First High Resolution Infrared Spectra of 2-13C-Propane Analyses of the ν26(B2) C-Type and ν9(A1) B-Type Bands Stephen J. Daunt, Robert Grzywacz Dept. Physics & Astronomy, The University of Tennessee, Knoxville, TN Walter J. Lafferty Optical Technology Division, NIST, Gaithersburg, MD Jean-Marie Flaud Universités Paris Est Créteil et Paris Diderot, LISA, Créteil, France Brant Billinghurst Canadian Light Source, University of Saskatchewan, Saskatoon, SK, Canada

How This All Started: Voyager IRIS Spectra of Titan Don Jennings/GSFC (UT PhD Alum) This work continued via Cassini CIRS data also

Donald’s Nicolet Data

Kitt Peak FT-IR Spectra

TDL (UTK & GSFC) & FTS (KPNO)

Assigning Transitions

39th ISMS (1984)

Propane Atlas (1988)

Typical Atlas Page: Observed FTIR and Simulation

The Central Q-Branch(es) Problem: Insufficient Resolution and the State of Computing at the Time

- How to really get the time to do research and. solve the propane - How to really get the time to do research and solve the propane problem? - First retire (Jan., 2015) from teaching, advising & committee duties! - Get help from colleagues to reconnect - Write & submit CLS proposal (Feb, 2015) - Proposal approved May, 2015 - First Spectra taken Cycle 22 in Sept, 2015

Canadian Light Source (CLS)

View of CLS Cyclotron

CLS Far-IR Beamline Brant 2m White cell Bruker IFS 125HR

Help in Rebooting SJD (2014 ISMS) Jon Hougen Jean-Marie Flaud Walt Lafferty

More Help: CLS Workshop at 2015 ISMS Bob McKellar, Brant Billinghurst , Colin Western

• Sparse Spectroscopic work on Isotopologues of Propane: Lide, MW: 1-13C & 2-13C K=0, J=0-6 (1960) and single D substitution on 12C species D-Substituted Only: Henry L. McMurry, IR (1949-51) Friedman & Turkevich, IR (1949) Gayles & King, IR (1965) Kondo & Saȅki, IR Band Intensities(1973) Gough & Murphy, Raman (1987) ab initio Villa, Senent & Carvajal (2013) single D and 13C

Flaud, Lafferty & Herman C2v Notation Confusion Flaud, Lafferty & Herman Gayles & King (1965) A1: v1 – v9 B-type B1: v10 - v16 A-type B2: v17 –v22 C-type A2: v23 – v27 ia

So - A Cautionary Note • Notation used here is the same as that used in Flaud, Lafferty & Herman JCP (2001) and Villa et al. (2013) • Mode numbering same as Shimanouchi in NBS books • This differs from Gayles & King, Pearce & Levin and most astronomical and other papers before 2000. A1: v1 – v9 B-type A2: v10 – v14 ia B1: v15 - v21 A-type B2: v22 –v27 C-type

P = 0.065 Torr; L = 72 m; Δv = 0.0009 cm-1 V26 (B2) V21 (B2) V20 (B1) V7 (A1) V8 (A1)

2-13C-Propane ν26(B2) C-type

Assignment Method 1 – Plotted out small sections using Bruker OPUS software; taped them together to make a continuous roll 2 – Used dividers and estimated A, B,C values to assign pQK & rQK Q-branch heads 3 – Then used dividers and estimated B bar to find and assign corresponding P and R line each K subband

4 – Convert OPUS files to data point (x,y) files and load into PGOPHER program 5 – Put estimated A,B,C and v0 values into PGOPHER program and simulate spectrum 6 – Use the divider assignments to connect the assigned observed to the simulated lines 7 – Fit lines to get better A,B,C and origin values 8 – Extend assignments and eventually add Centrifugal Distortion terms

2-13C-Propane V26(B2) P-Side pQ8 pQ7 pQ6 pQ5 pQ4

ν26 pQ7 Q-Branch

pPK(J) lines

Residual Plot for v26 Band of 2-13C-Propane

Work still needing to be done on this band: Try to assign lines from the (2v9-v9) hot band since Walter & Jean-Marie showed in their analysis of the normal propane that the 2v9 state is the perturber of the v26 Ka> 15 levels Fit the data for v26 and 2v9 together including the A-type Coriolis coupling between these states Produce a new simulated spectrum which can reproduce all Ka values observed in the CLS data

V9 (A1) B-Type Band of 2-13C-Propane CCC Bending Mode 2-13C-Propene

2-13C-Propane V9 (A1) pQ11 pQ10 pQ9 pQ8

ν9 pQ8 Q-Branch

2-13C-Propane V9(A1) R-Side rQ3(J)

v0 = 366.766’711 (11) cm-1

Residual Plot for v9 Band of 2-13C-Propane

Ground State Constants

Acknowledgements UTK & Dept. of Physics & Astronomy Canadian Light Source and its support agencies (NSERC, USask, Province of Saskatchewan) NIST Jon Hougen, Bob McKellar, Colin Western, Dennis Tokaryk, Scott Goudreau,