CePt2Al2: Structural and Bulk Properties.

This work is focused on the structural and physical properties of CePt2Al2, an intermetallic compound. At room temperature, the modulated orthorhombic structure Cmme(a00)000, with q→= (0.481, 0, 0) has been determined by single-crystal X-ray diffraction supplemented by dependence of lattice parameters above room temperature for which the X-ray powder diffraction was used. The compound undergoes a structural transition to a tetragonal structure above room temperature. This transition exhibits 50 °C hysteresis and creates a domain structure in the sample. The magnetic behavior has been studied by specific heat, magnetization, and transport measurements in the temperature range between 0.5 and 300 K. Specific heat and susceptibility shows an antiferromagnetic order below 2 K. On the basis of electrical resistivity and other bulk measurements, CePt2Al2 can be considered a Kondo lattice material. The presence of a modulated crystal structure opens the possibility of a charge density wave state in CePt2Al2 as observed for (Re)Pt2Si2.

Activity of (+)-Discadenine as a Plant Cytokinin.

Discadenine (1), a self-spore germination inhibitor from the cellular slim mold Dictyostelium discoideum, is structurally related to the plant hormone cytokinin. This compound was synthesized from l-aspartic acid, and its activities were confirmed by three classical cytokinin bioassays as well as by using binding and activation assays with the Arabidopsis cytokinin receptors AHK3 and CRE1/AHK4.