Evaluation of PVP/Au Nanocomposite Fibers as Heterogeneous Catalysts in Indole Synthesis.
Electrospun nanocomposite fibers consisting of crosslinked polyvinylpyrrolidone (PVP) chains and gold nanoparticles (Au NPs) were fabricated, starting from highly stable PVP/Au NP colloidal solutions with different NP loadings, followed by thermal treatment. Information on the morphological characteristics of the fibers and of the embedded Au NPs was obtained by electron microscopy. Cylindrical, bead-free fibers were visualized by Scanning Electron Microscopy (SEM) while Transmission Electron Microscopy (TEM) and Energy Diffraction X-ray (EDX) analysis supported the presence of Au NPs within the fibers and gave information on their morphologies and average diameters. These materials were briefly evaluated as heterogeneous catalytic supports for the gold-catalyzed intramolecular cyclisation of 2‑(phenylethynyl)aniline to form 2-phenyl-1H-indole. The performance of the gold catalyst was strongly dependent on the Au NP size, with the system containing the smallest Au NPs being the more effective. Moreover, a slight drop of their catalytic efficiency was observed after three consecutive reaction runs, which was attributed to morphological changes as a consequence of fiber merging.
Department of Mechanical and Manufacturing Engineering, University of Cyprus, P. O. Box 20537, 1678 Nicosia, Cyprus. joan.savva@gmail.com.
Ioanna
I
Savva
Department of Chemistry, University of Cyprus, P. O. Box 20537, 1678 Nicosia, Cyprus. akalog@ucy.ac.cy.
Andreas S
AS
Kalogirou
Department of Mechanical and Manufacturing Engineering, University of Cyprus, P. O. Box 20537, 1678 Nicosia, Cyprus. achilleos.mariliz@ucy.ac.cy.
Mariliz
M
Achilleos
Department of Physics, Politehnica University of Bucharest, 313 Splaiul Independentei, Bucharest 060042, Romania. eugenia.vasile27@gmail.com.
Eugenia
E
Vasile
Department of Chemistry, University of Cyprus, P. O. Box 20537, 1678 Nicosia, Cyprus. koutenti@ucy.ac.cy.
Panayiotis A
PA
Koutentis
Department of Mechanical and Manufacturing Engineering, University of Cyprus, P. O. Box 20537, 1678 Nicosia, Cyprus. krasia@ucy.ac.cy.
Theodora
T
Krasia-Christoforou
D000814:Aniline Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D011205:Povidone / Q000737:chemistry*
D000814:Aniline Compounds; D007211:Indoles; D006046:Gold; D011205:Povidone; C542223:2-phenylindole
catalysis; electrospinning; gold nanoparticles; indole; polymers