Non-Covalent Functionalization of Multi-Walled Carbon Nanotubes with Organic Aromatic Compounds

Abstract

Several aromatic compounds derived from benzene by its annelation (naphthalene, anthracene, phenanthrene, pyrene) and exocyclic substitution (e.g., nitrobenzene, dinitrobenzenes, trinitrobenzene, chlorobenzene, N,N-dimethylaniline, and others) and endocyclic substitution (pyridine, quinoline, isoquinoline) efficiently sorbed on multi-walled carbon nanotubes (MWCNTs). Equilibrium constants for the sorption process have been determined. Computations of the energy of formation were performed for surface complexes of those arenes on single-walled carbon nanotubes (SWCNTs). Formation energies of those complexes were correlated against the experimental equilibrium constants. The latter were also correlated against calculated LUMO energy of the arenes. Solely, limited tendencies to the linearity could be observed. The analysis of the results of the correlations indicated that the arenes acting as the charge acceptors formed stronger complexes than arenes with a high electron density in the molecular orbital, for instance, N, N-dimethylaniline. The area of the arene--SWCNT contact was very essential for the complexation. The proximity of the HOMO orbital of SWCNT and LUMO of the arene was another essential factor. Bulky substituents in the arene molecules obscured their efficient contact with SWCNT.

Interactions of carbon nanotubes with pyrene‐functionalized linear‐dendritic hybrid polymers

“…Both small molecules and macromolecules have been used to disrupt nanotube bundles and provide individual nanotubes in solution, strictly by supramolecular interactions 68–70. The utilization of small molecules to noncovalently functionalize nanotubes has largely focused on derivatives of polycyclic aromatic hydrocarbons (PAH's), such as naphthalene, phenanthrene, and pyrene 69–75. Pyrene can π‐stack to CNTs with a binding energy of up to 50 kJ/mol 76.…”

Recent Advances in Nucleic Acid Targeting Probes and Supramolecular Constructs Based on Pyrene-Modified Oligonucleotides

“…When conjugated with a cargo, the pyrene moiety provides its anchoring on a carbon surface. The π-π stacking interactions that drive the anchoring are irreversible at standard and physiological conditions and stable towards the displacement with surfactants, biomolecules, and most part of polyaromatic compounds [ 20 , 21 ]. These properties make carbon nanoparticles bearing anchored oligonucleotides prospective tools for molecular diagnostics and therapeutics.…”

“…Specific examples of pyrene-modified oligonucleotides reviewed here include sensitive fluorescent probes for the sequence-specific detection of nucleic acids (NAs) and discrimination of single nucleotide polymorphisms (SNPs), aptamer-based biosensors for the detection of a wide range of various targets, agents for binding of dsDNAs, building units of supramolecular complexes, and other applications. These simple synthetically-accessible molecules integrate an excellent recognition capability of oligonucleotides and ability of pyrene to act as microenvironment-sensitive fluorescent label [ 1 , 2 , 3 , 4 ], excimer- or exciplex-generating molecule [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ], NA complex intercalator [ 16 , 17 , 18 , 19 ], or π-π-staking hydrophobic moiety [ 20 , 21 ]. It is worth noting that these functions of pyrene are especially brightly expressed in the NA context.…”

Unravelling Radicals Reactivity Towards Carbon Nanotubes Manipulation/Functionalization

“…Albeit the progresses which have been made in the last ten years, many efforts are still needed for improving CNTs manipulation. The main approaches for modifying CNTs can be categorized in two groups: (a) the non-covalent interaction of specific surfactants [14] and (ii) the covalent attachment of organic/inorganic pendants [15]. The former approach produces nanotubes with unchanged chemical and physical properties surrounded by a shell of surfactant molecules, like primarily surfactants [16], biomacromolecules [17] or polymers [18].…”