Synthesis of new mediators for electrochemical nad/nadh recycling

Khalily, Mohammad Aref
The synthesis of enantiopure compounds can be achieved by using dehydrogenases as biocatalysts. For instance, reduction reactions of prochiral compounds (ketones, aldehydes and nitriles) into chiral compounds can be achieved by dehydrogenases. These dehydrogenases are cofactor dependent where cofactor is Nicotinamide Adenin Dinucleotite having some restrictions that confines usage of dehydrogenases in organic synthesis including instability of cofactor in water and high cost. Therefore, suitable recycling methods are required and developed which are enzymatic and electrochemical. We will use an electrochemical approach for the regeneration of reduced co-factors. All active compounds; mediator, cofactor and enzyme, will be immobilized on the electrode surface of the constructed reactor surface. Therefore only educts and products will exist in the reactor medium. A gas diffusion electrode will be employed as a counter electrode; which delivers clear protons to the system. Mediator will carry electrons to the cofactor for cofactor regeneration. Then, enzyme will utilize the cofactor and change the substrates to the products in high stereoselectivity. Our aim in this project is the synthesis of mediators and suitable linkers for enzyme, cofactor and mediator immobilization. In the first part of the study, mediators were synthesized which are pentamethylcyclopentadienyl rhodium bipyridine complexes. In the second part of the study, a conductive monomer (SNS) and linker were synthesized for immobilization of the enzyme. In the last part of the study, the reaction of galactitol dehydrogenase with monomer (SNS) was achieved.


Electrochemical copolymerization of thiophene containing pseudo-polyether cages with pyrrole
Cihaner, Atilla; Önal, Ahmet Muhtar (2006-01-01)
Conducting copolymers were synthesized via the electrochemical oxidation of pyrrole (Py) in the presence of the monomer 1,12-bis(2-thienyl)-2,5,8,11-tetraoxadodecane (1). The presence of monomer I in the electrolytic solution greatly changed the CV behavior of Py during its potensiodynamic polymerization. The electroactivity of poly(I-co-Py) increased with the increasing amount of I in the comonomer mixture. Copolymer films were prepared via constant potential electrolysis in an electrolytic solution contai...
Synthesis and electrochromic properties of conducting polymers of 4-(2,5-di(thiophen-2-yl)-1h-pyrrol-1-yl) benzenamine and their use in electrochromic devices
Yıldız, Ersin; Toppare, Levent Kamil; Department of Chemistry (2009)
A monomer, 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl) benzenamine (SNS-NH2), was synthesized via the reaction of 1,4-di(2-thienyl)-1,4-butanedione with benzene-1,4-diamine. Chemical polymerization of the monomer yielded a polymer which was completely soluble in organic solvents. The chemical structures of both the monomer and the polymer were characterized by Nuclear Magnetic Resonance Spectroscopy (1H-NMR and 13C-NMR) and Fourier Transform Infrared (FTIR) Spectroscopy. The average molecular weight of the che...
Synthesis and characterization of a bifunctional amido-thiophene monomer and its copolymer with thiophene and electrochemical properties
AK, M; Çırpan, Ali; Yılmaz, Fatih; YAGCI, Y; Toppare, Levent Kamil (2005-05-01)
A bifunctional amido-thiophene namely hexamethylene (bis-3-thiophene acetamide) (HMTA) was synthesized by the reaction of 3-thiophene acetic acid with hexamethylene diamine. Copolymerization in the presence of thiophene was achieved electrochemically in tetrabutylammonium tetrafluoroborate/acetonitrile (TBAFB/AN). Spectroelectro-chemical analysis of the resulting copolymer [P(HMTA-co-Th)] reflected electronic transitions at 505 nm, 740 nm and similar to 1000 nm, revealing pi to pi* transition, polaron and b...
Electrochemical copolymerization of 2-substituted thiophene derivative linked by polyether bridge with thiophene
Cihaner, A; Önal, Ahmet Muhtar (2005-09-01)
New conducting copolymers have been synthesized via electrochemical oxidation of thiophene (Th) in the presence of monomer bis(2-thienyl)ethyl (1). Cyclic voltammetry (CV) studies showed that the presence of monomer I in the electrolytic solution greatly changes the CV behaviour of the formation of the polythiophene films. It is found that the increasing ratio of I was found to decrease electroactivity of copoly(I-Th). Electrochemical synthesis of copolymer films was achieved via constant potential electrol...
Synthesis of Fe-4.6 wt% B alloy via electro-deoxidation of mixed oxides
Ors, Taylan; Tan, Serdar; Öztürk, Tayfur; Karakaya, İshak (2009-07-01)
Fe-4.6 wt% B alloy was synthesized via electro-deoxidation of the mixed oxide precursor. The oxides, Fe2O3 and B2O3, mixed in suitable proportions were sintered at 900 A degrees C yielding pellets with a two-phase structure; Fe2O3 and Fe3BO6. The sintered pellets, connected as cathode, were then electro-deoxidized in molten CaCl2 or in CaCl2-NaCl eutectic, against a graphite anode at 3.1 V. The electrolysis at 850 A degrees C has successfully yielded a powder mixture of Fe and Fe2B. Sequence of changes duri...
Citation Formats
M. A. Khalily, “Synthesis of new mediators for electrochemical nad/nadh recycling,” M.S. - Master of Science, Middle East Technical University, 2011.