Investigation of ionic clustering using a novel designed Pulsed-electron High-Pressure Mass Spectrometer

Fundamental studies of stepwise ionic solvation

The theoretical solvation of aqueous species and ions is paramount to the understanding of the properties under most conditions of relevance to reactions occurring in crustal fluids. These solvation properties are still not adequately represented through theoretical means even at relatively low temperatures and pressures. Currently vast strides are being made in fundamental cluster chemistry at Berkeley (especially of water) and experimental mass spectrometry at Alberta. Our research program involves the measurement of the energetics associated with ligand clustering around positive and negative ions and will build on the recent molecular results for ionic clustering. For this purpose we have constructed (after many years of machining) a Kebarle-style pulsed-electron high pressure mass spectrometer (p-HPMS) using high-temperature enthalpy calorimeters as models. Imperative to this measurement technique is the unambiguous knowledge of temperature and sampling conditions. Concurrent analyses of structural and theoretical values using GAUSSIAN are also underway. Long term uses in addition to the elucidation of fundamental reaction schemes are involved with the development of new theoretical approaches for the prediction of high temperature and pressure properties of various important geological species in water. The same measurements are also directly informative on the nature and chemistry of volcanic gas reactions and gaseous species in the stratisphere.
Tour and history of the p-HPMS Laboratory

• Overall HPMS experimental representation with labels
• The "original" HPMS machine (started life as an 7070H, then upgraded to an 7070E, hence it's larger size than standard issue 70E).
• Build History = chopping and drilling....
• Internal cylindrical source volume
• The our (Kebarle-style) Gas Handling Plant with 5L mixing bulb
• The our differentially pumped electron gun
• The electronics console showing multi-channel scalar and state of the art pdp-11/73 microcomputers.
• The cooling coil, a simple design, complicated bends, but it goes easily to -100 by passing clean nitrogen through a Cu tube immersed in liquid nitrogen.
• The source pretty much assembled
• Finding leaks with a cool Leybold refurbished He leak detector
• Coming soon... movies of ion/electron hunting
• Plot of ionic distribution in ion source (assumed spherical symmetry) vs time for average (n=2) water clusters

People and Contacts:

	Dr. Jamey K. Hovey Ion-cluster Laboratory Leader.
	Prof. Terry Seward Geochemistry Group Leader.		Dr. Oleg Suleimenov Postdoctoral Fellow (plans to start working with us soon ....

Email contacts:

Supported By:

• Swiss National Science Foundation,
• ETH Research Commission,
• Micromass, The Mass Spectrometry People

A collaborative effort including:

• Professor Paul Kebarle, Chemistry Department, The University of Alberta
• Dr. Alan Hogg and ALL of the people in the Mass Spectrometry Laboratory, Chemistry Department, The University of Alberta
• Professor Terry McMahon, Chemistry Department, The University of Waterloo
• The machinists and electronics personel here in the IMP workshop at the ETH ( Bruno Zürcher, Urs Graber, IMP; Urs Menet, IGMR) and the University of Alberta (Roman, Randy, and the rest of the Machine and Electronic Shops in the Chemistry Department at the University of Alberta).