Iron‐Containing Poly(propylene imine) Dendromesogens with Photoactive Properties

Abstract

Here, we report the first results of investigation the local structure and photoactive properties of iron‐containing dendromesogens based on decyloxybenzoate substituted poly(propylene imine) dendrimers of the first to fifth generations. Iron ions existing in a high‐spin state are coordinated in dendrimer ligands by two kinds of iron‐complexing sites with an octahedral and a tetrahedral symmetry. Octahedral (high‐symmetry) centers are located at the border of the dendrimeric core, while the tetrahedral centers with strong rhombic distortion of iron environment are distributed throughout all branching of the dendrimeric core. It has been found that all iron‐containing dendromesogens exhibit light‐harvesting and fluorescence properties.

Magnetic Resonance and Mössbauer Studies of Superparamagnetic γ‐Fe2O3 Nanoparticles Encapsulated into Liquid‐Crystalline Poly(propylene imine) Dendrimers

“…Therefore, the value of the length of the decyloxy chain segments surrounding the PPI core of 1.505 nm was obtained by subtracting the diameter of the core (1.86 nm) from the value of a h (4.87 nm). According to our results [15,27] and those published by other groups, [13,14,46] we may conclude that maghemite NPs are electrostatically coupled with reactive (amido and amino) nitrogen periphery atoms and incorporated among the branches of PPI dendrimers. It has also been shown that iron oxide NPs have a narrow size distribution (0.5 nm) [46] Iron oxide NPs are relatively well-separated inside the dendrimer and the suggested model for the location of the NPs is presented in Scheme 1.…”

“…The second-generation dendrimeric iron(III) complex of 3,4-bis(decyloxybenzoyl) PPI derivatives were synthesized as previously reported. [27] The purity and individuality of the desired product was checked by different physical/chemical methods. Electrolytic gel-permeation chromatography was performed by means of the following chromatography setup: SDV columns (30 80 mm, 5 nm particle size): 102, 103, and 104 pore sized from the Polymer Standards Service (PSS); pump: Spectra Physics P100; UV detector: Waters 440, l = 254 nm; IR detector: Waters 410; flow rate: 0.5 mL min À1 ; eluent: THF with 0.25 wt % tetrabutylammoniumbromide; internal standard: 1,2-dichlorbenzene.…”

“…[27] The structure of the liquid-crystalline, second-generation PPI dendrimer is presented in Scheme 1. The preparation of the sample is described as follows.…”

“…The iron-dendrimer nanocomposite [2-D-(Fe 2 O 3 ) y ] was synthesized in three stages. Equation (1) gives the synthetic scheme for the nanocomposite based on the dendrimer complex derived from second-generation 3,4-bis(decyloxybenzoyl) PPI and iron(III) chloride [2-D-(FeCl 3 ) 4.7 ]: [27][28][29] 2-D-ðFe 3þ Þ…”

Metallomesogens: Retrospectives and Perspectives

“…[134]. Заслуживает внимания и развиваемое направление, связанное с синтезом и исследованием ЖК металлодендримеров [135][136][137].…”