1994 Fiscal Year Final Research Report Summary
A novel method for detection of free radicals in the gas phase ; usage of Li^+ ion attachment to chemical species
| Project/Area Number |
04804033
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Astronomy
|
|---|
| Research Institution | National Institute for Environmental Studies |
|---|
Principal Investigator |
FUJII Toshihiro National Institute for Environmental Studies, Environmental Chemistry Division, Head of Laboratory, 化学環境部, 室長 (60109907)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
FURUTA Naoki Chuou University, Faculty of Science and Technology, Professor, 理工学部, 教授 (90101055)
|
|---|
| Project Period (FY) |
1992 – 1994
|
| Keywords | Free Radical / Detection Method / Ion Attachment Reaction / Mass Spectrometry / Ab initio MO |
|---|
| Research Abstract |
This project develops a new method for detection and identification of intermediate radical species in the gas phase. It provides mass spectra of quasi-molecular ions formed by lithium ion attachment to the radical species under high pressure. Results are obtained in the form of mass spectrometric trace of Li^+ adduct radicals. As an example, the mtethod was applied to the study of the microwave discharge in CH_4 and was successfully used for the qualitative analysis of the compositions of hydrocarbon radicals in the discharge. Various kinds of hydrocarbon radicals were identified.
Then an apparatus has been modified to sample the ionic and neutral species that emerge from microwave discharge in order to study the main products of CH_4/O_2 plasmas as a function of the partial oxygen pressure in MW flow tube with 2.45GH_z,10W,and 2.2 torr of total pressure. Mass spectrometry was used for the identification of the products. Studies have clearly shown the presence of various O-containing ionic species. The relative peak intensity profiles of these ionic products have been determined as a function of O_2 composition in the feed gas. It is apparent from a comparison with the neutral species in this plasma that the proton transfer reaction plays a significant role in the ion chemistry of the CH_4/O_2 plasma.
The final study concerns the determination of Li^+ affinity of C_2H_3 and C_2H_5 radicals on which ab initio molecular orbital calculations at the UHF-MP2/6-31G^* level of theory has been carried out. We believe that the determination of Li^+ affinity of radicals will be essential in future development of the Li^+ ion attachment/mass spectrometry technique for radical detection.
|
Research Products
(11 results)
