1. THE STRUCTURE OF PHENYLGLYCINOL
A. SIMAO, I. PEÑA, C. CABEZAS, J.L. ALONSO
Grupo de Espectroscopia Molecular. Unidad asociada CSIC
Laboratorios de Espectroscopia y Bioespectroscopia
Edificio Quifima. Parque Científico
Universidad de Valladolid SPAIN

2. QUADRUPOLE COUPLING HYPERFINE STRUCTURE
Phenylglycinol: unveiling the conformational panorama
0 cm-1
368 cm-1
116 cm-1
QUADRUPOLE COUPLING HYPERFINE STRUCTURE I
III II
14N V IV
AROMATIC AMINO ALCOHOL
674 cm-1
707 cm-1
HIGH FLEXIBILITY
MP2/ G(d,p) level of theory

3. Phenylglycinol: experimental strategy
Broadband CP-FTMWspectroscopy + laser ablation source
EFFICIENT CONFORMATIONAL SEARCH
Rotational constants: A, B, C
14N
2. Narrowband LA-MB-FTMW spectroscopy
Sub-doppler resolution
Nuclear quadrupole coupling constants: aa, bb, cc

4. + CP-FTMW experimental setup CP-FTMW spectroscopy Laser Ablation (LA)
Broadband FT-MW spectrometer
Supersonic Expansion
6-18 GHz
S. Mata I. Peña, et al. J. Mol. Spectr. 280 (2012) 91–96
Picosecond Laser

5. CP-FTMW experimental setupNe
Rotary
Diffusion
pump
Nd:YAG laser

6. CP-FTMW experimental setup
Gas pulse
Jet Ne
Laser pulse
Solid
sample
Rotary
Diffusion
pump
Laser
Nd:YAG laser

7. CP-FTMW experimental setup
spectrometer
Gas pulse
MW field
Polarization Ne
Laser pulse
Chirped MW pulse
Rotary
Diffusion
pump

8. CP-FTMW experimental setup
spectrometer
Gas pulse
Molecular emission Ne
Laser pulse
Chirped MW pulse
Rotary
Diffusion
pump
Detection
Detection
Frequency-domain
Time-domain FT

9. LA-MB-FTMW experimental setup
Laser Ablation Molecular Beam Fourier Transform Microwave Spectroscopy *
LA-MB-FTMW
J. L. Alonso et al. PCCP 11 (2009) 617–627

10. Phenylglycinol: Rotational spectra
J’J’’= 5 4
6 5
7 6
8 7
14N
B + C  1435 MHz
Intense a-type R-branch progressions
Rotamer assigned
LA-MB-FTMW
CP-FTMW

11. SEARCHING FOR THE SECOND CONFORMER…
Phenylglycinol: Results
Theory
Experiment I II
III IV V
Rotamer Aa
3085.2
3053.6
3019.7
2255.3
2459.5
(76)g B
735.7
757.9
756.9
936
918
(24) C
700.9
700.2
699.2
804.3
838
(25)
χaa
-4.54
1.35
1.14
1.91
-0.41
(46)
χbb
2.27
-0.82
-0.84
1.59
-0.6
2.2247(54)
χcc
-0.53
-0.31
-3.49
1.01
2.0444(54) a
-2.8 1
0.3
Observedf b
0.9
-1.7 -1
Observed c
1.4
-0.7
1.3
-0.2
ΔEb
115
330
773
678 -
ΔGc
116
368
674
707 d
2.6 Ne 40
SEARCHING FOR THE SECOND CONFORMER…
OHN
NH H-bonds
[a] A, B, and C represent the rotational constants (in MHz), |µa|, |µb| and |µc| are the absolute values of electric dipole moment components (in D). [b] Electronic energies including zero-point energy correction (in kJmol-1). [c] Gibbs energies calculated at 298 K. [d] Rms deviation of the fit. [e] Number of fitted transitions. [f] Standard error in parenthesis in the units of the last digit. [g]Observation of a-, b-, and c-type transitions for each structure.

12. Phenylglycinol: Isotopic species
13C and 15N isotopologues in natural abundance of the rotamer observed
CP-FTMW

13. Rotational Constants (MHz)
Phenylglycinol: rs structure
Rotational Constants (MHz)
Isotope aA B C
13C2
(60)b
(2)
(4)
13C3
(42)
(2)
(3)
15N4
(3)
(3)
(5)
13C6
(81)
(9)
(2)
13C7
(20)
(1)
(2)
13C8
(101)
(7)
(6)
13C9
(27)
(1)
(2)
13C10
(19)
(9)
(2) C4 C5 C9
C10 C1 N2 O1
C17 C3 C8
Substitution coordinates a b c C3
1.248(28)
-0.17(20)
0.31(11) C4
-1.083(10)
(22)
0.395(72) C5
-2.479(13)
(29)
0.13(26) C8
-3.027(9)
0.16 (22)
-0.31(11) C9
-2.178(10)
1.245(35)
-0.580(79)
C10
-0.690(2)
1.176(40)
-0.533(93)
C17
2.013(5)
-0.24(17)
-0.840(50) N2
1.802(5)
0.8125(20)
1.3474(12)
rs structure
r(C4-C5)
1.426(58)a
 C4C5C8
119.7(46)
r(C5-C8)
1.46(21)
C8C9C10
124.4(62)
r(C8-C9)
1.40(18)
C5C8N2
120.4(27)
r(C9-C10)
1.489(72)

14. Conclusions
Detection of one rotamer of neutral phenylglycinol, which is stabilized by an OH∙∙∙N bond, within the ethanolamine moiety, and one NH∙∙∙π bond with the phenyl ring
The high sensitivity reached with this experimental approach, based on a parabolic reflector system, has allowed the observation of eight monosubstituted isotopic species in natural abundance for the most stable conformer
The combination of CP-FTMW and LA-MB-FTMW represents an excellent experimental approach to face the challenge of investigating biological systems with an expected rich conformational behavior

15. CSD 2009-00038 Molecular Astrophysics
ACKNOWLEDGMENTS
Grupo de Espectroscopia Molecular (GEM) Laboratorios de Espectroscopia y Bioespectroscopia, Unidad Asociada CSIC, UVa,Valladolid, Spain
Grants CTQ ,
AYA and AYA
CSD Molecular Astrophysics
Grants VA070A08 and CIP13/01