C 9168 (OTTO) Cesium chloride, 99.999% Cas 7647-17-8 - used in organic chemistry. C 9168 (OTTO) Cesium chloride, 99.999% Cas 7647-17-8 - used in centrifugation in a technique known as isopycnic centrifugation. C 9168 (OTTO) Cesium chloride, 99.999% Cas 7647-17-8 - used for sensitive synthesis when a balanced strong base is needed.