Ab-initio investigations on H-bonded molecular clusters [Elektronische Ressource] / vorgelegt von Dominik Schemmel

Informations

• Publié par: universitat_regensburg
• Publié le: 01 janvier 2010
• Nombre de lectures: 42
• Poids de l'ouvrage: 9 Mo

Extrait

Ab initio Investigations
on H Bonded
Molecular Clusters
Dissertation
zur Erlangung des Doktorgrades der Naturwissenschaften (Dr. rer. nat.)
der Fakultat IV¨
- Chemie und Pharmazie -
der Universita¨t Regensburg
vorgelegt von
Dominik Schemmel
aus Stuttgart
Regensburg 2010Promotionsgesuch eingereicht am: 17. September 2010
Tag des Kolloquiums: 12. November 2010
Diese Arbeit wurde eingeleitet von: Prof. Dr. Martin Schutz¨
Promotionsausschuss
Vorsitzender: Prof. Dr. J¨org Daub
Erstgutachter: Prof. Dr. Martin Schutz¨
Zweitgutachter: Prof. Dr. Bernhard Dick
Drittpru¨fer: Prof. Dr. Arno PfitznerDie Ergebnisse dieser Arbeit sind bereits ver¨offentlicht worden:
Kapitel 2
D. Schemmel and M. Schutz¨
”Phenol-water revisited: An ab initio study on the photophysics1≤n≤3
of these clusters at the level of coupled cluster response theory”
Journal of Chemical Physics, 127, 174304 (2007), doi: 10.1063/1.2794037
Ausgewahlt fur: Virtual Journal of Biological Physics Research, 14/10 (2007).¨ ¨
Kapitel 3
D. Schemmel and M. Schutz¨
”The 2-naphthol-water cluster: Two competing2
types of hydrogen-bonding arrangements”
Journal of Chemical Physics, 129, 034301 (2008), doi: 10.1063/1.2952271
Kapitel 4
D. Schemmel and M. Schutz¨
”Molecular aniline clusters. I. The electronic ground state”
Journal of Chemical Physics, 132, 174303 (2010), doi: 10.1063/1.3419505
Kapitel 5
D. Schemmel and M. Schutz¨
”Molecular aniline clusters. II. The low-lying electronic excited states”
Journal of Chemical Physics, 133, 134307 (2010), doi: 10.1063/1.3488227
Kapitel 6
D. Hoppe, D. Schemmel, M. Schu¨tz and A. Pfitzner
”Nb and Ta adduct compounds: Connecting
0d metal chlorides and phosphorus sulfide cages”
Chemistry - A European Journal, 15, 7129-7138 (2009),
doi: 10.1002/chem.200900370Acknowledgements
First I thank Prof. Dr. Martin Schu¨tz for the supervision of my doctoral studies.
I am very grateful for his expert advice and all his time and support.
I am indebted to Dr. Diana Hoppe and Prof. Dr. Arno Pfitzner for fruitful coop-
eration and all their ideas, expertise and dedication.
Iamgratefultoallmyinstructorsinthefieldoftheoreticalandphysicalchemistry.
Thisworkwouldnothavebeenpossiblewithoutoutstandingteacherssharingtheir
knowledge and fascination for science.
I thank my colleagues Dr. Denis Usvyat, Dr. Uwe Birkenheuer, Dr. Keyarash Sa-
deghian, Dr. Danylo Kats, Marco Lorenz, Stefan Loibl, Thomas Merz and Katrin
Freundorfer for their support, friendliness, and the time we shared. I am grateful
to Klaus Ziereis for helping me whenever technical difficulties appeared.
Financial support from the Deutsche Forschungsgemeinschaft (DFG) is gratefully
acknowledged.
This thesis is dedicated with love and gratitude to my family and friends.Contents
1 General introduction 3
1.1 Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3 Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.3.1 Synopsis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.3.2 Supermolecule method . . . . . . . . . . . . . . . . . . . . . 9
1.3.3 Coupled cluster model . . . . . . . . . . . . . . . . . . . . . 10
1.3.4 MP2 and CC2 . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.3.5 Spin component scaled methods . . . . . . . . . . . . . . . . 12
1.3.6 Local approximation . . . . . . . . . . . . . . . . . . . . . . 13
1.3.7 Density fitting approximation . . . . . . . . . . . . . . . . . 13
1.4 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2 Phenol-water clusters 151≤n≤3
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2 Computational Methods . . . . . . . . . . . . . . . . . . . . . . . . 18
2.3 Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3.1 Minimum energy geometries . . . . . . . . . . . . . . . . . . 20
2.3.2 Conical Intersection and Proton Transfer . . . . . . . . . . . 30
2.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3 2-Naphthol-water clusters 332
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.2 Computational methods . . . . . . . . . . . . . . . . . . . . . . . . 35
3.3 Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.3.1 S minimum-energy geometries . . . . . . . . . . . . . . . . 370
3.3.2 S minimum-energy geometries . . . . . . . . . . . . . . . . 431
3.3.3 Excitation energies and transition moments . . . . . . . . . 48
3.3.4 Vibrational modes . . . . . . . . . . . . . . . . . . . . . . . 52
3.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
4 Aniline clusters in the electronic ground state 55
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
1Contents
4.2 Computational methods . . . . . . . . . . . . . . . . . . . . . . . . 57
4.3 Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.4 Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.4.1 Structures and interaction energies . . . . . . . . . . . . . . 61
4.4.2 Vibrational frequencies of the N–H stretch modes . . . . . . 68
4.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5 The low-lying electronic excited states of aniline clusters 71
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
5.2 Computational methods . . . . . . . . . . . . . . . . . . . . . . . . 73
5.3 Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 74
5.3.1 The aniline dimer, An . . . . . . . . . . . . . . . . . . . . . 742
5.3.2 The aniline trimer, An . . . . . . . . . . . . . . . . . . . . . 793
5.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
6 Adducts of tantalum chlorides and phosphorus sulfide cages 85
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
6.2 Computational methods . . . . . . . . . . . . . . . . . . . . . . . . 86
6.3 Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.3.1 Constitution and packing. . . . . . . . . . . . . . . . . . . . 87
6.3.2 Conformation . . . . . . . . . . . . . . . . . . . . . . . . . . 89
6.3.3 Bond lengths . . . . . . . . . . . . . . . . . . . . . . . . . . 91
6.3.4 Alternative coordination modes . . . . . . . . . . . . . . . . 95
6.4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
7 Summary 103
Bibliography 106
21 General introduction
1.1 Preface
Starting from the time of the ancient Indians and Greeks we know about the
concept that the microscopic world around us is built of smallest units. Two and
a half millenia later there is no doubt that the matter around us is composed of
distinct molecules and macromolecular structures which themselves are consisting
of nuclei and electrons. This gluing of the atoms to extended structures is due
to the formation of chemical bonds, i.e. a stable equilibrium of the electrons and
nuclei in their mutual electric fields.
However,regardingthemacroscopicbehaviorofgasesandliquids,evenourdaily
experiences tell us that also attractive and repulsive forces between the molecules
havetobepresent,sincetheworldarounduscanneitherbearbitrarilycompressed
norevaporated. Startingfromthenineteenthcenturythistopichasbeenaddressed
by science. Whereas the ideal gas law assumes non interacting and non colliding
molecules, startingwithvanderWaalsandhisfamouscorrectionstothisequation,
the field of intermolecular interactions has been founded.
Figure 1.1: Exemplary intermolecular potential function.
31 General introduction
A typical intermolecular potential curve can be estimated as seen in figure 1.1.
The steep incline at small distances shows that the volumes of the interacting
molecules refuse to penetrate each other. At very large distances, the interaction
iszero,beingconformwiththegoodapplicabilityoftheidealgaslawondescribing
gases of low density. At intermediate distances, attractive forces and a minimum
can be assumed, reflecting the observation that a gas can condense into a liquid,
because the molecules tend to glue to each other. Usually the depth of the mini-
mum is shallower than that of a chemical bond, since a phase transition can take
place without altering the bonding patterns in the molecules. Whereas the bind-
ing energy of the weakest covalent bonds start at approximately 50 kcal/mol, the
intermolecular binding energies lie in the range of a few kcal/mol only.
Interestingly, thepresenceofintermolecularforceseminentlyinfluencesourview
onourenvironment. Theyarenotonlycrucialforthedescriptionofthefluids, but
also influence chemical reactions in solvents. The vast field of biochemistry mainly
describes systems and reactions in aqueous solution. The macroscopic properties
of elastic polymers and the folding of proteins are all governed by intermolecular
forces. Furthermore the biological phenomena such as the climbing abilities of the
Tokay geckos rely on weak intermolecular interactions [1]. There are numerous
further examples.
From the physica