Search results for "platinum"
showing 10 items of 629 documents
In vitro comparison of platinum-iridium and gold tip electrodes: lesion depth in 4 mm, 8 mm, and irrigated-tip radiofrequency ablation catheters
2009
Aims We compared a newly developed irrigated gold tip electrode ablation catheter and a gold tip 4 and 8 mm catheter with the corresponding platinum–iridium (Pt) tip catheters in an in vitro setting. Methods and results In a flow chamber simulating physiological flow conditions, radiofrequency catheter ablation was performed on tissue samples of porcine endomyocardium and liver. Lesion depth, energy and temperature delivery, and popping frequency were determined. Two hundred and fifty-three ablations were conducted. Four and eight millimetre, gold tip electrode catheters produced significantly deeper lesions compared with the Pt tip electrode (liver 4 mm: 4.67 ± 1.7 vs. 2.9 ± 1.0 mm, P < 0.…
Cis-diaminedichloro platinum ototoxicity. An experimental study.
1985
Four groups of guinea pigs received different doses of cis-platinum. SEM and TEM showed a direct relation between the dose and the damage. The first row of OHC is the first one to be damaged. The IHC are more resistant than the OHC. The pattern of destruction is similar to the one produced by the aminoglucoside antibiotics.
Novel platinum(II) complexes with heterociclyc ligands: Synthesis and structural chracterization.
2008
An array of mononuclear complexes of Pt(II) with triazine and (benzimidazolyl)pyridine heterocycles is reported. The mononuclear complexes [PtCl2(Kdptdn)] [dbtdn=5,6- diphenyl-3-(2-pyridyl)-1,2,4-triazine-4’,4’’-disulfonate sodium salt hydrate], [PtCl2(bbp)] [bbp=2,6-bis(2-benzimidazolyl)pyridine] and [PtCl2(H2dpt)]PtCl4 [dpt=5,6-diphenyl-3-(2- pyridyl)-1,2,4-triazine] have been prepared and structurally characterized. Both neutral and ionic complexes are present, with bifunctional Pt(II) moieties, whose size and shape enable them to behave as novel scaffolds for DNA binding.
An efficient method for selective oxidation of (oxime)Pt(II) to (oxime)Pt(IV) species using N,N-dichlorotosylamide
2016
The oxidation of (oxime)PtII species using the electrophilic chlorine-based oxidant N,N-dichlorotosylamide (4-CH3C6H4SO2NCl2) was studied. The reactions of trans-[PtCl2(oxime)2] (where oxime = acetoxime, cyclopentanone oxime, or acetaldoxime) with this oxidant led to trans-[PtCl4(oxime)2] products. The oxidation of trans-[Pt(o-OC6H4CH = NOH)2] at room temperature gave trans-[PtCl2(o-OC6H4CH = NOH)2], whereas the same reaction upon heating was accompanied by electrophilic substitution of the benzene rings. peerReviewed
Self-Consistent Charge Density-Functional Tight-Binding Parametrization for Pt–Ru Alloys
2017
We present a self-consistent charge density-functional tight-binding (SCC-DFTB) parametrization for PtRu alloys, which is developed by employing a training set of alloy cluster energies and forces obtained from Kohn-Sham density-functional theory (DFT) calculations. Extensive simulations of a testing set of PtRu alloy nanoclusters show that this SCC-DFTB scheme is capable of capturing cluster formation energies with high accuracy relative to DFT calculations. The new SCC-DFTB parametrization is employed within a genetic algorithm to search for global minima of PtRu clusters in the range of 13-81 atoms and the emergence of Ru-core/Pt-shell structures at intermediate alloy compositions, consi…
A Self-Consistent Charge Density-Functional Tight-Binding Parameterization for Pt-Ru Alloys
2017
We present a self-consistent charge density-functional tight-binding (SCC-DFTB) parametrization for PtRu alloys, which is developed by employing a training set of alloy cluster energies and forces obtained from Kohn–Sham density-functional theory (DFT) calculations. Extensive simulations of a testing set of PtRu alloy nanoclusters show that this SCC-DFTB scheme is capable of capturing cluster formation energies with high accuracy relative to DFT calculations. The new SCC-DFTB parametrization is employed within a genetic algorithm to search for global minima of PtRu clusters in the range of 13–81 atoms and the emergence of Ru-core/Pt-shell structures at intermediate alloy compositions, consi…
Self-healing, luminescent metallogelation driven by synergistic metallophilic and fluorine–fluorine interactions
2020
Square planar platinum(ii) complexes are attractive building blocks for multifunctional soft materials due to their unique optoelectronic properties. However, for soft materials derived from synthetically simple discrete metal complexes, achieving a combination of optical properties, thermoresponsiveness and excellent mechanical properties is a major challenge. Here, we report the rapid self-recovery of luminescent metallogels derived from platinum(ii) complexes of perfluoroalkyl and alkyl derivatives of terpyridine ligands. Using single crystal X-ray diffraction studies, we show that the presence of synergistic platinum-platinum (PtMIDLINE HORIZONTAL ELLIPSISPt) metallopolymerization and f…
PtII versus PdII-assisted [2+3] cycloadditions of nitriles and nitrone. Synthesis of nitrile-derived arylamido platinum(II) and Δ4-1,2,4-oxadiazoline…
2019
Abstract The reactions of bis(organonitrile) platinum(II) complexes trans-[PtCl2(N CR)2] (R = C6H4(p-HC O), CH2C6H4(p-CH3)) with pyrroline N-oxide −O+N CHCH2CH2CMe2 afford arylamido platinum(II) complexes trans-[PtCl2{(O CR)N CCH2CH2CMe2NH}2] (R = C6H4(p-HC O) (1), CH2C6H4(p-CH3) (2)). The spectral data of 1 and 2 show that the oxadiazoline rings in both cases have opened by a spontaneous N O bond cleavage to form (Z)-p-formyl-N-(5,5-dimethylpyrrolidin-2-ylidene)benzamide or (Z)-N-(5,5-dimethylpyrrolidin-2-ylidene)-2-p-tolylacetamide ligands, respectively, where the N-atoms of the benzamide or acetamide moieties coordinate to platinum(II) metal centre in trans positions. However, the reacti…
Non-conventional synthesis and photophysical studies of platinum(ii) complexes with methylene bridged 2,2′-dipyridylamine derivatives
2019
Methylene bridged 2,2′-dipyridylamine (dpa) derivatives and their metal complexes possess outstanding properties due to their inherent structural flexibility. Synthesis of such complexes typically involves derivatization of dpa followed by coordination on metals, and may not always be very efficient. In this work, an alternative synthetic approach, involving the derivatization step after – rather than prior to – coordination of dpa on metal center, is proposed and applied to synthesis of a number of platinum(II) complexes with substituted benzyldi(2-pyridyl)amines. Comparison with the more conventional synthetic route reveals greater efficiency and versatility of the proposed approach. The …
Supramolecular Assembly of Metal Complexes by (Aryl)I⋯dz2[PtII] Halogen Bond
2020
The theoretical data for the half‐lantern complexes [Pt(C^N)(μ‐S^N)] 2 ( 1 – 3 ; С^N is cyclometalated 2‐Ph‐benzothiazole; S^N is 2‐SH‐pyridine 1 , 2‐SH‐benzoxazole 2 , 2‐SH‐tetrafluorobenzothiazole 3 ) indicate that the Pt···Pt orbital interaction leads to an increment of the nucleophilicity of the outer d z 2 ‐orbitals to provide assembly with electrophilic species. 1 – 3 were co‐crystallized with bifunctional halogen bond (XB) donors to give adducts ( 1 – 3 ) 2 ∙(1,4‐diiodotetrafluorobenzene) and infinite polymeric [ 1 ·1,1’‐diiodoperfluorodiphenyl] n . X‐ray crystallography revealed that the supramolecular assembly is achieved via (Aryl)I∙∙∙ d z 2 [Pt II ] XB between iodine σ‐holes and …