Daniel P. Zaleski, Hansjochen Köckert, Susanna L. Stephens, Nick R. Walker
School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
The Pure Rotational Spectrum of PbI from Broadband Rotational Spectroscopy
The Ohio State 69th International Symposium on Molecular Spectroscopy, June 19th, 2014.
Lisa-Maria Dickens and Corey Evans
Department of Chemistry, University of Leicester, Leicester, LE1 7RH, UK.
Introduction
PbI has a 2П1/2 ground state
Radical diatomics in this state have garnered interest in the past
- SnCl- PbCl (RC07 2010 ISMS)
There has been spectroscopic in the past for PbI.
J. Mol. Spectrosc., 1993, 161, 552-559.
Chem. Phys. Lett., 1992, 190, 271-278.
J. Mol. Spectrosc., 2012, 280, 85-90.J. Mol. Spectrosc., 1998, 191, 108-116.
Chirped Pulse FTMW Spectroscopy
Broadband spectrometers with instantaneous frequency coverage from 2-8 GHz, 6.5-18.5 GHz, 18.5-26 GHz, and 25 – 40 GHz have been constructed.
Current Technology:AWG 24 Gs/s (12 GHz)Digital Oscilloscope 100 Gs/s (33 GHz)
600k FID’sCF3I, 6 bar Ar, Pb rod
Dynamic Range ~10,000:1
No Coils
200x
3 Primary Isotopes:
208Pb ~52%207Pb ~22%206Pb ~24%
207Pb spin 1/2
Exp. Theory*
B (MHz) 818.2834(3) 790.2489
D (kHz) 0.092(2)
A (THz) |239.034|
a (MHz) 186.85(5)
d (MHz) 239.76(1)
eQq (MHz) -701.42(5)
(p+2q) (MHz) 163.142(4)
(q) (MHz) -21.0(3)
* MP2/aug-cc-pVTZ-PP
Chem. Phys. Lett., 1992, 190, 271-278.
S/N ~50:1
Be = 819.3010(7) MHz
𝐵𝑒=18(15𝐵0−10𝐵1+3𝐵2)
αe = 2.0352(9) MHz
𝛼𝑒=2𝐵0−3𝐵1+𝐵2
𝑈 (𝑟 )=𝐷𝐸 ¿
ωe = 161.02(4) cm-1
Chem. Phys. Lett., 1992, 190, 271-278.
~241 kJ/mol
𝜔𝑒𝑥𝑒=𝐵𝑒(𝛼𝑒𝜔𝑒
6 𝐵𝑒2 +1)
2
ωeχe = 9690(12) MHz
DE = 20003(2178) cm-1
𝐷𝐸=𝜔𝑒2
4𝜔𝑒𝑥𝑒
300x
3 Primary Isotopes:
120Sn ~32%118Sn ~24%116Sn ~14%
Exp. Theory*
B (MHz) 1120.2711(4) 1126.6139
D (kHz) 0.1608(5)
A (THz) |72.19|
a (MHz) 224.71(7)
d (MHz) 99.96(3)
eQq (MHz) -697.6(2)
(p+2q) (MHz) -143.285(2)
* MP2/aug-cc-pVTZ-PP
S/N ~30:1
MC-SCF
Be = 1121.7667(9) MHz
αe = 2.991(9) MHz
γe = 0.9(5) kHz
𝑈 (𝑟 )=𝐷𝐸 ¿
ωe = 241.1(1) cm-1
ωeχe = 16740(16) MHz
DE = 25971(2823) cm-1
~311 kJ/mol
Trans. Farad. Soc.,1967, 64, 616-619.
Conclusions
Both PbI and SnI have a 2П1/2 ground state
Assigned a number of vibrational states for each of the Pb and Sn isotopes
Modeled the PES using Morse potential
ED are on the order of ~240 – 310 kJ/mol
Acknowledgments
Engineering and Physical Sciences Research Council
AWE (Aldermaston)
University of Bristol Colin Western
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