New frontiers in hybrid materials: noble metal nanoparticles – supramolecular gel systems

The last decade has witnessed an increasing interest in the development of hybrid materials with novel properties. Noble metal NPs–gel materials represent a new class of hybrid composites, envisaged by many to have great potential for technological applications, as a consequence of the beneficial integration of the properties of both the NPs and the gelling compounds. This review article provides an up-todate account of the most interesting and inspiring works published in the field, especially focusing on their preparation and characterization. Some examples of practical uses of such intriguing materials are also described

Responsive aggregation-induced emissive supramolecular gels based on bis-cyanostilbene derivatives

In aromatic solvents, V-shaped bis-cyanostilbene derivative 1 forms stable and emissive gels which are capable of responding to light and, selectively, to TFA via a gel-to-sol transformation

Synthesis of Selected Naturally Occurring Glucosides of Volatile Compounds. Their Chromatographic and Spectroscopic Properties

Naturally occurring glucosides of benzyl alcohol, (±)-menthol, (+)-borneol, thymol, carvacrol and eugenol were synthesized by the Koenigs-Knorr-Zemplén method (yields 19.5–52.2 %). Their β-D-glucopyranosidic structures were determined by one- and two-dimensional homoand heteronuclear 1H and 13C NMR spectroscopy. The β-configuration was additionally confirmed by the hydrolysis with β-glucosidase. Tetraacetyl-β-D-glucopyranosides, as intermediates, were GC-MS analyzed. Diastereomeric β-glucoside tetraacetates of (±)-menthol were well separated on the HP-101 column. The mass spectra of glucopyranoside tetraacetates were mutually compared, as well as with the spectra of their aglycones

Synthesis of Selected Naturally Occurring Glucosides of Volatile Compounds. Their Chromatographic and Spectroscopic Properties

Naturally occurring glucosides of benzyl alcohol, (±)-menthol, (+)-borneol, thymol, carvacrol and eugenol were synthesized by the Koenigs-Knorr-Zemplén method (yields 19.5–52.2 %). Their β-D-glucopyranosidic structures were determined by one- and two-dimensional homoand heteronuclear 1H and 13C NMR spectroscopy. The β-configuration was additionally confirmed by the hydrolysis with β-glucosidase. Tetraacetyl-β-D-glucopyranosides, as intermediates, were GC-MS analyzed. Diastereomeric β-glucoside tetraacetates of (±)-menthol were well separated on the HP-101 column. The mass spectra of glucopyranoside tetraacetates were mutually compared, as well as with the spectra of their aglycones

Synthesis of selected naturally occurring glucosides of volatile compounds. Their chromatographic and spectroscopic properties

Naturally occurring glucosides of benzyl alcohol, (+/-)-menthol, (+)-borneol, thymol, carvacrol and eugenol were synthesized by the Koenigs-Knorr-Zemplen method (yields 19.5-52.2%). Their beta-D-glucopyranosidic structures were determined by one- and two-dimensional homo- and heteronuclear H-1 and C-13 NMR spectroscopy. The beta-configuration was additionally confirmed by the hydrolysis with P-glucosidase. Tetraacetyl-beta-D-glucopyranosides, as intermediates, were GC-MS analyzed. Diastereomeric beta-glucoside tetraacetates of (+/-)-menthol were well separated on the HP-101 column. The mass spectra of glucopyranoside tetraacetates were mutually compared, as well as with the spectra of their aglycones

Preparation of potentially porous, chiral organometallic materials through spontaneous resolution of pincer palladium conformers

Understanding the mechanism by which advanced materials assemble is essential for the design of new materials with desired properties. Here, we report a method to form chiral, potentially porous materials through spontaneous resolution of conformers of a PCP pincer palladium complex ({; ; 2, 6-bis[(di-t-butylphosphino)methyl]phenyl}; ; palladium(II)halide). The crystallisation is controlled by weak hydrogen bonding giving rise to chiral qtz-nets and channel structures, as shown by 16 such crystal structures for X = Cl, and Br with various solvents like pentane and bromobutane. The fourth ligand (in addition to the pincer ligand) on palladium plays a crucial role ; the chloride and the bromide primarily form hexagonal crystals with large 1D channels, whereas the iodide (presumably due to its inferior hydrogen bonding capacity) forms monoclinic crystals without channels. The hexagonal channels are completely hydrophobic and filled with disordered solvent molecules. Upon heating loss of solvent occurs and the hexagonal crystals transform into other non-porous polymorphs. Also by introducing strong acid, the crystallisation process can be directed to a different course, giving several different non-porous polymorphs. In conclusion a number of rules can be formulated dictating the formation of hexagonal channel structures based on pincer palladium complexes. Such rules are important for a rational design of future self-assembling materials with applications in storage and molecular recognition

Crystal structures and magnetic properties of a set of dihalo-bridged oxalamidato copper(II) dimers

A set of four copper(II) complexes, L1–X and L2–X (X = Cl, Br ; L1 = N-(L-leucine methyl ester)-N′-((2-pyridin-2-yl)methyl)oxalamide and L2 = N-benzyl-N′-((2-pyridin-2-yl)methyl)oxalamide), have been synthesized and characterized by X-ray structural analysis, electron paramagnetic resonance (EPR) spectroscopy on single crystals and by SQUID magnetization measurements. X-ray diffraction studies show one-dimensional hydrogen bonded networks of dimeric copper(II)-complexes bridged by two halide ions and with the two metal centers 3.44–3.69 Å apart. The geometry at each copper(II) atom is ideal or near ideal square pyramidal. EPR and SQUID studies indicate that all complexes exhibit weak antiferromagnetic interactions between the Cu(II) paramagnetic centers, with exchange parameter |J| ~ 1 cm−1. Magneto-structural comparisons among similar dihalo-bridged Cu(II) dinuclear complexes are also provided, and a possible correlation has been established