Benzyl Alcohol Research Articles

A new perspective for palladium(II)-catalyzed alcohol oxidation in aerobic means

The development of alternative and environmentally safe routes for the oxidation of primary and secondary alcohols has attracted the attention of several researchers due to the importance of these oxidized products in industries. Thereby, the oxidation of β-citronellol, geraniol, nerol, borneol, isoborneol, cinnamic alcohol, and benzyl alcohol is described herein. These reactions occurred in an aerobic environment, with or without system pressurization. Acetonitrile was the solvent used. The process was catalyzed by the bimetallic complex formed with palladium(II) acetate and copper(II) acetate, using p-benzoquinone as a cocatalyst in some reaction conditions. The applied system obtained 62.5 points on the eco-scale, with yields above 61%. Alcohol oxidation products are of great importance in industrial applications. Thus, this work presents a cleaner, more sustainable alternative to alcohol oxidations.

Revealing the activity and selectivity of atomically dispersed Ni in Zn3In2S6 for benzyl alcohol photoreforming

Photoreforming enables simultaneous H2 production and organic synthesis in a one-pot system. In this study, a single-step synthesis approach was employed to fabricate atomically dispersed Ni in Zn3In2S6 (NixZIS) for benzyl alcohol photoreforming. While neat ZIS exhibits high selectivity toward hydrobenzoin via C-H activation and C-C coupling, its H2 evolution rate remains below feasible levels. Incorporating Ni single atoms significantly enhances ZIS activity by improving the carrier dynamics, resulting in an optimal H2 evolution rate of 9.13 mmol g−1 h−1 on Ni4ZIS, over five times higher than neat ZIS. The presence of Ni single atoms also alters selectivity, suppressing C-C coupling products and promoting benzaldehyde generation. The Ni single atoms induce facile O-H activation following the C-H activation of benzyl alcohol on ZIS, inhibiting the desorption of carbon radicals and causing consecutive oxidation to benzaldehyde. This study elucidates the role of Ni single atoms in driving activity and selectivity during organic photoreforming.

Versatile catalytic performance of magnetic and reusable mesoporous Co3(PO4)2 in benzyl alcohol oxidation and esterification with acetic acid

Versatile catalytic performance of magnetic and reusable mesoporous Co3(PO4)2 in benzyl alcohol oxidation and esterification with acetic acid

Ethanol Foams Stabilized by Isobutyl-Based POSS-Organosilica Dual-Particle Assemblies.

Nonaqueous foams in low-surface tension solvents (<25 mN·m-1) are highly desired for applications in fire extinguishers and detoxification gels. However, their formation is a Holy Grail of the chemical industry due to the need for stabilizers with low surface energy and high recyclability. Herein, we disclose a new strategy to generate abundant foams in ethanol and a variety of low-surface tension solvents relying on the interfacial coadsorption of two different particles. The particles consist of surface-active fluorinated silica particles, used as a stabilizer, and a novel amphiphilic polyhedral oligomeric silsesquioxane (POSS) decorated with isobutyl cage substituents, used as a frother. The interaction between POSS and fluorinated particles at the ethanol-air interface was thoroughly investigated by combining physicochemical methods (contact angle, dynamic surface tension, and dynamic light scattering methods) and catalytic tests using the model aerobic oxidation reaction of benzyl alcohol. Both particles could be conveniently recycled for at least 5 consecutive runs with high foamability and catalytic activity.

CuInSe2 nanoplatelets decorated CdS nanosheets as 2D-2D S-scheme photocatalyst for photocatalytic H2 generation coupled with benzyl alcohol oxidation and microplastic degradation

In this work, a novel 2D layered heterojunction for various photocatalytic reactions is constructed by hybridizing CdS nanosheets and CuInSe2 nanoplatelets. By adjusting CuInSe2 content, the CdS-16% CuInSe2 sample displays a visible-light-induced H2 production rate of 4382 μmol g−1 h−1, approximately 7.5 times higher than pristine CdS. Furthermore, CdS-16% CuInSe2 demonstrates exceptional photocatalytic activity in H2 evolution simultaneous benzyl alcohol (BA) oxidation and polyethylene terephthalate (PET) degradation. The superior photocatalytic activity is ascribed to the unique S-scheme heterojunction and 2D-2D CdS–CuInSe2 layered heterostructures that effectively separate photoinduced charge carriers and provide appropriate interfacial band structures. The photocatalytic mechanism is thoroughly examined through experiments and density functional theory calculations. This work offers a valuable platform to develop innovative layered photocatalysts that are highly effective for a wide range of photocatalytic reactions.

Nicotine sensing behavior of nickel(II) complexes catalyzed oxidation and coupling reactions

One of the main source of demise during the next ten years will be coronary heart disease and stroke, which are brought on by smoking (nicotine). To identify the percentage (%) of nicotine consumption by electrocatalytic sensor towards nicotine for target-specific prevent stroke, four uninuclear Ni2+ complexes of substituted butanimidamide Schiff base ligands [H2L1-4] was prepared. All the complexes were thoroughly analyzed by using several spectroscopic techniques such as CHNS analysis, FT-IR, NMR (1H &13C) UV–Vis and NMR. The analyses showed tetradentate binding mode of ligand around nickel(II) metal ion leads to the structure of square planar with N2X2 (X = O, S) donor fashion. In addition, the well-defined nickel(II) complexes were utilized for oxidation of various alcohols such as cyclohexanol, and benzyl alcohol were produced to the assorted oxidized products with high yield respectively using greener co-oxidant (molecular oxygen). In addition, Nickel(II) complexes was further utilized as catalyst for aryl-aryl coupling reaction via Suzuki-Mayura method to obtain biphenyl compound. Furthermore, nickel(II) complexes were exploited for electrochemical detection of nicotine sensing in μM concentration.

Streamlined synthesis of iron and cobalt loaded MCM-48: High-performance heterogeneous catalysts for selective liquid-phase oxidation of toluene to benzaldehyde

Hydrothermal synthesis of MCM-48 molecular sieves featuring the incorporation of both iron and cobalt with Si/M ratios of 20, 40 and 80 (where M represents either iron or cobalt) was performed using tetraethyl orthosilicate as the silica source and cetyltrimethylammonium bromide as a template. To gain a comprehensive understanding of the synthesized materials, these were thoroughly characterized using various techniques, including XRD, XPS, UV–Vis (DRS), FT-IR, N2 adsorption-desorption analysis, SEM with EDX, TEM, TGA and NH3-TPD analysis. XRD analysis revealed the presence of well-ordered MCM-48 structure in the metal-incorporated materials, while XPS and UV–Vis DRS confirmed the successful partial incorporation of metal ions precisely in their desired tetrahedral coordination within the framework. To assess their catalytic performance, we studied the activity and selectivity of these catalysts in liquid phase oxidation of toluene using tert-butyl hydroperoxide as the oxidant. Under optimized conditions, employing a 6% (w/w) Fe-MCM-48 (40) catalyst and maintaining a toluene to oxidant molar ratio of 1:3 at 353 K in a solvent-free environment for 8 h, the oxidation reaction resulted in the formation of benzaldehyde (88.1%) as the major product and benzyl alcohol (11.9%) as the minor product.

Volatile organic compounds produced by Metschnikowia pulcherrima yeast T-2 inhibited the growth of Botrytis cinerea in postharvest blueberry fruits

Postharvest rot of blueberry fruits caused by Botrytis cinerea led to huge economic losses in storage and transportation. In this study, Metschnikowia pulcherrima T-2 was isolated from the surface of blueberry fruits and significantly reduced postharvest rot of blueberry fruits. The weight loss rate of T-2 soaked blueberry fruits was decreased; the contents of total soluble solids, titratable acidity and vitamin C of T-2 treated blueberry fruits were increased at a humidity of 85% and 25 °C. T-2 also enhanced the control of gray mold in blueberry fruits, but could not directly inhibit the growth of B. cinerea in vitro. The volatile organic compounds (VOCs) produced by T-2 could inhibit the growth of B. cinerea, and significantly reduced the postharvest rot of blueberry fruits. According to Gas Chromatography-Mass Spectrometry (GC–MS) analysis and antibacterial analysis, the benzyl alcohol, phenylethyl alcohol, benzaldehyde, 2-ethyl-1-hexanol, acetic acid, octanoic acid, 3-hydroxy-2-butanone, 2, 5-dimethyl-pyrazine and isoamyl acetate were selected. The influence of the above 9 volatiles on B. cinerea growth was assessed by treating B. cinerea in vitro with various concentrations of volatile. The lowest effective amounts of 9 volatiles were established to reduce the postharvest rot of blueberry fruits. These results shed light on the roles of T-2 VOCs in the control of postharvest blueberry fruits to B. cinerea, and provided a new method of postharvest storage.

Solvent-induced microphase separation membranes of block poly (aryl ether sulfone) copolymer with high selectivity of O2/N2 separation

Gas separation membranes have a wide range of applications in industry, and there are two important factors in judging membrane standards permeability and selectivity. How to improve the selectivity of gas separation membranes while improving permeability is a challenge. In this study, poly (aryl ether sulfone) (PES) block copolymers were synthesized from fluorine-terminated polysulfone (PSF–F) and hydroxyl-terminated cardo PES containing phenyl substituted isoindolinone side group (PES-PPI-OH). Large side groups can enlarge the free volume and hinder chain movement to improve gas permeation behavior. Solvent-induced microphase separation of block copolymers by casting membranes with solvent benzyl alcohol (BA) can improve selectivity. The PSF-b-PES-PPI (10:10) BA membrane maintain good mechanical properties and tensile strength up to 93 MPa which compared to random polymer membrane rises to 14 MPa. Gas permeation at 23 °C showed that the O2/N2 selectivity of PSF-b-PES-PPI (5:15)BA membrane was 10.6, which was the 2008 Robeson upper bound. Thus, poly (aryl ether sulfone) materials showed great potential application for O2/N2 separation.

Potassium tert‐Butoxide‐Catalyzed Selective Synthesis of 1,4‐Benzodioxepines via 7‐exo/7‐endo‐dig Cyclization of Alkynol: Experimental and DFT Study

AbstractA new method utilizing base catalysis is outlined for the synthesis of 1,4‐benzodioxepines, introducing a unique scaffold containing a seven‐membered ring heterocycle. The reaction proceeded under thermal conditions, with no waste was generated during the transformation, highlighting its remarkable atom efficiency and environmental friendliness. A straightforward metal‐free reaction condition utilizing 2‐propynyloxy benzyl alcohols as starting material and a catalytic amount of t‐BuOK in mesitylene at 100 °C for 1 hour was employed for this intramolecular cyclization transformation, resulting in the formation of 1,4‐Benzodioxepines in good to excellent yields and high regio‐ and diastereo‐selectivity. The density functional theory (DFT) calculations yielded the relative internal energy (U), enthalpy (H), and Gibbs free energy (G) values for all possible products, aligning closely with our experimental data.

Phenalenyl-Based Photocatalyst for Bioinspired Oxidative Dehydrogenation of N-Heterocycles and Benzyl Alcohols.

The environmental benefits of molecular oxygen as the oxidizing agent in oxidation reactions that synthesize fine chemicals cannot be overstated. Increased interest in developing robust photocatalysts is stimulated by the fact that the current photocatalytic transformation boom has made previously inaccessible synthetic approaches possible. Motivated by enzymatic catalysis, employing a reusable phenalenyl-based photocatalyst, we have successfully developed oxidative dehydrogenation utilizing molecular oxygen as a greener oxidant. Under photoinduced oxidative dehydrogenation conditions, different types of saturated N-heterocycles and alcohols were successfully dehydrogenated. The versatility of this bioinspired protocol is demonstrated by the fact that a wide variety of N-heteroaromatics, such as quinoline, carbazole, quinoxaline, acridine, and indole derivatives, as well as aldehydes and ketones, were successfully synthesized. Detailed mechanistic studies validate the proposed mechanism. Fluorescence lifetime and CV experiments revealed the crucial role of water on the efficiency of the reaction. The present protocol also provides chemoselectivity and scalability, leading to superior results and allowing for the functionalization of bioactive molecules at a late stage in a sustainable manner.

Physiological and Biochemical Analysis Revealing the Key Factors Influencing 2-Phenylethanol and Benzyl Alcohol Production in Crabapple Flowers.

Floral scent (FS) plays a crucial role in the ecological functions and industrial applications of plants. However, the physiological and metabolic mechanisms underlying FS formation remain inadequately explored. Our investigation focused on elucidating the differential formation mechanisms of 2-phenylethanol (2-PE) and benzyl alcohol (BA) by examining seven related enzyme concentrations and the content of soluble sugar, soluble proteins, carbon (C) and nitrogen (N), as well as the C/N ratio. The findings revealed that the peak content of 2-PE in M. 'Praire Rose' and BA in M. 'Lollipop' occurred during the end flowering stage (S4) and flowering stage (S3) periods, respectively. The enzyme concentration change trends of phenylpyruvate decarboxylase (PDL), phenylacetaldehyde reductase (PAR), soluble protein, C, N, and C/N ratio changes during the S3-S4 period in M. 'Praire Rose' and M. 'Lollipop' were entirely opposite. Correlation and PCA analysis demonstrated that the content of CYP79D73 (a P450) and N, and the C/N ratio were key factors in 2-PE production in M. 'Praire Rose'. The production of BA in M. 'Lollipop' was more influenced by the content of phenylacetaldehyde synthase (PAAS), CYP79D73, and soluble sugar. As CYP79D73 exits oppositely in correlation to 2-PE (M. 'Praire Rose') and BA (M. 'Lollipop'), it is hypothesized that CYP79D73 was postulated as the primary factor contributing to the observed differences of 2-PE (M. 'Praire Rose') and BA (M. 'Lollipop') formation. These results carry significant implications for crabapple aromatic flower breeding and the essential oil industry etc.

Guest-Regulated Generation of Reactive Oxygen Species from Porphyrin-Based Multicomponent Metallacages for Selective Photocatalysis.

The development of novel materials for highly efficient and selective photocatalysis is crucial for their practical applications. Herein, we employ the host-guest chemistry of porphyrin-based metallacages to regulate the generation of reactive oxygen species and further use them for the selective photocatalytic oxidation of benzyl alcohols. Upon irradiation, the sole metallacage (6) can generate singlet oxygen (1O2) effectively via excited energy transfer, while its complex with C70 (6⊃C70) opens a pathway for electron transfer to promote the formation of superoxide anion (O2⋅-), producing both 1O2 and O2⋅-. The addition of 4,4'-bipyridine (BPY) to complex 6⊃C70 forms a more stable complex (6⊃BPY) via the coordination of the Zn-porphyrin faces of 6 and BPY, which drives fullerenes out of the cavities and restores the ability of 1O2 generation. Therefore, benzyl alcohols are oxidized into benzyl aldehydes upon irradiation in the presence of 6 or 6⊃BPY, while they are oxidized into benzoic acids when 6⊃C70 is employed as the photosensitizing agent. This study demonstrates a highly efficient strategy that utilizes the host-guest chemistry of metallacages to regulate the generation of reactive oxygen species for selective photooxidation reactions, which could promote the utilization of metallacages and their related host-guest complexes for photocatalytic applications.

Guest‐Regulated Generation of Reactive Oxygen Species from Porphyrin‐Based Multicomponent Metallacages for Selective Photocatalysis

AbstractThe development of novel materials for highly efficient and selective photocatalysis is crucial for their practical applications. Herein, we employ the host‐guest chemistry of porphyrin‐based metallacages to regulate the generation of reactive oxygen species and further use them for the selective photocatalytic oxidation of benzyl alcohols. Upon irradiation, the sole metallacage (6) can generate singlet oxygen (1O2) effectively via excited energy transfer, while its complex with C70 (6⊃C70) opens a pathway for electron transfer to promote the formation of superoxide anion (O2⋅−), producing both 1O2 and O2⋅−. The addition of 4,4′‐bipyridine (BPY) to complex 6⊃C70 forms a more stable complex (6⊃BPY) via the coordination of the Zn‐porphyrin faces of 6 and BPY, which drives fullerenes out of the cavities and restores the ability of 1O2 generation. Therefore, benzyl alcohols are oxidized into benzyl aldehydes upon irradiation in the presence of 6 or 6⊃BPY, while they are oxidized into benzoic acids when 6⊃C70 is employed as the photosensitizing agent. This study demonstrates a highly efficient strategy that utilizes the host‐guest chemistry of metallacages to regulate the generation of reactive oxygen species for selective photooxidation reactions, which could promote the utilization of metallacages and their related host‐guest complexes for photocatalytic applications.

Benzyl alcohol promoted electrocatalytic reduction of carbon dioxide and C2 production by Cu2O/Cu

Oxide-derived copper (OD-Cu)-based materials containing Cuδ+ (0 < δ ≤ 1) have been considered as promising electrocatalysts for electrochemical CO2 reduction reaction (ECO2RR) to produce valuable C2 products, which, however, suffer from poor stability, mainly due to the inevitable reduction of Cuδ+. We report here that the benzyl alcohol (BA) introduced in catholyte presents a markedly positive effect on the durability and C2 selectivity enhancement of ECO2RR when OD-Cu-based material is adopted as cathode electrocatalyst. The critical evidence of ECO2RR intermediates has been provided by in situ Raman and FTIR spectroscopy, which reveals the surface mechanisms of BA-assisted ECO2RR over OD-Cu catalysts. On the one hand, the introduction of BA increases the CO2 supply for ECO2RR by slowing down its neutralizing reaction, which results in the increased intermediate species coverage on the catalytic surface therefore the delayed self-reduction of Cuδ+; On the other hand, the interaction between BA and the intermediate species *CO during ECO2RR brings an enhanced selectivity of C2 products (FE C2 = 85.5 % at −1.38 V vs RHE). Besides, an energy-savings and economic electrolyzer can be achieved by coupling anodic BA oxidation reaction to benzoic acid and ECO2RR to C2 products with much lowered cell voltages.

Aerobic benzyl alcohol oxidation by copper(I)(2,2′-bipyridine)-based catalysts

“In situ” prepared cationic Cu(I) complexes bearing 2,2’-bipyridine ligands and trifluoromethylsulfonate (triflate) have been used to catalyze the aerobic oxidation of benzyl alcohol to benzaldehyde in acetonitrile in the presence of (2,2,6,6-tetramethylpiperidin-1-yl) oxyl (TEMPO). A combination of catalytic reactions, operando1H NMR spectroscopic studies and the analysis of the molecular structure of the Cu(I) precatalysts in acetonitrile by means of DFT calculations shed light on the notable influence of counter-anion ligand interactions on the observed catalytic activity.

A Survey of Preservatives Used in Cosmetic Products

The aim of this study was to indicate the type of preservatives used in selected categories of cosmetic products sold in Poland (part of the EU market) and determine the frequency of their use. The tested products consisted of 200 leave-on cosmetics, viz. body lotions (n = 100) and face creams (n = 100) and rinse-off cosmetics (n = 100) and mascaras (n = 25). The product labels of 325 adult cosmetic products from international brands were analyzed for the presence of preservatives based on the INCI compositions. The survey focused on preservatives included in Annex V of the Regulation (EC) No. 1223/2009 of the European Parliament and Council of 30 November 2009 on cosmetic products. The tested products contained 29 different preservatives belonging to eight chemical groups. Most preservatives were alcohols or their derivatives, carboxylic acids or their salts, or parabens. The most common types were phenoxyethanol, present in 198/325 (60.9%) formulations, followed by sodium benzoate, in 137 (42.2%), potassium sorbate, in 116 (35.7%), benzyl alcohol, in 76 (23.4%), and methylparaben in 33 (10.2%). Also, 33 of the 60 preservatives included in Annex V of Regulation (EC) No. 1223/2009 were not used in any of the tested preparations. In each category of products, the most common were combinations of two preservatives per single product (34.8% of all products), followed by single-preservative products (25.5%) and three-preservative products (19.4%).

Characterization of A π–π stacking cocrystal of 4-nitrophthalonitrile directed toward application in photocatalysis

Photoexcitation of the electron-donor-acceptor complexes have been an effective approach to achieve radicals by triggering electron transfer. However, the catalytic version of electron-donor-acceptor complex photoactivation is quite underdeveloped comparing to the well-established utilization of electronically biased partners. In this work, we utilize 4-nitrophthalonitrile as an electron acceptor to facilitate the efficient π-stacking with electron-rich aromatics to form electron-donor-acceptor complex. The characterization and energy profiles on the cocrystal of 4-nitrophthalonitrile and 1,3,5-trimethoxybenzene disclose that the electron transfer is highly favorable under the light irradiation. This electron acceptor catalyst can be efficiently applied in the benzylic C−H bond photoactivation by developing the Giese reaction of alkylanisoles and the oxidation of the benzyl alcohols. A broad scope of electron-rich aromatics can be tolerated and a mechanism is also proposed. Moreover, the corresponding π-anion interaction of 4-nitrophthalonitrile with potassium formate can further facilitate the hydrocarboxylation of alkenes efficiently.

Sulfonic grafted graphitic-like carbon nitride for the improved photocatalytic production of benzaldehyde in water

This work reports the modification of graphitic carbon nitride (CN) through sulfonation (SCN) as an enhanced strategy for photocatalytic activity during the oxidation of benzyl alcohol to benzaldehyde. CN was prepared from melamine and functionalized with -SO3H groups using different doses of chlorosulfonic acid. The textural, structural, morphological, chemical, and optical properties of the prepared samples were characterized by diverse techniques. The increase in the doping dose produced, a decrease in surface area, a blue-shifted absorption edge under irradiation, and a decrease in the recombination charges. The -SO3H improved the kinetics of benzyl alcohol oxidation (BA) in aqueous solution and raised the selectivity to benzaldehyde (BD). An optimum dosage of precursor led to an SCN sample with the highest removal rate and selectivity. This optimized sample was selected for the study of the reactive oxidant species involved during the photocatalytic process, suggesting that the species with the highest contribution during BA oxidation was the superoxide radical, especially in terms of selectivity for the aldehyde formation. This work examples the modification of carbon nitride to enhance the production of an aldehyde with interest in the industry under a sustainable scheme that involves the transformation of light into chemical energy in aqueous solution.

HPLC/MS Analysis of Riboflavin Sodium Phosphate Consisting of Several Structural Isomers Together with Thiamine HCL, Pyridoxine HCL, Dexpanthenol, and Nicotinamide in A Multi-Vitamin Injection Solution

We were tasked with testing a multicomponent aqueous solution for injection used in medicine. The composition of the solution included the following components: Riboflavin sodium phosphate (vitamin B2), Thiamine HCl (vitamin B1), Pyridoxine HCl (vitamin B), Dexpanthenol (vitamin B5), and Nicotinamide (vitamin B3), also benzyl alcohol. The complexity of the simultaneous determination of these components was that they differ in their acid-base properties, physical-chemical properties, concentration in solution, and solubility in the mobile phase. The key to solving this task is the correct choice of method for analyzing riboflavin sodium phosphate in each vitamin mixture. Riboflavin is taking particular attention because this component has a few isomers that are separated by HPLC.