Theoretical Investigation of Compounds with Triple Bonds [Elektronische Ressource] / Deepa Devarajan. Betreuer: Gernot Frenking

Deepa

Informations

• Publié par: philipps-universitat_marburg
• Publié le: 01 janvier 2011
• Nombre de lectures: 59
• Langue: English
• Poids de l'ouvrage: 22 Mo

Extrait

Theoretical Investigation of Compounds with Triple Bonds




Dissertation
zur
Erlangung des Doktorgrades
der Naturwissenschaften
(Dr. rer. nat.)




dem
Fachbereich Chemie
der Philipps-Universität Marburg
vorgelegt von


Deepa Devarajan
aus Puthupatti/Indien






Marburg/Lahn 2011
























Vom Fachbereich Chemie der Philipps-Universität Marburg
als Dissertation angenommen am 05.07.2011


Erstgutachter Professor Dr. Gernot Frenking
Zweitgutachter Dr. Ralf Tonner
Tag der mündlichen Prüfung: 07.07.2011

To












My Parents










































Preface

This thesis presents my work at the Department of Chemistry, the Philipps University of Marburg,
Germany. This study has been carried out from August 2008 until May 2011, under the supervision of
Professor Dr. Gernot Frenking.

I would like to thank Prof. Frenking for his continuous support, guidance, encouragement, and
discussions on my research projects. My special thanks go to Thomas Reuter, Gerda Jansonius,
Susanne Klein, Nozomi Takagi, Moritz von Hopffgarten, Nicole Holzmann, Shimizu Takayasu, and
all the members of the group, “AK Frenking”, for their kind help and support.

Thanks to Dr. Rosalyne Cowie for her invaluable effort in correcting this thesis.

I thank my teachers Prof. D. Vimala Devi and Prof. P. Venuvanalingam for their support,
encouragement, and inspiring lectures during the days of my Bachelor and Master Degrees, which
motivated me to continue on to study a Ph.D. in the field of chemistry.

My heartfelt thanks go to my friends Karthik, Shanthi, Nhung, and Fereshteh and all of my family
members for their moral support and encouragement during my stay in Marburg.

I thank the Deutsche Forschungsgemeinschaft (DFG) for the financial assistance.


Depa Devarjn












Abstract

In this thesis, compounds with potential triple-bonding character involving the heavier main-group
elements, Group 4 transition metals, and the actinides uranium and thorium were studied by using
molecular quantum mechanics. The triple bonds are described in terms of the individual orbital
contributions ( σ, π, and π ), involving electron-sharing covalent or donor–acceptor interactions || ┴
between the orbitals of two atoms or fragments. Energy decomposition, natural bond orbital, and
atoms in molecules analyses were used for the bonding analysis of the triple bonds. The results of this
thesis suggest that the triple-bonding character between the heavier elements of the periodic table is
important and worth further study and exploration.


























Zusammenfassung

In dieser Dissertation wurden Moleküle der schwereren Hauptgruppenelemente, der
Übergangsmetalle der 4. Gruppe und der Actinoide Uran und Thorium auf mögliche Element-
Element-Dreifachbindungen hin mit quantenchemischen Methoden überprüft.

Die einzelnen Komponenten der Dreifachbindungen ( σ, π und π ) werden dabei entweder als ┴ ║
Elektronenpaarbindung oder als Donor-Akzeptor-Bindungen beschrieben. Dazu wurden diese
Bindungen wurden mit der Energiedekompositionsanalyse (EDA), der natürlichen
Bindungsorbitalanalyse (NBO) und der Quantentheorie der Atome in Molekülen (AIM)
untersucht.

Die Ergebnisse dieser Untersuchungen zeigen, dass auch zwischen den schwereren Elementen
Bindungen mit nicht zu vernachlässigendem Dreifachbindungscharakter existieren, die auch
in Zukunft Teil der Forschung auf dem Gebiet der Bindungsanalyse sein sollten.
















Table of Contents

1. Introduction 1

2. Theoretical Background and Methods 3
2.1 Schrödinger Equation 3
2.2 Ab Initio Methods 3
2.2.1 Born-Oppenheimer Approximation 3
2.2.2 Variation Principle 4
2.2.3 Pauli Exclusion Principle 4
2.2.4 Hartree-Fock Approximation 4
2.2.5 LCAO-MO Approximation 6
2.2.6 Configuration Interaction 7
2.2.7 Møller-Plesset Perturbation Methods 8
2.2.8 Coupled-Clusters Methods 8
2.3 Density Functional Theory 9
2.4 Basis sets 12
2.5 Effective Core Potential 13
2.6 Geometry Optmization 14
2.7 Natural Bond Orbital Analysis (NBO) 15
2.8 Energy Decomposition Analysis 16
2.9 Natural Orbitals for Chemical Valence (NOCV) 18
2.10 ETS-NOCV 19
2.11 Topological Analysis of Electron Densities 19

3. Heavier Homologues of HCN-HNC 21
3.1 Introduction 21
3.2 Methods 21
3.3 (H, N, E) System 22
3.3.1 Geometries and Energies 22
3.3.2 Natural Bond Orbital Analysis 23
3.3.3 Energy Decomposition Analysis 27
3.4 (H, P, E) System 28
3.4.1 Geometries and Energies 28
3.4.2 Natural Bond Orbital Analysis 30
3.4.3 Energy Decomposition Analysis 31
3.5 (H, As, E) System 34 3.5.1 Geometries and Energies 34
3.5.2 Natural Bond Orbital Analyses 36
3.6 (H, Sb, E) System 38
3.6.1 Geometries and Energies 38
3.6.2 ses 38
3.7 (H, Bi, E) System 39
3.7.1 Geometries and Energies 39
3.7.2 Natural Bond Orbital Analysis 41
3.7.3 Energy Decomposition Analysis 42
3.8 (H, P, Si) versus (H, Bi, Si) 44
3.9 Summary 49

4. Compounds with Triple Bonds to Sulfur 51
4.1 Introduction 51
4.2 Methods 52
4.3 Nature of the CS bond in HCSF, HCSH, HCSOH and F SCSF 53 5 3
4.3.1 HCSF 53
4.3.2 HCSH 60
4.3.3 HCSOH 63
4.3.4 F SCSF 65 5 3
4.3.5 Topological Analysis 68
4.4 Nature of the SiS bond in HSiSF and HSiSH 71
4.4.1 HSiSF 71
4.4.2 HSiSH 81
4.4.3 Topological Analysis 84
4.5 Nature of the NS bond in NSF, NSH and NSOH 85
4.5.1 NSF 85
4.5.2 NSH 92
4.5.3 NSOH 92
4.5.4 Topological Analysis 92
4.6 Nature of the PS bond in PSF, PSH and PSOH 94
4.6.1 PSF 94
4.6.2 PSH 99
4.6.3 PSOH 100
4.6.4 Topological Analysis 101
4.7 Summary 102