Raman spectra of cornetite, libethenite, pseudomalachite, reichenbachite and ludjibaite were obtained at 298 and 77 K using a Raman microprobe in combination with a thermal stage. Raman spectra of cornetite, libethenite and pseudomalachite are different, in line with differences in crystal structure and composition. Raman spectra of the three polymorphs pseudomalachite, reichenbachite and ludjibaite are similar, particularly in the stretching region, but characteristic differences in the deformation regions are observed. Differences are also observed in the phosphate deformation and stretching regions.
Twelve metallointercalators of the type [Pt(I(L))(A(L))](2+), where A(L) is either the R,R or S,S enantiomer of 1,2-diaminocyclopentane (DACP) and I(L) is either 1,10-phenathroline, 4-methyl-1,10-phenanthroline, 5-methyl-1,10-phenanthroline, 4,7-dimethyl-1,10-phenanthroline, 5,6-dimethyl-1,10-phenanthroline or 3,4,7,8-tetramethyl-1,10-phenanthroline, were synthesised, characterised and the cytotoxicity to the L1210 cell line was determined. The crystal structures of PHENRRDACP and PHENSS were obtained as monoclinic with a space group of P2(1) (a/Å = 11.4966, b/Å = 6.6983, c/Å = 12.0235) and P2(1) (a/Å = 11.5777, b/Å = 7.0009, c/Å = 12.5079), respectively. The R,R enantiomer of 1,2-diaminocyclopentane (RRDACP) produced the most cytotoxic metallointercalators. The most cytotoxic metallointercalators were 56MERRDACP and 47MERRDACP with IC(50) values of 0.16 and 0.17 μM, respectively, in comparison to cisplatin (1 μM).
Copper(II) (1(Cu)-21(Cu)) and previously established experimental anticancer platinum(II) metallointercalator complexes (1(Pt)-16(Pt)) have been prepared and investigated for their antimicrobial properties. These complexes are of the general structure [M(I(L))(A(L))](2+) where I(L) represents functionalised 1,10-phenanthrolines (1(IL)-10(IL)), and A(L) represents 1,2-diaminoethane, 1S,2S- or 1R,2R-diaminocyclohexane. The structures of synthesised complexes were confirmed using a combination of elemental analysis, UV spectrometry, circular dichroism, (1)H and [(1)H-(195)Pt]-HMQC NMR, X-ray crystallography, and electrospray ionisation mass spectrometry and where appropriate. Crystallisation attempts yielded single crystals of [Cu(4-methyl-1,10-phenanthroline)(1R,2R-diaminocyclohexane)](ClO(4))(2) (4(Cu)), [Cu(5,6-dimethyl-1,10-phenanthroline)(1R,2R-diaminocyclohexane)(H(2)O)](ClO(4))(2)·1.5H(2)O (10(Cu)) and [Cu(5,6-dimethyl-1,10-phenanthroline)(3)](ClO(4))(2)·5,6-dimethyl-1,10-phenanthroline·2H(2)O (21(Cu)). Growth inhibition of liquid cultures of bacteria (Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa), and yeast (Saccharomyces cerevisiae) discerned the most antimicrobially potent metal complexes ≤20 μM, as well as that of their intercalating ligands alone. To further investigate their mode of antimicrobial activity, membrane permeabilisation caused by selected complexes was visualised by means of a cell viability kit under fluorescence microscopy.
The crystal structures of the isomorphous salts M'6[Mo,024],4H20 (M = NH, or K) have been refined by threedimensional X-ray diffraction methods. Unit cell dimensions of these monoclinic compounds, space group P2Jc with Z = 4, are, ammonium salt: a = 8.3934 f 0.0008, b = 36.1 703 f 0.0045, c = 10.471 5 f 0.001 1 8, p = 11 5.958" f 0.008"; and potassium salt:By use of multiple Weissenberg patterns, 81 97 intensity data (Mo-K, radiation) for the ammonium compound and 2178 (Cu-K, radiation) for the potassium compound were estimated visually and used to test and refine Lindqvist's proposed structure in the space group P2,lc. Lindqvist's structure was confirmed and the full matrix least-squares isotropic refinement led to R 0.076 (ammonium) 0.1 20 (potassium), with direct unambiguous location of the cations and water molecules in the potassium compound.31 68, Australia THE nature of the polymolybdate complex ion as it is The most thorough study has been carried out by preformed in aqueous solution has long been controversial. cision e.m.f. methods by Sasaki and S i l l h ls2 who Y.
Studies of the stability of the oxides schafarzikite, FeSb2O4, and tripuhyite, FeSbO4, have been undertaken to clarify the roles these secondary minerals may have in determining the dispersion of antimony in oxidizing environments. Solubilities were determined at 298.15 K in aqueous HNO3, and these data were used to calculate values of ΔGfϴ at the same temperature. The derived Δ Gfϴ (s, 298.15 K) values for FeSb2O4 and FeSbO4 are – 959.4±4.3 and – 836.8±2.2 kJ mol–1, respectively. These results have been compared with electrochemically derived data, extrapolated from 771–981 K. The present study shows conclusively that although the mobility of Sb above the water table is limited by simple Sb(III) and Sb(V) oxides and stibiconite-group minerals, depending upon the prevailing redox potential and pH, tripuhyite is an important ultimate sink for Sb in the supergene environment. It is highly insoluble even in strongly acidic conditions and its anomalous stability at ambient temperatures causes the common mineral goethite, FeOOH, to react to form tripuhyite at activities of Sb(OH)5(aq) as low as 10–11. The comparatively limited numbers of reported occurrences of tripuhyite in the supergene zone are almost certainly due to the fact that its physical properties, especially colour and habit, are remarkably similar to those of goethite. In contrast, the small number of reported occurrences of schafarzikite can be related to its decomposition to tripuhyite as redox potentials rise at the top of the supergene zone and the fact that it decomposes to sénarmontite, Sb2O3, in acidic conditions, releasing Fe2+ ions into solution. In general, the findings confirm the immobility of Sb in near-surface conditions. Geochemical settings favouring the formation of the above minerals have been assessed using the results of the present study and data from the literature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.