The Wanaka group was formed in February 2013, becoming the 9th Regional branch of the Royal Society of New Zealand which is based in Wellington. Consistent with the aims of the central organisation, the main objective of the Wanaka Branch is to advance and promote science, technology and humanities in Wanaka and the Wanaka region. Read more on the history and philosophy of the Branch.
The Branch seeks to achieve this by offering a series of 6 to 10 lectures each year. It aims to bring speakers who are highly regarded in their field of knowledge and expertise, as well as good communicators. Each year a number of eminent national and international speakers, who tour New Zealand under the umbrella of the Royal Society Wellington are included in the programme.
The Wanaka Branch is constituted as an unincorporated society and comprises a membership who appoint an executive committee at an AGM held in May each year. Members receive advance notices of lectures and other communications by email. Lectures are open to the public, and usually held at 6pm on a Friday in the Presbyterian Community Centre, 91 Tenby St, Wanaka.
Speaker: Professor Keith Gordon, Department of Chemistry, University of Otago.
Vibrational spectroscopy is a potent method of analysing molecular structure within small volumes and at fast timescales. In this presentation I will try to cover off three related but distinct areas of interest.
Firstly, I will discuss how using a suite of spectroscopic methods, and by studying a series of complexes (metal-based donor-acceptor systems) in which parameters are carefully controlled,1 it is possible to develop design principles for excited state properties such that one can enhance electronic absorption and increase excited state lifetimes.2 Useful properties in both solar cells3 and photocatalysis. The understanding of how these properties, both ground and excited state, are modulated by driving force and effective conjugation is not straightforward.
Secondly, the use of computational chemistry in modelling properties of compounds has become ubiquitous in modern chemistry. However these do not always predict molecular behaviour effectively and unpicking the extent of deviation between theory and experiment reveals some interesting problems in our reliance on computational methods.4 Our studies on the spectroscopy of donor-acceptor and π, π* systems highlight these issues.5
Finally, our experimental development, originally aimed at understanding ground and excited state properties of metal complexes and other donor-acceptor systems, has provided us with tools that are amenable to analytical spectroscopy. These are critical techniques that can add value to products in New Zealand. I will outline some of these in the study of primary produce and pharmaceuticals. More recently we have used low-frequency Raman spectroscopy6 to evaluate crystallinity (and order in general) in structures as varied as solar cell polymers7 to active pharmaceutical ingredients.8 Our studies in these areas will also be described.
Speaker: Emeritus Professor Colin Townsend, University of Otago
You may not be surprised to learn that if New Zealand’s rivers were to be placed end to end they would total 9,471 km in length. But did you know that the streams that feed those rivers total more than 400,000 km! Did you know that the beds of such streams that have been reached by the introduced brown trout tend to be more slippery than those still occupied by native fish? Or that an ancient whitebait species became ‘landlocked’ into headwater streams of the South Island and evolved into 12 or more new non-migratory species? Or that streams whose beds are disturbed at an intermediate rate have a higher biodiversity than streams turned over by more frequent spates or not disturbed at all? Or which of the human-caused impairments (nitrogen, sediment, water abstraction, increased temperature) is most harmful to stream ecosystems? Well nor did I - until my research team started work three decades ago.