ABSTRACT
Mixed membrane matrices (MMMs) made up with Nafion and nanocrystals of zirconium metal-organic framework (MOF) UiO-66 or the analogous sulfonated SO3H-UiO-66 were prepared by varying the filler loading and the size of the crystals. The combined effects of size and loading, together with the presence of sulfonic groups covalently linked to the MOFs, were studied with regard to the conductivity and mechanical properties of the obtained composite matrices. A large screening of membranes was preliminarily made and, on the most promising samples, an accurate conductivity study at different relative humidities and temperatures was also carried out. The results showed that membranes containing large crystals (200 nm average size) in low amounts (around 2%) displayed the best results in terms of proton conductivity values, reaching values by 30% higher than those of pure Nafion, while leaving the mechanical properties substantially unchanged. On the contrary, MMMs containing MOFs of small size (20 nm average size) did not show any conductivity improvements if compared to pure Nafion membranes. The effect of MOF sulfonation was negligible at low filler loading whereas it became important at loading values around 10%. Finally, membranes with a high filler loading (up to 60 wt %) of sulfonated UiO-66 showed a slight reduction of conductivity in comparison with membranes loaded at 20% of nonsulfonated ones.
ABSTRACT
Metal complexes of the type [Co(phen)2(4-NO2pcyd)2].CH3OH, 1, [Zn(phen)2(4-NO2pcyd)2].CH3OH, 2, [Cd(phen)2(4-NO2pcyd)2], and 3, (phen = 1,10-phenanthroline, 4-NO2pcyd = 4-nitro phenylcyanamide) have been studied. The synthesis, characterization, and the biological activities of complexes 1-3 have been investigated. The geometries of complexes 1-3 were confirmed by single-crystal X-ray crystallography. The interactions of complexes 1-3 with human serum albumin (HSA) were studied using fluorescence and circular dichroism spectroscopy. The thermodynamic studies have showed the reaction for the binding of complexes 1-3 with HSA is hydrophobic (ΔH0 Ë 0 and ΔS0 > 0). The in vitro cytotoxic potential of complexes 1-3 and their complexes with HSA were examined. The complexes 1-3 with HSA enhance about 3-fold cytotoxicity in cancer cells lines.
Subject(s)
Coordination Complexes/chemistry , Cyanamide/chemistry , Serum Albumin, Human/chemistry , Binding Sites , Cadmium/chemistry , Circular Dichroism , Cobalt/chemistry , Coordination Complexes/chemical synthesis , Copper/chemistry , Crystallography, X-Ray , Humans , Protein Binding/drug effects , Zinc/chemistryABSTRACT
In the title compound, [Ni(C(7)H(4)N(3)O(2))(2)(C(12)H(8)N(2))(2)]·CH(3)OH, the Ni(II) atom is six-coordinated in a distorted N(6) octa-hedral geometry and is chelated by two phenanthroline ligands and two phenyl-cyanamide groups which occupy cis positions. The (4-nitro-phen-yl)cyanamide anions act as monodentate ligands. There is one classical inter-molecular O-Hâ¯N hydrogen bond and several C-Hâ¯O hydrogen bonds are also observed.
ABSTRACT
In the title coordination polymer, [Cd(C(7)H(4)N(3)O(2))(2)(C(3)H(7)NO)(2)](n), the Cd(II) atom, lying on an inversion center, is six-coordinated in a distorted N(4)O(2) octa-hedral geometry. The N atoms of the 4-nitrophenylcyanamide anions form the equatorial plane and the O atoms of the dimethyl-formamide mol-ecules occupy the axial positions. The anions act as bridging ligands, connecting the Cd atoms into a one-dimensional coordination polymer along [100].
