1. Angela Y. Chung, Eric A. Arsenault, and Stewart E. Novick
Nitrogen splittings here, there, and everywhere: A Reinvestigation of the Electronic Properties of 2-Bromopyridine with High Resolution Microwave Spectroscopy
Angela Y. Chung, Eric A. Arsenault, and Stewart E. Novick

2. High Resolution Microwave Spectroscopy and 2-bromopyridine

3. Predicted Rotational Spectrum of 2-bromopyridine
assigned transitions
81BrC5H4N
79BrC5H4N

4. 14N Hyperfine Structure * *
𝐽 𝐾 𝑎 ′′ 𝐾 𝑐 ′′ ′′ 𝐹 1 ′′ 𝐹 2 ′′ ← 𝐽 𝐾 𝑎 ′ 𝐾 𝑐 ′ ′ 𝐹 1 ′ 𝐹 2 ′
F1 = J + I1    (I1 = 3/2; spin of 79Br, 81Br) 
F2 = F1 + I2   (I2 = 1; spin of 14N)
*Caminati, W.; Forti, P. Chem. Phys. Lett. 1972, 15,

5. Spectroscopic Parameters of 79BrC5H4N from ab initio and experiments
MP2/
G(d,p)
aug-cc-pVTZ (anharmonic)
Caminati & Forti
This work
A0 /MHz
5886
5886*
5869.7(2)
(16)
B0 /MHz
1020
1030*
(3)
(26)
C0 /MHz
869
876*
(2)
(20)
DJ /kHz -- *
0.0308(9)
DJK /kHz
0.203*
0.203(11)
DK /kHz
1.08*
1.52(39)
d1 /Hz
-5.3*
-5.3(11)
d2 /Hz
-0.80*
-0.81(19)
79Braa /MHz
553.65
474.72*
552.2(12)
(27)
79Brbb /MHz *
-304.4(6)
(21)
79Brcc /MHz *
-248.1(23)
(32)
|79Brab| /MHz
0.2885 *
14Naa /MHz *
-0.085(12)
14Nbb /MHz
-2.996 *
-3.005(12)
14Ncc /MHz
3.026
3.1009*
3.090(17)
|14Nab|/MHz
2.946 *
2.98(28)
Nlines 44
172
RMS /kHz 50
2.5
*During the conference and in following communications we were clarified on an issue with our Gaussian calculations. Specifically that without the keyword “density=current” the calculation would run with the initial calculation wavefunction rather than the wavefunction of the specified theory level. The MP2/6-311G++(d,p) calculation presented here has been re-run, however  the MP2/aug-cc-pVTZ calculation is still in progress. We would like to thank Mark Marshall for his assistance.
Caminati, W.; Forti, P. Chem. Phys. Lett. 1972, 15,

6. Spectroscopic Parameters of 2-bromopyridine
79BrC5H4N
81BrC5H4N
Caminati & Forti
This work
A0 /MHz
5869.7(2)
(16)
5869.9(3)
(17)
B0 /MHz
(3)
(25)
(4)
(28)
C0 /MHz
(2)
(20)
(3)
(20)
DJ /kHz --
0.0308(9)
0.0304(10)
DJK /kHz
0.203(11)
0.204(11)
DK /kHz
1.53(39)
1.53(38)
d1 /Hz
-5.2(11)
-5.2(12)
d2 /Hz
-0.81(19)
-0.78(20)
Braa /MHz
552.2(12)
(23)
460.4(20)
(23)
Brbb /MHz
-304.4(6)
(19)
-252.6(7)
(21)
Brcc /MHz
-248.1(23)
(32)
-207.9(33)
(32)
14Naa /MHz
-0.085(12)
-0.090(12)
14Nbb /MHz
-3.005(12)
-3.001(12)
14Ncc /MHz
3.090(17)
3.091(17)
14Nab /MHz
-2.99(28)
-2.73(34)
Nlines 44
172
173
RMS /kHz 50
2.5
Caminati, W.; Forti, P. Chem. Phys. Lett. 1972, 15,

7. Structural Parameters for 2-bromopyridine
MP2/
G(d,p)
aug-cc-pVTZ
Caminati
&
Forti
This work
C-Br Bond Length r0 /Å
1.903
1.890
1.88(1)
1.8983(39)
Br NQC Asymmetry Parameter a
(79BrC5H4N,
81BrC5H4N) , *, *
-0.102(4),
-0.097(7)
(5),
(5)
a is a measure of the asymmetry of the nuclear quadrupole coupling tensor, where  = 𝜒 𝑏𝑏 − 𝜒 𝑐𝑐 𝜒 𝑎𝑎
*During the conference and in following communications we were clarified on an issue with our Gaussian calculations. Specifically that without the keyword “density=current” the calculation would run with the initial calculation wavefunction rather than the wavefunction of the specified theory level. The MP2/6-311G++(d,p) calculation presented here has been re-run, however  the MP2/aug-cc-pVTZ calculation is still in progress. We would like to thank Mark Marshall for his assistance.
Caminati, W.; Forti, P. Chem. Phys. Lett. 1972, 15,

8. Pyridine vs. 2-bromopyridine Structural Analysis
MP2/aug-cc-pVTZ results /Å
pyridine
2-bromopyridine r1
1.341
1.325
C-H1
1.084
1.082 r2
1.343
C-H2
1.080 r3
1.393
1.390
C-H3
1.081 r4
1.391
C-H4
1.079 r5
1.389
C-H5 -- r6
1.394
C-Br5
1.890

9. Reinvestigation of 2-bromopyridine: Anticipating work

10. Acknowledgements Daniel A. Obenchain Wallace (Pete) Pringle
Stephen A. Cooke
Susanna Stephens
Wilman Orellana
Eric A. Arsenault
Angela Y. Chung
Yoon Jeong Choi
Stewart E. Novick
Novick Group
*not pictured above: Robert Melchreit