%0 Journal Article
%T Isotope labeling and infrared multiple
%A Evan Perez
%A Giel Berden
%A John K Gibson
%A Jonathan Martens
%A Jos Oomens
%A Michael J Van Stipdonk
%A Theodore A Corcovilos
%J European Journal of Mass Spectrometry
%@ 1751-6838
%D 2019
%R 10.1177/1469066718809881
%X Electrospray ionization was used to generate species such as [ZnNO3(CH3OH)2]+ from Zn(NO3)2£¿XH2O dissolved in a mixture of CH3OH and H2O. Collision-induced dissociation of [ZnNO3(CH3OH)2]+ causes elimination of CH3OH to form [ZnNO3(CH3OH)]+. Subsequent collision-induced dissociation of [ZnNO3(CH3OH)]+ causes elimination of 47 mass units (u), consistent with ejection of HNO2. The neutral loss shifts to 48£¿u for collision-induced dissociation of [ZnNO3(CD3OH)]+, demonstrating the ejection of HNO2 involves intra-complex transfer of H from the methyl group methanol ligand. Subsequent collision-induced dissociation causes the elimination of 30£¿u (32£¿u for the complex with CD3OH), suggesting the elimination of formaldehyde (CH2£¿=£¿O). The product ion is [ZnOH]+. Collision-induced dissociation of a precursor complex created using CH3-18OH shows the isotope label is retained in CH2£¿=£¿O. Density functional theory calculations suggested that the ¡°rearranged¡± product, ZnOH with bound HNO2 and formaldehyde is significantly lower in energy than ZnNO3 with bound methanol. We therefore used infrared multiple-photon photodissociation spectroscopy to determine the structures of both [ZnNO3(CH3OH)2]+ and [ZnNO3(CH3OH)]+. The infrared spectra clearly show that both ions contain intact nitrate and methanol ligands, which suggests that rearrangement occurs during collision-induced dissociation of [ZnNO3(CH3OH)]+. Based on the density functional theory calculations, we propose that transfer of H, from the methyl group of the CH3OH ligand to nitrate, occurs in concert with the formation of a Zn¨CC bond. After dissociation to release HNO2, the product rearranges with the insertion of the remaining O atom into the Zn¨CC bond. Subsequent C¨CO bond cleavage, with H transfer, produces an ion¨Cmolecule complex composed of [ZnOH]+ and O£¿=£¿CH2
%K Metal-mediated reactions
%K tandem mass spectrometry
%K infrared multiple-photon photodissociation
%K ion spectroscopy
%K ion structure
%U https://journals.sagepub.com/doi/full/10.1177/1469066718809881