Abstract

Abstract A new setup named Fast On-line Reaction Apparatus (FORA) is presented which allows for the efficient investigation and optimization of metal carbonyl complex (MCC) formation reactions under various reaction conditions. The setup contains a 252Cf-source producing short-lived Mo, Tc, Ru and Rh isotopes at a rate of a few atoms per second by its 3% spontaneous fission decay branch. Those atoms are transformed within FORA in-situ into volatile metal carbonyl complexes (MCCs) by using CO-containing carrier gases. Here, the design, operation and performance of FORA is discussed, revealing it as a suitable setup for performing single-atom chemistry studies. The influence of various gas-additives, such as CO2, CH4, H2, Ar, O2, H2O and ambient air, on the formation and transport of MCCs was investigated. O2, H2O and air were found to harm the formation and transport of MCCs in FORA, with H2O being the most severe. An exception is Tc, for which about 130 ppmv of H2O caused an increased production and transport of volatile compounds. The other gas-additives were not influencing the formation and transport efficiency of MCCs. Using an older setup called Miss Piggy based on a similar working principle as FORA, it was additionally investigated if gas-additives are mostly affecting the formation or only the transport stability of MCCs. It was found that mostly formation is impacted, as MCCs appear to be much less sensitive to reacting with gas-additives in comparison to the bare Mo, Tc, Ru and Rh atoms.

Highlights

  • A new setup named Fast On-line Reaction Apparatus (FORA) is presented which allows for the efficient investigation and optimization of metal carbonyl complex (MCC) formation reactions under various reaction conditions

  • The setup contains a 252Cf-source producing short-lived Mo, Tc, Ru and Rh isotopes at a rate of a few atoms per second by its 3% spontaneous fission decay branch. Those atoms are transformed within FORA in-situ into volatile metal carbonyl complexes (MCCs) by using CO-containing carrier gases

  • Metal carbonyl complexes (MCCs) and their derivatives are an important class of substances in modern chemistry

Read more

Summary

Introduction

Metal carbonyl complexes (MCCs) and their derivatives are an important class of substances in modern chemistry. If single atoms of group 6 up to group 9 transition metals are emitted into CO-containing atmospheres, they were found to form in-situ volatile MCCs [10,11,12,13,14,15,16,17] This method enables a number of potential applications, i.e., the possible generation of yet unavailable radioactive beams of refractory elements in accelerators [18, 19] or the chemical investigation of transactinides (elements with Z ≥ 104) which are not volatile in their elemental state [10,11,12,13,14,15,16,17, 20,21,22]. Experiments targeted at investigating and comparing the chemistry of group 6 MCCs were suffering so far from low chemical and transport yields, ranging from about 40% for Mo(CO) to 10–20% for W(CO) and 5% for Sg(CO)6 [26] This caused serious doubts about investigating heavier TAs in form of MCCs in general. This work is intended to systematically investigate experimental parameters influencing the overall synthesis and transport yield of MCCs in single-atom chemistry experiments

The FORA-setup
FORA-operation
Determination of absolute yields
Addition of gas-additives
FORA-characterization
Potential experimental flaws or interferences
FORA: H2O
FORA: air
Are gas-additives affecting formation or transport yields?
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call