1. S. Sheybani-Deloui, J. Norooz Oliaee, M. Rezaei, N. Moazzen- Ahmadi Department of Physics and Astronomy University of Calgary A.R.W. Mckellar Steacie Institute for Molecular Sciences National Research Council of Canada

2.  Objectives  Theoretical Calculations  Observed Spectra  Experimental Rotational Constants  Inter-conversion Tunneling Motion in C 2 H 2 dimer  Experimental Structure

3. N 2 O-C 2 H 2 OCS-C 2 H 2 Near parallel structure Near parallel structure C s symmetry 1 C s symmetry 2 1. M. Dehghany, Mahin Afshari, J. Norooz Oliaee, N. Moazzen-Ahmadi, A.R.W. McKellar, Chemical Physics Letters 473, 26 (2009). 2. J. Norooz Oliaee, Mahin Afshari, M. Dehghany, N. Moazzen-Ahmadi, A.R.W. McKellar, Journal of Molecular Spectroscopy 157,133 (2009).

4. J. Norooz Oliaee, A.R.W. McKellar. N. Moazzen-Ahmadi, Chemical Physics Letters, 512(2011), p.167. Second Lowest energy isomers Loose barrel Shape structures Lowest energy isomers Planar structures C s symmetry c a b d

5.  Lowest energy minima of N 2 O-(C 2 H 2 ) 2 -1496 cm -1  Observed Planar Structure  Second lowest energy minima -1414 cm -1 E/cm -1 -1496 A/MHz3142 B/MHz1075 C/MHz801 0.000002 E/cm -1 -1414 A/MHz2174 B/MHz1788 C/MHz1229 -103.8238

6. Theoretical Values: R(10,1)5.03530 (Å) R(5,1)3.29215 (Å) A(5,1,2)85.331˚ A(6,5,1)100.313˚ A(10,1,2)27.402˚ A(11,10,1)33.106˚

7. Jet Trigger 12 bit DAQ Card Timer Controller Card (CTR05) DAQ Trigger Gas Supply Ref. Gas Jet Signal IR Detectors Etalon QCL PZT Controller Function Generator Valve Controller (Iota One) Experimental Setup

8. 2232.81244(6) A”/MHz B”/MHz C”/MHz A'/MHz B'/MHz C'/MHz 9.1 Inertial defect/Amu. Å 2 0.000002 Multiplied by 2

9. 2233.0098(4) A”/MHz B”/MHz C”/MHz A'/MHz B'/MHz C'/MHz 9.2 Inertial defect/Amu. Å 2 0.000002 Multiplied by 2

10. 2163.40845(7) A”/MHz B”/MHz C”/MHz A'/MHz B'/MHz C'/MHz 8.3 Inertial defect/Amu. Å 2 0.000003 Multiplied by 2

11. Rotational Constants Experimental data (MHz) Theoretical data (MHz) Cal.-Exp. (MHz) A (N 2 O-(C 2 H 2 ) 2 )2871.42438(1)3142.08003270.65565 B (N 2 O-(C 2 H 2 ) 2 )1140.67569(0.2)1075.03097-65.64472 C (N 2 O-(C 2 H 2 ) 2 )816.45943(0.1) 800.98280-15.47663 A (N 2 O-(C 2 D 2 ) 2 )2689.66719(1.8)2937.22521247.55802 B (N 2 O-(C 2 D 2 ) 2 )1072.88785(0.1)1011.54576-61.34209 C (N 2 O-(C 2 D 2 ) 2 )767.58642(0.09)752.42088-15.16554 A ( 15 N 2 O-(C 2 H 2 ) 2 )2837.05187(5.9)3092.26268251.21081 B ( 15 N 2 O-(C 2 H 2 ) 2 )1114.90533(0.1)1067.40500-47.50033 C ( 15 N 2 O-(C 2 H 2 ) 2 )801.95108(0.2)793.50009-8.45099

12. ~33 cm -1

13. Experimental Values: B(10,1) B(5,1) A(5,1,2) A(6,5,1)? A(10,1,2) A(11,10,1)?

14. Experimental StructureTheoretical Structure B(10,1)5.035(Å) B(5,1)3.292(Å) A(5,1,2)85.331˚ A(6,5,1)?100.31˚ A(10,1,2)27.401˚ A(11,10,1)?33.106˚

15. K. H. Michaelian Natural Resources Canada, CANMET Western Research Center