| Abstract: | The negative ion chemical ionization mass spectra, with ammonia and methane as reagent gases, of the (η6-arene)Cr(CO)3 complexes, where the arene is C6H5COCH3, C6H5COC2H5, C6H5COC3H7, C6H5COC(CH3)3, 2-CH3C6H4COC3H7, C6H5COOCH3, C6H5CH3, 1,3,5-(CH3)3C6H3 and C6H5CH2COC2H5, are reported. Similar behaviour is observed with the two reagent gases, but ammonia shows a much higher abundance for the ions produced by reactions of [NH2]? with sample molecules. The compounds containing the C6H5CO group display an abundant [M]? ˙, whereas the other compounds exhibit [M? H]? as base peak, produced by ion/molecule reactions. A comparison of the negative ion chemical ionization mass spectra of the (η6-arene)Cr(CO)3 complexes with those of the corresponding ligands shows the strong electron withdrawing power of the Cr(CO)3 group in the gas phase. |
