Integrated Calendar

http://departments.agri.huji.ac.il/plantscience/people/Yehoshua_Saranga/

Host: Prof. Jonathan Gressel

How do high nuclearity inorganic and supramolecular assemblies form? Can understanding the minimal information content of the structures help us understand their assembly? Is there a general route to explore the mechanism and how can one given compound dominate from a combinatorial explosion of possibilities? In our current work we are using new approaches to probability theory and template design to explore the possibility of using high probability templates to assemble low probability structures with 1000s of atoms in a single molecule. Take the example of a recent molecule discovered in our laboratory: A palladium oxometalate {Pd84}-ring cluster 3.3 nm in diameter; [Pd84O42(OAc)28(PO4)42]70- ({Pd84} ≡ {Pd12}7) which is formed in water just by mixing two reagents at room temperature and can be observed in solution within a few days mixing and crystallised with a week, see Figure 1. The key question is how could a ring as large as the {Pd84} spontaneously form and crystallize within the period of days. Indeed the state space for the molecule, just considering the unique arrangements of distinct 84 Pd atoms, ignoring symmetry, gives an upper limit on the combinatorial space of 84! = 3.3 × 10126. It is therefore perhaps safe to assume that the structure therefore did not ‘spontaneously’ form by random chance, but a series of templating events, combined with the correct kinetics, allowed this cluster to be selected from the vast envelope of possible structures available in solution. In this lecture I will propose a new theory that may explain the mechanism of self-assembly of gigantic systems, as well as an approach to understand and use the information content of complex molecular structures.

10:20 Gathering and coffee