Date of Award
Chemistry and Biochemistry
Reported here is the first octaalkylthiosubstituted tetraazaporphyrin (TAP) that contains four terminal carboxylic acid groups to generate an amphiphilic TAP for applications in LB films and self-organizing materials. A key step of the chosen synthesis is the step-wise alkylation of sodium maleonitriledithiolate, with two different alkyl bromides and has not been reported previously. The formation of dialkylthio-maleodinitrile side-products with two identical side-chains could not be avoided when the reactions were conducted in round bottom flasks (batch reactor) but selective monoalkylation and dialkylation was achieved in a flow reactor. However, the three different dialkylthio-maleodinitrile products could be separated by chromatography because of their different numbers of carboxylic ester groups. Conversion of the dialkylthio-maleonitrile derivatives to the TAP macrocyclic was achieved by the established Mg templated cyclization in refluxing propanol as long as the carboxylic acid groups are protected as esters. The obtained tetra-ester TAP was demetallated in acetic acid and hydrolyzed to the tetra-acid in warm potassium hydroxide following procedures previously reported for octa-acid TAPs
ABDULHAMIED, ELMAHDY, "First Synthesis of Amphiphilic Octa-Alkylthio Substituted Tetraazaporphyrin Derivatives with Four Terminal Carboxylic Acid Groups" (2016). Electronic Theses and Dissertations. 5794.