(https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PPT-050112ak.ppt ) CH3I: agust,www,...rempi/ch3i/PPT-050112ak.ppt (https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PPT-050112ak.ppt ) agust,heima,...REMPI/CH3I/PXP-050112ak.pxp https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-230112ak.pxp (energetics and abs. spectrum) https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/XLS-230112ak.xls (energetics) Content: pages: compound: availability and physical properties….. 2-3 Absorption spectra on www………………………………. 4-14 Papers………………………………………………………………. 12-33 Rydberg state peaks / spectra…………………………. 16-20 VMI-REMPI exp. Plan (Ry. Peaks)……………………. 18-21-24 Important papers (summary table)………………… 33-34 Energetics…………………………………………………….. …………. 35-43 REMPI spectra and assignments from the literature:…………………………………… .. 43-53 Comparison of absorption and REMPI spectra………………………………………… 48 High energy REMPI vs abs. spectra………… ………. 56,64-66 Exp. Progress vs. Dates…………………………….. 86-88 CH3I and CH3I+ (X´s) energetics, vibrational modes and energies………………………………………. 89-91 CH3 and CH3+ energetics……………………….. 92-94 Updated: 171011

Eiríks project 1) CH3I: Svana´s e-mail, 071211:

http://en.wikipedia.org/wiki/Methyl_iodide : liquid Vapor pressure: CRC: 1 mm 10 40 100 400 760 mp S -45.8oC -24.2 -7.0 +25.3 42.4 -64.4 Vapor pressure = 100 Torr for -7 oC See cooling baths: http://www.chem.orst.edu/carter/Baths.html

ATH 1 ATH 2

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf ATH 1 (2007) agust,heima,...REMPI/CH3I/PXP-050112ak.pxp; Lay:0, Gr:0

ATH 1 agust,heima,...REMPI/CH3I/PXP-050112ak.pxp; Lay:0, Gr:0

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/cp365-109-09.pdf ATH 2 agust,heima,...REMPI/CH3I/PXP-050112aka.pxp; Lay:0, Gr:0

Absorption references: https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/cp365-109-09.pdf

Absorption references: https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf

Absorption references: https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf See tables 4-7 in The paper

no.: no.: (9) (2) (8) (11) (7) (3) (5) (6) (10) https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf no.: (9) no.: (2) (8) (11) (7) (3) (5) (6) (10)

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf (1)

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf (3) (10) (5) (6) no.:

VMI-REMPI experimental plan: CH3I: no. 2hv/ eV 2hv/cm-1 1hv/cm-1 l / nm(1hv) Rydberg state converging to ref: Comment 1 6.906 55700.63 27850.31283 359.062394 6s (1/2) +v2 2E1/2 $ Table 5* Not accessable by MOPO; try dye laser 2 7.306 58926.84 29463.42102 339.4039 6p (0…) # 2E3/2 Table 4* Try use MOPO 3 7.36 59362.38 29681.19062 336.9137083 6p(3/2) +v3 Table 6 * 4 7.381 59531.76 29765.8788 (?) Unassigned peak, relatively strong (?) 5 7.402 59701.13 29850.56698 335.0020121 6p(3/2) +nv6 6 7.642 61636.86 30818.43189 324.4811428 6p(3/2) +nv1 7 7.82 63072.53 31536.26504 317.0952549 5d(0,…) # 8 7.996 64492.07 32246.03264 310.1156695 6p(0,…) # 9 8.022 64701.77 32350.88467 309.1105576 7s(0,…) # 10 8.299 66935.92 33467.96209 298.7932152 7s(3/2) +nv2 Table 6* 11 8.429 67984.44 33992.22225 294.184944 7p(0,…) # 12 8.652 69783.06 34891.53006 286.6025073 i.e. 6 fundamental (0,…) bands (#); 5 vibrational bands; 1 uncertain band(?) / three bands for convergence to 2E1/2 ($) *ref: https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf ; see slides below(figs) and above (Tables) https://notendur.hi.is/agust/rannsoknir/Crete17/XLS-170919.xlsx ; sheet: Ry spectra

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf (1) See slide 21 above

? See slide 21 above (no.) (2) (3) (5) (6) (7) (8) (9) (10) (11) (4) https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf (no.) (2) (3) (5) (6) (7) (8) (9) (10) (11) ? See slide 21 above (4)

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf (12) See slide 21 above

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf

Check REMPI work -by Donovan et al. -references in CH3Br REMPI paper etc. With repect to Rydberg state structure.

Papers: See also Eirik´s folder Rydberg states: https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp99-836-93.pdf RESONANCE-ENHANCED MULTIPHOTON IONIZATION PHOTOELECTRON- SPECTROSCOPY ON NANOSECOND AND PICOSECOND TIME SCALES OF RYDBERG STATES OF METHYL-IODIDE Abstract: Rydberg states of methyl iodide have been investigated using resonance enhanced multiphoton ionization in combination with photoelectron spectroscopy with nanosecond and picosecond laser pulses. The study of the ns (6 less-than-or-equal-to n less-than-or-equal-to 10) Rydberg states in two-, three-, and four-photon excitations has resulted in an unambiguous identification of state [1] in the 7s and 8s Rydberg states. As a consequence, it is concluded that the transition to 6s[1] in two- and three-photon excitations is anomalously weak. The application of photoelectron spectroscopy to identify the electronic and vibrational nature of a resonance has led to a major reinterpretation of the excitation spectrum of the 6p Rydberg state in two-photon excitation. In many of the recorded photoelectron spectra anomalous electrons are observed, which derive from a one-photon ionization process. This process is suggested to find its origin in the mixing of 6p and 7s character into higher-lying Rydberg states. The major difference between resonance enhanced multiphoton ionization photoelectron spectroscopy with nanosecond and picosecond lasers is found in a less effective dissociation of the molecule in the picosecond experiments. ...Ry states, state mixing, vibr. Freq. Modes, (2+1)REMPI spectra and assignments of Rydb. states

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/cpl156-151-89.pdf (2+1)REMPI..3p Ry https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/cpl173-257-90.pdf

https://notendur. hi. is/agust/rannsoknir/papers/CH3X/CH3I/jpc86-60-82 https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jpc86-60-82.pdf Shows 1) mass spectra and 2) energetics

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/cpl345-57-01.pdf Bond energies, ..

Less useful but new papers: 1) https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/cpl516-23-11.pdf Isotopic effect in the (2+1) REMPI spectra of (13)C-substituted methyl iodide for UV selective dissociation To investigate a possible means of achieving isotopic enrichment of methyl iodide (CH(3)I), we studied the 6s Rydberg states of (13,12)CH(3)I by (2+1) resonance-enhanced multiphoton ionization. For 3; 3(1)(0) band (v3 hot band) excitation ( at a full width at half maximum of 14 cm (1)), we observed a well-resolved isotope shift of +16 cm (1). The band shape, which has a broad shoulder on the red side and an abrupt decrease on the blue side, indicates that this resonance is ideal for enriching the concentration of the desired lighter isotope (the isotopomer). (C) 2011 Elsevier B.V. All rights reserved. 2) https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jms257-200-09.pdf Photoelectron imaging of 8p Rydberg states of atomic iodine following methyl iodide A-band decomposition Photoelectron imaging technique has been applied to study (2 + 1) REMPI of atomic iodine through 8p Rydberg states around 253 nm. Full three-dimensional state-specific speed and angular distributions of the photoelectrons were recorded. The branching ratios among the different I(+) levels revealed that the perturbation on ((3)P(2))8p series is particularly large among the ((3)P(2))np series. The violation of core-conserving ionization is attributed to the interactions between the ((3)P(2))8p and ((1)D(2))6p series. The photoelectron angular distributions were found to be well characterized by P(2)(cos theta) and P(4)(cos theta). A relatively high positive beta(2) and a relatively low beta(4) observed in (2 + 1) REMPI process indicated that the ionization process can be approximately considered as single-photon ionization via the weakly aligned ((3)P(2))8P intermediate states. (C) 2009 Elsevier Inc. All rights reserved.

https://notendur. hi. is/agust/rannsoknir/papers/CH3X/CH3I/jams2-93-11 https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jams2-93-11.pdf

URLs: Authors; Titles Important papers: https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf S. Eden,*,1, P. Lima˜o-Vieira ,2, S.V. Hoffmann , N.J. Mason; VUV spectroscopy of CH3Cl and CH3I https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/cp365-109-09.pdf R. Locht ,*, B. Leyh, H.W. Jochims , H. Baumgärtel; Medium and high resolution vacuum UV photoabsorption spectroscopy of methyl iodide (CH3I) and its deuterated isotopomers CD3I and CH2DI. A Rydberg series analysis https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp99-836-93.pdf M. R. Dobber, W. J. Buma, and C. A. de Lange ; Resonance enhanced multiphoton ionization photoelectron spectroscopy on nanosecond and picosecond time scales of Rydberg states of methyl iodide ; REMPI https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/cpl156-151-89.pdf David W. CHANDLER, John W. THOMAN Jr. , Maurice H.M. JANSSEN, David H. PARKER ; PHOTOFRAGMENT IMAGING: THE 246 nm PHOTODISSOCL4TION OF CHXI https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/cpl173-257-90.pdf Steven P. Sapers and D.J. Donaldson; A REMPI investigation of methyl iodide Rydberg state predissociation https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jpc86-60-82.pdf D. H. Parker and R. B. Bernsteln; Multlphoton Ionization-Fragmentation Patterns of Alkyl Iodides https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/cpl345-57-01.pdf Juan Chen et al.; VUV photoionization of (CH3I)n (n = 1-4) molecules. https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/cpl516-23-11.pdf Atsushi Wakai et al.; Isotopic effect in the (2+1) REMPI spectra of 13C-substituted methyl iodide for UV selective dissociation https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jms257-200-09.pdf Huan Shen et al.; Photoelectron imaging of 8p Rydberg states of atomic iodine following methyl iodide A-band decomposition https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jams2-93-11.pdf Debra Jo Scardino et al.; The multiphoton ionization spectrum of methyl iodide revisted: 1.67–2.2 eV excitation https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jce59-879-82.pdf Ian J. McNaught; Structural Parameters of Methyl Iodide by Infrared Spectroscopy https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jppbA100-9-96.pdf Zhiyuan Min, T. Ridley, K.P. Lawley *, R.J. Donovan; Two-colour bound-free-bound spectroscopy of the [2E1/2]c6S Rydberg states of CHgI and CD3I https://notendur.hi.is/agust/rannsoknir/papers/jcsft94-2689-98.pdf .. T. Ridley, K. P. Lawley* and R. J. Donovan; Ionic and Rydberg states of studied by high resolution CF3 I photoelectron (ZEKE-PFI) and resonance-enhanced multiphoton ionisation spectroscopy

URLs: Authors; Titles https://notendur.hi.is/agust/rannsoknir/papers/jcp131-174309-09.pdf L. Rubio-Lago et al.; The photodissociation of CH3I in the red edge of the A-band: Comparison between slice imaging experiments and multisurface wave packet calculations https://notendur.hi.is/agust/rannsoknir/papers/jcp107-7187-97.pdf Young-Jae Jung et al.; Photoelectron imaging spectroscopy for „211… resonance-enhanced multiphoton ionization of atomic iodine produced from A-band photolysis of CH3I https://notendur.hi.is/agust/rannsoknir/papers/jcp004-539-36.pdf W.C. Price; The Far Ultraviolet Absorption Spectra and Ionization Potentials of the Alkyl Halides. Part I https://notendur.hi.is/agust/rannsoknir/papers/jmsp59-355-76.pdf S. FELPS, P. KOCHMANN, P. BRINT, AND S. P. MCGLYNN ; Molecular Rydberg Transitions The Lowest-Energy Rydberg Transitions of s-Type in CH3X and CD3X, X = Cl, Br, and I L 2 https://notendur.hi.is/agust/rannsoknir/papers/pccp13-18485-11.pdf N. Thire´, ab R. Cireasa,ab D. Staedter,ab V. Blanchet*ab and S. T. Prattc; Time-resolved predissociation of the vibrationless level of the B state of CH3I https://notendur.hi.is/agust/rannsoknir/papers/jcp135-021102-11.pdf M. G. González, J. D. Rodríguez, L. Rubio-Lago, and L. Bañaresa); Communication: First observation of ground state I(2P3/2) atoms from the CH3I photodissociation in the B-band https://notendur.hi.is/agust/rannsoknir/papers/pccp13-16404-11.pdf M. G. Gonza´lez,a J. D. Rodrı´guez,a L. Rubio-Lago,a A. Garcı´a-Velab and L. Ban˜ares*a; Slice imaging and wave packet study of the photodissociation of CH3I in the blue edge of the A-band: evidence of reverse 3 Q0 ’ 1 Q1 non-adiabatic dynamics https://notendur.hi.is/agust/rannsoknir/papers/pccp13-8186-11.pdf L. Rubio-Lago,ab J. D. Rodrı´guez,a A. Garcı´a-Vela,c M. G. Gonza´lez,a G. A. Amarala and L. Ban˜ares*a; A slice imaging and multisurface wave packet study of the photodissociation of CH3I at 304 nm https://notendur.hi.is/agust/rannsoknir/papers/pccp17-29958-15.pdf Sonia Marggi Poullain,a Marta G. González,a Peter C. Samartzis, b Theofanis N. Kitsopoulos,b,c Luis Rubio-Lagoa and Luis Bañaresa∗ ; New insights in the photodissociation of methyl iodide at 193 nm: Stereodynamics and product branching ratios https://notendur.hi.is/agust/rannsoknir/papers/jpcC117-22383-13.pdf Andreas Kartakoullis,†,‡ Peter C. Samartzis,† and Theofanis N. Kitsopoulos*,†,‡; Photodissociation of Methyl Iodide and Methyl Iodide Clusters at 193 nm https://notendur.hi.is/agust/rannsoknir/papers/pccp19-7886-17.pdf A velocity map imaging study of the photodissociation of the methyl iodide cation https://notendur.hi.is/agust/rannsoknir/papers/jcp122-104310-05.pdf Bailin Zhang, Jinghui Zhang, and Kopin Liu; Imaging the “missing” bands in the resonance-enhanced multiphoton ionization detection of methyl radical https://notendur.hi.is/agust/rannsoknir/papers/jcp79-571-83.pdf Jeffrey W. Hudgens, T. G. DiGiuseppe, and M. C. Lin; Two photon resonance enhanced multiphoton ionization spectroscopy and state assignments of the methyl radical

Now we need to look at the energetics, analogous to that for CH2Br2: http://www3.hi.is/~agust/rannsoknir/rempi/ch2br2/PPT-010211ak.ppt (See slides 6 -11)

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/cp365-109-09.pdf Fig 10:

NIST IE: 76945.25 cm-1

http://www.sciencedirect.com/science/article/pii/S0009261401008648 19195.9852 cm-1

CH3:

CH3I   D: 2.38 eV http://www.sciencedirect.com/science/article/pii/S0009261401008648 19195.9874 cm-1 Factors: f1: 8.36E+01 cm-1 / (kJ mol-1) f2: 3.50E+02 cm-1 / (kcal mol-1) f3: 8065.54093 cm-1/eV E(6s) = 54633.46 E(4P;5s)+D= 73829.45 IE(CH3I)= 9.54 NIST 76945.26047 IE(I)= 84295.1 http://physics.nist.gov/cgi-bin/ASD/energy1.pl E(S/O;I)= 7602.97 E(CH3+I*(1/2))= 26798.95741 E(CH3+I+ + e)= 103491.0874 IE(CH3) = 9.84 79364.92275  NIST E(CH3+ + e + I) 98560.91016 EA(I) = 3.0590463 http://en.wikipedia.org/wiki/Electron_affinity_%28data_page%29 24672.8631 E(CH3+ + I-)= 73888.04703 E(I+)-E(I*)= 76692.13 https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/XLS-230112ak.xls

cm-1 CH3I+ + e; 76945.26047 CH3I CH3 + I+ + e; 103491.0874 CH3+ + e + I; 98560.91016 CH3I+ + e; 76945.26047 CH3 + I**(min); 73829.45 CH3 + I*; 26798.95741 CH3 + I; 19195.9874 CH3I https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-230112ak.pxp

Abs. spectrum CH3I+ + e; 76945.26047 CH3I (n) = number of photons (4) 103491.0874 CH3+ + e + I; 98560.91016 Abs. spectrum (3) CH3I+ + e; 76945.26047 CH3 + I**(min); 73829.45 70000 (2) 55000 (1) CH3 + I*; 26798.95741 CH3 + I; 19195.9874 CH3I https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-230112ak.pxp

70000 cm-1 CH3+ + e + I; 65707.27 cm-1 ..threshold hv(Laser)=16426.82 CH3 + I+ + e; 68994.06 cm-1 ..threshold: hv(Laser) = 17248.51 (579.7601 nm) CH3+ + e + I; 65707.27 cm-1 ..threshold hv(Laser)=16426.82 (608.7606 nm) https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-230112ak.pxp

REMPI spectra and assignments from the literature:

n = number of resonance excitation photons https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp99-836-93.pdf n: 2 n = number of resonance excitation photons s -States and spectra observed in Two-photon REMPI

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp99-836-93.pdf n: 2 s -States and spectra observed in Two-photon REMPI

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp99-836-93.pdf n: 2 s -States and spectra observed in Two-photon REMPI

2hv : p -States and spectra observed in Two-photon REMPI 58000 64000 https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp99-836-93.pdf 58000 64000 2hv : p -States and spectra observed in Two-photon REMPI

Comparison of absorption and REMPI spectra Abs. Spectrum: https://notendur.hi.is/agust/rannsoknir/papers/CH3X/cp331-232-07.pdf Comparison of absorption and REMPI spectra : REMPI spectrum: https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp99-836-93.pdf 2hv(cm-1/ eV) 58000/ 7.191 60000/ 7.439 62000/ 7.687 64000/ 7.935

s states spectra Ca. Spectral observed region for in (2+n) REMPI Ca. Spectral region for R590! 66640-69480 p states spectra observed in (2+n) REMPI https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-250112ak.pxp

s states spectra observed in (2+n) REMPI p states spectra observed 64000 p states spectra observed in (2+n) REMPI 58000 https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-250112ak.pxp

Comparison of absorption and REMPI spectra: p states spectra observed in (2+n) REMPI Comparison of absorption and REMPI spectra: 64000 62000 60000 58000 https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-250112ak.pxp

72900 72500

Abs. spectrum CH3I+ + e; 76945.26047 CH3I (n) = number of photons (4) 103491.0874 CH3+ + e + I; 98560.91016 Abs. spectrum (3) CH3I+ + e; 76945.26047 CH3 + I**(min); 73829.45 70000 (2) 55000 The A-band x100 (1) CH3 + I*; 26798.95741 CH3 + I; 19195.9874 CH3I https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-260112ak.pxp

CH3I+ + e; 76945.26047 Abs. spectrum The A-band n s*(C-I) x100 (n) = number of photons CH3I+ + e; 76945.26047 70000 68994.06 cm-1 (2) Abs. spectrum 65707.27 cm-1) 55000 The A-band n s*(C-I) x100 (1) https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-260112ak.pxp

Absorption spectrum CH3+ 1D REMPI uncorrected 2hv https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/Experiment-260112vhwak.pxp

??? cm-1 pnt https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/Experiment-260112vhwak.pxp

IDEA!: an I2+ mass peak observed could be due to a molecular dimer (CH3I)2 ERGO: let´s see the effect of less cooling, i.e. less % argon 2) less backing pressure . Let´s check the literature Literature: http://www.chemthes.com/entity_datapage.php?id=1851 : Van der Waals complexes http://jcp.aip.org/resource/1/jcpsa6/v97/i1/p189_s1?isAuthorized=no https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp97-189-92.pdf : “Ground electronic state I2 is formed from the photolysis of methyl iodide dimers” Sjá meira neðar See example for effect of buffer gas (rare gas) on jet cooling next slide:

http://www.nature.com/nphys/journal/v4/n8/box/nphys1031_BX1.html : Small molecular density= molecular diffusion Largest molecular density= molecular beam Skimmer; Not used in our case Beam axis medium molecular density

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jppbA100-9-96.pdf :

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jpc100-11559-96.pdf : http://jcp.aip.org/resource/1/jcpsa6/v97/i1/p189_s1?isAuthorized=no & https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp97-189-92.pdf :

Ln(p) ln(p) vs 1/T is nonlinear suggesting less importance of 1 mm 10 40 100 400 760   P Torr S -45.8 -24.2 -7 25.3 42.4 t/oC 227.35 248.95 266.15 298.45 315.55 T/K 0.0043985 0.004017 0.003757 0.003351 0.003169 1/T (K-1) 2.30258509 3.688879 4.60517 5.991465 6.633318 ln(p) 0.434294 3.68887945 0.271085 4.60517019 0.217147 5.99146455 0.166904 6.63331843 0.150754 Ln(p) ln(p) vs 1/T is nonlinear suggesting less importance of dimers as temperature rizes. 1/T (K-1) https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/XLS-270112ak.xls https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-270112ak.pxp

This could mean that CH3I dimers are even formed in the vapour above the trap when cooled with CCl4 slash bath (-23oC)!! --further suggesting that it might be better to use less cooling for the trap: How about to use cold water only (analogous to that used for CH2Br2 earlier) ???

No clear correspondance between REMPI and absorption spectra in this region Absorption spectrum CH3+ 1D REMPI uncorrected 2hv https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-100212ak.pxp

What on earth is that??? CH3+ 1D REMPI uncorrected Absorption spectrum 2hv https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-100212ak.pxp

This looks like P, Q and R brances Of symmetric top: seen next slide CH3+ 1D REMPI uncorrected Absorption spectrum D = 19.16..18.36..16.8 19.84 19.84 19.84 2hv https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-100212ak.pxp

IR róf topsamhverfra sameinda / IR spectra for symmetric top molecules: http://notendur.hi.is/agust/kennsla/ee10/eeb/PPT/IR%20rof.ppt: CH3I: B: Fundamentals of Molecular Spectroscopy  eftir C.N. Banwell og E.M. McCash, (McGraw-Hill, 4. útg. 1994)

Are these all iodine atomic lines? What transitions are these, Eiríkur? hv(laser) https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-100212ak.pxp

Same molecular peak seen in the I+ and CH3+ spectra Small but significant peak C atomic lines hv(laser) https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-100212ak.pxp

CH3+ REMPI 69852.92828 cm-1 https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-250312ak.pxp og ftp://130.208.167.52/Data/CH3I/Calibartion Work/calibration/ allt I cal, 16220_17510 funky17540_17650-210312.pxp

CH3+ REMPI 773.5337 cm-1 8.408 8.4 70626.462 cm-1 https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-250312ak.pxp og ftp://130.208.167.52/Data/CH3I/Calibartion Work/calibration/ allt I cal, 16220_17510 funky17540_17650-210312.pxp

I+ REMPI https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-250312ak.pxp og ftp://130.208.167.52/Data/CH3I/Calibartion Work/calibration/ allt I cal, 16220_17510 funky17540_17650-210312.pxp

Symmetric top: http://www.hi.is/~agust/kennsla/ee05/ee405/rotst.ppt https://notendur.hi.is/agust/kennsla/ee10/ees10/snthrep.htm

69852.92828 cm-1 OUR CH3+ REMPI spectrum At 69852.9 is Due to CH3 !!!! http://webbook.nist.gov/cgi/cbook.cgi?ID=C2229074&Units=SI&Mask=800#Electronic-Spec: OUR CH3+ REMPI spectrum At 69852.9 is Due to CH3 !!!! Check this reference

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp89-3986-88.pdf :

https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp89-3986-88.pdf : 69852.92828 cm-1 Ours NB!: DK = 0

Coupling terms Excited state NB!: DK = 0 Ground state https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp89-3986-88.pdf : Coupling terms Excited state NB!: DK = 0 Ground state

..but what about this spectrum: 773.5337 cm-1 70626.462 cm-1 It must be because of CH3 There is no reported electronic state for CH3 at this wavenumber The spacing of 773.5 cm-1 between the two CH3+ spectra suggests that it could be A vibrationally excited state

Let´s check references Could be the a2 n2 (OPLA) vibrational mode Let´s check references out‐of‐plane large amplitude (OPLA)-mode = umbrella modes http://webbook.nist.gov/cgi/cbook.cgi?ID=C2229074&Units=SI&Mask=800#Electronic-Spec:

...but these seem, generally to be the lowest numbers NB!: OPLA modes can be significantly different for excitede states than for The ground state, thus: NIST: ...but these seem, generally to be the lowest numbers http://webbook.nist.gov/cgi/cbook.cgi?ID=C2229074&Units=SI&Mask=800#Electronic-Spec:

Our spectrum simulated for parameters in https://notendur.hi.is/agust/rannsoknir/papers/CH3X/CH3I/jcp89-3986-88.pdf : Calculations were performed in 69852.92828 cm-1 https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/XLS-020412ak.xls P Q R S O https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-020412ak.pxp

70626.462 cm-1 Since the Q branch in the 70626.462 cm-1 system is degraded to red (low wavenumber) opposide of what is found for the 69852.92828 cm-1 system (slide 72) it suggest that B´< B´´ opposide of what is found for the 69852.92828 cm-1 sysem (see slide 68) where B´= 9.90 cm-1 and B” = 9.577..cm-1 First attempts to simulate the vibrationally excited band of CH3:

70626.462 cm-1 9.57789 = B” 0.0007699 =DN” -0.0001358 =DNK” 9 =B´ 0.00107 =DN´ -0.00212 =DNK´ 70627.2 “=n0 -0.088 =DC 0 =DDK DK = 0 Q P R O S https://notendur.hi.is/agust/rannsoknir/rempi/ch3i/PXP-020412aka.pxp

date Exp. work Nm (pred/exp.) Comments/ref. 18.9 Mo NOT 19.9 Tue CH3I (2) (CH3+,PES) 339.4039/ 339.467 MOBO, File: 20170919 (and 20170920 partly) 20.9 We CH3I(1) (CH3+,CH2+,I+,PES) 359.06239/ 358.835 MOBO power fell down; switched to Exc./dye File: 20170920, partly 21.9 Thu CH3I(12) (CH3+) 573.177 (dye l)/ 286.60251(pred.)/ 286.5885(exp.) Exc./dye, (Rhodamin 6G in MeOH); NB: polarizer was not inserted; ERGO: the angular distrib. Is invalid. File: 20170921 22.9 Fri CH3I(12) (CH3+, I+, PES) 573.171 (dye l)/ 286.60251(pred.)/ 286.5885(exp.) Exc./dye, (Rhodamin 6G in MeOH); polarizer IN; CH2+ signal too week. Calibration for ion images changed from eV = 3.41407e-5 x (pix)2 (used 19.-21.9.2017) TO eV = 3.50e-5 x (pix)2 (to be used from now) 23.9 Sa Psiloritis, 19 km. hot 24.9 Su 25.9 CH3I(11) (CH3+, I+, PES) 589.599 (dye l)/ 294.7995(pred.)/ 294.18494(exp.) Exc./dye, (Rhodamin 6G in MeOH); Abel conversion performed for CH3+ images (CH3+ signal week) 26.9 CH3I(ca.12)CH3+, I+ and PES 573.2(dye l.)/ ------/ 286.6(exp.) Off resonance signals near Ry(12) 27.9 NO experiment: problem with circulator; however good signal for Ry(1) 28.9 CH3I (1) and off res.: (CH3+,I+,PES) Exc./dye, (DMQ in dioxine) 29.9 CH3I (2) (CH3+,CH2+,I+,PES) 339.444/ 339.4039 To top

Sternes = Koudouma (46 km) 1.10 Su Work at home; CH32I & CH3Br 2.10 Mo To top date Exp. work nm /predicted and used Comments/ref: 30.9 Sa Sternes = Koudouma (46 km) 1.10 Su Work at home; CH32I & CH3Br 2.10 Mo CH3I(3): CH3+, CH2+, I+, PES 336.979(exp.)/ 336.91371(pred.?) Lot of rings! 3.10 Tu CH3I(4a):CH3+,I+,PES & CH3I(4b):CH3+ 336.357(exp.) & 335.735(exp.) 4.10 We CH3I(4b): I+ & CH3I(4c):CH3+,I+,PES (?) 335.735(exp.)& 333.902(exp)(?) Something strange about the data storaging for (4c) 5.10 Th CH3I(7): CH3+,I+,PES 634.240(dye l.)/ 317.09525(pred.)/ 317.120(exp.) Lot of rings in PES due to I** +hv -> I++e 6.10 Fr CH3I(8): CH3+, I+, PES 620.305 (dye l.)/ 310.11567 (pred.)/ 310.1525(exp.) PG fiddled with the PES calibration and came to the conclusion that f = 3.20e-5 (or even lower) is more appropriate than 3.29e-5 7.10 Gorge north of Zaros (15.51.km) 8.10 „Keilir“ =Amodara (28.79 km) 9.10 Checked Ry(8) for space charging 620.292(dye l.)/ 310.11567(pred.)/ Leak in excimer laser; Found evidences for space charging effects 10.10 CH3I(6): CH3+, I+, PES CH3I(9): I+, PES(?) (6): 649.003(dye l.) / 317.09525(pred.)/ 317.12(exp.); (9): 618.220(dye l.)/ 309.11056(pred.)/ 309.11(exp.) PG: PES for (9) is strange (e-mail 171010) (9) Too week signal to record CH3+

To top date Exp. work nm predicted and used Comments/ref: 11.10. We (9): PES 2) CH3+,I+,PES 3) (6): PES 618.22(dye l.) 2) 619.518(dye l.)(?) 3) 649.00(dye l.) Checked Ry(9) again; no major change from yesterday; still stange behavious; moved to Ry(6) to see if that is reproducable; tested space charge effect 12.10. Th (3): CH3 2) (2): CH3 1) 336.979 (dye l.) 2) 339.467 (dye l.) Checked (2) and (3) for space charge effects; less space charging observed for adiluted sample by higher laser power! Look at PG PPT file 13.10 Fr Ath Costas 9:30(?)..CF arrives tonight. 14.10 Sa Ólöf arrives in the evening

CH3I(X) energetics: http://webbook.nist.gov/cgi/cbook.cgi?ID=C74884&Units=SI&Mask=800#Electronic-Spec :

CH3I+(X) energetics: http://webbook.nist.gov/cgi/cbook.cgi?ID=C12538726&Units=SI&Mask=800#Electronic-Spec :

CH3I+(X) energetics: http://webbook.nist.gov/cgi/cbook.cgi?ID=C12538726&Units=SI&Mask=800#Electronic-Spec :

X(CH3): Methyl Radical, CH3 Vibrational states of the ground To top X(CH3): Methyl Radical, CH3 Vibrational states of the ground electronic state http://webbook.nist.gov/cgi/cbook.cgi?ID=C2229074&Units=SI&Mask=800#Electronic-Spec

*3 *2 * CH3** *6 *5 *4 Methyl Radical, CH3 electronic state To top http://webbook.nist.gov/cgi/cbook.cgi?ID=C2229074&Units=SI&Mask=800#Electronic-Spec

http://webbook. nist. gov/cgi/cbook. cgi http://webbook.nist.gov/cgi/cbook.cgi?ID=C14531534&Units=SI&Mask=800 X(CH3+):