Online Seminar Announcement: Thursday 4 June 2020

Due to the cancellation of many scientific conferences, the AUCAOS committee is pleased to announce an online seminar series. We intend to run seminars on the first Wednesday of every month until normal conferences can resume.

Date: Thursday 4 June

Time:
1pm (QLD, NSW, ACT, Vic, Tas)
12:30pm (SA, NT)
11am (WA)
3pm (New Zealand)

Click this link to join the meeting: https://jcu.zoom.us/j/99887544733?pwd=TVk1ZFl3WGtSWHJmMTM3dG9BVk1jQT09

Seminar schedule
Each talk is 20 minutes duration followed by approximately 5 minutes for questions and discussion.

Time (QLD time, adjust as needed): Presentation:
1:00 – 1:25pm An introduction into synthetic molecular motors

Jos Kistemaker
The University of Queensland

Scientific advances made in the last three decades, inspired by Nature’s example, has led to a diverse collection of synthetic molecular machinery. A prominent example of this machinery is the molecular motor developed by Feringa and co-workers which is based on a light driven overcrowded alkene. The study of several generations of molecular motors and their properties have had primarily academic merit, however, later developments have shown that these nanomachines can be used to do actual work and might prove to be the driving force in the transition to actual applications.
This talk will provide an introduction into the field of synthetic molecular motors with an emphasis on light driven rotary motors. The role of autonomy and chirality in different designs will be highlighted and several examples will be used to showcase the expression and translation of these features to other groups, molecules and larger scales.

1:25 – 1:50pm Electronic coupling: A significant contributor to electron transfer between similarly structured surface-bound porphyrins and Co2+/3+ complex electrolytes

Mr Inseong Cho
University of Wollongong

Electronic coupling is often assumed to play a minor role in interfacial electron transfer (ET) between similarly structured electron donors and acceptors. To check this assumption, we investigated the ET kinetics between four surface-bound free-base and Zn porphyrins and five Co2+/3+ complexes redox mediators with different ligands using transient absorption spectroscopy (TAS). The ET rates measured in this work are the fastest reported in the literature for surface-bound molecules and donors dissolved in electrolytes. By using a novel sub-ns TA setup, the importance of enhanced TAS time-resolution is demonstrated. Fitting the measured ET rate versus –ΔG resulted in poor fits with unrealistic trends in reorganisation energy values. This is explained by up to 60% variation of the electronic coupling (HDA) depending on the size of the alkyl-substituent of the Co2+/3+ complexes redox mediator. The HDA values obtained by assuming a constant reorganisation energy are shown to be dependent on tunnelling distances, characterised by tunnelling attenuation factor βel = 0.16 to 2.0 Å-1. This work suggests that changes in electronic coupling even by small structural modification previously considered negligible can be as significant as the effect of driving force.

1:50 – 2:00pm Open discussion

 

During the seminar:

  • Please keep your microphone muted unless you are speaking. This is to reduce the background noise and avoid disrupting the presenter.
  • You will be automatically muted when you join the virtual meeting room. To speak, you will need to unmute yourself by using the audio controls in the lower left of the Zoom window.
  • If you have not used Zoom before, then it is recommended that you join 5 minutes before the starting time to ensure that you have your software set up correctly.

Please be aware that the talks will be recorded and posted on the AUCAOS website.

Previous seminars

Previous seminars can be viewed here: https://seminars.aucaos.org.au/

Call for abstracts

Seminars are held on the first Wednesday of each month.

In the spirit of building a community in these challenging times, you are encouraged to give a talk. Do you have a talk that you would have given at a conference that was cancelled? Please consider adapting that talk for this format.

Submit abstract by email to bronson[dot]philippa[at]jcu[dot]edu[dot]au.