Custom-built block

Coleman and co-workers36 performed a three-component reaction employing 2-oxothioacetamides, aldehydes and alkyl halides in ethanol with Na2 C03 as the catalyst to form a 24-member library of substituted 4-sulphonyl-l-ff-imidazoles (Scheme 5.20). The products were formed in yields of 40-96% and purities of 20-96%. The library was synthesised in a custom-built reaction block with expandable reaction vessels. The expandable reaction blocks were designed to accommodate the expanding gas volume caused by the elevated temperature without releasing any of it into the cavity. Unfortunately, this approach limited the temperatures used in the reactions to the boiling point... 

The design of a cell that is compatible with more than one technique was illustrated by Couves et al. (1991). They briefly presented a cell design that allowed the collection of both XAFS spectra (in a dispersive geometry) and X-ray diffractograms. The cell operated at atmospheric pressure and included a pressed wafer of the catalyst. Little detail was provided, but the authors stated that the cell consisted of a custom-built Kanthal heating element embedded in a pyrophyllite block with a recess for the pressed sample. The sample could be heated to 1073 K in a flow of gas. More detail of the design was published by Dent et al. (1995). In essence, there is an outer container fabricated from aluminum that has the necessary Kapton windows and water-cooled end caps. A pyrophyllite heat shield fits inside the outer container, and a wire-wound heater, into which the sample holder fits, is placed inside this heat shield. The furnace was capable of operation from 373 to 1473 K. 

Electrical and fluidic interconnections to the chip are made using a custom built connection block, machined from PEEK polymer. Fluidic and electrical connections are made by clamping the chip within the block. Spring loaded connectors are used to make contact with the chip electrodes and miniature 0-rings used to seal the fluidic connection between the block and chip. Microfluidic tubing and connectors are used to connect the PEEK block to the sample, waste and wash reservoirs. The connector block is mounted on a PCB which has the impedance detection circuitry and the... 

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