Electrospray ionization mass spectrometry of organogermanium compounds

Abstract

A detailed study of the solution chemistry and mass spectrometry of six carboxylato‐organogermanium compounds in aqueous solution has been carried out using electrospray ionization and MSn techniques. The different types of hydrolysis products and their probable structures, which include the oligomers and their fragment ions plus water adduct ions formed by ion‐molecule reactions, are presented, e.g., HO‐cyclic‐(‐Ge(O−)CH2CH2COO) A, HO‐cyclic‐(‐Ge(O‐cyclic‐(Ge(O−)CH2CH2COO)CH2CH2COO) B, −OGeO‐cyclic‐(‐Ge(OH)CH2CH2COO) C, and −CH=CHGeO‐cyclic‐(‐Ge(OH)CH2CH2COO) D, etc. The proposed cyclic structures are confirmed by theoretical calculations. Copyright © 2001 John Wiley & Sons, Ltd.

Characterization of bis-carboxyethyl germanium sesquioxide and its complexes with amino acids using electrospray QqTOF mass spectrometry

“…The loss of water is occurring for all reactions in agree- Table 5 Elemental composition of ions determined from spectra in Fig. 1E ment with the formation of polymeric structures of Ge-132, for which the occurrence of condensation products has been reported previously [20]. The most probable products of the condensation reaction are shown in Fig.…”

“…The full scan mass spectra of pure Ge-132 were previously measured using ion trap analyzer and particular ions having the polymeric character were described [20]. Similar ionic structures were identified in the full scan mass spectra in our measurements, as shown in Fig.…”

“…Another possibility, only applicable for pure compounds, is the use of direct infusion MS, which we have successfully applied for the characterization of organotin and organonickel compounds [17][18][19]. Only a few papers dealing with MS analysis of Ge-132 have been published so far [20][21][22][23].…”

Structural analysis of organometallic compounds with soft ionization mass spectrometry

“…Only a few articles of MS of organogermanium compounds can be found in the literature, and most of them are devoted to the analysis of so called Ge-132 (germanium sesquioxide) (Lamb & Sweetman, 1996;Wei, Chen, & Miller, 2001;Jirásko, Holčapek, & Rosenberg, 2009). ESI with an ion-trap analyzer was used for Ge-132 characterization.…”

Assessing Ge-132 as an antioxidant in organic and water-containing media

“…In a number of previous studies [ 31 ], MS spectra of Ge-132 are essentially obtained from aqueous or CH 3 CN-H 2 O solutions and therefore reflect a complex dynamic equilibrium of its hydrolysis. Albeit M, 2M -H 2 O, 3M -2H 2 O [ 31,32 ] and higher, up to a nonamer [ 33 ], mass clusters were observed in such mixtures (heavier oligomer forms of Ge-132 were reported for solid polymer samples, see e.g. [ 24 ]), the product distribution in these reports, -depending on the media, temperature and other experimental conditions, -attests that the presence of water promotes the formation of the hydrolyzed triol form of Ge-132 [ 25 ] (for first structurally characterized germane triol see [ 34 ]), lacking the Ge-O-Ge unit and therefore devoid of the antioxidant properties.…”