Title：	A Porous Molecular Network from Tetrahydroxybenzene
Speaker：	Fabian Bebensee ( Aarhus University，Denmark)
Time：	2011-10-14　 10:00
Location：	3#210

 

 

 

 

 

 

 

 

 

Two-dimensional covalently interlinked molecular networks on surfaces exhibiting long-range order are a highly attractive and sought after new class of materials. However, major breakthroughs were not reported from this field until very recently due to persisting problems with the synthesis of networks of substantial extent and high degree of order.

One promising route to generate such complex structures may be the confinement of covalent organic frameworks (COFs) to truly 2-dimensional structures. In this direction, we explore the behavior of a popular building block in COFs, tetrahydroxzbenzene (THB). Surprisingly, this simple molecule shows a quite complex behavior upon adsorption on different metal surfaces under UHV conditions: depending on annealing temperature and initial coverage, it may form a porous network structure or simply dehydrogenate without changing its morphology significantly. Using X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM), we are able to elucidate these processes. Especially the use of two complementary techniques, probing morphology and chemistry, presented a key factor in the understanding of this system.