19179-44-3Relevant academic research and scientific papers
Mechanistic investigation of the autooxidation of cumene catalyzed by transition metal salts supported on polymer
Hsu, Ying Fang,Cheng, Cheu Pyeng
, p. 1 - 11 (1998)
The autooxidations of cumene to cumene hydroperoxide (CHP) in the presence of various transition metal salts supported on Bio-Rex 70 which is a macroreticular polyacrylate with carboxylate functional group, were investigated. The polymer supported catalyst is denoted as MS-BR-r in which MS represents transition metal salt, BR represents the polymer support and r is the loading of metal salt in the unit of mmoles per gram of dry support. In a catalyst loading of 0.20 g per 10 ml of cumene and initial O2 pressure 103 kPa at 363 K, the catalyzed autooxidation rate follows the order: Mn(OAc)2-BR-0.6 > Co(OAc)2-BR-0.6 > FeCl2-BR-0.6 > Cu(OAc)2-BR-0.6 > Cr(NO3)3-BR-0.6 >> Ni(OAc)2-BR-0.6. The selectivities to CHP are 97% for Cu(OAc)2-BR-0.6 and Cr(NO3)2-BR-0.6; and 92% for Mn(OAc)2-BR-0.6, Co(OAc)2-BR-0.6 and FeCl2-BR-0.6. These data indicate that Cu(OAc)2-BR-0.6 is the best catalysts among the catalysts investigated in this work. The metal loading effect was investigated for Co(OAc)2-BR-r, r = 0.3, 0.6, 1.5, 2.0 and 2.5. In the catalyst loading of 0.20 g per 10 ml of cumene and initial O2 pressure 100 kPa at 363 K, the oxidation rate increases with r from 3.96 X 10-5 M/s at r = 0.3 to 8.35 X 10-5 M/s for r = 2.5. The selectivity to CHP decreases with increasing r from 93.8% for r = 0.3 to 88.1% for r = 2.5 at a conversion of 7%. When cumene autooxidation catalyzed by Co(OAc)2-BR-2.0 was investigated at temperatures in the range of 363 K to 323 K, we found that oxidation rate decreases with temperature. However, unexpectedly, the selectivity decreases with temperature. This is interpreted by considering the competing reactions between the formation of CHP which has a high activation energy and the catalyzed redox decomposition of CHP which has a low activation energy. When temperature decreases, the rate of formation of CHP decreases more than that of the decomposition of CHP. When the autooxidation is catalyzed by a small amount of soluble copper(II) laurate or copper(II) stearate, the oxidation rate is faster and the selectivity to CHP is lower than that catalyzed by Cu(OAc)2-BR-0.6 under similar reaction conditions. The carboxylate coordination environment on copper(II) reaction center is not sufficient for Cu(OAc)2-BR-0.6 to be an effective catalyst in cumene autooxidation. We propose that the role played by the polymer support is that the backbone of the polymer reduces the rate of the catalyzed redox decomposition of CHP by hindering the change of the coordination environments on the copper center during the redox decomposition reaction of CHP.
Electrochemical synthesis and: In vitro cytotoxicity study of copper(ii) carboxylates with different fatty acid alkyl chain lengths
Nordin, Norazzizi,Yahaya, Badrul Hisham,Yusop, Muhammad Rahimi
, p. 15127 - 15135 (2018)
In the present study, an electrochemical technique based on the release of Cu2+ ions from a Cu anode in the presence of unsaturated fatty acids with different alkyl chain lengths has been used to synthesize Cu(ii) carboxylates. The fatty acids used in this study are lauric acid (C12:0) and stearic acid (C18:0). Optimum electrolysis conditions for the synthesis of Cu(ii) laurate (CuLa2) and Cu(ii) stearate (CuSt2) have been determined to maximize percentage yield and minimize energy consumption and loss of the Cu anode. We observe that both compounds (99.21%) are produced with lower energy consumption (～21.01 W h L-1) and anode loss (～0.57 mg L-1) by using the same optimum conditions of 10 V of applied voltage for 4 hours of electrolysis time in 0.1 M CH3COONH4 electrolyte solution. The cytotoxicity study on selected tumor cells (A549 and HeLa) shows that the synthesized compounds have moderate cytotoxic effects with IC50 in the range from 19.50 to 44.67 μM. CuLa2 with C12 alkyl chains provides better cytotoxicity effect on the selected tumor cells due to lower IC50 than CuSt2 with C18 alkyl chains. This shows that the length of alkyl chain also affects the compound toxicity towards selected tumor cells.
Coordination polymers from mild condition reactions of copper(II) carboxylates with pyrazole (Hpz). Influence of carboxylate basicity on the self-assembly of the [Cu3(μ3-OH)(μ-pz)3]2+secondary building unit
Massignani, Sara,Scatena, Rebecca,Lanza, Arianna,Monari, Magda,Condello, Francesca,Nestola, Fabrizio,Pettinari, Claudio,Zorzi, Federico,Pandolfo, Luciano
, p. 618 - 626 (2016/12/14)
The reaction of some saturated and unsaturated aliphatic copper(II) monocarboxylates, Cu(RCOO)2[R = C6H5CH2(phenylacetate, Phac), CH2[dbnd]CHCH2(vinylacetate, Vnac), C6H5/s
Spectroscopic study of the phase transitions of copper(II) n-alkanoates
Redondo, M. I.,Garcia, M. V.,Gonzalez-Tejera, M. J.,Cheda, J. A. R.
, p. 341 - 348 (2007/10/02)
FTIR spectra of copper nonanoate, decanoate, undecanoate and dodecanoate are recorded every 5 K from room temperature to 390 K.Changes detected in the infrared spectra when heating the sample allow the heat absorptions observed in some of these samples prior to the transition to the mesophase to be explained as due to conformational changes taking place in the alkyl chain next to the carboxylate group.Low frequency infrared and Raman spectra are consistent with a D4h geometry for the ionic core where the copper ions are located.Moreover, the study of the low frequency region at the temperature of the mesophase permit the detection of rearrangement around the central core in the transition from the crystal to the mesophase.
