Arsenault and Stewart E Novick Nitrogen splittings here there and everywhere A Reinvestigation of the Electronic Properties of 2Bromopyridine with High Resolution Microwave Spectroscopy ID: 634460
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Slide1
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 SpectroscopySlide2
High Resolution Microwave Spectroscopy
and 2-bromopyridineSlide3
Predicted Rotational Spectrum
of 2-bromopyridine
Br
81
BrC
5
H
4
N
79
BrC
5
H
4
N
assigned transitionsSlide4
14
N Hyperfine Structure
F
1
= J + I
1
(I
1
=
3/2; spin
of
79
Br,
81
Br)
F
2
= F
1
+ I
2
(I
2
= 1; spin of 14N)
*
Caminati, W.; Forti, P. Chem. Phys. Lett. 1972, 15, 343349.
*
*Slide5
Spectroscopic Parameters of
79BrC5H4
Nfrom ab initio and experimentsCaminati, W.; Forti, P. Chem. Phys. Lett.
1972
,
15
, 343349.
MP2/
6-311
++
G(
d,p
)
MP2/
aug
-cc-
pVTZ
(
anharmonic)
Caminati
&
Forti
This work
A
0 /MHz 58865886*5869.7(2)5869.9333(16)B0 /MHz 10201030*1026.139(3)1026.14510(26)C0 /MHz 869876*
873.377(2)
873.37532(20)
DJ /kHz--0.02989*--
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)79Braa /MHz 553.65474.72*552.2(12)551.750(27)79Brbb /MHz -299.43-262.12*-304.4(6)-304.172(21)79Brcc /MHz -254.22-212.60*-248.1(23)-247.578(32)|79Brab| /MHz 0.2885-0.6896*----14Naa /MHz -0.0297-0.15696*---0.085(12)14Nbb /MHz -2.996-2.9440*---3.005(12)14Ncc /MHz 3.0263.1009*--3.090(17)|14Nab|/MHz 2.946-2.7806*--2.98(28)Nlines----44172RMS /kHz----502.5
Br
*
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.Slide6
Spectroscopic Parameters
of 2-bromopyridine
79BrC5H4
N
81
BrC
5
H
4
N
Caminati
&
Forti
This work
Caminati
&
Forti
This
work
A
0
/MHz 5869.7(2)5869.9333(16)5869.9(3)5869.9260(17) B0 /MHz
1026.139(3)1026.14509(25)
1015.526(4)
1015.52827(28) C0
/MHz
873.377(2)
873.37532(20)
865.669(3)
865.67201(20)
D
J
/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)Braa /MHz 552.2(12)551.750(23)460.4(20)460.899(23)Brbb /MHz -304.4(6)-304.172(19)-252.6(7)-254.098(21)Brcc /MHz -248.1(23)-247.578(32)-207.9(33)-206.801(32)14Naa /MHz ---0.085(12)---0.090(12)14Nbb /MHz ---3.005(12)---3.001(12)14Ncc /MHz --3.090(17)--3.091(17)14Nab /MHz ---2.99(28)---2.73(34)Nlines4417244173RMS /kHz502.550
2.5
Br
Caminati
, W.;
Forti
, P.
Chem. Phys. Lett.
1972
,
15
, 343349.Slide7
Structural Parameters for
2-bromopyridine
Caminati, W.; Forti, P. Chem. Phys. Lett. 1972, 15, 343349.
Br
MP2/
6-311++
G(
d,p
)
MP2/
aug
-cc-
pVTZ
Caminati
&
Forti
This work
C-Br Bond Length
r
0
/Å1.903
1.890
1.88(1)
1.8983(39)
Br NQC Asymmetry Parameter
a
(
79
BrC
5
H4N, 81BrC5H4N)-0.0817, -0.0817-0.1043*, -0.1054*-0.102(4),-0.097(7)-0.1026(5),-0.1026(5)a is a measure of the asymmetry of the nuclear quadrupole coupling tensor, where *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.Slide8
Pyridine vs. 2-bromopyridine Structural Analysis
MP2/
aug-cc-pVTZ
results /Å
pyridine
2-bromopyridine
pyridine
2-bromopyridine
r
1
1.341
1.325
C-H
1
1.084
1.082
r
2
1.341
1.343
C-H
2
1.082
1.080
r
3
1.393
1.390
C-H
3
1.082
1.081
r
4
1.391
1.393C-H41.0821.079r51.3911.389C-H5 1.084--r61.3931.394 C-Br5--1.890pyridine2-bromopyridineSlide9
Reinvestigation of 2-bromopyridine: Anticipating work Slide10
Acknowledgements
*not pictured above: Robert
Melchreit
Eric A. Arsenault
Angela Y. Chung
Susanna Stephens
Daniel A.
Obenchain
Wilman
Orellana
Stephen A. Cooke
Yoon
Jeong
Choi
Wallace (Pete) Pringle
Stewart E.
Novick
Novick
Group