Transcript PH3-AgI_Ohio2012.ppt

1
Engineering and Physical Sciences
Research Council
Broadband Rotational Spectrum and
Molecular Geometry of H3PAgI
Nicholas R. Walker, Susanna L. Stephens, Anthony C. Legon
67th International Symposium on Molecular
Spectroscopy, Ohio State University, 2012.
P
Ag
I
water
hydrogen sulphide
What is the nature of the
interaction between each of
these molecules and a
single metal atom in
isolation?
What is the structure of the
complex? What is the bond
distance separating the ligand
and the metal?
carbon monoxide
What is the extent of charge
transfer?
ethene
acetylene
ammonia
Are the observations
consistent with high-level
theory?
Recent Results (r0 structures)
1.914(10) Å
2.062(6) Å
40.9(13)
2.1531(3) Å
2.0633(3) Å
78.052(6)
H2OCuCl rapidly inverts on the
timescale of the molecular
rotation.
2.15444(6) Å
H2SCuCl is
rigidly pyramidal
2.26333(6) Å
NH3AgCl is a symmetric top.
These studies are further described in publications;
Angew. Chem. Int. Ed., 49, 181-183 (2010)
J. Chem. Phys., 134, 134305 (2011)
J. Chem. Phys. 135, 014307 (2011)
Chem. Phys. Lett. 499, 16 (2010)
CP-FTMW Spectrometer
Pin diode limiter
300 W Power
amplifier
SPST switch
Adjustable
attenuator
Low noise amplifier
7.0 - 18.5 GHz
7.0 - 18.5 GHz
Power divider
Mixer
12.2 GHz Low-pass band filter
AWG (0.5-12 GHz)
PDRO (19.00 GHz)
10 MHz reference frequency
Mixer
Oscilloscope (0-12 GHz)
1% H3P, 1% CF3I, 6 bar argon, Ag
66000 shots
[8 hours of averaging]
CF3I
AgI
8000
10000
12000
14000
Frequency/MHz
16000
18000
H3P, CF3I, Ag
AgI
AgI
13400
13600 13800 14000
Frequency / MHz
14200
H3PICF3
10600
10800
11000
11200 11400 11600
Frequency / MHz
H3PAgI
J  J = 8 9
109Ag
H3PAgI
J  J = 10 11
109Ag
107Ag
107Ag
11240 11260 11280
13750 13760 13770
Spectrum Fitting in
PGOPHER
H3P107AgI
H3P109AgI
Exp.
http://pgopher.chm.bris.ac.uk/
C.M. Western
Sim.
Sim.
13740
13750
13760
Frequency / MHz
13770
H3P 107AgI
H3P 109AgI
B0 / MHz
626.01307(23)
624.76423(17)
DJ / kHz
3.182(89) 10-2
3.238(64) 10-2
DJK / kHz
4.46(14)
4.04(10)
aa(I) / MHz
733.83(34)
734.54(27)
N
88
93
 / kHz
12.0
9.0
Structure of H3P109AgI
P
Ag
I
r(PAg) = 2.36588(7)* Å
• Spectrum fit to the Hamiltonian of a symmetric top molecule.
• K-1 = 1 transitions observed so complex contains equivalent hydrogen atoms.
• Structure of the PH3 sub-unit fixed at the rz geometry provided by F.Y. Chu
and T. Oka, J. Chem. Phys. 60 4612 (1974).
• r(AgI) assumed equal to the value of the parameter in the r0 geometry of
OCAgI. This is approximately 0.01 Å shorter than r(AgI) in free AgI.
*The standard deviation of the fit and not the true precision of the quoted bond length.
Nuclear Quadrupole Coupling Constants
LAgCl
aa(Cl) / MHz
1
LAgI
aa(I) / MHz
AgX1
36.4
1062.6
ArAgX2
34.5

KrAgX2
33.8

H2OAgX3
32.3

H3NAgX3
29.8

H2SAgX3
29.4
807.4
C2H2AgX3
28.9
793.7
OCAgX2,3
28.1
769.8
C2H4AgX3
27.9
761.6
H3PAgX3

733.8
C.M. Johnson, R. Trambarulo and W. Gordy, Phys. Rev. 84, 1178 (1951)
2 M.C.L. Gerry and co-workers
3 N.R. Walker, A.C. Legon and co-workers
H3PICF3
Exp.
Sim.
14120
14140
14160
Frequency / MHz
14180
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Acknowledgements
University of Bristol
Susanna L. Stephens
Anthony C. Legon
Newcastle
Bristol
Financial Support
Engineering and Physical
Sciences Research Council