Sapphyrin−Nanotube Assemblies

Abstract

Single wall carbon nanotubes (SWNTs) bind strongly to sapphyrins, quintessential pentapyrrolic "expanded porphyrin" macrocycles, through donor-acceptor stacking interactions. The specific use of a functionalized sapphyrin diol yields stable water-suspendable nanotubes and also permits the formation of well-defined assemblies in ionic liquids. The absorption and steady-state fluorescence spectra of the resulting noncovalently functionalized nanotube complexes have been analyzed in aqueous media and ionic liquids, yielding a description of the photophysical properties of the nanotube-sapphyrin complexes as donor-acceptor species for light-harvesting.

On the efficiency of bile salt for stable suspension and isolation of single-walled carbon nanotubes—spectroscopic and microscopic investigations

“…Thus, the stability of the solution stirred for 17 days was estimated. Additionally, it is worth noting that the presence of the van Hove singularities in the optical spectrum of the solution indicates that nanotube/DOC interaction (via an electronic polarization) is not sufficiently strong to smear out the vHS, which usually occur if charge transfer takes place [13][14][15]. The full disappearance of the optical bands due to a Fermi level shift was previously reported [17].…”

“…The specimen for HR-TEM was prepared with a single drop of the analyzed suspension placed on the holey carbon filmed grids at room temperature. Optical and vibrational response of SWCNTs can be strongly dependent on the nanotube-surfactant interaction leading to a charge transfer or an electronic polarization [13][14][15]. Therefore, in order to confirm the stability of the created suspension turbidity measurements were also conducted (data not shown here) [16].…”

Novel Electron Donor Acceptor Nanocomposites

“…In a final example, SWNT were found to make complexes with sapphyrins. The resulting SWNT/ sapphyrins undergo photoexcited intramolecular charge transfer from SWNT to the sapphyrin moiety upon photoexcitation, for which proof came from a combination of steady state investigations, femtosecond transient absorption spectroscopies and pulse radiolysis experiments [185].…”

Methodology for Homogeneous Dispersion of Single-walled Carbon Nanotubes by Physical Modification

“…Porphyrin derivatives 114,[119][120][121][122][123][124][125][126] as well as their analog molecules such as phthalocyanines [127][128][129] and sapphyrin 130 have been reported to serve as dispersants for the CNTs.…”