A novel mobile phase for continuous-flow liquid secondary ion mass spectrometry of high molecular mass phthalocyanines

✍ Scribed by Lloyd W. Sumner; Warren T. Ford; Young H. Chang; Kyung H. Choi; Jae J. Lee

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 245 KB
• Volume: 28
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210280437

✦ Synopsis

OMS Letters

Dear Sir, A Novel Mobile Phase for Continuous-flow Liquid Secondary Ion Mass Spectrometry of High Molecular Mass Phthalocyanines Dihydrogen and metallophthalocyanines (Pc's) substituted with four or more branched or flexible chains at the perimeter of the benzene rings (see Fig. ) possess thermotropic liquid crystalline phases'-4 and nonlinear optical proper tie^.^.^ To aid in our understanding of the influence of varying side-chain length, degree of branching, and the central metal atom on the above properties, we have synthesized a series of octaalkoxy Pc's. We report here a new method for determining structures of the Pc's shown in Fig. by continuous-flow liquid secondary ion mass spectrometry (CF-LSIMS) using a novel mobile phase.

The Pc's investigated are characterized by molecular masses in the 1 OOO to 3 OOO Da range. Owing to their high molecular masses, octaalkoxy Pc's are typically nonvolatile and not amenable to electron impact (EI) ionization mass spectrometry.' Thus, an alternative method of mass analysis is required. These facts prompted us to examine liquid secondary ion mass spectrometry (LSIMS).* This particle-induced desorption technique is very similar to fast atom bombardment (FAB) mass spectrometryg and has been illustrated as a powerful tool capable of mass analyzing polar, non-volatile, and thermally labile species with a high degree of success." More specifically, the literature reports successful FAB mass spectrometry of porphyrins,'0-'2 which are very similar in structure to phthalocyanines. Our initial LSIMS analyses of Pc's using typical matrices that had been reported for the FAB mass spectrometry of porphyrins, such as glycerol,

Yours