An inherently non-peroxide forming ether solvent, 2,2,5,5-tetramethyltetrahydrofuran (2,2,5,5-tetramethyloxolane), has been synthesized from readily available and potentially renewable feedstocks, and its solvation properties have been tested.

The photophysical and hydrodynamic properties of dendrimers (GnPZn and GnTPPH2) with zinc porphyrin (PZn) and tetraphenylporphyrin (TPP) cores are studied in tetrahydrofuran (THF) and dimethylformamide (DMF). UV−vis absorption spectra of GnPZn exhibit a small red shift of the Soret band upon increasing the generation as a result of interactions between the dendrons and the core. All fluorescence decays obtained from global analysis show a monoexponential profile. The intrinsic viscosity obtained for GnPZn from the hydrodynamic volume (V h) passes through a maximum as a function of generation (G) in agreement with earlier experimental findings and calculations suggesting that the internal density profile of dendrimers decrease monotonically outward from the center of the molecule. Within the investigated range (G = 1−3), GnTPPH2 exhibits an approximately constant intrinsic viscosity due to the linear dependence between the hydrodynamic volume and the molecular weight. The differences observed between GnPZn and GnTPPH2 are correlated to structural differences in their cores. The additional phenyl group of the TPP in GnTPPH2 increases the distance between the branches and the porphyrin moiety compared to GnPZn, resulting in a more flexible structure. The enhanced flexibility allows the terminal groups to sample more conformational space and therefore decreases the volume of the dendrimer as compared to the theoretical fully extended structure where V h ∝ G 3. A comparison of the results obtained from analysis of fluorescence anisotropy decays with previously reported viscometry measurements shows a dependence of the structural collapse on the core size.

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The size of poly(benzyl ether) dendrimers with different molecular architectures was measured by small angle neutron scattering (SANS). Both polar and non‐polar solvents were used to measure the effect of solvent type. The radius of gyration (Rg) of all of the dendrimers follows a scaling law of Rg ∝ M1/3 consistent with literature values of other chemically different dendrimers. The effect of solvent type on dendrimer size was minimal.

200F, 3001 Leuven (Heverlee), Belgium Two tert-butyldiphenylsilyl-protected synthons 7 and 9 are prepared in excellent yields and used in a one-pot synthesis of higher generation polyether dendrons.

A "top down" approach to the development of sustainable, greener, low-polarity solvents is presented.Methyl butyrate, ethyl isobutyrate, methyl pivalate and pinacolone were identified as potential target solvents from trends in Hansen solubility parameters and known physical properties. Solubility, flammability and physical properties were determined which showed their potential to replace traditional, hazardous, volatile, non-polar solvents such as toluene. Each new candidate then demonstrated their suitability to replace these traditional solvents in solubility tests, despite being esters and ketones, each candidate demonstrated their similarity to traditional volatile non-polar solvents in terms of their solubility properties by their ability to dissolve natural rubber, a particularly low-polarity solute. This was reinforced by their performance in a model Menschutkin reaction and a radical-initiated polymerisation for the production of pressure-sensitive adhesives, where their performance was found to be similar to that of toluene.Importantly, a preliminary toxicity test (Ames test) suggested non-mutagenicity in all candidates. Each of the four candidates can be synthesised via a catalytic route from potentially renewable resources, thus enhancing their green credentials.

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