Hybrid nickel-free graphene/porphyrin rings for photodegradation of emerging pollutants in water.

A novel hybrid photoactive material based on graphene foam (G) coupled with porphyrin-based polymers (Porph rings) was formulated by using a time-saving procedure to remove nickel from the final device. Specifically, Porph rings were spin coated onto the G platform with the double function of a visible-light photocatalyst and protective agent during nickel etching. The characterization of G-Porph rings was assessed by Scanning Electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL).

Freestanding photocatalytic materials based on 3D graphene and polyporphyrins.

A new concept in the formulation of hybrid nanostructured materials combining high quality graphene 3D supported by Nickel foam and polyporphyrins for visible light photocatalytic application is here reported. Our innovative approach involves the development of a freestanding device able to: i) offer a high surface area to bind the photosensitizers by π-π interactions, and ii) enhance stability and photocatalytic efficiency by using cyclic porphyrin polymers. For these purposes, homo- and co-polymerization reactions by using different porphyrin (free or zinc complexed) monomers were performed.

Synthesis and matrix-assisted laser desorption/ionization time-of-flight characterization of bisphenol-A copolyformals containing nickel(II)/Schiff base, eicosane and 2-butene units in the main chain.

Some bisphenol-A copolyformals, containing in the main chain different amounts of a Ni-diimine nonlinear optical (NLO)-chromophore, eicosane and/or 2-butene units, were synthesized by condensation reaction between dibromomethane and suitable mixtures of Ni(II)/Schiff base complex, 1,20-di(bisphenol-A)ether-eicosane and/or 1,4-di(bisphenol-A)ether-2-butene. Structural composition and thermal properties of polymeric materials were inferred by analyses by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and thermogravimetry (TG). MALDI-TOF data show that both Ni-diimine and unsaturated units are present in the copolyformals with a homogeneous arrangement in all the polymer mass range (GPC data).

Uncharged water-soluble Co(II)-porphyrin: a receptor for aromatic alpha-amino acids.

Changes in the UV-vis spectra and induced circular dichroism (ICD) signals observed, in correspondence with the porphyrin Soret region, for aqueous solutions of achiral 5,10,15,20-tetrakis{p-[omega-methoxy poly(oxy-ethylene)]phenyl}porphyrin cobalt (II) (Co-P) and aromatic alpha-L-amino acids (Trp and Phe) give direct evidence for the coordination between the Co-P and amino acids. Considering that Co-P, besides the Co atom (one-fixation-point system), does not contain in the molecule active ligand groups and that no ICD signals have been observed in the case of Co-P/Ala, it has been concluded that hydrophobic interactions or stacking interactions between the aromatic rings of the porphyrin and those of Trp or Phe, acting as further amino acid (AA) fixation points, can strongly reduce the mobility of the chiral guest, thus permitting the generation of ICD signals. The effects of changes of both pH (in the range 2-9) and amino acid structure on the ICD phenomenon have also been investigated.

Effect of delay time and grid voltage changes on the average molecular mass of polydisperse polymers and polymeric blends determined by delayed extraction matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

The dependence of the calculated average molecular mass of a polyethylene glycol with a large polydispersity on the instrumental parameters adopted in the acquisition of mass spectra using delayed extraction matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (DE MALDI-TOFMS) was investigated. It has been shown that a combined effect of delay times and potential gradients can act on the ion cloud in the source chamber affecting both mass resolution and average molecular mass value of the analyzed polymeric sample. Also examined was a blend of two different polymers (a PEG and a PMMA commercial sample having a similar average molecular mass), which presents an additional problem concerning the discrimination among the different polymer species as a function of the experimental conditions.

Interactions between water soluble porphyrin-based star polymer and amino acids: spectroscopic evidence of molecular binding.

Molecular interactions giving rise to stable complexes between an uncharged water soluble cobalt-porphyrin and amino acids are investigated by time-resolved fluorescence, uv-vis, and circular dichroism measurements. This metalloporphyrin seems to act, by means of the coordination site of the cobalt of the core, as a recognition host, preferentially, with amino acids possessing aromatic groups. The binding with aliphatic amino acids requires longer time scales to be efficient and likely involves a slow kinetic process.

Coordination features of difunctionalized beta-cyclodextrins with carnosine: ESI-MS and spectroscopic investigations on 6A,6D-di-(beta-alanyl-L-histidine)-6A,6D-dideoxy-beta-cyclodextrin and 6A,6C-di-(beta-alanyl-L-histidine)-6A,6C-dideoxy-beta-cyclodextrin and their copper(II) complexes.

The synthesis and characterization of two beta-cyclodextrins (beta-CD) functionalized with two units of carnosine (beta-alanyl-L-histidine) through the amino group, 6A,6C-(beta-alanyl-L-histidine)-6A,6C-dideoxy-beta-cyclodextrin (ACCDAH) and 6A,6D-(beta-alanyl-L-histidine)-6A,6D-dideoxy-beta-cyclodextrin (ADCDAH), are reported. NMR and C.D.