Duncombe Bridgette J, Duale Khadar, Buchanan-Smith Annabelle, Stace Anthony J
Department of Physical Chemistry, School of Chemistry, The University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
J Phys Chem A. 2007 Jun 21;111(24):5158-65. doi: 10.1021/jp0717286. Epub 2007 May 31.
A detailed study has been undertaken of the gas-phase chemistry of [Cu(H2O)N]2+ and [Cu(NH3)N]2+ complexes. Ion intensity distributions and fragmentation pathways (unimolecular and collision-induced) have been recorded for both complexes out as far as N=20. Unimolecular fragmentation is dominated by Coulomb explosion (separation into two single charged units) on the part of the smaller ions, but switches to neutral molecule loss for N>7. In contrast, collisional activation promotes extensive electron capture from the collision gas, with the appearance of particular singly charged fragment ions being sensitive to the size and composition of the precursor. The results show clear evidence of the unit [Cu(X)8]2+ being of special significance, and it is proposed that the hydrogen-bonded structure associated with this ion is responsible for stabilizing the dipositive charge on Cu2+ in aqueous solution.
对[Cu(H₂O)ₙ]²⁺和[Cu(NH₃)ₙ]²⁺配合物的气相化学进行了详细研究。记录了这两种配合物直至N = 20的离子强度分布和碎裂途径（单分子和碰撞诱导）。较小离子的单分子碎裂主要由库仑爆炸（分离成两个单电荷单元）主导，但对于N>7时转变为中性分子损失。相比之下，碰撞活化促进了从碰撞气体中广泛的电子捕获，特定单电荷碎片离子的出现对前体的大小和组成敏感。结果清楚地证明了[Cu(X)₈]²⁺单元具有特殊意义，并提出与该离子相关的氢键结构负责稳定水溶液中Cu²⁺上的二价电荷。
