Comparative study of cyclic polyaniline oligomers with linear and bent structures

Coaxially Conductive Organic Wires Through Self-Assembly

“…This observation is consistent with previous theoretical calculations that suggest the frontier orbitals in macrocyclic polyanilines should be evenly spread among the electronically coupled nitrogen centers. 14,15 This is in contrast to linear oligo[n]aniline systems, which have an uneven dispersion of charge density due to the different on-site energies of N-sites in a linear chain (e.g., at chain ends). Doubly oxidized macrocycles assemble into trimers in the solid state.…”

“…In its oxidized and neutral emeraldine base (EB) form, PANI is found to be diamagnetic and demonstrates low bulk conductivity (10 –10 S·cm –1 ). , When proton doped, PANI converts to a highly conductive (10 –2 –10 0 S·cm –1 ) polyradicaloid state . However, structural and electronic inhomogeneity present in PANI and its derivatives produces several orders of magnitude of variation in the bulk conductivity. − Theoretical studies suggest that macrocyclic oligo-anilines will exhibit delocalization of their frontier orbitals and thus will have more uniform electron distribution and enhanced stability. , There are several studies that create functionalized derivatives of N -containing macrocycles, ,− but these macrocycles, due in large part to the tertiary substitution of the heteroatoms or bulky substitution of their backbone, lack the rich redox and pH sensitivity inherent to PANI …”

“…10−13 Theoretical studies suggest that macrocyclic oligo-anilines will exhibit delocalization of their frontier orbitals and thus will have more uniform electron distribution and enhanced stability. 14,15 There are several studies that create functionalized derivatives of N-containing macrocycles, 14,16−22 but these macrocycles, due in large part to the tertiary substitution of the heteroatoms or bulky substitution of their backbone, lack the rich redox and pH sensitivity inherent to PANI. 14 Here, we prepare and study for the first time the macrocyclic versions of the oligoanilines, which we have named Macrocyclic Anilines (MAs).…”