Aminopropyl-modified magnesium-phyllosilicates: layered solids with tailored interlayer access and reactivity.

Despite its wide application, the synthesis of aminopropyl-modified magnesium-phyllosilicates was known only in the case where every silicon atom bore an organic pending group. This paper shows the preparation of aminopropyl-modified talc where tailored amounts of silicon atoms are bound to an aminopropyl group. The decrease in the concentration of the organoamino group leaves a proportional concentration of interlayer SiOH groups that can be used to react with other silylation agents.

Spin transition in magnesiowüstite in earth's lower mantle.

Iron in the major lower mantle (LM) minerals undergoes a high spin (HS) to low spin (LS) transition at relevant pressures (23-135 GPa). Previous failures of standard first principles approaches to describe this phenomenon have hindered its investigation and the clarification of important consequences. Using a rotationally invariant formulation of LDA + U we report a successful study of this transition in low solute concentration magnesiowüstite, (Mg(1-x)Fe(x)(O), (x < 0.