Maurizio Ciofalo

AB INITIO CONFORMATIONAL STUDY OF 2,2':5',2''-TERTHIOPHENE

Abstract The conformers of 2,2′:5′,2″-terthiophene were determined through ab initio MO full geometry optimization with a 6-31G * basis set. Different minima were found corresponding to twisted anti, anti, syn, anti and syn, syn structures. An estimate of the interconversion rate between conformers was performed.

Removal of Pesticide Oxadixyl from an Aqueous Solution

ABSTRACT The mycelium of Phomopsis helianthi (Ascomycete) was hydrolyzed with boiling NaOH to give an insoluble fraction composed of chitosan and glucans. The biomass obtained was tested as an agent for the removal of pesticides from an aqueous solution. Oxadixyl, which has a solubility in water of 3400 mg L−1, has been chosen as a hydrophilic organic contaminant model. The new, cheap material was demonstrated to recover up to 6 mg of oxadixyl per gram of adsorbent. The experimental data show an excellent correlation with the Langmuir isotherm model.

Gas-phase ion chemistry of protonated melatonin.

The gas-phase ion chemistry of protonated melatonin has been investigated by mass spectrometric (MS) techniques involving chemical ionisation, fast atom bombardment and electrospray ionisation. Either naturally-occurring or collision-induced decomposition experiments have been carried out using side chain tetra-deuterium-labelled derivatives, as well as the corresponding N–D derivatives obtained by exchange with D2O. The analysis of experimental results allows definite pathways for the formation of the ion at m/z 174 to be assigned and sheds some more light on the overall fragmentation pathways. Experiments on labelled derivatives evidenced H–D scrambling processes during fragmentation.