טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentZolotarev Vadim
SubjectSynthesis and Biosynthesis of pi-Conjugated Obligopeptides
DepartmentDepartment of Chemistry
Supervisor Professor Yoav Eichen


Abstract


The development of more compact and faster-reacting elements of electronic circuits is responsible for the success of computer industry in the past three decades. Nevertheless, it is believed that the current method of fabricating integrated circuits, based on photolithography, is approaching its limitations. Therefore, new fabrication methods should be developed in order to support the steady-state growth of computer complexity.


In 1974 Ratner and Aviram offered the use of single organic molecules as building blocks of electric circuits. To date, constructing molecular based electronic circuitry is still to be attained. The major obstacle is probably due to the lack of an "engineer-approach" to organic synthesis, namely assembling relatively simple building blocks into complex functional systems like LEGO bricks, one at a time, using sequence independent means.


It was shown by others that amide bond supports the electron delocalization in aromatic polyamides; hence π-conjugated aromatic polyamides can serve as potential nanowires.


In the present work we report on the preparation of di- and tripeptides based on 5-aminothiophene-2-carboxylic acid. We showed that solution of the dipeptide in tetrahydrofuran reversibly changed its color from yellow to red after the addition of triethylamine, presumably because of the increased p-conjugation of amide bond upon deprotonation. In the crystal structure of the dipeptide, we found a supramolecular packing that resembled β-sheets of natural polyamides. Attempts to couple N- to C-protected 6-aminonicotinic acid by reagents used in solid phase peptide synthesis failed, probably because of the weak nucleophilicity of this aromatic amino acid.