Tetrathiafulvalene-Based Nanotweezers—Noncovalent Binding of Carbon Nanotubes in Aqueous Media with Charge Transfer Implications

Abstract

Electron donor-acceptor hybrids based on single wall carbon nanotubes (SWCNT) are one of the most promising functional structures that are currently developed in the emerging areas of energy conversion schemes and molecular electronics. As a suitable electron donor, π-extended tetrathiafulvalene (exTTF) stands out owing to its recognition of SWCNT through π-π stacking and electron donor-acceptor interactions. Herein, we explore the shape and electronic complementarity between different types of carbon nanotubes (CNT) and a tweezers-shaped molecule endowed with two exTTFs in water. The efficient electronic communication between semiconducting SWCNT/multiwall carbon nanotubes (MWCNT), on one hand, and the water-soluble exTTF nanotweezers 8, on the other hand, has been demonstrated in the ground and excited state by using steady-state as well as time-resolved spectroscopies, which were further complemented by microscopy. Importantly, appreciable electronic communication results in the electronic ground state having a shift of electron density, that is, from exTTFs to CNT, and in the electronic excited state having a full separation of electron density, that is oxidized exTTF and reduced CNT. Lifetimes in the range of several hundred picoseconds, which were observed for the corresponding electron transfer products upon light irradiation, tend to be appreciably longer in MWCNT/8 than in SWCNT/8.

Controlling the crystalline three-dimensional order in bulk materials by single-wall carbon nanotubes

“…1a gave rise under soft basic conditions (NaHCO 3 solutions at pH 9) to the diagnostic absorption band of p-p interacting exTTFs at around 490 nm 42,43 (Fig. 2a).…”

“…Multiwavelength analyses of the bleaching characteristics resulted in complex dynamics with two dominant lifetimes, namely, 0.6 and 68 ps (ref. 43). In control experiments, 1a and 1b were probed by photoexcitation at 387 nm ( Supplementary Fig.…”

“…Here important contributions stem from the geometrical complementarity between concave exTTF and convex CNTs 41 . Inspired by the crystallization of semicrystalline polymers in CNT composites, together with the well-documented affinity of the concave geometry of exTTF towards CNTs 42,43 , we hypothesized that SWCNTs could be useful additives to control the order of bulk materials. As such, the main goal of the current work is to explore the function of SWCNTs to nucleate long-range order in 3D materials starting from short-range-ordered architectures, particularly exTTF nanostructures (Fig.…”

Carboxylated carbon nanotubes as an efficient and cost-effective adsorbent for sustainable removal of insecticide fenvalerate from contaminated solutions

“…For each experiment, 10 ml of fenvalerate stock (5 mg/l) was added to Erlenmeyer flasks. Samples were conducted at predetermined time of contact (10,20,30,40,50,60, and 70 min) and filtered through 0.25_mfilters. The concentration of residual fenvalerate was analyzed by UV-Vis spectrophotometry after filtering.…”

“…where q (fenvalerate uptake) is the concentration of adsorbed fenvalerate on the CMNTs (mg/g), V is the amount of fenvalerate in contact with the CMNTs (mL), C 0 is the initial, C e is equilibrium (residual) concentration of fenvalerate (mg/L), respectively, and m is the amount of CMNTs adding to solution (g) [20]. Percentage of removal fenvalerate contacting with the CMNTs was determined according to:…”