Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List

Full text release has been delayed at the author's request until September 01, 2026

ETD Abstract Container

Abstract Header

Photochemistry of Vanadium Clusters and Applications For Responsive Materials

Edirisinghe, E.A. Kalani D.
http://orcid.org/0000-0001-9261-7216
http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1657130290259526

Abstract Details

2022, Doctor of Philosophy (Ph.D.), Bowling Green State University, Photochemical Sciences.
A new, reversible photochemical transformation of V(V) tartrate clusters into V(IV) tartrate is described. While the initial V(V) tartrate cluster and photoproduct are known, this research uncovers a previously unreported photochemical transformation. Irradiation of V(V) tartrate in buffer at pH 5.8 showed color changes from orange yellow through a green intermediate to purple, developing a UV-vis spectrum characteristic of V(IV) tartrate. X–ray crystallography revealed an initial tetranuclear Na5[V4O8(2R,3R–tart) (2S,3S–tart)] •11H2O, and final photoproduct in solution which crystallized to a Na4[(VO)2(2R,3R–tart) (2S,3S–tart)] •12H2O dimer. EPR spectroscopy confirmed the reduction from diamagnetic V(V) to paramagnetic V(IV) photoproduct. CO2 was also produced during photolysis, indicating oxidation of the tartrate ligand during photolysis. These results highlight how light irradiation tunes the oxidation state of V(V/IV) clusters and thus these species have the potential to control the reactivity of these vanadium-based catalysts using light. Incorporation of the transition metal V(V) into hydrogels has been used to impart photo-responsive behavior which was used to tune materials properties during light irradiation. The photoreaction in the cellulose-agarose hydrogels coordinated with vanadium was evidenced by a clear color change of yellow to blue through a green intermediate. This color change was attributed to the reduction of V(V) to V(IV) as described above. A concomitant oxidative breakdown of the polysaccharide chain was noticeable upon the reduction of V(V) with a decrease in stiffness (G’) of the hydrogel material. This reduction of the metal ion and breakdown of polysaccharide chain induce irreversible changes in the microstructure of the hydrogel which enables the controlled delivery of V(IV) and/or encapsulated cargo. Polyaniline (PANI) is a famous conductive polymer. When V(V) was reduced to V(IV) upon irradiation, this ultimately causes an oxidative polymerization for polyaniline on hydrogels. Thus, we have developed conductivity in cellulose-agarose hydrogels with the light responsive properties of vanadium. Thus, we explained the photochemistry in vanadium tartrate clusters and developed interesting macroscopic effects with the light responsive properties of vanadium at the molecular level.
Alexis D. Ostrowski, Ph.D. (Committee Chair)
Nathan S. Hensley, Ph.D. (Other)
Malcolm D.E. Forbes, Ph.D. (Committee Member)
George S. Bullerjahn, Ph.D. (Committee Member)
155 p.
Chemistry; Organic Chemistry; Polymer Chemistry
Vanadium; Photoresponsive clusters; Polysaccharides; Hydrogels; Conductive hydrogels; Polyaniline; Photochemistry; Photoreduction; Metal coordination; Bioavailable; Bioinorganic; quaternized cellulose; vanadium tartrate; agarose

Recommended Citations

Citations

  • Edirisinghe, E.A. K. D. (2022). Photochemistry of Vanadium Clusters and Applications For Responsive Materials [Doctoral dissertation, Bowling Green State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1657130290259526

    APA Style (7th edition)

  • Edirisinghe, E.A. Kalani. Photochemistry of Vanadium Clusters and Applications For Responsive Materials. 2022. Bowling Green State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1657130290259526.

    MLA Style (8th edition)

  • Edirisinghe, E.A. Kalani. "Photochemistry of Vanadium Clusters and Applications For Responsive Materials." Doctoral dissertation, Bowling Green State University, 2022. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1657130290259526

    Chicago Manual of Style (17th edition)

bgsu1657130290259526
© 2022, all rights reserved.
This open access ETD is published by Bowling Green State University and OhioLINK.