ABSTRACT
A stable 3d-4f heterometallic cluster, namely, {Dy4Ni5L10(NO3)4(CO3)4(CH3OH)2}·CH3CN (Dy4Ni5, HL = 8-hydroxyquinoline), has been solvothermally synthesized and structurally characterized. The compound exhibits an interesting structure in which a tetrahedron based on 4f ions interpenetrates with a square pyramid based on 3d ions. Besides, a unique intermolecular interaction was found in Dy4Ni5, giving rise to its high stability not only when it is in the solid state but also when it dissolves in organic solvents. In addition, the magnetic behavior of solid Dy4Ni5 and the magneto-optical activity of the Dy4Ni5 solution were also studied.
ABSTRACT
Differences in key odor-active volatile compounds among the head, heart, and tail fractions of freshly distilled spirits from Spine grape (Vitis davidii Foex) wine were identified for the first time by gas chromatography-olfactometry and gas chromatography-mass spectrometry. Results from aroma extract dilution analysis (AEDA) showed that there were 34, 45, and 37 odor-active compounds in the head, heart and tail fractions, respectively. Besides, 20, 22, and 17 quantified compounds, respectively, showed odor activity values (OAVs) > 1. The head fraction was characterized by fruity, fusel/solvent notes owing to higher concentrations of higher alcohols and esters, while the tail fraction had more intense smoky/animal, sweaty/fatty attributes due to higher concentrations of volatile phenols and fatty acids. Finally, the heart fraction was characterized by ethyl octanoate, ethyl hexanoate, ethyl 3-phenylpropanoate, ethyl cinnamate, isoamyl alcohol, guaiacol, 4-ethylguaiacol, 4-vinylguaiacol, 2,3-butanedione, and (E)-ß-damascenone. Furthermore, observation of the distillation progress indicated that different volatiles with various boiling points and solubilities followed diverse distillation patterns: concentrations of most esters, higher alcohols, terpenes and C13-norisoprenoids decreased, while concentrations of volatile phenols, fatty acids and some aromatic compounds increased during distillation. As a result, their final concentrations in the three distillate fractions varied significantly.
