Aqueous Solutions Of K2 Research Articles

In vitro and in vivo antitumor activity of the halogenated boroxine dipotassium-trioxohydroxytetrafluorotriborate (K2[B3O3F4OH

Dipotassium-trioxohydroxytetrafluorotriborate K2[B3O3F4OH] was listed as a promising new therapeutic for cancer diseases. For in vitro and in vivo investigation of its antitumor effects 4T1 mammary adenocarcinoma, B16F10 melanoma and squamous cell carcinoma SCCVII were used. The detailed in vitro investigation undoubtedly showed that K2[B3O3F4OH] affects the growth of cancer cells. The proliferation of cells depends on the concentration so that aqueous solution of K2[B3O3F4OH], the concentrations of 10−4 M and less, does not affect cell growth, but the concentrations of 10−3 M or more, significantly slows cells growth. B16F10 and SCCVII cells show higher sensitivity to the cytotoxic effects of K2[B3O3F4OH] compared to 4T1 cells. Under in vivo conditions, K2[B3O3F4OH] slows the growth of all three tumors tested compared to the control, and the inhibitory effect was most pronounced during the application of the substance. There is almost no difference if K2[B3O3F4OH] was applied intraperitoneally, intratumor, peroral or as ointment. Addition of 5-FU did not further increase the antitumor efficacy of K2[B3O3F4OH].

Synthesis, structure and biological activities of Pd(II) and Pt(II) complexes with 2-(diphenylphosphino)benzaldehyde 1-adamantoylhydrazone

The reaction of an ethanolic solution of the newly synthesized 2-(diphenylphosphino)benzaldehyde 1-adamantoylhydrazone (HL) with aqueous solutions of K2[MCl4] (M=Pd(II), Pt(II)) resulted in neutral complexes of the general formulae [M(L)Cl]. These complexes have a square-planar structure that was achieved by tridentate PNO coordination of the monoprotonated Schiff base and a chloride ligand. The ligand and its metal complexes were analyzed for their antimicrobial activity and their in vitro cytotoxicity in human larynx carcinoma cells (Hep-2) and non-cancerous human lung fibroblast cells (MRC-5). The platinum(II) complex shows cytotoxicity towards Hep-2 cells comparable to oxaliplatin and exhibited improved selectivity for cancer cells. The ligand and its complexes were characterized by elemental analysis, NMR and IR spectroscopy, and single crystal X-ray diffraction analysis.

Study of sorption of platinum and palladium cyanometallate complexes as the key to understanding the mechanism of binding the [Au(CN)2]− anion with carbon adsorbents

Goldcarb WSC-207C GR activated carbons with platinum and palladium complexes adsorbed from aqueous solutions of K2[Pt(CN)4], K2[Pt(CN)6], and K2[Pd(CN)4] were studied by the methods of X-ray photoelectron spectroscopy and IR spectroscopy with Fourier transformation, and also by MALDI massspectrometry. Platinum and palladium cyanide complexes are not reduced onto surface of active charcoal while adsorption. A certain part of the [Pd(CN)4]2− and [Pt(CN)4]2− anions directly bound to active centers on the activated carbon is oxidized more deeply and functions as particles-anchors, forming oligomers resembling Krogmann salt. A correspondence between the structure of the complex cyanometallate ion and a mode of its binding with active carbon is found. The adsorption of complex species with a linear structure or a square planar structure is defined by a possibility of the formation of donor-acceptor and metallophilic bonds. The mode of the anion [Au(CN)2]− binding with the surface of active carbon was considered.

Partial molar compressibilities of halogeno complexes of platinum and palladium in aqueous solutions at 25°C

Ultrasonic propagation velocities were measured at 25°C for dilute aqueous solutions of K2[PtX4], K2[PtX6], K2[PdX4], and K2[PdX6] (X = Cl, Br, or SCN). The data obtained were combined with our previous density data to calculate the adiabatic compressibilities of each solution. Then, the infinite dilution values of partial molar adiabatic compressibilitiesKos were evaluated. By subtraction of theKos (K+) from those of the complexes, the values ofKos for the halogeno complex ions [PtX4]2-, [PtX6]2-, [PdX4]2- and [PdX6]2- were determined. The values for the thiocyano complex ions [Pt(SCN)4]2- and [Pt(SCN)6]2- are positive, showing that the interaction of the ligand SCN- with the solvent water is very weak. Although the V2o behavior of the complex ions [PtCl6]2- and [PdCl6]2- differed only slightly, compressibility measurement has indicated that the ion [PdCl6]2- interacts more strongly than [PtCl6]2-.

Partial molar volumes of hologeno complexes of platinum and palladium in aqueous solutions and differences in volume between tetra- and hexa-coordinated forms

The partial molar volumes of dilute aqueous solutions of K2[PtX4], K2[PtX6], K2[PdX4] and K2[PdX6] complexes (X = Cl, Br or SCN), have been determined from density data measured at 298.15 K. The values of V02(K2[MX4]) and V02(K2[MX6]) can be predicted roughly by combining, respectively, the V02 values for K2[MCl4] and K2[MCl6] and the difference between V02(MX) and V02(KCl). Platinum and palladium complexes have quite similar V02, but the V02 values for the latter are larger by 1.7–1.9 cm3 mol–1 than those for the former. The increase of V02 with change of coordination number from four to six was compared for the ions Cl–, Br– and SCN–. For the hard ion, Cl–, the degree of volume increase was much smaller than for the soft ions Br– and SCN–.

Kinetics of bromine exchange in complex platinum bromides

1. Experimental data have been obtained with the object of elucidating the dependence of the extent of isotopic exchange. of bromine in K2[PtBr4] and K2[PtBr6] (aqueous solutions) on the duration of the exchange reaction, the concentration of the complex ion, the concentration of bromide ions, the temperature, and the presence of sunlight. An exchange-acceleration effect was detected in aqueous solutions of K2[PtBr4] that had been allowed to stand. 2. On the basis of the data obtained, tentative calculations were made of the activation energies of the exchange process in the [PtBr4]−− and [PtBr6]−− ions. Under the conditions studied the activation energy for bromine exchange in the [PtBr6] j-- ion (4-10 kcal/ mole) was found to be appreciably less than the activation energy for the [PtBr4[−− ion (about 17 kcal/ mole). 3. On the basis of the data obtained it is concluded that the mechanism of the exchange reaction is different in the [PtErg]-- and [PtBr6]−− ions. 4. Over the concentration range studied, exchange with K2[PtBr4] in aqueous solution proceeds to a large extent though the intermediate formation of aquo ions. 5. The character of the dependence of the degree of exchange on the bromide ion concentration, the values obtained for the activation energy, the effect of sunlight on the degree of exchange, and also some previously studied properties of quadrivalent platinum derivatives enable us to postulate that exchange with K2[PtBr6] proceeds mainly via an oxidation-reduction equilibrium. 6. The data obtained in this work for the [PtBr4]−− and [PtBr6]−− ions again confirm the conclusion first reached by Grinberg and Nikolskaya, namely, that the instability of a complex ion, as measured by its instability constant, by no means always determines the rate at which it undergoes exchange.