Hydrazine-Modified Topology-Dependent Conductivity of Cyclic NDI as a Molecular Circuit

• Published in: Journal of physical chemistry. C Vol. 126; no. 1; pp. 675 - 682
• Main Authors: Nandi, Sujay Kumar, Díaz, David Díaz, Haldar, Debasish
• Format: Journal Article
• Language: English
• Published: American Chemical Society 13.01.2022
• Subjects: amino acids; C: Physical Properties of Materials and Interfaces; Fourier transform infrared spectroscopy; hydrazine; mass spectrometry; nuclear magnetic resonance spectroscopy; physical chemistry; semiconductors; topology; voltammetry; X-ray diffraction
• ISSN: 1932-7447; 1932-7455; 1932-7455
• DOI: 10.1021/acs.jpcc.1c08659

Significant conductance enhancement can be achieved by topology modification of n-type semiconducting naphthalenediimide (NDI) as a molecular circuit. Hydrazine not only reduces electron-deficient NDI to NDI•–radical anions but also modifies the topology by selectively replacing the amino acid methyl esters from NDI 1 and forms a cyclic NDI nanorim. On treatment with hydrazine, the NDI 1 emission band at 525 nm gradually disappears, and a new band appears at 607 nm, presumably due to NDI oligomer formation. Eventually, a shiny black, almost insoluble precipitate of the NDI nanorim appeared. The cyclic NDI nanorim was characterized by powder X-ray diffraction, high-resolution mass spectrometry, Fourier transform infrared, and 13C CP-MAS NMR spectroscopy. Cyclic voltammetry (CV) of NDI 1 possesses two sequential one-electron cathodic waves at −0.4661 and −0.9456 V versus Ag/Ag+ due to NDI•– and NDI2– formation. However, CV of the NDI nanorim reveals four distinct reversible one-electron waves due to electronic communication between the four NDI redox centers within the nanorim. The I–V measurements show sevenfold conductance enhancements by topology modification from linear NDI to a nanorim.