Characterization of Calixarenes by Positive- and Negative-ion Californium-252 Plasma Desorption Mass Spectrometry

✍ Scribed by Katharina Linnemayr; Erich R. Schmid; Günter Allmaier

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 167 KB
• Volume: 11
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(199703)11:5<427::aid-rcm873>3.0.co;2-7

✦ Synopsis

Californium

-252 plasma desorption (PD) mass spectra of eleven nitrogen-free calixarenes (four newly synthesized compounds) have been acquired in both positive-and negative-ion mode with a short linear time-of-flight instrument. For molecular weight determination of the calixarenes, the positive-ion mass spectra exhibit radical molecular ions with high abundance and sometimes [M + Na] + ions. The formation of [M] + . ions, while unusual for biopolymers in PDMS, has been found as a normal feature in the PD mass spectra of calixarenes. In the positive-ion mode strong fragmentation was observed which provided structural information. The negative-ion mass spectra exhibited, in all cases, [M-H] -ions but less fragmentation was found compared with the positive-ion mode. For compounds (5-9) carrying an ester group the loss of an acyl group generated intense fragment ions. Samples have been prepared by the spin deposition technique on plain aluminium covered targets, on nitrocellulose covered targets as support and 3-(3-pyridyl) acrylic acid covered targets as matrix resulting in different molecular/fragment ion abundances.