Synthesis and characterization of phosphorus-containing dendrimers bearing rhodamine derivatives as terminal groups

Abstract

The synthesis of two new derivatives of Rhodamine B functionalized by phenols is reported. For one rhodamine derivative, the equilibrium between the open form and the ring-closed (spirolactam) form is completely shifted toward the latter, whereas the constitution of the other rhodamine derivative precludes ring closure. The spirolactam derivative was grafted as terminal group to a first generation phosphorus-containing dendrimer. Attempts to open the spirolactam form by adding HCl failed and resulted only in protonation of the NEt 2 substituent of rhodamine.

A highly selective turn-on fluorescent probe for iron(ii) to visualize labile iron in living cells

“…2a). In basic conditions, chemical shis for H A and H B were observed at 6.6 ppm, which are typical values for the closed conguration 42,62,68 (Fig. 2c).…”

“…These chemical shis are comparable with those of the opened form of rhodamine derivatives. 62,67,68 In acidic conditions, large downeld shis for H A and H B were observed, which meant protonation of the nitrogen atom of the diethylamino group and formation of the lactone (Fig. 2a).…”

Fluorescent Phosphorus Dendrimers: Towards Material and Biological Applications

“…Attempts to open the spirolactam ring by adding HCl failed, and only protonation of the NEt 2 substituent of rhodamine was obtained, thus no fluorescence was observed with this dendrimer. [27] A small dendron, constituted of five dansyl groups and one tyramine linked to a cyclotriphosphazene was synthesized (Figure 2f), and the fluorescence properties were studied in different conditions. A notable decrease of the fluorescence quantum yield (Φ) of this dendron was observed, upon going from pure dioxane (Φ = 51) to pure water (Φ = 17).…”

“…The ring‐closed form of a rhodamine derivative, functionalized by a phenol was grafted to the P(S)Cl 2 terminal groups of a first generation dendrimer (Figure e). Attempts to open the spirolactam ring by adding HCl failed, and only protonation of the NEt 2 substituent of rhodamine was obtained, thus no fluorescence was observed with this dendrimer …”

Phosphorhydrazones as Useful Building Blocks for Special Architectures: Macrocycles and Dendrimers

“…They comprise several ferrocene derivatives functionalized in most cases with a phosphine, eventually linked to the cyclopentadienyl ring through a spacer . Many functionalized phenols have been prepared from tyramine;, this includes functions having biological properties such as azabisphosphonic acid salts, of different types, diverse amino phosphonates, azabis carboxylate and azabis sulfonate salts, several mannose derivatives, ethacrynic acid, diverse phosphines such as an azabisphosphine, a thiazolylphosphine, and an iminophosphine, diverse fluorophores such as a maleimide, and a derivative of rhodamine . Other functionalized phenols comprise ligands for catalysis, such as phosphine, and diphosphine, iminophosphine, aminophosphine, diketone, pyridineimine, terpyridine, bisoxazoline, prolinol derivative, and cinchonine, diverse other compounds, such as aminophosphoniums, thioesters and thioamides, two types of ethacrynic derivatives,, long chains of type alkyl or perfluoroalkyl, or PEG (polyethyleneglycol), and fluorescent groups based on stilbazole or fluorene derivatives , .…”