Jia-Lin Chen

Two mixed-NH3/amine platinum (II) anticancer complexes featuring a dichloroacetate moiety in the leaving group

Two mixed-NH3/amine platinum (II) complexes of 3-dichoroacetoxylcyclobutane-1, 1-dicarboxylate have been prepared in the present study and characterized by elemental analysis and IR, HPLC-MS and 1H, 13C-NMR. The complexes exist in equilibrium between two position isomeric forms and undergo hydrolysis reaction in aqueous solution, releasing the platinum pharmacophores and dichloroacetate which is a small-molecular cell apoptosis inducer. Both complexes were evaluated for in vitro cytotoxic profile in A549, SGC-7901 and SK-OV-3 caner cells as well as in BEAS-2B normal cells. They exhibit markedly cytoxicity toward cancer cells by selectively inducing the apoptosis of cancer cells, whereas leaving normal cells less affected. They have also the ability to overcome the resistance of SK-OV-3 cancer cells to cisplatin. Our findings offer an alternative novel way to develop platinum drugs which can both overcome the drug resistance and selectively target tumor cells.

Synthesis and crystal structures of mononuclear iridium (III) acetylacetonate complexes bearing an axial bipyridine ligand

Three new iridium (III) acetylacetonate complexes with an axial bipyridine ligand were synthesised via the direct reaction of [bis(acac-O,O′)(acac-C3)Ir(H2O)] and the corresponding bipyridine, and their molecular structures were determined by using single-crystal X-ray diffraction. The bipyridine used was di-2-pyridylketone, 2,2′-bipyridine and 2,2′-bipyridylamine, respectively. The results revealed that only mononuclear iridium complexes were obtained, although bipyridine has two N coordinate atoms, probably due to the great steric hindrance existing around the coordinate sphere if two bis(acac-O,O′)(acac-C3)Ir units were bridged by bipyridine. All these complexes are coordinated in one axial direction by bipyridine as a mono-dentate ligand in a slightly distorted octahedral coordination geometry.

The influence of sodium and barium ions on the structures of iridium (III) acetylacetonate complexes

Abstract Two iridium acetylacetonate complexes [Na(H2O)Ir(acac)2Cl2]n (compound1) and [Ba(H2O)5Ir(acac)2Cl2Ba(H2O)5][Ir(acac)2Cl2]3·2H2O (compound2) were synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, NMR, IR, and absorption spectra. The influence of sodium and barium ions on their molecular structures was explored.

CCDC 853247: Experimental Crystal Structure Determination

Related Article: Qiao-Wen Chang, Chang-Yi Hu, Jia-Lin Chen, Qing-Song Ye, Xi-Zhu Chen, Yao Yu, Li-Qiao Chen, Wei-Ping Liu|2011|Z.Kristallogr.-New Cryst.Struct.|226|357|

Crystal structure of bis(acetylacetonato-) k2O,O')-(diacetylmethanido-kC)- (3-pyridylmethanol)iridium(III), Ir(C5H7O2)3(C6H7NO)

C21H28IrNO7, monoclinic, C1c1 (no. 9), a = 16.938(2) Å, b = 8.0768(8) Å, c = 16.265(2) Å, / = 95.124(1)°, V = 2216.3 Å, Z = 4, Rgt(F) = 0.028, wRref(F ) = 0.053, T = 298 K.

Crystal structure of bis(acetylacetonato-) k2O,O')-(diacetylmethanido- kC)- (3-hydroxypyridine)iridium(III) dihydrate, Ir(C5H7O2)3(C5H5NO) · 2H2O

C20H30IrNO9, monoclinic, P21/n (no. 14), a = 10.574(1) Å, b = 18.662(2) Å, c = 11.888(1) Å, / = 94.178(1)°, V = 2339.7 Å, Z = 4, Rgt(F) = 0.038, wRref(F ) = 0.091, T = 298 K.

Crystal structure of diammonium bis(oxalato)palladium(II) dihydrate, (NH4)2[Pd(C2O4)2] · 2H2O

C4H12N2O10Pd, monoclinic, P121/c1 (no. 14), a = 6.7795(7) Å, b = 14.377(2) Å, c = 6.1774(7) Å, ) = 111.052(1)°, V = 561.9 Å, Z = 2, Rgt(F) = 0.018, wRref(F) = 0.048, T = 298 K. Source of material To a solution of palladium(II) chloride (0.89 g, 5.0 mmol) in dilute hydrochloric acid (2 M, 6 mL), ammonium oxalate (1.86 g, 15.0 mmol) in 10 mL of distilled water was added. The resulting solution was stirred for 1 h at 60 °C, and then the pH was adjusted to 5.5 by adding dilute sodium hydroxide solution. After cooling to room temperature, a yellow prodct precipitated from the solution. The product was filtrated, washed with ice-cold water, and dried under vaccuum at 70 °C. The crystals suitable for crystallographic studies were obtained by slow evaporation from the aqueous solution of the product at room temperature. Experimental details All H atoms were found in difference Fourier maps and refined independently. Discussion The crystal structure of the title complex comprises discrete ammonium cations, [Pd(C2O4)] anions and water molecules (figure, top). The Pd atom occupying the inversion centre is coordinated in a slightly distorted square manner by the four oxygen atoms of two oxalate ligands. The average Pd—O distance is 2.000(2) Å, while the angles O1–Pd–O2 and the O1–Pd–O2A are 83.64(6)° and 96.36(6)°, respectively. All of these agree well with the data of related palladium complexes [1,2]. The C1—O1 and C2—O2 bond length are 1.289(3) and 1.291(3) Å, respectively, while the C1—O3 and C2—O4 bond length are 1.222(3) and 1.217(3) Å, respectively, which indicate a monodentate coordination mode for the carboxylates [3,4]. The crystal packing of the title complex is stablilized by extensive hydrogen bonds formed between ammonium cations, water molecules and O atoms of the oxalates with d(O···O) of 2.951(3) Å and 2.888(3) Å, and d(N···O) of 2.910(3), 2.983(3), 2.935(3), 2.865(3) and 2.871(3) Å (figure, bottom). The mean planes defined by the four coordinated O atoms are parallel to each other along [001] with a distance of 3.356 Å between the nearest neighbors, and the distance Pd···Pd is 6.177 Å. Z. Kristallogr. NCS 225 (2010) 423-424 / DOI 10.1524/ncrs.2010.0186 423