,8)374(0,11) B1B1 18 CH antisym. str s3062 (18)3055 s3043(8,87)3044(8,87)3040(8,88)3043(8,87) 19 α-CH 2 sym. str. (o.p.) 2873 s2882 (57)2866 s2880(55,82)2883(54,75)2895(97,40)2896(95,33) 20 α-CH 2 def. (o.p.) 1438 vw1444 m1460(3,71)1463(2,71)1464(3,53)1466(2,56) 21 CH in-plane bend (o.p.) 1353 m1354 (2)1350 vw1351(2,0)1358(2,0)1352(2,1)1360(1,3) 22 α-CH 2 wag (o.p.) 1297 (5)1291(0,7)1296(0,7)1287(2,0)1295(1,0) 23 β-CH 2 wag 1167 vw1201(0,36)1205(0,29)1246(0,25)1247(1,19) 24 Ring str w1030 (1)1025 w1014(2,36)1015(2,29)1018(2,24)1071(2,18) 25 Ring str. 933 w 933 (2)899(8,0)900(7,0)891(12,7)891(11,5) 26 Ring def. 770 vw768(0,7)771(0,7)773(1,6)776(1,4) B2B2 27 α-CH 2 antisym. str. (i.p.) 2933 s 2929 (30)2925 s2916 (5,66) 2918 (4,61) 2910 (33,3) 2910 (35,2) 28 β-CH 2 antisym. str s2973 (39)2949 s2969 (44,87) 2970 (43,84) 2972 (43,74) 2973 (43,74) 29 α-CH 2 twist (i.p.) 1207 m 1209 (2) 1205 m1207(2,50)1209(2,43)1201(2,40)1204(2,38) 30 α-CH 2 rock (i.p.) 1047 s1047 (1)1043 s1047(8,7)1052(7,7)1042(9,2)1048(8,3) 31 CH out-of-plane bend (i.p.) 695 s 690 (1) 696 s699(39,14)702(31,21)660(46,8)663(37,16) 32 β-CH 2 rock 803 vw802(1,7)803(1,7)766(8,9)770(7,11) 33 Ring puckering (0,14)130(0,7) (1) Villarreal, J. R.; Laane, J.; Bush, S. F.; Harris, W. C., Spectrochem. Acta, 1979, 35A, 331. (2) This work. * Values shown in italic are from condensed-phase experiments.

9 Vibrational Reassignments for Cyclopentene-d 8 Assignments Observed * Calculated (Scaled) at DFT-B3LYP Vapor IR 1 Vapor Raman 1 CsCs C 2v G**cc-pVTZ G**cc-pVTZ A1A1 1 CD sym. str s2305 (68)2314(9,74)2315(9,78)2313(9,74)2314(10,78) 2 β-CD 2 sym. str w2145 (100)2157(18,75)2160(18,67)2166(23,84)2168(22,77) 3 α-CD 2 sym. str. (i.p.) 2100 (136)2126(11,141)2128(10,132)2132(0,143)2135(1,134) 4 C=C str m1577 (50)1591(6,205)1600(4,143)1602(6,76)1609(5,123) 5 β-CD 2 def w1113 (7)1109(1,14)1110(1,14)1110(2,13)1110(1,11) 6 α-CD 2 def. (i.p.) 1070 m1072 (2)1068(1,18)1071(1,19)1069(0,16)1072(0,18) 7 α-CD 2 wag (i.p.) 750 w 750 (7)743(1,14)744(1,13)749(1,16)750(0,14) 8 CD in-plane bend (i.p.) 853 w 850 (7)783(0,32)785(0,38)779(0,33)781(0,33) 9 Ring str vw1158 (2)1148(0,6)1149(1,4)1149(0,4)1148(0,6) 10 Ring breathing 878 m 878 (100)869(3,100)871(2,100)863(1,100)865(0,100) 11 Ring def. 682(0,4)681(0,3)643(0,5)645(0,6) A2A2 12 α-CD 2 antisym. str. (o.p.) 2202 (15)2191(7,79)2190(7,79)2185(0,98)2186(0.96) 13 α-CD 2 twist (o.p.) 868 w 860 (5)887(2,18)890(1,19)888(0,16)891(0,16) 14 β-CD 2 twist 921 w 930 (1)926(0,5)929(0,4)926(0,4)930(0,2) 15 CD out-of-plane bend (o.p.) 724 m 720 (6)725(2,5)728(1,3)730(0,4)733(0,4) 16 α-CD 2 rock (o.p.) (0,0)661(0,0)670(0,0)673(0,0) 17 Ring twist 317 (2)318(0,6)320(2,9)305(0,4)308(0,7) B1B1 18 CD antisym. str m2268 (15)2268(3,44)2270(3,44)2267(3,44)2268(3,44) 19 α-CD 2 sym. str. (o.p.) 2138 m2132 (20)2126(37,29)2128(38,24)2131(47,24)2133(46,19) 20 α-CD 2 def. (o.p.) 1062 m1060(2,14)1062(2,14)1058(2,11)1059(1,9) 21 CD in-plane bend (o.p.) 709 w (7,5)707(6,2)705(9,2)706(8,2) 22 α-CD 2 wag (o.p.) 1024 vw1020(1,0)1027(1,0)1023(1,0)1029(1,0) 23 β-CD 2 wag 790 (7)786(0,23)788(0,20)804(0,19)804(0,14) 24 Ring str. 1124(1,4)1122(1,3)1114(1,5)1113(1,6) 25 Ring str. 1191(0,9)1195(0,10)1195(1,9)1198(1,9) 26 Ring def. 754(1,1)757(1,0)758(1,1)760(1,3) B2B2 27 α-CD 2 antisym. str. (i.p.) 2200 s2202 (15)2193(22,34)2192(23,31)2185(24,3)2186(24,2) 28 β-CD 2 antisym. str s2235 (30)2229(22,41)2230(22,40)2232(20,36)2233(20,37) 29 α-CD 2 twist (i.p.) 849 s848(6,27)852(5,29)854(9,9)857(8,9) 30 α-CD 2 rock (i.p.) 954 w 950 (1)951(0,10)954(0,8)939(0,7)943(0,5) 31 CD out-of-plane bend (i.p.) 465 s 460 (1)460(16,5)464(13,3)481(24,3)483(19,6) 32 β-CD 2 rock 543 s 550 (1)546(13,4)549(10,8)571(5,3)574(4,4) 33 Ring puckering (0,3)103(0,1) (1) Villarreal, J. R.; Laane, J.; Bush, S. F.; Harris, W. C., Spectrochem. Acta, 1979, 35A, 331. * Values shown in italic are from condensed-phase experiments.

10 Vibrational Reassignments for 1-Cyclopentene-d 1 Assignments Observed (*) Calculated (Scaled) at DFT-B3LYP Vapor IR 1 Vapor Raman 1 C1C1 CsCs G**cc-pVTZ G**cc-pVTZ A’ 1 CH str m3066 (188)3054(15,138)3056(16,138)3051(15,139)3054(16,139) 2 β-CH 2 sym. str s2904 (122)2935(53,188)2937(54,178)2939(45,172)2943(43,157) 3 α-CH 2 sym. str s2879 (105)2880(54,80)2882(53,74)2895(25,225)2897(12,246) 4 α-CH 2 sym. str 2859 s2859 (224)2879(32,242)2881(31,220)2895(73,99)2896(85,57) 5 =C-D str m2290 (37)2291(6,54)2293(7,55)2288(6,54)2291(7,56) 6 C=C str m1597 (79)1619(4,270)1628(3,177)1628(5,229)1637(4,153) 7 β-CH 2 def m1472 (22)1479(3,42)1481(2,62)1484(4,41)1486(3,66) 8 α-CH 2 def m1448 (32)1461(3,76)1464(2,77)1463(3,53)1466(2,60) 9 α-CH 2 def w1455(2,136)1458(1,154)1455(0,124)1459(0,153) 10 CH in-plane bend 1261 m1257 (3)1254(1,21)1263(1,15)1260(1,16)1266(1,14) 11 α-CH 2 wag 1300 w1298 (10)1299(1,13)1303(1,17)1302(1,12)1305(1,13) 12 α-CH 2 wag 1322 s1327 (5)1324(2,4)1329(2,6)1325(2,4)1330(2,9) 13 β-CH 2 wag 1116 w1121 (1)1286(2,11)1288(2,14)1240(0,31)1242(0,21) 14 Ring str m1029 (8)1019(3,39)1020(3,38)1023(3,29)1023(3,31) 15 CD in-plane bend 988 w 978 (65)969(1,86)971(2,85)965(2,76)967(2,64) 16 Ring str. 966 w 952 (33)945(2,49)946(2,38)950(2,35)950(1,33) 17 Ring breathing 893 w 899 (100)886(2,100)886(2,100)876(1,100)877(1,100) 18 Ring str. 750 w 750 (1)745(3,6)747(3,15)748(3,12)751(3,13) 19 Ring def. 698 w 708 (8)772(1,7)774(1,8)797(3,11)800(3,10) 20 Ring def. 634 s 630 (1)638(6,5)642(4,6)680(0,5)683(0,6) A” 21 α-CH 2 antisym. str s2939 (126)2925(38,118)2925(38,117)2913(0,188)2913(0,184) 22 α-CH 2 antisym. str s2924 (126)2917(6,66)2918(4,61)2911(3,33)2910(35,2) 23 β-CH 2 antisym. str s2969 (60)2969(44,87)2969(43,84)2972(43,74)2973(43,74) 24 α-CH 2 twist 1211 s1202 (2)1206(2,46)1208(2,43)1200(1,40)1203(1,41) 25 α-CH 2 twist 1137 w (2,1)1133(1,2)1139(0,2)1140(0,3) 26 β-CH 2 twist 1207 w1196(0,45)1199(0,38)1249(0,22)1253(0,27) 27 α-CH 2 rock 1044 s (6,5)1048(6,5)1038(7,2)1044(6,5) 28 CH out-of-plane bend 897(2,15)902(2,17)910(1,18)915(1,13) 29 α-CH 2 rock 855 s 855 (1)860(4,3)864(3,18)861(5,4)866(4,10) 30 β-CH 2 rock 812(3,4)813(3,6)744(0,1)747(0,4) 31 CD out-of-plane bend 565 s 565 (1)563(30,7)567(25,15)578(37,7)579(30,12) 32 Ring twist 369 w 369 (3)370(0,5)372(0,10)355(0,5)359(0,12) 33 Ring puckering (0,3)129(0,4) (1) Villarreal, J. R.; Laane, J.; Bush, S. F.; Harris, W. C., Spectrochem. Acta, 1979, 35A, 331. * Values shown in italic are from condensed-phase experiments.

11 Assignments Observed * Calculated (Scaled) at DFT-B3LYP Vapor IR 1 Vapor Raman 1 C1C1 CsCs G**cc-pVTZ G**cc-pVTZ A’ 1 CD str m2313 (13)2314(10,67)2315(11,71)2312(10,68)2314(11,72) 2 β-CH 2 sym. str s2941 (20)2933(52,165)2934(52,156)2938(43,146)2941(41,134) 3 α-CD 2 sym. str s2100 (51)2127(24,95)2128(24,87)2134(25,97)2135(24,89) 4 α-CH 2 sym. str 2854 s2861 (46)2879(41,167)2882(41,152)2895(49,167)2897(48,156) 5 =C-D str m2265 (5)2268(3,45)2270(3,44)2266(3,45)2268(3,44) 6 C=C str m1580 (51)1595(4,195)1604(4,141)1605(6,191)1613(5,132) 7 β-CH 2 def m1467 (4)1474(3,23)1477(1,27)1480(3,22)1483(2,30) 8 α-CH 2 def m1452 (7)1457(2,72)1459(1,82)1458(1,74)1461(1,77) 9 α-CD 2 def vw1085 (4)1081(0,18)1084(0,20)1082(0,17)1085(0,22) 10 CD in-plane bend 800 w 802 (3)796(0,27)798(0,28)792(0,28)793(0,32) 11 α-CH 2 wag 1286 w1290 (1)1284(1,9)1286(1,10)1270(1,13)1272(1,18) 12 α-CD 2 wag 821 m 825 (7)813(1,18)815(1,22)822(1,30)823(1,27) 13 β-CH 2 wag 1027 w1309(2,4)1314(1,8)1310(2,2)1315(1,2) 14 Ring str m1100 (1)1101(3,8)1104(2,6)1099(3,8)1102(2,8) 15 CD in-plane bend 715 vw (2,3)715(2,4)716(7,4)719(7,4) 16 Ring str w1151(0,10)1153(0,7)1164(1,9)1167(1,9) 17 Ring breathing 910 m 910 (100)901(1,100)903(1,100)894(1,100)897(1,100) 18 Ring str. 985 vw 985 (2)973(0,23)974(0,20)979(0,17)978(0,14) 19 Ring def. 725 w 726 (1)767(1,6)769(1,9)769(2,4)771(2,3) 20 Ring def. 604 m 604 (1)603(4,3)607(4,5)661(0,5)664(0,4) 599 s A” 21 α-CH 2 antisym. str s2905 (20)2919(18,78)2920(17,74)2912(17,92)2913(18,90) 22 α-CD 2 antisym. str s2194 (10)2192(16,55)2191(16,53)2187(15,53)2187(15,51) 23 β-CH 2 antisym. str s2969 (30)2967(37,87)2969(36,84)2970(33,71)2971(33,72) 24 α-CH 2 twist 1163 vw1160 (1)1163(2,16)1166(1,15)1160(0,11)1162(0,14) 25 α-CD 2 twist 872 s 875 (4)872(4,20)875(3,24)874(4,13)878(3,11) 26 β-CH 2 twist (1)1226(0,13)1229(0,15)1236(0,22)1240(0,19) 27 α-CH 2 rock 1041 s1045 (1)1038(2,8)1042(2,4)1031(1,4)1037(1,3) 28 CD out-of-plane bend 735 w 733 (1)733(3,8)736(3,4)723(1,4)729(1,3) 29 α-CD 2 rock 703(2,1)706(2,2)666(1,5)669(0,1) 30 β-CH 2 rock 858 m 860 (3)848(1,4)849(1,8)841(0,3)844(0,2) 31 CD out-of-plane bend 502 s 500 (1)502(28,2)506(23,8)511(31,4)514(26,12) 32 Ring twist 337 w 338 (2)337(0,4)338(0,6)323(0,3)327(0,7) 33 Ring puckering (0,3)120(0,2) Vibrational Reassignments for 1,2,3,3-Cyclopentene-d 4 (1) Villarreal, J. R.; Laane, J.; Bush, S. F.; Harris, W. C., Spectrochem. Acta, 1979, 35A, 331. * Values shown in italic are from condensed-phase experiments.

12 Numbers of Revised Assignments in Cyclopentene-d 0, -d 1, -d 4, and -d 8 # of Vibrations Reassigned Cyclopentene-d 0 5 Cyclopentene-d 1 7 Cyclopentene-d 4 16 Cyclopentene-d 8 14

13 Experimental (Liquid-phase) and Calculated Infrared Spectra of Cyclopentene 5x 4x

14 Experimental (Liquid-phase) and Calculated Raman Spectra of Cyclopentene 10x5x

15 Conclusions Conformational structures and vibrational frequencies of cyclopentene and its deuterated isotopomers were studied with ab initio calculations, and the results were compared with previously reported experimental results. The barrier to planarity predicted by the MP2 theory (247 cm -1 ) agrees very well with our previously far-IR data (233 cm -1 ). The DFT barrier (42 cm -1 ), however, was predicted to be considerably low. DFT calculated frequencies using the G** and cc-pVTZ basis sets agree very well with experimental frequencies (even though the calculated band intensities are not as good) and help in reassigning some vibrational modes in the four molecules. The MP2 method gives a more reliable prediction of the calculated energies and structures while the DFT method predicts the frequencies very well.

16 Acknowledgments The National Science Foundation. The Robert A. Welch Foundation. The Texas Advance Research Program.

17 Calculated Structure of Cyclopentene-d 0 C 2v CsCs

18 Assignments Observed 1 Calculated (Scaled) at DFT-B3LYP Comments from Calculation Vapor IR * Vapor Raman * CsCs C 2v G**cc-pVTZ G**cc-pVTZ A1A1 1 CD sym. str s2305 (68)2314(9,74)2315(9,78)2313(9,74)2314(10,78) 2 β-CD 2 sym. str w2145 (100)2157(18,75)2160(18,67)2166(23,84)2168(22,77) 3 α-CD 2 sym. str. (i.p.) 2100 (136)2126(11,141)2128(10,132)2132(0,143)2135(1,134) 4 C=C str m1577 (50)1591(6,205)1600(4,143)1602(6,76)1609(5,123) 5 β-CD 2 def w1113 (7)1109(1,14)1110(1,14)1110(2,13)1110(1,11) 6 α-CD 2 def. (i.p.) 1070 m1072 (2)1068(1,18)1071(1,19)1069(0,16)1072(0,18) 7 α-CD 2 wag (i.p.) 921 w 930 (1)926(0,5)929(0,4)926(0,4)930(0,2) 14 8 CD in-plane bend (i.p.) 853 w 850 (7)783(0,32)785(0,38)779(0,33)781(0,33) 9 Ring str. 750 w 750 (7)743(1,14)744(1,13)749(1,16)750(0,14) 7 10 Ring breathing 878 m 878 (100)869(3,100)871(2,100)863(1,100)865(0,100) 11 Ring def. 574 w ?682(0,4)681(0,3)643(0,5)645(0,6) A2A2 12 α-CD 2 antisym. str. (o.p.) 2202 (15)2191(7,79)2190(7,79)2185(0,98)2186(0.96) 13 α-CD 2 twist (o.p.) 790 (7)786(0,23)788(0,20)804(0,19)804(0,14) β-CD 2 twist 1124(1,4)1122(1,3)1114(1,5)1113(1,6) CD out-of-plane bend (o.p.) 754(1,1)757(1,0)758(1,1)760(1,3) α-CD 2 rock (o.p.) (0,0)661(0,0)670(0,0)673(0,0) 17 Ring twist 317 (2)318(0,6)320(2,9)305(0,4)308(0,7) B1B1 18 CD antisym. str m2268 (15) 2268(3,44)2270(3,44)2267(3,44)2268(3,44) 19 α-CD 2 sym. str. (o.p.) 2138 m2132 (20) 2126(37,29)2128(38,24)2131(47,24)2133(46,19) 20 α-CD 2 def. (o.p.) 1062 m 1060(2,14)1062(2,14)1058(2,11)1059(1,9) 21 CD in-plane bend (o.p.) 1150 vw1158 (2) 1148(0,6)1149(1,4)1149(0,4)1148(0,6) 9 22 α-CD 2 wag (o.p.) 954 w 950 (1) 951(0,10)954(0,8)939(0,7)943(0,5) β-CD 2 wag 868 w 860 (5) 887(2,18)890(1,19)888(0,16)891(0,16) Ring str vw 1020(1,0)1027(1,0)1023(1,0)1029(1,0) 25 Ring str. 724 m 720 (6) 725(2,5)728(1,3)730(0,4)733(0,4) Ring def. 709 w (7,5)707(6,2)705(9,2)706(8,2) 21 B2B2 27 α-CD 2 antisym. str. (i.p.) 2230 s2235 (30) 2229(22,41)2230(22,40)2232(20,36)2233(20,37) β-CD 2 antisym. str s2202 (15) 2193(22,34)2192(23,31)2185(24,3)2186(24,2) α-CD 2 twist (i.p.) 878 m (0,9)1195(0,10)1195(1,9)1198(1,9) α-CD 2 rock (i.p.) 849 s 848(6,27)852(5,29)854(9,9)857(8,9) CD out-of-plane bend (i.p.) 543 s 550 (1) 546(13,4)549(10,8)571(5,3)574(4,4) β-CD 2 rock 465 s 460 (1) 460(16,5)464(13,3)481(24,3)483(19,6) Ring puckering (0,3)103(0,1)---- (1) Villarreal, J. R.; Laane, J.; Bush, S. F.; Harris, W. C., Spectrochem. Acta, 1979, 35A, 331. * Values shown in italic are from condensed-phase experiments. Experimental and Calculated Frequencies for Cyclopentene-d 8