Synthesis of Neutral Metallodendrimers Possessing Adamantane Termini:  Supramolecular Assembly with β-Cyclodextrin

Abstract

First and second generations of 1 → (2 + 1) C-branched metallodendrimers were prepared employing terpyridine−RuII−terpyridine connectivity. Each surface dendron is comprised of a terpyridinyl (focal group), a diester (capable of easy hydrolysis), and a terminal adamantyl moiety (for encapsulation). Internal incorporation of counterbalancing carboxylate moieties derived by ester cleavage with formic acid and subsequent treatment of the intermediate diacid with base gave access to overall charge−neutral dendritic macromolecules. Aqueous solubility was effected by the supramolecular encapsulation of the terminal adamantane moieties with β-cyclodextrin, causing dissolution of the water-insoluble dendrimers (11 and 15) into an aqueous environment.

Multifunctionalization of Dendrimers through Orthogonal Transformations

“…Our synthetic strategy towards synthesizing these dendrimers is based on the convergent synthetic approach and the 1!A C H T U N G T R E N N U N G (2+1) C-branching monomers reported by Newkome and co-workers, [57] who have reported a variety of applications of these materials in recent years. [62][63][64] Dendron A is a key building block in our design and introduces single and dual functionalities onto the dendrimer surface. Dendron A is obtained by a series of convergent steps from dendrons 5, C, and D.…”

From Dendrimers to Macrocycles: 80 Years George R. Newkome—Milestones of a Gentleman Scientist

“…Furthermore, it was also possible to functionalize those ruthenium‐based metallodendrimers with adamantane at the outer shell resulting in the possibility to selectively bind cyclodextrin molecules due to host–guest interactions ( Figure ) . The combination of two or more supramolecular binding motifs in one molecule represents a new approach at that time and starts nowadays to be in the focus of interest, since two non‐covalent interactions can potentially be addressed independently from each other .…”

“…Schematic representation of two examples of ruthenium containing dendrimers with either terpyridine (above) or bipyridine (bottom) as ligand (the hexafluorophosphate counter ions in case of the bipyridine are not depicted) …”

Carbosilane and Carbosiloxane Dendrimers

“…Dendrimer purifications are performed by traditional analytical methods such as column chromatography and recrystallization [ 2 ], but they are identified and characterized using newly developed technologies such as AFM (atomic force microscopy), STM (scanning tunneling microscopy) and PL (photoluminescence) etc. [ 3 ]. Lately, the structures of various dendrimers have been accurately confirmed as having only one class of groups on their peripheries [ 4 ].…”