0000000000240237
AUTHOR
Salvatore Caccamese
showing 5 related works from this author
Mass spectrometric investigation of polymers: Thermal degradation of truxillic and truxinic polyamides
1975
The thermal degradation mechanism of four isomeric truxillic and truxinic polyamides were investigated by direct pyrolysis in the ion source of a mass spectrometer. Thermal degradation reactions were followed directly by this method by detecting the thermal and electron impact-induced fragments. The results obtained have shown that the thermal degradation products are sensibly different for the head-to-head (hh) and head-to-tail (ht) polymers and that the predominant pyrolytic process is the cyclobutane ring cleavage. In the hh isomers, both symmetrical and asymmetrical cyclobutane ring cleavage was detected, while in the ht isomers only symmetrical cleavage occurs; this explains the notice…
Photodimers of cinnamic acid and related compounds. A stereochemical study by electron-impact and field desorption mass spectrometry
1974
The low energy (13 eV) electron-impact and field desorption mass spectra of some photodimers of cinnamic acid and related compounds containing the cyclobutane ring are reported and the fragmentation patterns analysed in order to obtain stereochemical information on the substituent position on the cyclobutane ring. Both symmetrical and asymmetrical splittings of the cyclobutane ring were detected, allowing characterisation of the head-to-head and head-to-tail structures of the title compounds. A ring opening rearrangement of the McLafferty type was also found.
Enantiomerization of an inherently chiral resorcarene derivative: determination of the interconversion barrier by computer simulation of the dynamic …
2001
Abstract The inherently chiral tetrabenzoxazine resorcarene derivative 1 shows characteristic plateau-formation during enantioselective HPLC separation on the chiral stationary phase Chiralpak AD. By computer assisted peak form analysis of the elution profiles, obtained from temperature dependent dynamic HPLC (DHPLC) experiments, with ChromWin, the enantiomerization barrier Δ G # (298 K)=92±2 kJ mol −1 and the activation parameters Δ H # =53.0±1.8 kJ mol −1 and Δ S # =−131±14 J (K mol) −1 were determined.
Copolyamides from adipic and truxillic acids: Synthesis and characterization by direct pyrolysis in the mass spectrometer
1977
The synthesis of a series of polyamides and copolyamides containing α-truxillic and adipic units in the chain is reported. The thermal degradation of these polymers was investigated by direct pyrolysis in the ion source of a mass spectrometer. Thermal degradation reactions were followed directly by this method by detecting the thermal- and electron-impact-induced fragments. The results obtained show a good correlation between the intensity of mass peaks characteristic of truxillic and adipic moieties and the composition of the copolyamides, as ascertained by elemental analysis. This is an important result since it shows the potential of the direct pyrolysis method in the analysis of copolym…
Resolution of inherently chiral resorcarene derivatives by enantioselective HPLC
1999
Abstract The HPLC enantiomeric resolution of five inherently chiral tetrabenzoxazine derivatives of resorcarenes has been achieved by HPLC using Whelk-Ol and in one case Chiralpak AD as stationary phases. Enantiomeric separation was only observed in a very narrow range of mobile phase compositions. On-column enantiomeric interconversion of a racemic compound with a typical plateau-like elution profile was observed using a Chiralpak AD column