Cataldi Tommaso R I, Ricciardi Giampaolo, Bianco Giuliana, Pietrangeli Daniela, Abate Salvatore
Dipartimento di Chimica, Università degli Studi di Bari, Campus Universitario, Via E. Orabona 4, 70126 Bari, Italy.
Rapid Commun Mass Spectrom. 2009 Jul;23(13):1927-33. doi: 10.1002/rcm.4094.
Some newly synthesized (10)B nido-carborane derivatives, i.e., 7,8-dicarba-nido-undecaborane monoanions (7-Me-8-R-C(2)B(9)H(10)K(+), R = H, butyl, hexyl, octyl and decyl), have been fully characterised and examined by electrospray ionization and Fourier transform ion cyclotron resonance mass spectrometry with liquid chromatographic separation (LC/ESI-FTICR-MS). These boron-containing compounds exhibit abundant molecular ions (M) at m/z 140.22631 C(3) (10)B(9)H(14), m/z 196.28883 C(7) (10)B(9)H(22), m/z 224.32032 C(9) (10)B(9)H(26), m/z 252.35133 C(11) (10)B(9)H(30) and m/z 280.38354 C(13) (10)B(9)H(34) at the normal tube lens voltage setting of -90 V, which was an instrumental parameter value selected in the tuning operation. Additional M-nH(2) (n = 1-4) ions were observed in the mass spectra when higher tube lens voltages were applied, i.e., -140 V. High-resolution FTICR-MS data revealed the accurate masses of fragment ions, bearing either an even or an odd number of electrons. Collision-induced dissociation of the M-nH(2) ions (n = 0-4) in the quadrupole linear ion trap (LTQ) analyzer confirmed the loss of hydrogen molecules from the molecular ions. It is suggested that the loss of H(2) molecules from the alkyl chain is a consequence of the stabilization effect of the nido-carborane charged polyhedral skeleton.
一些新合成的（10）B巢式碳硼烷衍生物，即7,8 - 二碳 - 巢式 - 十一硼烷单阴离子（[7 - 甲基 - 8 - R - C₂B₉H₁₀]⁻K⁺，R = 氢、丁基、己基、辛基和癸基），已经通过电喷雾电离和傅里叶变换离子回旋共振质谱联用液相色谱分离（LC/ESI - FTICR - MS）进行了全面表征和研究。这些含硼化合物在调谐操作中选择的仪器参数值 - 90 V的正常管透镜电压设置下，在m/z 140.22631 [C₃(10)B₉H₁₄]⁻、m/z 196.28883 [C₇(10)B₉H₂₂]⁻、m/z 224.32032 [C₉(10)B₉H₂₆]⁻、m/z 252.35133 [C₁₁(10)B₉H₃₀]⁻和m/z 280.38354 [C₁₃(10)B₉H₃₄]⁻处显示出丰富的分子离子（[M]⁻）。当施加更高的管透镜电压，即 - 140 V时，在质谱中观察到额外的[M - nH₂]⁻（n = 1 - 4）离子。高分辨率FTICR - MS数据揭示了带有偶数或奇数电子的碎片离子的精确质量。在四极杆线性离子阱（LTQ）分析仪中对[M - nH₂]⁻离子（n = 0 - 4）进行碰撞诱导解离，证实了分子离子中氢分子的损失。据推测，烷基链中H₂分子的损失是巢式碳硼烷带电多面体骨架稳定作用的结果。
