Pyrroles fused with aromatic rings (isoindole derivatives) have been readily prepared by the reaction of aromatic nitro compounds with ethyl isocyanoacetate in the presence of DBU. The ease of this reaction depends on the aromaticity of the starting nitro aromatics. Polycyclic aromatic nitro compounds such as 1-nitroacenaphthylene or 9-nitrophenanthrene are more reactive than simple nitro aromatics such as nitrobenzene or nitronaphthalenes and give the corresponding pyrroles in good yields. Pyrroles prepared by this method have been converted into porphyrins fused with various aromatic rings by the reduction with LiAlH, followed by treatment with an acid catalyst and oxidation with chloranil or oxygen. Tetra-lY2-naphthoporphyrin has been prepared by the reaction of 2-nitro-3,4dihydronaphthalene or 1-nitronaphthalene with ethyl isocyanoacetate followed by reduction, tetramerization and oxidation. Thus, highly conjugated porphyrins are readily prepared starting from aromatic nitro compounds, and their electronic and optical properties can be controlled by choice of the starting aromatic nitro compound.

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Communications of Au on Si/Si02, fabricated using e-beam writing and with PMMA as the rcsist films. Before casling of the PDMS replicas, the original Cr master was silanized with ChFI3CZH4SiCl3 solution in hexane (-2%, wiw) to avoid sticking of PDMS to the surfaces of the Si/Si02; the Au masters were treated with C6FLIC2H4SiC13 solution in hexane and CbF13C2H4SH solution (-2 mM) in ethanol to avoid sticking of PDMS to the surfaces of the Sii Si02 and Au. AFM images of Figure 3 were obtained using a Topometrix TMX 2010 scanning probe microscope (Mountain View, CA); the images were obtained in the contact mode with a supertip (Model # 1700-00). Fig. 3. AFM images of A) Au master before it was used to cast PDMS replicas; B) Au master after it has been used to cast seven PDMS replicas; C) the first PU replica produced from the fourth PDMS master cast from the Au master; D) the sixth PU replica cast from the fifth PDMS master cast from this Au master; E) another Au master before it was used to cast PDMS replicas; .and F) the PU replica generated from a PDMS master (cast from this Au master) while this elastomeric master was mechanically deformed by bending.

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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.