1. MARIYAM FATIMA 1,2,3, CRISTÓBAL PÉREZ1,2,3 , MELANIE SCHNELL 1,2,3
BROADBAND MICROWAVE SPECTROSCOPY AS A TOOL TO STUDY INTERMOLECULAR INTERACTIONS IN THE DIPHENYLETHER - WATER SYSTEM
MARIYAM FATIMA 1,2,3, CRISTÓBAL PÉREZ1,2,3 , MELANIE SCHNELL 1,2,3
1 Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany, 2Deutsches Elektronen-Synchrotron, Hamburg, Germany 3Christian-Albrechts-Universität zu Kiel, Kiel, Germany

2. INTRODUCTION DIPHENYLETHER (DPE) φ1 φ2 twist φ1 ≈ φ2 ≈ 41° ∆E=0 kJ/mol
O---H
φ1 ≈ φ2 ≈ 41°
∆E=0 kJ/mol π
skew
φ1 = 90°, φ2 = 0°
∆E=1 kJ/mol
Floppy molecule
Two stable conformers (twist, skew)
Most stable: twist conformer
Offers two different docking sites for intermolecular interaction
n = 1, 2, 3
WATER

3. CHIRPED PULSE MICROWAVE SPECTROSCOPY
Sample introduction
2-8 GHz
20 kHz linewidth
Microwave Horn Antenna (Receiver)
Supersonic Expansions
Microwave Horn Antenna (Emitter)
Backing pressure of neon: 3 bar
Temperature for diphenylether: 90° C

4. DIPHENYLETHER-WATER (I): AB INITIO RESULTS
OH---O
OH---π
∆E=1.4 kJ/mol
∆E=0 kJ/mol
Calculated at B3LYP-D3/aug-cc-pVTZ

5. DIPHENYLETHER-WATER (I): EXPERIMENTAL RESULTS
5 million acquisitions, 19 hours measurement
Other lines from DPE monomer, 13C’s of DPE- water (I),
DPE-water (II), DPE-water (III)

6. DIPHENYLETHER-WATER (I): RESULTS
OH---π
State 0-
State 0+
B3LYP-D3/aug-cc-pVTZ
MP2/6-311G++(d,p)
A(MHz)
(42)
(11)
B(MHz)
(14)
(45)
404.91
413.82
C (MHz)
(13)
(43)
366.04
370.50
∆J (kHz)
(85)
0.0235(24)
∆JK (kHz)
0.2683(48)
0.263(21)
µa/µb/µc (D)
0.6/1.1/0.8
1.5/0.13/0.15
σ (kHz)
5.6
6.6
Nlines a
95 (71/0/24)
78 (57/0/21)
a The number of fitted lines.

7. DIPHENYLETHER-WATER (I): RESULTSb a c
OH---O
Experiment (b type)
B3LYP-D3/aug-cc-pVTZ
A(MHz)
B(MHz)
429.67
C (MHz)
341.38
µa/µb/µc (D)
1.3/2.5/0.6
Nlines a 29
a The number of fitted lines.

8. DIPHENYLETHER-WATER (II): EXPERIMENTAL RESULTS
S/N ratio for DPE-water (II) is 450:1

9. DIPHENYLETHER-WATER (II): AB INITIO RESULTS
Calculated at B3LYP-D3/aug-cc-pVTZ

10. DIPHENYLETHER-WATER (II): RESULTS
Experiment
B3LYP-D3/aug-cc-pVTZ
A(MHz)
(24)
850.51
B(MHz)
(13)
391.08
C (MHz)
(13)
335.29
∆J (kHz)
(86)
∆JK (kHz)
0.1766(34)
∆K (kHz)
0.6324(47) δJ
(31) δK
0.142(12)
µa/µb/µc (D)
1.4/1.6/1.4
σ (kHz)
9.9
Nlines a
294 (81/119/94)
a The number of fitted lines.

11. DIPHENYLETHER-WATER: EXPERIMENTAL STRUCTURES
H218O measurement to find the experimental positions of water
Experimental structural positions obtained from Kraitchman method vs results from B3LYP-D3/aug-cc-pVTZ

12. DIPHENYLETHER-WATER (III): EXPERIMENTAL RESULTS

13. DIPHENYLETHER-WATER (III): AB INITIO RESULTS

14. DIPHENYLETHER-WATER (III): RESULTS
Experiment
B3LYP-D3/aug-cc-pVTZ
A(MHz)
(33)
651.20
B(MHz)
(13)
354.10
C (MHz)
(12)
282.18
∆J (kHz)
(56)
∆K (kHz)
0.331(11)
δJ (kHz)
(37)
µa/µb/µc (D)
1.3/1.8/1.8
σ (kHz)
6.9
Nlines a
190 (68/69/53)
a The number of fitted lines.

15. CONCLUSION: DIPHENYLETHER-WATER
skew
twist φ1 φ2
φ1 = 90°
φ2 = 0°
φ1 ≈ φ2 ≈ 41°
∆E=0 kJ/mol
∆E=1 kJ/mol
OH-π
OH-O
φ1 = 47°
φ2 = 35°
φ1 = 50°
φ2 = 31°
DPE-water (II)
DPE-water (III)
φ1 = 70°
φ2 = 19°
φ1 = 87°
φ2 = 7°

16. CONCLUSIONS AND OUTLOOK
Identified diphenylether-water complexes up to three molecules of water.
Addition of water molecule changes the structure of diphenylether from most stable twist structure to skew structure (∆E = 1kJ/mol).
Increase in the intermolecular interaction is stabilizing skew structure of diphenylether. b a c

17. ACKNOWLEGEMENTS Benjamin Arenas MF07 Sérgio Domingos TC03
Cristóbal Pérez
TE09, WG08
Melanie Schnell
RG11
Anna Krin
RG02
Amanda Steber
TH02
Sébastien Gruet
WD07

18. THANK YOU