Preparation of Pt/activated carbon and Pt/alumina catalysts by impregnation with platinum complexes

1983 ◽  
Vol 48 (2) ◽  
pp. 517-526 ◽  
Author(s):  
Vladimír Machek ◽  
Vlastimil Růžička ◽  
Marie Šourková ◽  
Jiří Kunz ◽  
Leoš Janáček

Activated carbon and alumina catalysts were prepared by impregnation with solutions of platinum compounds differing substantially in the nature of their interaction with the supports: chloroplatinic acid (dissolved in water or acetone), tetraammineplatinum dichloride, and tetrakis (triphenylphosphine)platinum complex. The relations between the course of impregnation, distribution of platinum across the catalyst grain, and the activity of the catalyst in liquid phase hydrogenations were studied. Lower adsorption rates and amounts of the platinum compound adsorbed on the support bring about a more uniform platinum distribution across the grain. Catalysts with a uniform distribution exhibit higher activities than those with nonuniform distribution. The highest activity was achieved with Pt/alumina catalysts prepared from triphenylphosphine platinum comlex thermally treated in oxygen atmosphere prior to the reduction.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 10075-10075
Author(s):  
Kentaro Igarashi ◽  
Norio Yamamoto ◽  
Toshiharu Shirai ◽  
Katsuhiro Hayashi ◽  
Hideji Nishida ◽  
...  

10075 Background: Cisplatin is one of the most effective anti-cancer drugs available for the treatment of human solid tumors including osteosarcoma. As we had already reported, we have utilized caffeine in our chemotherapy protocol. And we achieved excellent clinical results. But effectiveness of cisplatin has been limited by side effects, and resistance. Here we developed two novel platinum compounds. 3Pt is trinuclear platinum complex bearing geminal bisphosphonate moieties, 1Pt is mononuclear platinum complex which has proteasome inhibitory activity. We performed comparative studies of our novel platinum compounds with osteosarcoma. Methods: Two novel platinum complexes were synthesized by Prof. Odani at school of pharmaceutical sciences of our university and cisplatin and caffeine were obtained from constructor. Three cell lines (MG63, 143B, and LM8) were used. Cell survival after a 72 hrs exposure to these compounds was assessed by WST-8 assay, and IC50 value was calculated for each compound. Apoptosis was assessed by DNA fragmentation and Annexin V-FITC/propidium iodine assay. Results: Each compound strongly caused concentration-dependent cytocidal effect. IC50 value of trinuclear compound is superior to cisplatin, and both complexes showed caffeine potentiation. Apoptosis induction and acetylation of histon H2AX were observed. In vivo, 1Pt showed almost same, 3Pt showed strong antitumor effect compared to cisplatin. Conclusions: Two novel platinum compounds that we developed showed strong ant-tumor effect in osteosarcoma in vitro and in vivo. As bisphosphonate has high affinity to calcium ions, 3Pt targets bone tissue and expected to reduce side effects at extraskeletal sites and to overcome the drug resistance. Proteasome inhibitory platinum compound has never been reported before, we will investigate its anti-tumor mechanism precisely.


1981 ◽  
Vol 46 (13) ◽  
pp. 3270-3277 ◽  
Author(s):  
Vladimír Machek ◽  
Jiří Hanika ◽  
Karel Sporka ◽  
Vlastimil Růžička ◽  
Jiří Kunz

The effect was studied of the solvent of chloroplatinic acid used for impregnation of activated carbon on the distribution and dispersion of platinum and on the catalyst activity. Using different solvents, catalysts were prepared exhibiting either surface platinum distribution (water) or its uniform distribution (ketones). Catalysts with uniform platinum distribution displayed a better stability of the platinum dispersity against sintering. The catalyst activities in liquid phase hydrogenation of 1-octene and of nitrobenzene were related to the platinum dispersity; the results suggest that the hydrogenations of the two substrates are governed by different mechanisms.


Author(s):  
Rajiv Sharma ◽  
Vikram Jeet Singh ◽  
Pooja A Chawla

Background: The platinum (II) complexes as anticancer agents have been well explored for the development of novel analogs. Yet, none of them achieved clinical importance in oncology. At present, anticancer compounds containing platinum (II) complexes have been employed in the treatment of colorectal, lung, and genitourinary tumors. Among the platinum-based anticancer drugs, Cisplatin (cis-diamine dichloroplatinum (II), cis-[Pt(NH3)2Cl2]) is one of the most potent components of cancer chemotherapy. The nephrotoxicity, neurotoxicity and ototoxicity, and platinum compounds associated resistant cancer are some major disadvantages. Objective: With the rapidly growing interest in platinum (II) complexes in tumor chemotherapy, researchers have synthesized many new platinum analogs as anticancer agents that show better cytotoxicity, and less off-target effects with less cellular resistance. This follows the introduction of oxaliplatin, water-soluble carboplatin, multinuclear platinum and newly synthesized complexes, etc. Method: This review emphasizes recent advancements in drug design and development, the mechanism of platinum (II) complexes, their stereochemistry, current updates, and biomedical applications of platinum-based anticancer agents. Conclusion: In the last few decades, the popularity of platinum complexes as potent anti-cancer agents has risen as scientists have synthesized many new platinum complexes that exhibit better cytotoxicity coupled with less off-target effects.


2019 ◽  
Vol 42 (2) ◽  
pp. 343-354 ◽  
Author(s):  
Meysam Hajilari ◽  
Ahmad Shariati ◽  
Mohammadreza Khosravi-Nikou

1988 ◽  
Vol 43 (4) ◽  
pp. 499-500 ◽  
Author(s):  
Eva Ehrenstorfer-Schäfers ◽  
Helmut Hartl ◽  
Wolfgang Beck

AbstractMetallic Platinum dissolves under oxygen atmosphere in aqueous histidine solution. About 0.1 to 0.3 μmol of a water soluble histidine platinum complex per ml solution have been found by atomic absorption spectroscopy.


2020 ◽  
Vol 35 (3) ◽  
pp. 103-110
Author(s):  
N.A. Magdalinova ◽  
◽  
K.M. Puzakova ◽  
M.V. Klyuev ◽  
◽  
...  

Author(s):  
Nasser Mohammed Hosny ◽  
Lamiaa A. A. Barakat

Since the discovery of the platinum based complex, cisplatin, medicinal inorganic chemistry has attracted much more attention and a large number of platinum complexes with promising pharmacological properties have been synthesized. In this work a new platinum complex of N-(5-indanyl(methylene)anthranilic acid(5-indanyl methylene)-hydrazide (HL) has been synthesized and characterized by physical and spectral techniques, as elemental analysis, IR, EI-MS, 1H-NMR, thermal analysis, transmittance electron microscope (TEM) and magnetic moment. The results indicated that the ligand binds to Pt(II) in the enol form. Square-planar stereochemistry was suggested for the Pt(II) complex. The morphological characterization showed nano-sized spherical particles with average size 92 nm of the isolated complex. The synthesized Pt(II) complex exhibited a significant cytotoxic activity against HCT116 and HEPG2. Also in vivo study of the Pt(II) complex showed cytotoxic activity towards Ehrlich ascites carcinoma (EAC).


Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 674 ◽  
Author(s):  
Haodong Tang ◽  
Bin Xu ◽  
Meng Xiang ◽  
Xinxin Chen ◽  
Yao Wang ◽  
...  

Nitrogen-doped activated carbon (N-AC) obtained through the thermal treatment of a mixture of HNO3-pretreated activated carbon (AC) and urea under N2 atmosphere at 600 °C was used as the carrier of Pd catalyst for both liquid-phase hydrodechlorination of 2,4-dichlorophenol (2,4-DCP) and gas-phase hydrodechlorination of chloropentafluoroethane (R-115). The effects of nitrogen doping on the dispersion and stability of Pd, atomic ratio of Pd/Pd2+ on the surface of the catalyzer, the catalyst’s hydrodechlorination activity, as well as the stability of N species in two different reaction systems were investigated. Our results suggest that, despite no improvement in the dispersion of Pd, nitrogen doping may significantly raise the atomic ratio of Pd/Pd2+ on the catalyst surface, with a value of 1.2 on Pd/AC but 2.2 on Pd/N-AC. Three types of N species, namely graphitic, pyridinic, and pyrrolic nitrogen, were observed on the surface of Pd/N-AC, and graphitic nitrogen was stable in both liquid-phase hydrodechlorination of 2,4-DCP and gas-phase hydrodechlorination of R-115, with pyridinic and pyrrolic nitrogen being unstable during gas-phase hydrodechlorination of R-115. As a result, the average size of Pd nanocrystals on Pd/N-AC was almost kept unchanged after liquid-phase hydrodechlorination of 2,4-DCP, whereas crystal growth of Pd was clearly observed on Pd/N-AC after gas-phase hydrodechlorination of R-115. The activity test revealed that Pd/N-AC exhibited a much better performance than Pd/AC in liquid-phase hydrodechlorination of 2,4-DCP, probably due to the enhanced stability of Pd exposed to the environment resulting from nitrogen doping as suggested by the higher atomic ratio of Pd/Pd2+ on the catalyst surface. In the gas-phase hydrodechlorination of R-115, however, a more rapid deactivation phenomenon occurred on Pd/N-AC than on Pd/AC despite a higher activity initially observed on Pd/N-AC, hinting that the stability of pyridinic and pyrrolic nitrogen plays an important role in the determination of catalytic performance of Pd/N-AC.


Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 504 ◽  
Author(s):  
Yi Yu ◽  
Yuxue Yue ◽  
Bolin Wang ◽  
Haihua He ◽  
Zhong-Ting Hu ◽  
...  

We studied the acetylene hydrochlorination in gas–liquid phase reactions using ionic liquids (IL) as the reaction media and CuCl2 as the catalyst. The Cu-IL catalyst showed strong synergy between the IL and the Cu(II) active catalytic species. For [PrMIm]Cl, the Cu-IL catalyst exhibited significant enhancement of the catalytic activity in comparison with the CuCl2 catalyst supported on activated carbon and the IL alone as the catalyst. We have also performed DFT calculations of the reaction process, which provides a good explanation of our experimental results and for the synergetic effect. Our result suggests that ILs may be used to improve the activity of other metallic catalysts for the hydrochlorination reaction of acetylene.


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