Wang Yang, Qin Zhi, Fan Fang-Li, Haba Hiromitsu, Komori Yukiko, Cao Shi-Wei, Wu Xiao-Lei, Tan Cun-Min
Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
Phys Chem Chem Phys. 2015 May 28;17(20):13228-34. doi: 10.1039/c5cp00979k. Epub 2015 Apr 29.
Gas-phase chemical behaviors of short-lived technetium carbonyl complexes were studied using a low temperature isothermal chromatograph (IC) coupled with a (252)Cf spontaneous fission (SF) source. Fission products recoiled from the (252)Cf SF source were thermalized in a mixed gas containing CO, and then technetium carbonyl complexes were formed from reactions between CO gas and various technetium isotopes. A gas-jet system was employed to transport the volatile carbonyl complexes from a recoil chamber to the IC. Short IC columns made of Fluorinated Ethylene Propylene (FEP) Teflon and quartz were used to obtain chemical information about the technetium carbonyl complexes. The results for the (104)Tc-(106)Tc carbonyl complexes were found to be strongly influenced by the precursors, and showed the chemical behaviors of (104)Mo-(106)Mo carbonyl complexes, respectively. However, (107)Tc and (108)Tc could represent the chemical information of the element technetium due to their high independent yields and the very short half-lives of their precursors (107)Mo and (108)Mo. An adsorption enthalpy of about ΔHads = -43 kJ mol(-1) was determined for the Tc carbonyl complexes on both the Teflon and quartz surfaces by fitting the breakthrough curves of the (107)Tc and (108)Tc carbonyl complexes with a Monte Carlo simulation program. Chemical yields of around 25% were measured for the Tc carbonyl complexes relative to the transport yields obtained with the gas-jet transport of KCl aerosol particles with Ar carrier gas. Furthermore, the influence of a small amount of O2 gas on the yields of the Mo and Tc carbonyl complexes was studied.
使用低温等温色谱仪（IC）结合²⁵²Cf自发裂变（SF）源研究了短寿命锝羰基配合物的气相化学行为。从²⁵²Cf SF源反冲的裂变产物在含有CO的混合气体中热化，然后通过CO气体与各种锝同位素之间的反应形成锝羰基配合物。采用气体喷射系统将挥发性羰基配合物从反冲室传输到IC。使用由氟化乙丙烯（FEP）特氟龙和石英制成的短IC柱来获取有关锝羰基配合物的化学信息。发现¹⁰⁴Tc - ¹⁰⁶Tc羰基配合物的结果受前体的强烈影响，分别显示出¹⁰⁴Mo - ¹⁰⁶Mo羰基配合物的化学行为。然而，¹⁰⁷Tc和¹⁰⁸Tc由于其高独立产率及其前体¹⁰⁷Mo和¹⁰⁸Mo的极短半衰期，可以代表锝元素的化学信息。通过用蒙特卡罗模拟程序拟合¹⁰⁷Tc和¹⁰⁸Tc羰基配合物的穿透曲线，确定了锝羰基配合物在特氟龙和石英表面上的吸附焓约为ΔHads = -43 kJ mol⁻¹。相对于用Ar载气对KCl气溶胶颗粒进行气体喷射传输获得的传输产率，测得锝羰基配合物的化学产率约为25％。此外，研究了少量O₂气体对Mo和Tc羰基配合物产率的影响。
