68 th OSU International Symposium on Molecular Spectroscopy

68 th OSU International Symposium on Molecular Spectroscopy Conformational Stability and Structural Parameters of Isocyanocyclopentane Dattatray K. Sawant, Joshua Klaassen and James R. Durig June 19, 2013

Introduction • Previous work on cyclopentane, cyanoclopentane, halocyclopentane, methyl cyclopentane etc. • Pseudorotation of cyclopentane and cyclopentane derivatives. • Need to determine most stable conformer and structural parameters. 1. 2. 3. 4. Pitzer KS, Donath WE (1959) J Am Chem Soc 81: 3213 -3218 Ekejiuba IOC, Hallam HE (1970) Spectrochim Acta 26 A: 59 -66 Ekejiuba IOC, Hallam HE (1970) Spectrochim Acta 26 A: 67 -75 Badawi HM, Herrebout WA, Zheng C, Mohamed TA, van der Veken BJ, Durig JR (2003) Struct Chem 14: 617 -635 5. Badawi HM, Herrebout WA, Zheng C, Mohamed TA, van der Veken BJ, Durig JR (2003) J Mol Struct 645: 89 -107 6. Wertz DW, Shasky WE (1971) J Chem Phys 55: 2422

Conformers Equatorial Planar Axial Twist

Energy Calculation Method/Basis Set Ax (Cs) Eq (Cs) MP 2(full)/6 -31 G(d) 0. 8233759 472 MP 2(full)/6 -31+G(d) 0. 8413727 405 MP 2(full)/6 -311 G(d, p) 1. 0925427 496 MP 2(full)/6 -311+G(d, p) 1. 0992962 460 MP 2(full)/6 -311 G(2 d, 2 p) 1. 1713903 421 MP 2(full)/6 -311+G(2 d, 2 p) 1. 1765392 430 MP 2(full)/6 -311 G(2 df, 2 pd) 1. 2797274 398 MP 2(full)/6 -311+G(2 df, 2 pd) 1. 284195 413 MP 2(full)/aug-cc-p. VTZ 1. 2975611 372 B 3 LYP/6 -31 G(d) 1. 7639881 -18 B 3 LYP/6 -31+G(d) 1. 7768865 -35 B 3 LYP/6 -311 G(d, p) 1. 8407078 55 B 3 LYP/6 -311+G(d, p) 1. 8439202 17 B 3 LYP/6 -311 G(2 d, 2 p) 1. 8515638 16 B 3 LYP/6 -311+G(2 d, 2 p) 1. 8544227 1 B 3 LYP/6 -311 G(2 df, 2 pd) 1. 8601515 1 B 3 LYP/6 -311+G(2 df, 2 pd) 1. 8627862 -11 B 3 LYP/aug-cc-p. VTZ 1. 8712454 -15 a Energy of conformer is given as –(E+287) H. b Difference is relative to twist form and given in cm -1 Twist (C 1) 194 207 189 194 223 229 234 186 80 88 83 90 81 95 81 93 95 Planar (Cs) 2632 2579 2657 2612 2788 2763 2806 2784 2512 1760 1678 1748 1695 1668 1646 1686 1654 1652

IR Spectra A. Observed spectrum of gas B. Observed spectrum of Xe solution at -70°C C. Observed spectrum of solid D. Spectrum of a mixture E. Simulated spectrum of Eq F. Simulated spectrum of Ax

Raman Spectra A. Observed spectrum of liquid B. Simulated spectrum of a mixture C. Simulated spectrum of Eq D. Simulated spectrum of Ax

IR and Raman Spectra

Vibrational Table Axial

Vibrational Table - Equatorial

Enthalpy Calculation Equatorial Axial

Enthalpy Table

Microwave Data

Structural Parameters

Conclusion • Conformers : Equatorial, Axial, Planar and Twist • Energy Calculation : Equatorial and Axial • Most stable conformer : Axial • Enthalpy difference : 102 +/- 3 cm-1

Acknowledgement • • • Prof. James R. Durig Prof. Michael Tubergen Dr. Todor Gounev Dr. Savitha Panikar Current and Past lab members UMKC chemistry department