Tensor 27 FT-IR Introduction
The departmental FT-IR system is a Bruker Tensor 27 system (purchased 2004) and is located in Choppin 702 (Figure 1). It is equipped with a room temperature DTGS detector, mid-IR source (4000 to 400 cm-1, and a KBr beamsplitter. Maximum resolution is 1 cm-1. This system is free to use. The FT-IR software keeps a log of every user so there is no physical log to fill out. There is an identical Tensor 27 FT-IR system located in Choppin 616 mainly used by the Stanley group for catalytic studies, but available as backup or for extended special FT-IR studies.

The standard sample cell in the FT-IR is a Pike Miracle single-bounce attenuated total reflectance (ATR) cell equipped with a ZnSe single crystal. ZnSe absorbs strongly below 650 cm-1 and data should not be collected below this wavenumber.

The sample that is placed on the ATR crystal can be solid, gel, liquid, or solution (non-corrosive, naturally). Since it will be out in the air the sample needs to be oxygen and moisture stable (for air-sensitive samples read on). You only need enough sample to cover the crystal surface and, if a solid, enough for the “crank down arm” to press the sample onto the crystal to have good contact with the crystal surface. The ZnSe is fairly soft, so be careful with “hard” solid samples.