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The gas-phase fragmentations of a series of TBA salts of Keggin、 Dawson and Lindqvist POMs with molecular formula of TBAn[XM12O40]、 TBA6[P2M18O62] and TBA2[M6O19] (X =P, Si;M =Mo, W) were studied by electrospray ionization tandem mass spectrometry.The non-covalent interaction primarily dominated by the Coulombic attraction between the anionic POMs and TBA+ completely changed the dissociation chemistry of POMs.The nature of the non-covalent interaction between POMs and TBA+ was addressed in detail via the example of {TBA[XM12O40]}(n-1)-.The non-covalent complexes {TBA[XM12O40]}(n-1)-and {TBAm[XM12O40]2}3-, formed by charge reduction during the electrospray process, underwent distinct dissociation routes: {TBA[XM12O40]}(n-1)-fragmented to give rise to its product ion {(C4H9)[XM12O40]}(n-1)-by cleaving the C-N covalent bond within the TBA+ cation whereas {TBAm[XM12O40]2}3-dissociated into a pair of product ions, {TBAi[XM12O40]}2-and {TBAm-i[XM12O40]}-, by breaking the non-covalent bond between [XM12O40]n-and TBA+.In addition, energy-variable CID could be used to map the relative gas-phase stabilities of the clusters.