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Fang Wang & Timothy C. Steimle Dept. Chem. & BioChem., Arizona State University, Tempe, AZ,USA
The 65th International Symposium
on Molecular Spectroscopy, June 2010
Optical Stark (and Zeeman) Spectroscopy of the B1A’’(0,0,0)<-X1A’(0,0,0) System of Copper Hydroxide: CuOH
Funded by: NSF
I. Motivation
Copper hydroxide , CuOH, is an ideal molecule because:
a) Nearly filled 3d-orbital
b) Closed shell ground state.
c) Relatively easy to generate
d) Only two isotopes: 63Cu(I=3/2) 69% and 65Cu(I=3/2) 31%
• Bonding in Transition Metal Containing Polyatomic Molecules
Relatively simple electronic state distribution
CuOH is a near prolate symmetric top
a
b
Cu O
H
Previous work -Experimental
Previous work -Theory
No experimental measurement of
Predicted Ground State, X1A’, properties:
total(D)
4.1185.405
5.315
H.F.Scheafer group (2005) total 1.363D
Predicted Excited State, B1A’’, properties:
3.981
a(D)
4.0455.303
5.240
?
Exp. Structure(Whitham et al)
1.77182 0.9616 110.12
B1A’’
Controversy concerning nature of excited states
Ground state
X1A’ (11A’)
Triplet or Singlet?
X1A’ (11A’)
Goals:
B. Comparison with isovalent CuF (J, Chem. Phys. 132 054301 (2010))
and other Cu containing molecules
A. Determination of permanent electric dipole moments
of B1A’’ and X1A’ states for 63CuOH
C. Test for paramagnetism
IV Experimental Set-up
Stark plates
Optical Stark spectroscopy
CH3OH&
Ar(carrier gas)
Well collimatedmolecular beam
Single freq. tunable laser radiation
PMT
Gated photon counter
Metal target (Cu)
Pulse valve
skimmer
Ablation laser
532
Two magnets
Optical Zeeman spectroscopy
0.963”
V The B1A’’-X1A’(0,0,0-0,0,0) band of CuOHField-free LIF Spectrum near the origin of Ka’’=0-Ka’=1 sub-band
N13
65CuOH Q(N’)
24
3
63CuOH Q(N’)
124 N
Next slide
1) Observation for field free spectrum-slow scan
LIF
Sig
nal
95MHz 69MHz
70MHz 50MHz
95MHz67MHz
Laser wavenumber-18400 cm-1
V The B1A’’-X1A’(0,0,0-0,0,0) band of CuOH
Laser wavenumber-18400 cm-1
F2.5
1.50.5
B1A’’N=1
X1A’
rR(000)-pred.
rQ(101)-pred.
rP(202)-pred.
Is the structure due to the nuclear hyperfine interaction? Quadrupole?, Spin-rotation?
Laser wavenumber-18400 cm-1
Caa=50MHz
2) Zeeman effect study
V The B1A’’-X1A’(0,0,0-0,0,0) band of CuOH
1150Gauss
0 Gauss
LIF
Sig
nal
LIF
Sig
nal
1150Gauss
0 Gauss
1150Gauss
0 GaussLIF
Sig
nal
The spectra are only broadenedaround 20MHz
Is the structure due to the nuclear hyperfine interaction?
Is the structure due to 1A/3A mixing? (i.e. spin splitting)1A / 3A mixing
interaction
rR(000)
3) Optical Stark Spectrum of the rR(000) line &the associated energy level pattern
V The B1A’’-X1A’(0,0,0-0,0,0) band of CuOH
Nkakc=000
Nkakc=110
rP(202)
3) Optical Stark Spectrum of the rP(202) line &the associated energy level pattern
V The B1A’’-X1A’(0,0,0-0,0,0) band of CuOH
Nkakc=202
Nkakc=110
rQ(101)
a
bc
*
*
A
B
C
D
EF
3) Optical Stark Spectrum of the rQ(101) line&the associated energy level pattern
V The B1A’’-X1A’(0,0,0-0,0,0) band of CuOH
Stark Induced
Nkakc=110
Nkakc=111
Nkakc=101
VI AnalysisSymmetric top basis function;
Nabasis MKN ,,
CuOH: B1A’’<-X1A’
Rotational structure
Rotational angular momentum operatorRotational Parameters A,B,C
N=0
N=1
N=2
≠0
≠0
Matrix representation of the Stark operator
a for the ground state3.968(32) D
Note: levels studied in X1A’ state are only effected by the “a” component of .
VII Results and Discussions
1) The energy level of excited state is perturbed by the other electronic
states, but the triplet state mixing contribution is small.
63CuOH: B1A’’<-X1A’
2) Comparison with theory: ground state, a (exp.)=3.968(32) D
total(D) a(D) Method Ref.
5.315 5.240 CASSCF C.W.Bauschlicher(1986)
5.405 5.303 SDCI(2) Y. Mochizuki(1991)
4.118 4.045 DK3-CCSD(T)
K. Hirao(2003)
4.118~5.526 K. Hirao(2003)
3.981~5.477 H.E.Schaefer III(2005)
total 1.363~1.843D H.E.Schaefer III(2005)a is less than 0. 5DB1A’’ Exp.
Excited state(B1A’’)
Is this consistent with Schaefer ?
Molecular orbital diagram for CuOH
10
CuOH(x1+) Linear
7
1
8
9
3
4
9a’
10a’
3a’’11a’
4a’’12a’
13a’
15a’
14a’5a’’
CuOH(X1’) Bend
5a”15a’
5a’’(OH3) 15a’(4s/3d0)
a
b
Cu O
H(X1A’)
(5a”15a’)
a
Small !
5a”15a’
(B1A”)
CuF X1 5.26(2 )D1 re=1.745A
CuO X23/2 4.57(3) D3 re=1.724ACuOH X1A’ 3.97(3 )D re=1.772ACuS X2 4.31(15 )D2 re=2.051A
3) Compare the dipole moment with CuF 5.26(2) and other Cu containing molecules for the ground state
F 3.98O 3.44OH 3.03S 2.58
Electronegativity
Molecular beam Laser Induced Fluorescence
1) F. Wang, and Steimle, T. C, THE JOURNAL OF CHEMICAL PHYSICS 132, 054301 20102)T.C. Steimle, W.L. Chang, and D. F. Nachman, J. M. Brown, J.Chem. Phys. 89(12), 19883)X. Zhuang, S. E. Frey and T. C. Steimle (accepted by JCP?)
VII Results and Discussions 63CuOH: B1A’’<-X1A’
3.98
3.58
3.18
2.79
2.39
3.014
2.713
2.411
2.110
1.808
Thank you!
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