Study of small carbon and silicon clusters using negative ion photodetachment techniques

1996 ◽  
pp. 113-148 ◽  
Author(s):  
Caroline C. Arnold ◽  
Daniel M. Neumark
Keyword(s):  
Negative Ion ◽  
Silicon Clusters

Laser Annealing of Semiconductor Clusters: Trimethylamine Reactions with Positive and Negative Clusters

1990 ◽  
Vol 206 ◽  
Author(s):  
S. Maruyama ◽  
L. R. Anderson ◽  
R. E. Smalley
Keyword(s):  
Fourier Transform ◽  
Cyclotron Resonance ◽  
Laser Annealing ◽  
The Other ◽  
Negative Ion ◽  
Ion Cyclotron Resonance ◽  
Silicon Clusters ◽  
Crystal Forms ◽  
Positively Charged ◽  
Ft Icr

ABSTRACTReaction studies with trimethylamine on positively charged laser-annealed silicon clusters of 39, 43, and 48 atoms magnetically levitated in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer reveal the same relative reaction pattern as previously observed for identical studies with ammonia and ethylene. The 39th cluster was found to be considerably less reactive than the other positive cluster sizes, and significantly, its negative ion is also relatively less reactive than the 43rd and 48th. The continued observation of this reactivity trend provides additional experimental evidence that the annealed clusters adopt well-organized structures, and that these crystal forms are similar for both charge states.

Confounding contaminants in mass spectrometric reaction monitoring

2018 ◽  
Author(s):  
Gilian T. Thomas ◽  
Landon MacGillivray ◽  
Natalie L. Dean ◽  
Rhonda L. Stoddard ◽  
Lars Yunker ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometric ◽  
Negative Ion ◽  
Reaction Monitoring ◽  
Schlenk Flask ◽  
Dynamic Analyses ◽  
Rubber Septa ◽  
Negative Ion Mode ◽  
Mode A

<p>Reactions carried out in the presence of rubber septa run the risk of additives being leached out by the solvent. Normally, such species are present at low enough levels that they do not interfere with the reaction significantly. However, when studying reactions using sensitive methods such as mass spectrometry, the appearance of even trace amounts of material can confuse dynamic analyses of reactions. A wide variety of additives are present in rubber along with the polymer: antioxidants, dyes, detergent, and vulcanization agents, and these are all especially problematic in negative ion mode. A redesigned Schlenk flask for pressurized sample infusion (PSI) is presented as a means of practically eliminating the presence of contaminants during reaction analyses.</p>

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