Figure 2

Figure 1

A common method used to determine the rate of gas uptake while keeping the pressure in the reactor constant is shown in Figure 1. The reaction gas is initially charged into the reservoir (A) at a pressure significantly higher than the pressure needed for the reaction. A gas regulator (R) is used to maintain the pressure in the reactor while a pressure transducer (B) measures the pressure drop in the reservoir. A second pressure transducer (C) is used to monitor the pressure inside the reactor. The regulator (R') controls the pressure in the reactor during the purging step before the actual reaction.

Figure 2 shows a close-up of such an arrangement in one of the low pressure reactor systems in the Center. Since the maximum pressure in the reservoir is fixed by the pressure rating of the cylinder and other safety considerations, the best way of using such a system for larger scale reactions is to change the size of the reservoir. A facile method for changing the reservoir size is shown in this Figure with different sized reservoirs connected to a selection valve.
In addition, the Center is well equipped for the analysis of the reaction products formed in our studies. We have GC-MS, several automated GC and HPLC instruments with a number of chiral and achiral columns as well as diffuse reflectance FTIR with which surface compositions can be measured during a gas phase reaction. Also available are the various instruments in the Department of Chemistry and Biochemistry which includes both 200 MHz and 500 MHz nmr's, a digital polarimeter and a Super CRC reaction calorimeter.