C2H5OH Solvent Research Articles

A Double Crown Hexakis[(Di-µ-benzylthio) Nickel] Cluster: Synthesis, Structure and Properties

The double crown hexakis[(di-µ-benzylthio) nickel] cluster, [Ni6(SCH2C6H5)12]·C2H5OH, was obtained by reacting C6H5CH2SNa with [(CH3)2CHOCS2]2Ni in EtOH. The results of electrochemical studies show that [Ni6(SCH2C6H5)12] is a quasi-reversible process. The crystal structure of [Ni6(SCH2C6H5)12]·C2H5OH is composed of discrete [Ni6(SCH2C6H5)12] and C2H5OH solvent molecules. Each Ni atom is surrounded by four S atoms of the µ2-SCH2C6H5 ligands in a distorted square-planar structure. The C6H5CH2S− side chains are arranged in the axial and equatorial positions, alternately, concerning the pseudo-hexagonal axis of the molecule. Strong π-π and C–H···π effects form the supramolecular nano-channel along the a-axis in the crystal, which wraps the solvent ethanol molecules in it. In addition, a wall is formed along the b- and c-axes, so that the ethanol molecules can freely enter and leave along the a-axis. These effects result in the ability of the title compound to adsorb and desorb ethanol molecules. Thermogravimetric analysis and powder X-ray diffraction at different temperature are provided to demonstrate this point.

One pot three component synthesis of 2-amino-4H-chromene derivatives under microwave irradiation using Sr2As2O7 nanocatalyst

2-Amino-4H-chromene compounds are belonged to an important heterocyclic groups that have extensive important in organic chemistry and medicine. The compounds have anti-cancer, anti-bacterial, anti-coagulation and anti-tumor properties and have applications to produce dye, make up and hygienic materials. Until know, several methods have been reported for the synthesis of the compounds. Most of them, suffers defects such as poisoning and volatile solvents, low yield, high length reaction time, and no reusability of used catalyst. In the present work, Sr2As2O7 pyrochlore material was used as a catalyst for the synthesis of 2-amino-4H-cromens derivatives using a three component one-pot synthesis method under microwave irradiation. The raw materials were aromatic aldehydes, malononitrile and beta-naphtol. Sr2As2O7 was synthesized by an ultrasonic assisted solvothermal method using H2O and C2H5OH solvents mixtures at the 1:1 volumetric ratio. The materials were characterized by PXRD, FESEM and FTIR techniques. Then, the catalytic performance of the synthesized nanomaterial was used for the synthesis of 2-amino-4H-chromene derivatives. To do the process, the reaction parameters such as reaction time, solvent type and catalyst amount were optimized and the reactions were performed under the conditions. It was found that the optimum conditions were 15 mg catalyst, H2O as solvent and 6-9 min reaction time.

Role of temperatures and solvents on hydrothermal liquefaction of Azolla filiculoides

The effects of temperatures (260–300 °C), reaction times (15–60 min), and various solvents including water (H2O), methanol (CH3OH), and ethanol (C2H5OH) were studied on hydrothermal liquefaction (HTL) of Azolla filiculoides. The products distribution in terms of bio-oil and bio-residue and its characterization were investigated. It was observed that the bio-oil yield significantly increased to 21.5–28.8 wt% under CH3OH and C2H5OH solvents as compared to H2O solvent (11–21.3 wt%). Maximum bio-oil was obtained with C2H5OH solvent (28.8 wt%), CH3OH solvent (28.7 wt%) and H2O solvent (21.5 wt%) at a temperature of 280, 260 and 280 °C for 60, 15 and 15 min reaction times, respectively. Gas Chromatography-Mass Spectrometry (GC-MS), Fourier Transform-Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (1H NMR) analysis of bio-oils indicated that Azolla filiculoides was converted to various valuable compounds including aromatics, nitrogenated and oxygenated compounds. Total organic carbon (TOC) of aqueous phase was observed to be highest at 31,000 mg/L liquefaction with water solvent, but when alcoholic solvent was used it decreased to 23,000–21,000 mg/L. However, opposite trend was observed in the case of total nitrogen (TN) concentration. The bio-residues characterization showed that the different solvents had different effects on biomass macromolecule decomposition into products.

Effects of temperature and solvent on hydrothermal liquefaction of the corncob for production of phenolic monomers

The hydrothermal liquefaction (HTL) process is a promising direction for the conversion of waste biomass into valuable chemicals/fuels. Optimization of the process parameters for HTL of biomass has been the research scope in recent years. The study aims to examine the effects of process variables such as the effect of temperature, the role of solvents: water (H2O), methanol (CH3OH), and ethanol (C2H5OH) on hydrothermal liquefaction of the corncob biomass. Hydrothermal liquefaction has been carried out at temperatures of 260, 280, and 300 °C with a reaction holding time of 15 min. The maximum bio-oil yield was obtained (38.0 wt%) at 280 °C in the presence of H2O, whereas in the case of CH3OH and C2H5OH solvents, the maximum bio-oil yield was 18.67 wt.% and 16.83 wt.% at 260 °C and 300 °C, respectively. The solvent efficiency in corncob liquefaction was observed as H2O ˃ CH3OH ˃ C2H5OH for bio-oil production. The obtained bio-oils were characterized in detail using GC-MS, FT-IR, and 1H NMR. From the GC-MS analysis of bio-oil, the phenolic compounds were observed to a higher degree (60%) in the case of H2O solvent than CH3OH and C2H5OH solvent (57% and 46%). Also, FT-IR analysis showed that higher aromatic functional groups present in bio-oil obtained with water solvent while liquefaction with alcoholic solvent showed higher ester functional groups. Moreover, the analysis of bio-residues indicated that the decomposition of the corncob occurred in a different way during HTL with the presence of different solvents.

A Chained Iodocuprate(I) and its Photoluminescence Behavior

The simple solvothermal self-assemble of CuI, 1,4-bis(2-methyl-1H-imidazol-1-yl)butane (L1) and HI in a C2H5OH solvent at pH = 2 created a new H2(L1)2+-templated 1-D chained iodocuprate(I) [H2(L1)][Cu3I5] 1. The crystal data reveal that the Cu-I chain mode in 1 is rare. Two folded Cu2I2 cores first aggregate into a trinuclear cluster by sharing an edge. Then the extra I− ions doublely bridge these trinuclear clusters into the title 1-D chain of 1. Synchronously, a non-folded Cu2I2 cluster is formed. In 1, all of the Cu···Cu distances are smaller than 2.8 A. The investigation on photoluminescence property indicates that with the decrease of the temperature, the photoluminescence emission for 1 exhibits a minor change from the green-yellow light (298 K) to yellow light (77 K). This means that 1 might possess the fluorescent thermochromic property.

Solvent-mediated structural transformations of copper(II) coordination polymers induced by different short-chain alcohols.

A three-dimensional copper(II) coordination polymer (CP), {Cu(L-F)(N3)}n (1), was synthesized by reacting Cu(NO3)2 with 5-fluoronicotinic acid (HL-F) and NaN3 in a water medium. Complex (1) shows a 3D network, in which the 1D [Cu2(COO)N3]n chains are interconnected via L-F ligands. By immersing (1) into different short-chain alcohols (CH3OH, C2H5OH and HOC2H4OH), three different CPs were isolated, including {Cu3(L-F)4(N3)2(CH3OH)2}n (2), {Cu3(L-F)4(N3)2(C2H5OH)2}n (3) and {Cu2.5(L-F)3(N3)2(HOC2H4OH)0.5}n (4). CPs (2) and (3) display a similar structure, in which trinuclear subunit [Cu3(COO)2(N3)2(solvent)2] is generated. Furthermore, such entities are interconnected via L-F ligands to give rise to a 3D network. As for (4), there are trinuclear [Cu3(COO)2(N3)2] and binuclear [Cu2(COO)N3] units, which are interconnected by L-F ligands to generate a 3D network. Notably, in (2) and (3), the coordination modes of CH3OH and C2H5OH solvents are monodentate; whereas for (4), the HOC2H4OH solvent adopts a bridging mode to link two Cu atoms. Of further interest, these processes are solvent-mediated structural transformations, with obvious colour changes in the crystals. Structural changes and mechanisms of transformation are discussed in detail.

Bioplastic from Chitosan and Yellow Pumpkin Starch with Castor Oil as Plasticizer

This study has been conducted on bioplastic synthesis of chitosan and yellow pumpkin starch (Cucurbita moschata) with castor oil as plasticizer. The purpose of this study is to determine the characteristics of the effect of chitosan and starch composition of pumpkins against solvent absorption, tensile strength and biodegradable. The first stage of the research is the making of bioplastic by blending yellow pumpkin starch, chitosan and castor oil. Further, it tested the absorption capacity of the solvent, tensile strength test, and biodegradable analysis. The optimum absorption capacity of the solvent is obtained on the composition of Pumpkin/Chitosan was 50/50 in H2O and C2H5OH solvent. Meanwhile the optimum absorbency in HCl and NaOH solvents is obtained by 60/40 composition. The characterization of the optimum tensile strength test was obtained on the 40/60 composition of 6.787 ± 0.274 Mpa and the fastest biodegradation test process within 5-10 days occurred in the 50/50 composition. The more chitosan content the higher the value of tensile strength test obtained, while the fastest biodegradation rate occureds in the composition of yellow pumpkin starch and chitosan balanced 50:50.

A DFT study on the mechanism of photoselective catalytic reduction of 4-bromobenzaldehyde in different solvents employing an OH-defected TiO2 cluster model

Density functional theory calculations are employed to study the mechanism of photoselective catalytic reduction of 4-bromobenzaldehyde (4-BBA) in acetonitrile and in ethanol solvents. A totally relaxed Ti3O9H6 cluster model is proposed to represent titanium dioxide (TiO2) surfaces. The reduction selectivity of an adsorbed 4-BBA molecule on Ti3O9H6 has been investigated. Owing to the difference in the proton and H atom donating capabilities between explicit CH3CN and C2H5OH solvent molecules, the photocatalytic reduction of 4-BBA is the debromination process in acetonitrile, whereas in ethanol it is the carbonyl reduction process. Therefore 4-BBA can be selectively reduced to benzaldehyde in acetonitrile and 4-bromobenzyl alcohol in ethanol, respectively. Our computational results have verified the reaction mechanism proposed by experiments and show that the debromination of 4-BBA would be efficient if both 4-BBA and Ti3O9H6 have an extra photoelectron. The Ti3O9H6 cluster, playing a role as a hydrogen source and a bridge to transfer photoelectrons from bulk TiO2, would have potential to be an ideal molecular model for understanding photocatalytic reactions on the TiO2 surface.

Crystal Structures of Two New Iodine Clusters: Tetranuclear [H2dabco](I4) (Dabco = 1,4-Diazabicyclo[2,2,2]octane) and Chained [Dedabco](I3)2 (Dedabco2+ = N,N′-Diethyl-1,4-Diazabicyclo[2,2,2]octane)

At the ambient condition, the simple self-assembly between ZnI2, KI, and dabco in acidic H2O/C2H5OH solution produced a tetranuclear iodine cluster with diprotonated dabco as the cation [H2dabco](I4) (dabco = 1,4-diazabicyclo[2,2,2]octane) 1. But the same precursors reacted under the solvothermal condition, producing a chained iodine cluster polymer with dedabco2+ as the cation [dedabco](I3)2 (dedabco2+ = N,N′-diethyl-1,4-diazabicyclo[2,2,2]octane) 2. Note that dedabco2+ originated from the solvothermal in situ N-alkylation of dabco with C2H5OH solvent in acidic KI solution.

New organically decorated cadmium halides incorporating the second or the third inorganic anionic groups

The room-temperature incorporation of the additional inorganic anionic groups SCN− and SO42− into the CdX2-piperazine (pip) system in acidic H2O/C2H5OH solutions generated the first example of a piperazinium-templated 1-D tube-like cadmium–bromothiocyanato sulfate [H2pip]4[Cd3Br8(SCN)2(SO4)2(H2O)]·4H2O 1 and the isostructural 1-D ribboned cadmium–halothiocyanato coordination polymers [CdX(SCN)L] [X− = Br−2, I−3; L = SC(OC2H5)NH2] with the ancillary organic S-donor ligand L. L was derived from the in situ nucleophilic addition reaction between the SCN−group and the C2H5OH solvent.

The isolation and properties of an unexpected cyano-bridged complex [(H2O)CoII(dppm)2(μ-CN)CoIICl3] · C2H5OH

One reaction of CoCl2·6H2O, dppm (diphenylphosphinomethane), and TCNE (tetracyanoethylene) in C2H5OH solvent gave one unexpected cyano-bridged complex [(H2O)CoII(dppm)2(μ-CN)CoIICl3]·C2H5OH 1. Compound 1 is built from Co(II) and Co(II) centers, which are bridged by one CN group. It was characterized by IR spectra, UV–Vis spectra, and cyclic voltammogram. It is worth noting that CoII ions in 1 exhibit thermally induced quartet↔doublet spin transitions, and there is an antiferromagnetic interaction between the adjacent CoII and CoII ions through the cyanide bridge in 1.