Diterpenes stability of commercial blends of roasted and ground coffees packed in copolymer coupled with aluminium and eco-friendly capsules.

Diterpenes are group of compounds of the terpenic fraction of roasted coffee and account for about 7-20 % (w/w) of the lipid fraction. Several parameters can influence their occurrence in coffee beans and beverages including species and post-harvest processing. Diterpenes in coffee have been studied extensively, but to the best of the authors' knowledge, there is no information in the literature on their stability over time. Coffee is a relatively stable product under optimal temperature, humidity and oxygen conditions. However, during storage it can undergo a series of chemical and physical reactions that alter its flavour and lead to rancidity, mainly due to the oxidative reactions that take place on the lipid fraction. In this study, the effect of long-term storage on the diterpene content of different commercial coffee blends and packaging is analysed and critically discussed. The Results show that the storage influences the internal environment of the capsules with an increase in moisture and a decrease in pH favouring more reactive conditions, especially for Eco capsules. Relative stability over time is observed for cafestol and kahweol. dehydro derivatives show a degradation up to T60 independently on the blends and packaging, which is not related to their precursors. The permeability of packaging and blends affect the modification of these components: while a drastic oxidation process takes place in Arabica eco compatible capsules (PC) when acidity and moisture increase, in Arabica/Robusta eco compatible capsules (IC) as well as in Arabica/Robusta and Arabica standard capsules (IS and PS) the peroxides tend to increase resulting in an autocatalytic propagation.

PtIV-Containing Hexaplatinate(II) [PtIVPtII6O6(AsO2(CH3)2)6]2- and Hexapalladate(II) [PtIVPdII6O6(AsO2(CH3)2)6]2.

The first PtIV-containing discrete polyoxoplatinate(II) [PtIVPtII6O6(AsO2(CH3)2)6]2- (Pt7) and polyoxopalladate(II) [PtIVPdII6O6(AsO2(CH3)2)6]2- (PtPd6) have been prepared and characterized in the solid state, in solution, and in the gas phase. The molecular structures of the noble metal-oxo clusters Pt7 and PtPd6 comprise a central, octahedral PtIVO6 hetero group surrounded by six square-planar MO4 (M = PtII, PdII) units, which are capped by six dimethylarsinate ligands. The polyanions were prepared under simple one-pot aqueous solution conditions by reacting H2Pt(OH)6 with either K2PtCl4 or Pd(NO3)2 in sodium dimethylarsinate buffer (pH 7) at 80 °C. Catalytic studies were performed on Pt7 supported on SBA15-apts for o-xylene hydrogenation at 300 °C and 90 bar H2 pressure and indicated excellent activity and recyclability with low activation temperature.

Mixed noble metal-oxo clusters: platinum(IV)-gold(III) oxoanion [PtIV2AuIII3O6((CH3)2AsO2)6].

The first discrete mixed platinum(IV)-gold(III) oxoanion [PtIV2AuIII3O6((CH3)2AsO2)6]- (1) was synthesized by reaction of H2Pt(OH)6 with H[AuCl4] in a simple one-pot procedure in aqueous solution at pH 7 and comprises two equivalent PtIVO6(As(CH3)2)3 units which are linked by three square-planar AuIIIO4 units. Polyanion 1 could be isolated as a potassium or sodium salt in good yield, which were structurally characterized in the solid state by single-crystal XRD and TGA, and in solution by multinuclear (1H, 13C, 195Pt) NMR, indicating that polyanion 1 is stable in solution, which was confirmed by ESI-MS studies. The sodium salt of 1 undergoes a clean single-crystal-to-single-crystal (SCSC) structural transformation upon rehydration and dehydration.

Mixed-valent palladium(IV/II)-oxoanion, [PdIVO6PdII6((CH3)2AsO2)6]2.

We report on the first example of a PdIV-containing polyoxopalladate(II). The discrete mixed-valent polyoxopalladate(IV/II), [PdIVPdII6O6((CH3)2AsO2)6]2-, comprising a central PdIV ion that is surrounded by a six-membered PdII-oxo ring capped by six dimethylarsinate groups, was synthesized and structurally characterized in the solid state, in solution and in the gas phase by multiple analytical techniques.

Discovery of Polythioplatinate(II) [Pt3S2(SO3)6]10- and Study of Its Solution and Catalytic Properties.

We have discovered the first polythioplatinate(II), [PtII3S2(SO3)6]10- (1), which was synthesized in aqueous basic medium (pH 11) by hydrothermal heating at 150 °C. Polyanion 1 comprises a discrete, triangular assembly of three Pt2+ ions linked by two µ3-sulfido ligands, and their square-planar coordination geometry is completed by two terminal S-bound sulfito ligands. Polyanion 1 was isolated as a hydrated sodium salt, Na10[PtII3(µ3-S)2(SO3)6]·22H2O (Na-1), which was characterized in the solid state by single-crystal X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectra, and elemental analysis, in solution by 195Pt NMR and atomic absorption spectroscopy, and in the gas phase by electrospray ionization mass spectrometry. Density functional theory calculations were performed, and the 195Pt NMR chemical shifts of 1 were computed theoretically and shown to match well with the experimental data. Furthermore, the discrete title polyanion 1 was immobilized on mesoporous SBA-15 support and used as a precatalyst for the hydrogenation of o-xylene.

Discrete, Cationic Palladium(II)-Oxo Clusters via f-Metal Ion Incorporation and their Macrocyclic Host-Guest Interactions with Sulfonatocalixarenes.

We report on the discovery of the first two examples of cationic palladium(II)-oxo clusters (POCs) containing f-metal ions, [PdII6 O12 M8 {(CH3 )2 AsO2 }16 (H2 O)8 ]4+ (M=CeIV , ThIV ), and their physicochemical characterization in the solid state, in solution and in the gas phase. The molecular structure of the two novel POCs comprises an octahedral {Pd6 O12 }12- core that is capped by eight MIV ions, resulting in a cationic, cubic assembly {Pd6 O12 MIV8 }20+ , which is coordinated by a total of 16 terminal dimethylarsinate and eight water ligands, resulting in the mixed PdII -CeIV /ThIV oxo-clusters [PdII6 O12 M8 {(CH3 )2 AsO2 }16 (H2 O)8 ]4+ (M=Ce, Pd6 Ce8 ; Th, Pd6 Th8 ). We have also studied the formation of host-guest inclusion complexes of Pd6 Ce8 and Pd6 Th8 with anionic 4-sulfocalix[n]arenes (n=4, 6, 8), resulting in the first examples of discrete, enthalpically-driven supramolecular assemblies between large metal-oxo clusters and calixarene-based macrocycles. The POCs were also found to be useful as pre-catalysts for electrocatalytic CO2 -reduction and HCOOH-oxidation.