Insights into molecular packing effects on the emission properties of fluorenone-based molecules in the aggregate state

A structure–packing–property relationship study of fluorenone-based molecules indicates that the formation of a three-dimensional molecular packing network is an effective way to suppress molecular motions to achieve AIE properties.

Packing subgroups in solvable groups

We show that any subgroup of a (virtually) nilpotent-by-polycyclic group satisfies the bounded packing property of Hruska–Wise [Packing subgroups in relatively hyperbolic groups, Geom. Topol. 13 (2009) 1945–1988]. In particular, the same is true for all finitely generated subgroups of metabelian groups and linear solvable groups. However, we find an example of a finitely generated solvable group of derived length 3 which admits a finitely generated metabelian subgroup without the bounded packing property. In this example the subgroup is a retract also. Thus we obtain a negative answer to Problem 2.27 of the above paper. On the other hand, we show that polycyclic subgroups of solvable groups satisfy the bounded packing property.