Sergio Daolio

Protective Coatings by Anodic Coupling Polymerization of o‐Allylphenol

The anodization of Fe sheets in hydroalcoholic solutions of o‐allylphenol containing allylamine leads to in situ formation of coherent coatings. These coatings consist of thermosetting polyoxyphenylenes which after thermal curing have good adhesion and impart corrosion protection to the substrate. The anodization time and electric power consumption are comparable with those typical of a conventional electrophoretic coating.

Anodic ethylation of lead by cathodically produced diethylcadmium

Summary Tetraethyllead was prepared by electrolysing DMF or DMSO solutions of ethyl iodide and ethyl bromide in an undivided cell equipped with a cadmium cathode and a lead anode. Ethylcadmium intermediates are produced at the cathode, and react with the anode to form the product. The yield of tetraethyllead synthesized this way is mainly determined by the cathodic formation of the ethylcadmium intermediates: when this reaction is favoured by either a high concentration of the ethyl halide or by use of a temperature of ca. 50°C, the yield of tetraethyllead is greatly increased.

Mass spectrometrically induced polymerization of hexaphenoxycyclo (triphosphazene)

The polymerization of hexaphenoxyclo(triphosphazene), carried out in the ion source of a mass spectrometer, leads to phenoxy-phosphazene polymers, with a polymerization degree of n= 12.

Mass spectometric studies on cyclo- and poly-phosphazenes. Part 5. Oligomerization of octachlorocyclotetraphosphazatetraene N4P4Cl8

The electron impact (e.i.) mass spectrometric behaviour of N4P4Cl8 shows that the main reaction process involves the formation of a heptachlorocyclophosphazene phosphorus cation [N4P4Cl7]+, which has a cyclotriphosphazatriene ring bearing a NPCl2 side group. This collapse of the cyclotetraphosphazatetraene structure to a cyclotriphosphazatriene moiety is a consequence of a ring-contraction reaction which yields more stable ionic trimeric phosphazene species. Ions [N3P3Cl5]+ are subsequently formed by the loss of the NPCl2 unit. Upon increasing the N4P4Cl8 vapour pressure to 0.65 Torr in the ionization chamber of the mass spectrometer, an oligomerization process takes place leading to chlorophosphazene oligomers, with oligomerization degree n of 12. Evidence is presented to show that the tetrameric ions [N4P4Cl8]˙+ formed from N4P8Cl8 under e.i. conditions have a different structure compared to analogous species produced during the gas-phase polymerization process of N3P3Cl6. This result gives further support to the mechanism proposed for gas-phase oligomerization of N3P3Cl6.

Mass spectrometric studies on cyclo- and poly-phosphazenes. Part 2. Oligomerization of hexa(aryloxy)cyclotriphosphazatrienes

A method of oligomerizing hexa(aryloxy)cyclotriphosphazatrienes to the corresponding oligomers is reported. The oligomerization has been carried out in the ion source of a mass spectrometer, at high vapour pressure of the trimers, and at a temperature of 200 °C. The effects on the oligomerization reaction of experimental parameters, such as temperature, nucleophilicity, electrophilicity, and bulkiness of substituent groups on the trimers, and the presence of acidic species, have been investigated. High reaction temperatures inhibit the oligomerization reaction, leading to the formation of pyrolysis products.

Use of diethyl sulphate for the anodic synthesis of tetraethyltin via alkylzinc intermediates

Tetraethyltin was prepared by electrolysing diethyl sulphate between a zinc cathode and a tin anode.