Cationic carbosilane dendrimers of generations 1-3 have been synthesized employing thiol-ene click chemistry. The obtained dendrimers present three different types of ammonium functions, two of them with the charge at the surface, -NH 3 + and -NMe 3 + , and other with the charge internalized by the presence of ethylalcohol moieties, -[NMe 2 (CH 2 CH 2 OH)] + . The influence of -NMe 3 + and -[NMe 2 (CH 2 CH 2 OH)] + in dendrimer structure have been studied by molecular dynamics. The antibacterial properties of these families of dendrimers have been evaluated against Gram-positive (Staphylococcus aureus CECT 240) and Gramnegative (Escherichia coli CECT 515) bacterial strains, and the results have been compared with those obtained for related cationic carbosilane dendrimers functionalized by hydrosilylation reactions. These data show the relevance of the sulfur atom versus the silicon atom close to the dendrimer surface and the outer charge versus the inner charge.Finally, the stability of the most active first generation dendrimers vs. pH and temperature has also been studied.

A variety of neutral and cationic carbosilane dendrons containing a wide range of active groups, such as −N 3 , −OH, −NH 2 , and −SH, at the focal points were synthesized from carbosilane vinyl dendrons BrG n V m from generations 1−3 by substitution of the bromine atom at the focal point and functionalization of the vinyl groups via thiol-ene click chemistry with HS(CH 2 ) 2 NMe 2 •HCl. These dendritic wedges were characterized by NMR, MS, and elemental analysis.

The bactericidal activity of a library of cationic dendritic systems depends on the hydrophilic/hydrophobic structural balance, being the presence of a sulfur atom proximal to the peripheral ammonium functions of relevance.