Doctoral defence in Chemistry - Arnar Hafliðason | University of Iceland Skip to main content

Doctoral defence in Chemistry - Arnar Hafliðason

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When 
Fri, 12/07/2018 - 14:00 to 16:00
Where 

Askja

Room 132

Further information 
Everybody welcome

Ph.D. student: Arnar Hafliðason

Dissertation title: Multiphoton dynamics and energetics of halogen containing reagents by mass resolved REMPI and velocity map imaging

Opponents: 
Dr.  Timothy Wright, Professor of Physical and Theoretical Chemistry, Nottingham University, UK.
Dr. Ragnar Jóhannsson, Head of Aquaculture Division Marine and Freshwater Institute of Iceland.

Advisor: Dr. Ágúst Kvaran, Professor at the Faculty of Physical Sciences, University of Iceland

Other members of the doctoral committee: 
Dr. Gísli Hólmar Jóhannesson, physical chemist and teacher at Keilir, Iceland.
Dr. Ragnar Björnsson, physical chemist and group leader at Max Planck Institute for Chemical Energy Conversion, Mulheim, Germany.
Dr. Kristján Matthíasson, physical chemist and Adjunct Lecturer at the Faculty of Physical Sciences, University of Iceland and teacher at Tækniskólinn, Iceland.

Chair of Ceremony: Dr. Oddur Ingólfsson, Professor and Head of the Faculty of Physical Sciences, University of Iceland.

Abstract:
The research focused on multiphoton dynamics and fragment formation for HBr, DCl, and bromomethanes, using mass resolved multiphoton ionization (MR-MPI) and velocity map imaging (VMI) techniques. Data interpretations were based on analysis of (2+n)REMPI spectra, kinetic energy release spectra (KERs) and angular distributions of ions formed. Experiments for HBr revealed perturbations due to interactions between triplet (3S) and singlet (1S) states, seen as line-shifts (LS) and line-intensity (LI) alterations in MR-REMPI spectra, and intensity anomalies in VMI data. DCl studies revealed five new Rydberg states, and eight new vibrational states of the ion-pair state, as well as strong perturbation effects between 1S Rydberg and 1S ion-pair state, seen as LS and LI effects, and chlorine isotope shifts. Comparison with analogous data for HCl was performed. Highly perturbed spectral region of four Rydberg states in CH and CD, caused by interaction with a repulsive state, was inspected via multiphoton photodissociation of bromoform in MR-REMPI. In addition to LS and LI effects, linewidth (LW) broadenings, were evident. Four band origins were assigned. A number of Rydberg states of CH3Br in two-photon excitation region of 66 000 – 80 000 cm-1 were resonantly excited. The multiphoton dynamics was explored with both one- and two-colour excitation schemes. One-, two- and three- photon initial excitations were found to form ground state fragments CH3 and Br/Br*, whereas CH3 Rydberg states along with Br/Br* were found to be the major products following three-photon excitations prior to ionization. Interaction between Rydberg and ion-pair states is found to be evident.

About the doctoral candidate:
Arnar Hafliðason graduated from the natural sciences track at Kvennaskólinn in Reykavik in 1998. In 2008 he completed his B.Sc. in chemistry at the University of Iceland and subsequently worked for Roche NimbleGen until 2013.

In 2013 he started his Ph.D studies in Chemistry at the University of Iceland.

Arnar’s parents are Arndís Sigurðardóttir and Hafliði Guðmundsson (1941-2011). Arnar has one brother, Sigurður Hafliðason, and a 4-year-old daughter, Elísa N. Arnarsdóttir.

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Arnar Hafliðason

Doctoral defence in Chemistry - Arnar Hafliðason