Zn(II) Curcuminate Complexes with 2,2′-bipyridine and Carboxylates
AbstractTwo novel zinc(II) compounds with curcuminate (abbreviated as cur−), [Zn(CH3COO)(cur)(bpy)](1)·CH3OH·2H2O (bpy = 2,2′-bipyridine) and [Zn(PhCOO)(cur)(bpy)] (2)·CH3OH, have been synthesized and characterized. Their composition has been determined by single-crystal X-ray structure analysis. Complexes 1 and 2 are similar: in both a five-fold coordination environment of zinc(II) consists of a monodentate carboxylate, a chelating bidentate 2,2′-bipyridine, and curcuminate, which is bound via a deprotonated 1,3-dione moiety. In 1, 2,2′-bipyridine nitrogen atoms and curcuminate oxygen atoms form the base of a square pyramid, whereas the acetate oxygen occupies its apex. The O3N2 donor set in 2 defines a polyhedron which more closely resembles a trigonal bipyramid. The packing in the crystal lattices of both compounds is governed by hydrogen-bonds. Complexes 1 and 2 display higher stability than curcumin in buffered media at pH = 7.0, however, the degradation of coordinated cur− is comparable to that of yellow pigment curcumin (curH) when the pH is raised to 7.2. Both complexes 1 and 2 in DMSO exhibit fluorescence with Stokes shifts of 5367 and 4634 cm−1, respectively. View Full-Text
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Grabner, S.; Modec, B. Zn(II) Curcuminate Complexes with 2,2′-bipyridine and Carboxylates. Molecules 2019, 24, 2540.
Grabner S, Modec B. Zn(II) Curcuminate Complexes with 2,2′-bipyridine and Carboxylates. Molecules. 2019; 24(14):2540.Chicago/Turabian Style
Grabner, Sabina; Modec, Barbara. 2019. "Zn(II) Curcuminate Complexes with 2,2′-bipyridine and Carboxylates." Molecules 24, no. 14: 2540.
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