Hybrid Zn-β-Aminoporphyrin-Carbon Nanotubes: Pyrrolidine and Direct Covalent Linkage Recognition, and Multiple-Photo Response.
Susana L H RebeloCésar A T LaiaMonika SzefczykAlexandra GuedesAna M G SilvaCristina FreirePublished in: Molecules (Basel, Switzerland) (2023)
To unveil and shape the molecular connectivity in (metallo)porphyrin-carbon nanotube hybrids are of main relevance for the multiple medicinal, photoelectronic, catalytic, and photocatalytic applications of these materials. Multi-walled carbon nanotubes (MWCNTs) were modified through 1,3-dipolar cycloaddition reactions with azomethine ylides generated in situ and carrying pentafluorophenyl groups, followed by immobilization of the β-amino-tetraphenylporphyrinate Zn(II). The functionalities were confirmed via XPS and FTIR, whereas Raman spectroscopy showed disruptions on the graphitic carbon nanotube surface upon both steps. The functionalization extension, measured via TGA mass loss and corroborated via XPS, was 0.2 mmol·g -1 . Photophysical studies attest to the presence of the different porphyrin-carbon nanotube connectivity in the nanohybrid. Significantly different emission spectra and fluorescence anisotropy of 0.15-0.3 were observed upon variation of excitation wavelength. Vis-NIR absorption and flash photolysis experiments showed energy/charge transfer in the photoactivated nanohybrid. Moreover, evidence was found for direct reaction of amino groups with a carbon nanotube surface in the presence of molecular dipoles such as the zwitterionic sarcosine amino acid.
Keyphrases
- carbon nanotubes
- walled carbon nanotubes
- raman spectroscopy
- photodynamic therapy
- energy transfer
- reduced graphene oxide
- amino acid
- single molecule
- electron transfer
- heavy metals
- resting state
- white matter
- genome wide
- drug delivery
- metal organic framework
- multiple sclerosis
- risk assessment
- dna methylation
- density functional theory
- gold nanoparticles
- visible light
- quantum dots
- gram negative
- antiretroviral therapy