Small-Angle X-ray Scattering Structural Investigations of Starburst Dendrimers in Solution

A series of polyamidoamine dendrimers (generations 1.5–4.0, with ethylenediamine as the central core) has been investigated in methanol solution by means of the small-angle X-ray scattering technique. The comparative analysis of the structural properties of integer and half-integer generations of the dendrimers seems to be dominated by rather different trends. While the integer generations, bearing terminal amino groups, approach a compact space-filling structure, the presence of residue charges on the terminal carboxylate groups in the half-integer generations leads to a less compact internal structure and a long-range electrostatic interaction (structural order) in the system.