13965-31-6Relevant articles and documents
Pt(II) diimine complexes bearing varied alkyl chains: Synthesis, tunable photophysical properties and aggregation-induced optical power limiting enhancement
Chen, Zhiyuan,Hu, Lai,Liu, Rui,Wang, Hongzhi,Zhu, Hongjun,Zhu, Senqiang
, (2021/11/30)
A series of Pt(II) diimine complexes with varied alkyl chains on 2,2′- dipyridyl ligands (Pt-C1–Pt-C3) have been synthesized and characterized. The photophysical properties and nonlinear absorption properties were elucidated using UV–vis absorption, emission and transient absorption spectroscopy, density functional theory (DFT) calculations and electrochemical experiments. It was found that increasing the alkyl chain led to regular changes in the photophysical properties of Pt-C1–Pt-C3. The original conjugated skeleton of the Pt(II) complexes were affected when the alkyl chain was introduced and extended. All complexes exhibited an obvious aggregation-induced phosphorescence emission (AIPE) in a mixed solution comprised of tetrahydrofuran/water. The formation of nanoparticles in the aggregated state induced these complexes to exhibit different excited state properties. When the water content increased, the emission intensity increases 3 ～ 13-flod and the excited state lifetime increased 98-flod due to the formation of Pt(II) complex nanoparticles. As a result, the optical power limiting (OPL) performance of these complexes was greatly improved. Based on the systematical investigation of nonlinear optical complexes in aggregated state, this work provided a theoretical basis for the development of new OPL materials. Furthermore, the Pt(II) complex nanoparticles will be more conducive to the potential application of OPL devices.
A comparative study of the effects of platinum (Ii) complexes on β-amyloid aggregation: Potential neurodrug applications
La Manna, Sara,Florio, Daniele,Iacobucci, Ilaria,Napolitano, Fabiana,De Benedictis, Ilaria,Malfitano, Anna Maria,Monti, Maria,Ravera, Mauro,Gabano, Elisabetta,Marasco, Daniela
, p. 1 - 13 (2021/03/18)
Herein the effects of three platinum complexes, namely (SP-4-2)-(2,2′-bipyridine)dichlorido platinum(II), Pt-bpy, (SP-4-2)-dichlorido(1,10-phenanthroline) platinum(II), Pt-phen, and (SP-4-2)-chlorido(2,2′:6′,2′ ′-terpyridine)platinum(II) chloride, Pt-terpy, on the aggregation of an amyloid model system derived from the C-terminal domain of Aβ peptide (Aβ21–40) were investigated. Thioflavin T (ThT) binding assays revealed the ability of Pt(II) compounds to repress amyloid aggregation in a dose-dependent way, whereas the ability of Aβ21–40 peptide to interfere with ligand field of metal complexes was analyzed through UV-Vis absorption spectroscopy and electrospray ionization mass spectrometry. Spectroscopic data provided micromolar EC50 values and allowed to assess that the observed inhibition of amyloid aggregation is due to the formation of adducts between Aβ21–40 peptide and complexes upon the release of labile ligands as chloride and that they can explore different modes of coordination toward Aβ21–40 with respect to the entire Aβ1–40 polypeptide. In addition, conformational studies through circular dichroism (CD) spectroscopy suggested that Pt-terpy induces soluble β-structures of monomeric Aβ21–40, thus limiting self-recognition. Noticeably, Pt-terpy demonstrated the ability to reduce the cytotoxicity of amyloid peptide in human SH-SY5Y neuroblastoma cells. Presented data corroborate the hypothesis to enlarge the application field of already known metal-based agents to neurodegenerative diseases, as potential neurodrugs.
The Influence of Redox-Active Linkers on the Stability and Physical Properties of a Highly Electroactive Porphyrin Nanoprism
Dutton, Kaitlyn G.,Emge, Thomas J.,Lipke, Mark C.,Pastore, Dakota B.,Rothschild, Daniel A.
supporting information, p. 12616 - 12624 (2020/09/15)
Redox-active metal-organic nanocages are of interest for many applications, but the development of cages with extensive redox activity is often hindered by their limited stability and solubility across multiple charge states. This report reveals that these properties can be tuned for cages with redox-active walls by incorporating additional redox activity into the linkers. In particular, new +12 charged triangular nanoprisms 1a,b were formed from three electroactive tetrakis(3-pyridyl)porphyrin walls linked by six [(TMEDA)Pt]2+ (for 1a) or [(2,2′-bipy)Pt]2+ (for 1b) vertices, the latter of which are also electroactive. Thus, 1b exhibits extensive redox activity, consisting of two porphyrin-centered (x3) and two 2,2′-bipy-centered (x6) reductions that provide reversible access to +12, +9, +3, 0, and -6 charge states, whereas 1a undergoes only two, porphyrin-centered (x3) reversible reductions. Comparisons of 1a and 1b (and monomeric control compounds) by cyclic voltammetry and UV-vis-NIR spectroelectrochemistry show that the redox-activity of the linkers in 1b lowers the second reduction potential of the porphyrins by 100 mV and improves the stability and solubility of this structure under highly reducing conditions (e.g., -2.25 V vs Fc+/0 in MeCN). These findings reveal new principles for controlling the properties of highly electroactive molecular nanostructures. Anion exchange rates (?103 s-1) were also probed, showing that the narrow apertures (≤3 ? van der Waals width) of 1a,b do not impede the loss/gain of PF6- anions during redox processes.
Synthesis, characterization, and cytotoxicity of Pt(IV) complexes containing 1,10-phenanthroline and 2,2′-bipyridine and diaminocyclohexane ligands
Zhao, Xiaowei,Zhang, Yamei,Hou, Xiaonan,Shi, Jianhong,Shen, Shigang,Huo, Shuying
, p. 219 - 228 (2017/03/16)
Four platinum(IV) complexes containing intercalating ligands [1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy)] and ancillary ligands [(1S,2S)-diaminocyclohexane (SS-DACH) and (1R,2R)-diaminocyclohexane (RR-DACH)] were synthesized and characterized by 1H nuclear magnetic resonance, electrospray ionization mass spectrometry, X-ray crystal structure analysis, elemental analysis, ultraviolet absorption spectroscopy, circular dichroism spectroscopy, and electrochemical analysis. The reactions between [Pt(phen)(SS-DACH)Cl2]2+ and glutathione and Ac-CPFC-NH2 were investigated by high-performance liquid chromatography. [Pt(phen)(SS-DACH)Cl2]2+ was reduced to its corresponding Pt(II) complex [Pt(phen)(SS-DACH)]2+, while glutathione and Ac-CPFC-NH2 were oxidized to glutathione-disulfide and a peptide containing an intramolecular disulfide bond, respectively. The cytotoxicities of the Pt(IV) complexes against a human non-small cell lung cancer cell line (A549) and the corresponding cisplatin-resistant cell line (A549cisR) were evaluated. These Pt(IV) complexes showed a higher activity toward A549 and A549cisR than did cisplatin. Also, the cytotoxicities of the Pt(IV) complexes were higher for A549cisR than for A549 cells. Moreover, the cytotoxicities of the (SS-DACH)-liganded platinum complexes were higher than those of the (RR-DACH)-liganded platinum complexes in either A549 or A549cisR cells. Phen-liganded platinum complexes were more cytotoxic than the bpy-liganded platinum complexes. The cytotoxicities of these Pt(IV) complexes had no correlation with reduction potentials.
Perfluoroalkylation of Square-Planar Transition Metal Complexes: A Strategy to Assemble Them into Solid State Materials with a π-π Stacked Lamellar Structure
Banikhaled, Mohammad O.,Becker, John D.,Koppang, Miles,Sun, Haoran
, p. 1869 - 1878 (2016/05/09)
Formation of π-π stacked lamellar structure is important for high performance organic semiconductor materials. We previously demonstrated that perfluoroalkylation of aromatics and heteroaromatics was one of the strategies to design organic crystalline materials with π-π stacked lamellar structures while improving air stability as a result of the strong electron withdrawing ability of perfluoroalkyl substituents. Square-planar transition metal complexes with large π-conjugated ligands are also an important category of semiconductor materials. We have perfluoroalkylated square-planar transition metal complexes, leading to the formation of a π-π stacked lamellar crystal packing motif in the solid state. Here we report six crystal structures of Pd and Pt complexes with bis-perfluorobutylated catechol ligand as one of the two ligands that bonds to the metal centers. This structural design possesses similar molecular topology when compared to perfluoroalkylated aromatics and heteroaromatics we have reported previously, again, demonstrating the steering power of the perfluoroalkyl substituents in engineering organic and organometallic solid state materials.
Design, synthesis and biological evaluation of palladium (II) complexes with 1-(substituted benzyl) azetidine-3,3-dicarboxylates as leaving group
Xu, Gang,Lu, Hua,Zhitao, Jiang,Zhang, Shuying,Gou, Shaohua
, p. 701 - 707 (2015/11/28)
A series of palladium complexes with 2,2′-bipyridine and 1-(substituted benzyl) azetidine-3, 3-dicarboxylates as ligands were synthesized and characterized by IR, 1H-NMR, ESI-MS spectra and elemental analysis. The in vitro cytotoxicity assays were carried out against A549, HCT-116, HepG-2 and SGC7901 cancer cell lines. The result showed that most of the complexes possessed moderate antiproliferative activity against HCT-116, HepG-2 and SGC7901 cell lines. Complex 12 (with 2,2′-bipyridine and 1-(3-methoxylbenzyl)azetidine-3,3-dicarboxylate as ligand) was the most potent antitumor agent among all thirteen complexes, which showed comparable or better cytotoxicity against all four tested cancer cell lines than carboplatin. The interaction between complex 12 and pET22b plasmid DNA was investigated by agarose gel electrophoresis, and the result of the study showed that complex 12 had no obvious interaction with the plasmid DNA.
Application of microwave-assisted heating to the synthesis of Pt(II) complexes
Gabano, Elisabetta,Gama, Sofia,Mendes, Filipa,Fregonese, Federico,Paulo, António,Ravera, Mauro
, p. 16 - 19 (2015/09/01)
The microwave-assisted synthesis of Pt(II) complexes containing several pyridines (i.e., pyridine L1, 2-picoline L2, 3-picoline L3, 4-picoline L4, 2,2′-bipyridine L5) is reported. For L1-L5, the reaction was successful in about 50% yield with all the ligands except L2. The same method applied to 4,4′-bis(2-morpholinoethoxy)-2,2′-bipyridine (L6, a ligand showing interesting antiproliferative properties because of a high DNA affinity), was unsatisfactory. The corresponding complex cis-[PtCl2(L6)] was obtained only heating at reflux a mixture of [PtCl2(1,5-cyclooctadiene)] and L6 in acetonitrile for 24 h. Antiproliferative activity of [PtCl2(L6)] on four cancer cell lines (ovarian A2780 and its cisplatin-resistant variant A2780cisR, prostate PC3 and breast cancer MDA-MB-231) was compared with that of its ligand and the model complex [PtCl2(L5)]. These studies showed that [PtCl2(L6)] has just marginal activity towards the tested cells if compared with cisplatin.
NMR characterisation and dynamic behaviour of [Pt(bipy)(R-Thiourea) 2]Cl2 and [Pt(phen)(R-Thiourea)2]Cl2 complexes
Rotondo, Archimede,Barresi, Salvatore,Cusumano, Matteo,Rotondo, Enrico,Donato, Paola,Mondello, Luigi
, p. 1 - 10 (2014/01/06)
We have recently reported the synthesis, characterisation and dynamic behaviour of 10 [Pd(bipy)(R-TU)2]Cl2 and [Pd(phen)(R-TU)2]Cl2 (bipy = 2,2′-bipyridyl; phen = 1,10-phenanthroline; R-TU = N-alkyl substituted thioureas) complexes; in this paper PtII analogues are presented to achieve a complete overview on this class of molecules. As expected, PtII derivatives increase the rotation barrier about the thioureas C-N bonds and once again the metal has proved to select preferential conformations for both mono and dialkyl thioureas. In this study, beyond the many shared features of the 20 PtII and PdII complexes, we extensively issue all the data concerning 13C, 15N and 195Pt hetero-nuclear NMR, stressing out the chemical shift differences that any free ligand undergoes upon coordination. To achieve this goal all the hetero-nuclear experiments were performed for the 7 free ligands and the 20 complexes in the same experimental conditions. Further support to the determined structures and dynamics is provided by mass spectrometry measurements by an ion-trap time-of-flight (IT-TOF) detector.
New PtII diimine-dithiolate complexes containing a 1,2-dithiolate-1,2-closo-dicarbadodecarborane: An experimental and theoretical investigation
Pintus, Anna,Aragoni, M. Carla,Coles, Simon J.,Coles, Susanne L.,Isaia, Francesco,Lippolis, Vito,Musteti, Ana-Daniela,Teixidor, Francesc,Vinas, Clara,Arca, Massimiliano
, p. 13649 - 13660 (2014/11/08)
Five new [Pt(N∧N)(dtoc)] complexes (1-5; N^N = diimine: 2,2′-bipyridine and its 4,4′-alkyl/aryl-substituted derivatives or 1,10-phenanthroline; dtoc2- = 1,2-dithiolate-1,2-closo- dicarbadodecaborane) have been synthesized and characterized by spectroscopic and electrochemical methods, and by means of X-ray diffraction in the case of complexes 1 and 4. Hybrid DFT and time-dependent (TD) DFT calculations were performed on complexes 1-5 and the previously reported complex [Pt(Ph 2phen)(dtoc)] (6; Ph2phen = 4,7-diphenyl-1,10- phenanthroline) both in the gas phase and in the presence of several solvents (CH2Cl2, CHCl3, CH3CN, acetone, THF, DMF, DMSO, and toluene) to gain an insight into the electronic structure of the complexes and explain their experimental features. Theoretical calculations allowed for the determination of structure-property relationships within the series of the six complexes considered, and the prediction of their second order nonlinear optical (SONLO) properties by evaluating their first static hyperpolarizabilities (βtot). the Partner Organisations 2014.
Reduction of some Pt(iv) complexes with biologically important sulfur-donor ligands
Jovanovi?, Sne?ana,Petrovi?, Biljana,Bugar?i?, ?ivadin D.,Van Eldik, Rudi
supporting information, p. 8890 - 8896 (2013/07/27)
The reduction of the Pt(iv) complexes [PtCl4(bipy)], [PtCl 4(dach)] and [PtCl4(en)] by glutathione (GSH), l-cysteine (l-Cys) and l-methionine (l-Met) was investigated by stopped-flow spectrophotometry at pH 2.0 (in 0.01 M perchloric acid) and at pH 7.2 (in 25 mM Hepes buffer). Kinetic measurements were performed under pseudo-first order conditions with an excess of the reducing agent. The order of the reactivity of the studied complexes was [PtCl4(bipy)] > [PtCl4(dach)] > [PtCl4(en)], and reactivity of investigated reducing agents followed the order GSH > l-Cys > l-Met. All the reactions between the selected Pt(iv) complexes and the sulfur donor biomolecules proceeded by a reductive elimination process that included nucleophilic attack by the reducing agent on one of the mutually trans-coordinated chloride ligands, which led to a two-electron transfer process. The final products of the redox reactions were the corresponding reduced Pt(ii) complexes and the oxidized form of the reducing agents.
