1. Quantum diffusion controlled chemistry: the H + NO reaction
Morgan Balabanoff
Anderson Research Group

2. Reactions in para-hydrogen matrix
pH2 allows for additional reactions with the host
Diffusion of H atom ( K)
Currently using in bi-molecular reactions
pH2
H + H2 → H2 + H

3. PES of the H+NO reaction
H + NO → 1HNO
H + NO → 3NOH
at our low temperatures we should only see HNO
U. Bozkaya, J.M. Turney, Y. Yamaguchi, H.F. Schaefer III, J. Chem. Phys. 136, (2012).

4. Outline Previous work 14NO Spectroscopy of isotopically labeled 15NO
Kinetics of H + 15NO in pH2

5. Kinetics of 14NOH and H14NO k = 1.67(3)x10-2 min-1
photolysis bar
3NOH
1HNO 14 NO
Describe reaction!
NO is reacting - decay
explain why we see NOH, didn’t expect to see
rate of NO is comparable to rates of NOH and HNO
k = 1.52(4)x10-2 min-1
k = 1.67(3)x10-2 min-1
k = 1.72(6)x10-2 min-1
M. Ruzi, D. Anderson, J. Chem. Phys. A 119, (2015).

6. PES of the H+NO reaction
H + NO → 1HNO
H + NO → 3NOH
the fact that we are even making NOH!
U. Bozkaya, J.M. Turney, Y. Yamaguchi, H.F. Schaefer III, J. Chem. Phys. 136, (2012).

7. Outline Previous work 14NO, spectroscopy and kinetics
Spectroscopy of isotopically labeled 15NO
Kinetics H + 15NO in pH2

8. Liquid helium bath cryostat
Deposit matrix at ~2.5 K
Pre-cooled H2 gas and dopant gas
Photolyze sample, 193 nm
Repeated FTIR scans

9. Spectroscopy of 15NO in pH2
multiple peaks – rotational fine struction
should see only a single peak, suggests rot

10. Rotation of 15NO in pH2 N=O pH2
should see only a single peak, suggests free rot
N=O

11. Spectroscopy of 15NOH in pH2
OH stretch
bend
fine structure “interesting”
See similar splitting patterns between the 𝜈1 and 𝜈3 peaks

12. 14NOH splittings D C E B F A G ν1 average Relative difference
ν1 average
Relative difference
ν3 average A
(1)
-0.600
(2)
-0.688 B
(1)
-0.295
(2)
-0.344 C
(3)
-0.100
(4)
-0.122 D
(5)
(1) E
(1)
0.143
(1)
0.123 F
(1)
0.351
(1)
0.334 G
(2)
0.649
(3)
0.638 D C E B A F G
quantified splittings
talk about average
roughly symmetric and same for both vibrations of NOH

13. 15NOH splittings D C E B F A G ν1 average Relative difference
ν1 average
Relative difference
ν3 average A
(3)
-0.601
(4)
-0.640 B
(1)
-0.296
(1)
-0.321 C
(1)
-0.110
(2)
-0.102 D
(2)
(1) E
(1)
0.107
(1)
0.118 F
(1)
0.300
(3)
0.319 G
(2)
0.598
(6)
0.601 D C E B A F G
see same patterns, comparable betw vibrations
work in progress!

14. Comparison of isotopomers – OH stretch15 15
15N
14N

15. Comparison of isotopomers – NOH bend15 15
14N
15N
reproducible on each vibration

16. Outline Previous work 14NO, spectroscopy and kinetics
Spectroscopy of isotopically labeled NO
Kinetics H + 15NO in pH2

17. Kinetics – Photolysis at 4.3K
photolysis bar 15
H15NO v2
talk through reaction!
similar to regular NO rxn, comparative magnitues

18. Kinetics – Photolysis at 1.8K15
H15NO v2

19. Increasing temperature gradually over ~50 minutes to 4.3K
Kinetics – Raising temperature to 4.3K 15
Increasing temperature gradually over ~50 minutes to 4.3K
H15NO v2

20. Increasing temperature gradually over ~50 minutes to 4.3K
Kinetics – Raising temperature to 4.3K
Increasing temperature gradually over ~50 minutes to 4.3K
H15NO v2 15

21. PES of the H+NO reaction
H + NO → 1HNO
H + NO → 3NOH
see what we originally expected to see
only HNO produced when annealed
U. Bozkaya, J.M. Turney, Y. Yamaguchi, H.F. Schaefer III, J. Chem. Phys. 136, (2012).

22. Comparison of rate constants
14NO average rates at 4.3K
15NO average rates at 4.3K
kNO = 1.52(0)x10-2 min-1
kNO = 1.72(1)x10-2 min-1
kNOH = 1.68(6)x10-2 min-1
kNOH = 1.89(2)x10-2 min-1
kHNO = 1.77(4)x10-2 min-1
kHNO = 1.70(2)x10-2 min-1
14NO rate at 1.8K
15NO rate at 1.8K
kNO = 0.6(1)x10-2 min-1
kNO = 0.64(4)x10-2 min-1
kNOH = 0.43(6) x10-2 min-1
kNOH = 0.5(5)x10-2 min-1
kHNO = 0.6(2)x10-2 min-1
kHNO = 0.60(9)x10-2 min-1

23. Conclusions
15NO spectra was collected to gain further information on previous work on 14NO
Both have same splitting pattern for NOH
Rate constants between isotopomers are comparable
Temperature dependence on the H + NO reaction
Displays typical “activated” chemistry

24. Future Work
Increase the concentration of HNO and NOH produced to study overtones
For kinetics studies, conduct reactions at intermediate temperature
open up more spectroscopically with higher concentrations

25. Thank you
Thank you everyone in the Anderson research group and Dr. Anderson for their help and support.
This research was funded by the Chemistry Division of the US National Science Foundation (CHE )

26. Questions?

28. Kinetic temperature dependence

29. Reaction of H + NO Because NO freely rotates, we see both products pH2
NOH
pH2

30. Kinetics – Photolysis at 4.3K