Zhao Xiang, Koyanagi Gregory K, Bohme Diethard K
Centre for Research in Mass Spectrometry and Centre for Research in Earth and Space Science, Department of Chemistry, York University, Toronto, Ontario, Canada M3J 1P3.
J Phys Chem A. 2006 Sep 14;110(36):10607-18. doi: 10.1021/jp062625a.
Reactions of CH(3)F have been surveyed systematically at room temperature with 46 different atomic cations using an inductively coupled plasma/selected-ion flow tube tandem mass spectrometer. Rate coefficients and product distributions were measured for the reactions of fourth-period atomic ions from K(+) to Se(+), of fifth-period atomic ions from Rb(+) to Te(+) (excluding Tc(+)), and of sixth-period atomic ions from Cs(+) to Bi(+). Primary reaction channels were observed corresponding to F atom transfer, CH(3)F addition, HF elimination, and H(2) elimination. The early-transition-metal cations exhibit a much more active chemistry than the late-transition-metal cations, and there are periodic features in the chemical activity and reaction efficiency that maximize with Ti(+), As(+), Y(+), Hf(+), and Pt(+). F atom transfer appears to be thermodynamically controlled, although a periodic variation in efficiency is observed within the early-transition-metal cations which maximizes with Ti(+), Y(+), and Hf(+). Addition of CH(3)F was observed exclusively (>99%) with the late-fourth-period cations from Mn(+) to Ga(+), the fifth-period cations from Ru(+) to Te(+), and the sixth-period cations from Hg(+) to Bi(+) as well as Re(+). Periodic trends are observed in the effective bimolecular rate coefficient for CH(3)F addition, and these are consistent with expected trends in the electrostatic binding energies of the adduct ions and measured trends in the standard free energy of addition. HF elimination is the major reaction channel with As(+), while dehydrogenation dominates the reactions of W(+), Os(+), Ir(+), and Pt(+). Sequential F atom transfer is observed with the early-transition-metal cations, with the number of F atoms transferred increasing across the periodic table from two to four, maximizing at four for the group 5 cations Nb(+)(d(4)) and Ta(+)(d(3)s(1)), and stopping at two with V(+)(d(4)). Sequential CH(3)F addition was observed with many atomic cations and all of the metal mono- and multifluoride cations that were formed.
使用电感耦合等离子体/选择离子流管串联质谱仪，在室温下系统地研究了CH(3)F与46种不同原子阳离子的反应。测量了第四周期从K(+)到Se(+)、第五周期从Rb(+)到Te(+)(不包括Tc(+))以及第六周期从Cs(+)到Bi(+)的原子离子反应的速率系数和产物分布。观察到主要反应通道对应于F原子转移、CH(3)F加成、HF消除和H(2)消除。早期过渡金属阳离子表现出比晚期过渡金属阳离子更活跃的化学性质，并且在化学活性和反应效率方面存在周期性特征，在Ti(+)、As(+)、Y(+)、Hf(+)和Pt(+)时达到最大值。F原子转移似乎受热力学控制，尽管在早期过渡金属阳离子中观察到效率的周期性变化，在Ti(+)、Y(+)和Hf(+)时达到最大值。仅在第四周期晚期从Mn(+)到Ga(+)、第五周期从Ru(+)到Te(+)以及第六周期从Hg(+)到Bi(+)的阳离子以及Re(+)中观察到CH(3)F的加成(>99%)。在CH(3)F加成的有效双分子速率系数中观察到周期性趋势，这些趋势与加合离子静电结合能的预期趋势以及加成标准自由能的测量趋势一致。HF消除是与As(+)反应的主要通道，而脱氢在W(+)、Os(+)、Ir(+)和Pt(+)的反应中占主导地位。在早期过渡金属阳离子中观察到顺序F原子转移，转移的F原子数在整个周期表中从两个增加到四个，对于第5族阳离子Nb(+)(d(4))和Ta(+)(d(3)s(1))，在四个时达到最大值，而在V(+)(d(4))时停止在两个。在许多原子阳离子以及形成的所有金属单氟化物和多氟化物阳离子中观察到顺序CH(3)F加成。
