Synthesis of zirconocene silsesquioxane complexes and their ethene polymerization activity in systems with methylaluminoxane

2010 ◽  
Vol 75 (1) ◽  
pp. 105-119 ◽  
Author(s):  
Vojtech Varga ◽  
Jiří Pinkas ◽  
Róbert Gyepes ◽  
Petr Štěpnička ◽  
Michal Horáček ◽  
...  
Keyword(s):  
Ir Spectra ◽  
Elemental Analysis ◽  
Molar Ratio ◽  
Stoichiometric Ratio ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Xps Spectra ◽  
Zirconocene Dichloride ◽  
Order Of Magnitude ◽  
Ethene Polymerization

Protocols for obtaining defined zirconocene complexes with polyhedral oligomeric silsesquioxanes with mono-, di-, and trisilanol functionality (SIPOSS, DIPOSS, and TRIPOSS) were established. The TRIPOSS silanolates binding one zirconocene and one chlorozirconocene moiety, [{(c-C5H9)7Si7O9O3}Zr2Cl(η5-C5H4R)4] (1, R = Bu; 2, R = H), were obtained by reacting the silanol with the respective zirconocene dichloride and triethylamine in CH2Cl2 in a 1.0:3.0:3.0 molar ratio, an excess of the zirconocene dichloride being required to suppress intramolecular dehydration of TRIPOSS. The related SIPOSS complex, [{(c-C5H9)7Si8O12O}2Zr(η5-C5H4Bu)2] (3), was prepared similarly at the stoichiometric ratio of [ZrCl2(η5-C5H4Bu)2]/ SIPOSS/NEt3 equal to 1.0:2.0:2.0. When employed in the 1.0:1.0:1.0 ratio, the same reagents afforded only the impure complex [{(c-C5H9)7Si8O12O}ZrCl(η5-C5H4Bu)2] (4), contaminated with 3 and unreacted [ZrCl2(η5-C5H4Bu)2]. Finally, the zirconocene complexes with SIPOSS and DIPOSS moiety, [{(c-C5H9)7Si8O12O}2Zr(η5-C5H5)2] (5) and [(c-C5H9)7Si7O9(OSiMe3)O2}- Zr(η5-C5H5)2] (6), respectively, were obtained by reacting [ZrMe2(η5-C5H5)2] with stoichiometric amounts of the appropriate silanols. All complexes were characterized by 1H, 13C, 29Si NMR and IR spectra, and by elemental analysis from XPS spectra. Preliminary ethene polymerization experiments showed that compounds 5 or 6 when combined with an excess of methylaluminoxane were nearly as active as [ZrCl2(η5-C5H5)2] whereas compound 2 was by about one order of magnitude less active.

Phosphor- und Schwefelhydrazin-Verbindungen / Phosphorus- and Sulfurhydrazine-Compounds

1971 ◽  
Vol 26 (12) ◽  
pp. 1232-1235 ◽  
Author(s):  
Herbert W. Roesky ◽  
Olaf Petersen
Keyword(s):  
Ir Spectra ◽  
Elemental Analysis ◽  
Mass Spectra ◽  
Molar Ratio ◽  
H Nmr ◽  
Chemical Behaviour

Pyrosulfonyldifluoride reacts with waterfree hydrazine in a molar ratio of 2 : 3 to give hydrazine -1,2-bis(sulfonylfluoride) in a low yield.. The reaction of N-fluorosulfonylamide and SOCl2 yields NH4⊕⊖ N(SO2F)2. This salt is converted to (C6H5)4P⊕⊖N(SO2F)2 in water by (C6H5)4PCl. (CH3)2NNH2 reacts with PSF3, PSF2Br, PSF2CH3 or PSF2C2H5 to yield the following compounds: (CH3)2NNHPSF2, (CH3)2NN (PSF2)2, (CH3)2NNHPSFCH3 and (CH3)2NNHPSFC2H5. The properties and the chemical behaviour of these substances are described. Results of ir-spectra, as well as 31P-, 19F- and 1H-nmr- and mass-spectra and elemental analysis characterize the compounds.

scholarly journals Síntese de novos complexos de platina(II) de interesse biológico. Um novo complexo dinuclear de platina(II) com 5-fluorouracil

2015 ◽  
Vol 40 (1) ◽  
pp. 180
Author(s):  
M. Cavicchioli ◽  
Filipe Boccato Payolla ◽  
Antonio Carlos Massabni
Keyword(s):  
Antitumor Activity ◽  
Ir Spectra ◽  
Metal Complexes ◽  
Elemental Analysis ◽  
Free Ligand ◽  
Molar Ratio ◽  
Bond Stretch

Many strategies have been used for the treatment of cancer and, following the success of cisplatin and carboplatin, metal complexes have been excelled and showed efficiency on the treatment of many types of cancer. The use of ligands that already have antitumor activity allows an increase on the drugs efficiency. In this work, synthesis of obtained a binuclear compound of platinum and 5-fluorouracil is described. The compound was characterized by elemental analysis and the results show a molar ratio of 2:1 (M:L). The IR spectra shows the complexation of the ligands to the metal by the N atoms of the ligand. On the free ligand spectrum, it is possible to note the N-H bond stretch at 3160 cm-1. The displacements of the frequencies of the C=O groups on the region of 1720cm-1 and 1652cm-1 to 1575cm-1 and 1504cm-1, respectively, occur because of the coordination of the metal to  the N neighbour atoms of the ligand.

Darstellung von m- und p-Phenylen-bis(dichlorstiban)/ Synthesis of m- and p-Phenylene-bis(dichlorostibane)

1985 ◽  
Vol 40 (8) ◽  
pp. 1045-1048 ◽  
Author(s):  
Rainer Stricker-Lennartz ◽  
H. P. Latscha
Keyword(s):  
Ir Spectra ◽  
Elemental Analysis ◽  
Molar Ratio ◽  
Lithium Diisopropylamide ◽  
Halogen Exchange ◽  
New Compounds

AbstractThe reaction of antimony(III)-chloride with lithiumdiisopropylamide in the molar ratio 1:2 in ether gives monochloro-bis(diisopropylamino)stibane (4). m -Bromophenyl-bis(diisopropylamino)stibane (2a) is prepared by reaction of m-bromophenyllithium with 4. p-Bromophenylbis(diisopropylamino)stibane (2b) can be obtained by reaction of p-brom ophenyl-dichlorostibane with lithium-diisopropylamide, or from p-brom ophenyllithium and 4. The metal-halogen-exchange of 2a, b by butyllithium in ether gives m- or p-Lithium phenyl-bis(diisopropylamino)- stibane (3a, b), respectively. Without isolation of the lithiated com pound m-/p-phenylene-bis[bis- (diisopropylamino)stibane] (5a, b) are prepared by reaction o f 3a, b with 4. Esterification of 5a, b with C2H5OH (1:4) yields m-/p-phenylene-bis(diethoxystibane) (6a, b). The reaction of 6a, b with acetylchloride in chloroform gives m -/p-phenylene-bis(dichlorostibane) (7a, b). The new compounds 2-7 are characterized by elemental analysis, NM R- and IR-spectra. 7a, b are also characterized by MS.

scholarly journals Synthesis and Spectroscopic Studies of Axially Ligated Zn(II)5,10,15,20-meso-tetra(p-chlorophenyl)porphyrin with Oxygen and Nitrogen Donors

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Gauri D. Bajju ◽  
Sujata Kundan ◽  
Ashu Kapahi ◽  
Deepmala Gupta
Keyword(s):  
Ir Spectra ◽  
Absorption Spectra ◽  
Elemental Analysis ◽  
Metal Ion ◽  
Electronic Absorption Spectra ◽  
Thermal Studies ◽  
Molar Ratio ◽  
Diffusion Method ◽  
Central Metal ◽  
H Nmr

Reaction of 5,10,15,20-meso-tetra(p-chlorophenyl)porphyrin[H2(p-Cl)pp] with zinc(II)acetate(Zn(OAc)2) and phenols results in the formation of corresponding axially ligated zinc(II)-meso-tetra(p-chlorophenyl)porphyrin (X-Zn-t(p-Cl)PP) (X = phenolates and pyridinates). The four-coordinated zinc porphyrin accepts one axial ligand in 1 : 1 molar ratio to form five-coordinated complex, which is purified by column chromatography and characterized by IR spectra,1H NMR, electronic absorption spectra, elemental analysis, mass spectroscopy, and TGA/DTA studies. IR spectra confirms the appearance of Zn– at 500–400 cm−1, Zn– at 650–570 cm−1and Zn–O at 650–350 cm−1.1H NMR spectra show that the protons of the Phenolic ring axially attached to the central metal ion are merged with the protons of the tetraphenyl rings of the porphyrin moiety. Absorption spectra reveal that complexes are accompanied by blue shift (hypsochromic shift) for phenolates and red shift (bathchromic shift) for pyridinates in comparison with the basic Zporphyrin emission bands. Mass Spectra determine them/zratio. The percentage of each element is confirmed by elemental analysis. According to the thermal studies, the complexes have a higher thermal stability and the decomposition temperature of these complexes depends on the axial ligation. Theinvitroantifungal activity of the complexes synthesized above had been done by disc diffusion method against the pathogen “Fusarium spp.,” which shows that with the increase in the concentration of the complexes, the colony diameter decreases and hence percent inhibition increases.

scholarly journals Ultra-strong bio-glue from genetically engineered polypeptides

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chao Ma ◽  
Jing Sun ◽  
Bo Li ◽  
Yang Feng ◽  
Yao Sun ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Covalent Bond ◽  
Genetically Engineered ◽  
Supramolecular Interactions ◽  
Molar Ratio ◽  
High Adhesion ◽  
Strong Adhesion ◽  
Order Of Magnitude

AbstractThe development of biomedical glues is an important, yet challenging task as seemingly mutually exclusive properties need to be combined in one material, i.e. strong adhesion and adaption to remodeling processes in healing tissue. Here, we report a biocompatible and biodegradable protein-based adhesive with high adhesion strengths. The maximum strength reaches 16.5 ± 2.2 MPa on hard substrates, which is comparable to that of commercial cyanoacrylate superglue and higher than other protein-based adhesives by at least one order of magnitude. Moreover, the strong adhesion on soft tissues qualifies the adhesive as biomedical glue outperforming some commercial products. Robust mechanical properties are realized without covalent bond formation during the adhesion process. A complex consisting of cationic supercharged polypeptides and anionic aromatic surfactants with lysine to surfactant molar ratio of 1:0.9 is driven by multiple supramolecular interactions enabling such strong adhesion. We demonstrate the glue’s robust performance in vitro and in vivo for cosmetic and hemostasis applications and accelerated wound healing by comparison to surgical wound closures.

scholarly journals Green Synthesis of N/Zr Co-Doped TiO2 for Photocatalytic Degradation of p-Nitrophenol in Wastewater

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 235
Author(s):  
Hayette Benkhennouche-Bouchene ◽  
Julien G. Mahy ◽  
Cédric Wolfs ◽  
Bénédicte Vertruyen ◽  
Dirk Poelman ◽  
...  
Keyword(s):  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Sol Gel ◽  
Visible Region ◽  
Chemical Properties ◽  
Pure Tio2 ◽  
Molar Ratio ◽  
Xps Spectra ◽  
Doped Tio2 ◽  
Co Doped

TiO2 prepared by a green aqueous sol–gel peptization process is co-doped with nitrogen and zirconium to improve and extend its photoactivity to the visible region. Two nitrogen precursors are used: urea and triethylamine; zirconium (IV) tert-butoxide is added as a source of zirconia. The N/Ti molar ratio is fixed regardless of the chosen nitrogen precursor while the quantity of zirconia is set to 0.7, 1.4, 2, or 2.8 mol%. The performance and physico-chemical properties of these materials are compared with the commercial Evonik P25 photocatalyst. For all doped and co-doped samples, TiO2 nanoparticles of 4 to 8 nm of size are formed of anatase-brookite phases, with a specific surface area between 125 and 280 m2 g−1 vs. 50 m2 g−1 for the commercial P25 photocatalyst. X-ray photoelectron (XPS) measurements show that nitrogen is incorporated into the TiO2 materials through Ti-O-N bonds allowing light absorption in the visible region. The XPS spectra of the Zr-(co)doped powders show the presence of TiO2-ZrO2 mixed oxide materials. Under visible light, the best co-doped sample gives a degradation of p-nitrophenol (PNP) equal to 70% instead of 25% with pure TiO2 and 10% with P25 under the same conditions. Similarly, the photocatalytic activity improved under UV/visible reaching 95% with the best sample compared to 50% with pure TiO2. This study suggests that N/Zr co-doped TiO2 nanoparticles can be produced in a safe and energy-efficient way while being markedly more active than state-of-the-art photocatalytic materials under visible light.

scholarly journals Isocyanate und verwandte Verbindungen des trimeren Phosphornitriddifluorids / Isocyanates and Related Compounds of Trimeric Phosphor-difluoronitride

1971 ◽  
Vol 26 (7) ◽  
pp. 679-683 ◽  
Author(s):  
Herbert W. Roesky ◽  
Enno Janssen
Keyword(s):  
Ir Spectra ◽  
Elemental Analysis ◽  
Mass Spectra ◽  
H Nmr ◽  
Carbonic Acids ◽  
Related Compounds

P3N3F5NCO was prepared by reaction of P3N3F5NSO with (COCl) 2. Substituted amides were obtained from the reaction of P3N3F5NSO with carbonic acids e. g. P3N3F5NHCOCH3, P3N3F5NHCOC2H5, and P3N3F5NHCOC3H7. If these substances were treated with PCl5 the following compounds P3N3F5N = CClCH3, P3N3F5N = CClCH5, and P3N3F5TN = CClC3H7 were formed. They reacted with nucleophiles to give P3N3F5N = CNH2CH3, P3N3F5N = TN (CH3) 2C2H5, and P3N3F5N = CN (CH3) 2CH7. The properties of these compounds are described. They were characterized by elemental analysis and IR-spectra. 19F-, 1H-NMR, and mass spectra are reported.

scholarly journals Synthesis, Characterization, and Electrochemical Behaviour of Cobalt(II) and Nickel(II) Complexes with N2O2 Chelating Ligand 4,4′-(Biphenyl-4,4′-diyldinitrilo)dipentan-2-one

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Lakhdar Sibous ◽  
Embarek Bentouhami ◽  
Mustayeen Ahmed Khan
Keyword(s):  
Schiff Base ◽  
Mass Spectroscopy ◽  
Elemental Analysis ◽  
Electrochemical Behaviour ◽  
Absolute Ethanol ◽  
Molar Ratio ◽  
H Nmr ◽  
Chelating Ligand ◽  
Metal Ligand

4,4′-Diaminobiphenyl reacts with 2,4-pentanedione in absolute ethanol in a molar ratio 1 : 2 to form mainly the product of [1 + 2] condensation, 4,4′-(biphenyl-4,4′-diyldinitrilo)dipentan-2-one (H2L). The Schiff base was used as tetradentate chelating ligand to coordinate CoII and NiII chlorides leading to complexes where the ratio of metal ligand was found to be 2 : 1 or 2 : 2. All the synthesized products were characterized by elemental analysis, infrared, electronic, and mass spectroscopy, 1H NMR, and DSC. The electrochemical behaviour of the ligand and its complexes in DMF is also investigated.

Bimetallic Group 6 Tricarbonyls Triply-Bridged by Bis(phenylthio)alkane Bidentate Ligands

2010 ◽  
Vol 93-94 ◽  
pp. 13-16
Author(s):  
Khalil J. Asali
Keyword(s):  
1H Nmr ◽  
Elemental Analysis ◽  
Thermodynamic Stability ◽  
Chlorinated Hydrocarbons ◽  
Metal Center ◽  
Molar Ratio ◽  
Bidentate Ligands ◽  
Group 6 ◽  
Ft Ir

Reactions of the labile complex (Me3tach)M(CO)3 (Me3tach = 1,3,5-trimethyl-1,3,5-triazacyclohexane; M = W, Mo) with bis(phenylthio)alkanes ( = PhS(CH2)nSPh), (2:3 molar ratio) in CH2Cl2 as solvent (at 35 oC M = W, 0 oC M = Mo) afforded in good yields bimetallic tricarbonyl complexes triply- bridged by bis(phenylthio)alkanes of the type [M(CO)3]2(μ-PhS-(CH2)n-SPh)3 [n = 3 (a), 4 (b), 5 (c), 6 (d); M = W (1), Mo (2)]. These new triply-bridged complexes were characterized by 1H NMR, FT-IR and elemental analysis. Additionally, it has been observed that the thermodynamic stability of some of these new complexes in chlorinated hydrocarbons depends mainly on the nature of the metal center and varies in the order W >> Mo.

scholarly journals New Perfluorophtalate Complexes of Platinum(II) With Chemotherapeutic Potential

1996 ◽  
Vol 3 (3) ◽  
pp. 117-122
Author(s):  
M. B. de Oliveira ◽  
J. Miller ◽  
R. E. Banks ◽  
L. R. Kelland ◽  
C. A. McAuliffe ◽  
...  
Keyword(s):  
Ir Spectra ◽  
Ovarian Carcinoma ◽  
Elemental Analysis ◽  
Nmr Spectra ◽  
Carcinoma Cell ◽  
Acquired Resistance ◽  
Cross Resistance ◽  
Carcinoma Cell Lines ◽  
Human Ovarian Carcinoma ◽  
Anti Hiv

Two new platinum(II) complexes have been synthesized and their anti-tumour and anti-HIV activities have been evaluated.The new complexes are: (i) cis-tetrafluorophthalate-ammine-morpholine-platinum(II) or MMF3 and (ii) cis-tetrafluorophthalate- ammine-piperidine-platinum(II) or MPF4. They were characterized by elemental analysis, IR spectra and H1 and C13 NMR spectra.They were tested against five human ovarian carcinoma cell lines, viz., CH1, CH1cisR, A2780, A2780cisR and SKOV-3. They were less active than cis-platin and showed cross-resistance with cis-platin in the CH1cisR and A2780cisR acquired resistance lines.They were also tested for possible anti-HIV activity using the HIV-I IIIB virus and C8166 cells, but they were inactive compared with AZT.

Sign in / Sign up

Export Citation Format

Share Document