Carbonyl Bond Research Articles

Deconvoluting the Role of Electrostatics in Metal Carbonyl Bonding: Dipole Moments and Energy Decomposition Analysis of Late Transition Metal Pincer Complexes

Deconvoluting the Role of Electrostatics in Metal Carbonyl Bonding: Dipole Moments and Energy Decomposition Analysis of Late Transition Metal Pincer Complexes

Polaritonic Chemistry Enabled by Non‐Local Metasurfaces

AbstractVibrational strong coupling can modify chemical reaction pathways in unconventional ways. Thus far, Fabry‐Perot cavities formed by pairs of facing mirrors have been mostly utilized to achieve vibrational strong coupling. In this study, we demonstrate the application of non‐local metasurfaces that can sustain surface lattice resonances, enabling chemical reactions under vibrational strong coupling. We show that the solvolysis kinetics of para‐nitrophenyl acetate can be accelerated by a factor of 2.7 by strong coupling to the carbonyl bond of the solvent and the solute with a surface lattice resonance. Our work introduces a new platform to investigate polaritonic chemical reactions. In contrast to Fabry‐Perot cavities, metasurfaces define open optical cavities with single surfaces, which removes alignment hurdles, facilitating polaritonic chemistry across large areas.

Synthesis and Characterisation of Cellulose Acetate/Polyethylene Glycol Membrane from Pineapple Hump by Phase Inversion Method

Cellulose is a natural polymer contained in growing fibres, such as pineapple fibres. Cellulose can be modified into cellulose acetate, a modified polymer that can be used in the synthesis of a cellulose acetate/polyethylene glycol (CA/PEG) membrane. The phase inversion method was used in this study to produce CA/PEG membranes. Variations in polyethylene glycol (PEG) concentration with a ratio of 1:1 to cellulose acetate, where variations in PEG concentrations used are 2%, 5% and 8%. Acetone and dimethylformamide are used as organic solvents. Membrane morphological analysis using scanning electron microscopy (SEM) and functional group analysis using a Fourier transform infrared (FTIR) spectrometer were performed for membrane characterisation. The result of the synthesis of the CA/PEG membrane is in the form of a thin white layer. The characterisation results of the FTIR spectrometer showed the vibration of the carbonyl bond at wavenumber 1729 cm−1 and the vibration of the hydroxyl bond torque at the wave number 648 cm−1, where the vibration intensity decreased with each addition to the concentration. The results of SEM characterisation show that the increase in PEG concentration increases the percentage porosity of the membrane. The membranes with 2%, 5% and 8% PEG have porosity percentages of 51.54%, 68.70% and 73.50%, respectively. As the membrane with 2% PEG has the lowest percent porosity, it has more potential in removing or filtering solutes from a fluid.

Investigating thermal and UV ageing effects on crumb rubber modified bitumen enhanced with emission reduction agents and carbon black

Over time, bitumen experiences deterioration due to factors like the exposure to oxygen, solar irradiation, and temperature fluctuations. While laboratory techniques like rolling thin film oven (RTFO) and pressure ageing vessel (PAV) were developed to simulate field ageing, they do not accurately replicate environmental factors normally occurring in the field, particularly solar irradiation. Limited research has focused on understanding the ageing processes of crumb rubber modified bitumen (CRMB). This study investigated how different ageing conditions affect the chemo-rheological properties of CRMB and CRMB with geopolymer-based fly ash (GFA), Portland cement paste (PCP), and carbon black (CB). GFA and PCP were added to reduce noxious fumes and VOC emissions from CRMB whereas CB is commonly employed as an antioxidant agent. RTFO and PAV were used to simulate short- and long-term ageing, while a SUNTEST XLS+ weatherometer was used for thermal and UV ageing simulations. A dynamic shear rheometer and attenuated total reflectance Fourier transform infrared spectroscopy were employed for rheological and chemical analysis. Results indicated that extended exposure to thermal conditioning and UV irradiation had the most impact on the chemo-rheological properties of the binders. The incorporation of CR into bitumen enhanced ageing resistance and mitigated the potential for stiffening and embrittlement. The addition of GFA, PCP, and CB to CRMB had a negligible impact on the chemo-rheological properties when subjected to RTFO, PAV, and thermal conditioning. However, following UV ageing, these additives led to a slight increase in carbonyl bonds and greater stiffness compared to pure CRMB

Ameliorating the sodium storage performance of hard carbon anode through rational modulation of binder

Hard carbon anodes have emerged as promising candidates for sodium-ion batteries due to their inherent advantages. Nevertheless, the surface imperfections in these materials often culminate in irreversible electrolyte consumption, fostering the development of a heterogeneous and fragile solid electrolyte interface (SEI), thereby compromising the initial Coulombic efficiency (ICE). Drawing inspiration from the catalytic potential of C=O (carbonyl) bonds in directing preferential salt reduction, we introduce a novel strategy that leverages the modulation of the binder, a long-term overlooked pivotal components in the electrode process. Specifically, Polymethyl methacrylate (PMMA), abundant in C=O groups, is partially substituted for PVDF, ensuring robust adhesion of the electrode material to the current collector while preserving superior mechanical properties. The accurate combination of two binders with delightful compatibility in the state-of-art electrode process, can promote a uniform formation of the SEI on the hard carbon surface enriched in inorganic components, which can ensure long-term interfacial stability and suppresses excessive solvent decomposition and facilitates Na+ transfer at the interface. Consequently, the initial Coulombic efficiency of the hard carbon anode with 70 %PMMA binder achieves 86 %, with prominent cycling stability (88 % capacity retention over 500 cycles) at a high current density of 1.2 A g−1. When paired with high loading cathodes to assemble the pouch cell, it also demonstrates stable operational scenarios.

Natural α-Methylene-γ-Butyrolactone Analogues: Synthesis and Evaluation of Isoaurone Derivatives as Antifungal Agents.

In order to develop novel, efficient and green fungicides, a series of novel isoaurone derivatives were designed and synthesized, which were characterized by 1H and 13C NMR, high-resolution mass spectra and melting points. The target compounds showed different inhibitory activities against seven plant pathogenic fungi. Compounds 1, 12, 17, 20, 22, 24 and intermediate A showed more than 90% inhibition rates against S. s at 50 mg/L. Interestingly, compound 22 and intermediate A showed the great inhibitory effect against S. s with EC50 values of 4.65 and 4.24 mg/L, which were better than the lead compound isoaurone (EC50 = 15.62 mg/L). The EC50 values of compounds 17 and 24 against B. c were 13.94 and 22.13 mg/L. Moreover, compound 19 displayed significant antifungal activity against G. g with the EC50 value of 11.88 mg/L. Theoretical calculations by DFT revealed that the α, β-unsaturated carbonyl bond and the benzyl ring are very importantly linked to the strength of the fungicidal activity. Therefore, this study identified a valuable antifungal lead compound for further development of green fungicides.

Fate and effect of Polyamide-6 microplastics in mesophilic and thermophilic anaerobic digestion

Research has demonstrated that depending on the type and concentration, microplastics affect anaerobic digestion (AD). Owing to the high abundance of polyamide-6 (PA6) in wastewater treatment plants and limited understanding of its behavior, this study investigates PA6 microplastics' effect in AD. Biochemical methane potential experiments were performed under mesophilic (35 °C) and thermophilic (55 °C) conditions using PA6 at concentrations from 0 to 200 particles/g total solids (TS). Under both conditions, methane production increased in the highest (200 particles/g TS) PA6-dosed reactors, with thermophilic conditions having a statistically significant effect. Methane yield increased from 403.1 ± 5.3 mL/g VS to 436.6 ± 9.2 mL/g VS under thermophilic and from 332.1 ± 1.5 to 340.6 ± 6.6 mL/g VS under mesophilic conditions for the 200 particles/g TS dose, corresponding to increases of 8.3% and 2.6% respectively. PA6 crystallinity decreased from 32.8% to 27.1% and 26.8%, corresponding to decreases of 17.4% in mesophilic and 18.2% in thermophilic reactors compared to pristine control. Similarly, crystallinity decreased in PA6 microplastics collected from abiotic reactors, with thermophilic conditions showing a greater effect. The carbonyl index (CI) values were similar between biotic and abiotic reactors, but PA6 from all reactors had significantly higher CI than pristine PA6, suggesting abiotic factors also affect carbonyl bonds. Additionally, an increase in average PA6 mass was observed for mesophilic and thermophilic conditions by 22.0 % and 23.0 %, respectively. The study shows that temperature and other abiotic factors, like sludge chemistry, significantly influence the fate and effect of PA6 microplastics in digesters. Including abiotic reactors seems crucial for a full understanding of the impact of microbial and non-microbial factors in microplastic studies in the AD process. Studying the effects of microplastics on AD is only one part of the picture, whereas simultaneously examining their fate in digestion is necessary for a complete understanding.

A magnetic nanocatalyst based on Bronsted acid and Lewis acid centers for the efficient synthesis of polycyclic melting 1,5-benzodiazepines

In this study, 3-(Triethoxysilyl)propyl chloride (CPTES) was used to modify the surface of magnetic nanoparticles Fe3O4@SiO2, and aminomethylphosphonic acid (AMPA) was further anchored on the surface. Then, Ce (III) was used as the ligand to immobilize the surface of the modified material with N/O as the donor. Magnetic nanocatalysts (Fe3O4@SiO2@CPTES@AMPA@CeCl3) were successfully prepared. The prepared catalysts were characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen absorption-desorption experiment (BET), vibrating sample magnetometer (VSM), energy dispersive spectroscopy (EDS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). A synergetic effect of Brønsted and Lewis acid (AMPA and CeCl3) of the magnetic nanocatalyst was examined to active carbonyl, imine or enamine bonds for the synthesis of polycyclic fused 1,5-benzodiazepine with quaternary carbon centers or quinoxaline ring in a one-pot method. It was found that this catalyst exhibited excellent catalytic activities (TON up to 111368, TOF up to 110232 h−1) and high selectivities in the synthesis of fused 1,5-benzodiazepine compounds (22 examples, 85–96 % yields). The mechanism for the synthesis of polycyclic fused 1,5-benzodiazepine catalyzed by Fe3O4@SiO2@CPTES@AMPA@CeCl3 was proposed. The nanocatalyst was readily recovered by simple magnetic decantation and can be recyclable without obviously reducing catalytic activity up to seven times.

Alkali metal-doped C20 fullerene sensors for COVID-19 biomarker detection: DFT insights into naked-eye and infrared techniques

Prompt diagnosis and prevention from coronavirus disease (COVID-19), a highly contagious infection, are critically required. While PCR testing is effective, it is costly, painful, and time-consuming. Alternatively, breath analysis for detecting COVID-19 provides a cost-effective and instant diagnostic approach. COVID-19 infected patients exhale ethyl butyrate (EB) as a biomarker of the infection. This study explores the doping of C20 fullerene with alkali metals to enhance its ability to detect ethyl butyrate. EB was weakly adsorbed onto C20 and strong adsorbed on doped fullerenes (M@C20) with maximum adsorption energies of −27.66 kcal/mol for Li@C20. QTAIM and IRI analyses confirmed Van der Waals interactions between EB and M@C20. NBO and MEP analyses provided evidence of charge transfer from the biomarker towards the M@C20. This charge transfer decreased the carbonyl bond stretching frequency from 1838 cm−1 to 1772, 1782, and 1788 cm−1 in three complexes (EB−Li@C20, EB−Na@C20, and EB−K@C20), respectively. This IR analysis supports the potential application of doped fullerenes in infrared-based detectors. Absorption maxima (λmax) were calculated as 534 nm (green), 594 nm (yellowish orange), and 587 nm (yellow) for three complexes. These shifts indicate potential application of M@C20 in naked-eye detectors. The shortest recovery time was 2.9 × 10−11 s for K@C20, suggesting it a suitable reusable sensor. These findings enable the development of fullerene-based sensors for both naked-eye and infrared-based detection of COVID-19.

Insight into the effects of large yellow croaker roe (Larimichthys Crocea) phospholipids on the conformational and functional properties of pork myofibrillar protein

The large yellow croaker roe phospholipids (LYPLs), rich in polyunsaturated fatty acids, is a potential phospholipid additive for meat products. In this work, the effects of LYPLs on the structural and functional properties of myofibrillar protein (MP) were determined, and compared with egg yolk phospholipids (EYPLs) and soybean phospholipids (SBPLs). The results revealed that LYPLs, similar to SBPLs and EYPLs, induced a transformation in the secondary structure of MP from α-helix to β-sheets and random coils, while also inhibited the formation of carbonyl and disulfide bonds within MP. All three phospholipids induced MP tertiary structure unfolding, with the greatest degree of unfolding observed in MP containing LYPLs. The MP with LYPLs had the highest surface hydrophobicity, emulsification properties and gel strength. In addition, MP with LYPLs added also demonstrated superior rheological properties and water-holding capacity compared with SBPLs and EYPLs. In conclusion, adding LYPLs endowed MP with improved functional properties.

Effect of Terminal Hydroxy Groups on the Structural Properties of Acyl Thioureas.

The 1-acyl thiourea family [R1C(O)NHC(S)NR2R3] exhibits the flexibility to incorporate a wide variety of substituents into their structure. The structural attributes of these compounds are intricately tied to the type and extent of substitution. In the case of 3-mono-substituted thioureas (R2=H), the conformational behavior is predominantly shaped by the presence of an intramolecular N-H ⋅ ⋅ ⋅ O=C hydrogen bond. This study delves into the structural consequences stemming from the inclusion of substituents possessing hydrogen-donor capabilities within four novel 1-acyl-3-mono-substituted thiourea derivatives. A comprehensive suite of analytical techniques, encompassing FTIR, Raman spectroscopy, multinuclear (1H and 13C) NMR spectroscopy, single-crystal X-ray diffraction, and supported by computational methods, notably NBO (Natural Bond Orbital) population analysis, Hirshfeld analysis, and QTAIM (Quantum Theory of Atoms in Molecules), was harnessed to scrutinize and characterize these compounds. In the crystalline state, these compounds exhibit an intricate interplay of intermolecular interactions, prominently featuring an expansive network of hydrogen bonds between the hydroxy (-OH) groups and the carbonyl and thiocarbonyl bonds within the 1-acyl thiourea fragment. Notably, the topological analysis underscores significant distinctions in the properties of the acyl thiourea fragment and the intramolecular >C=O ⋅ ⋅ ⋅ H-N bond when transitioning from the isolated molecule to the crystalline environment.

A rational design of metal doped C20 fullerene based sensor for the selective detection of ethyl butyrate as COVID-19 biomarker

The detection of ethyl butyrate as a COVID-19 biomarker in exhaled breath could be a novel, rapid, less expensive, painless and non-invasive technique compared to a costly, painful and time-consuming PCR test. The potential of alkaline earth metals doped C20 fullerenes (M@C20) was explored as sensing materials to detect ethyl butyrate selectively. The ethyl butyrate (EB) exhibited the physisorption on pristine C20 fullerene with adsorption energy of -4.16 kcal/mol, while chemisorption was observed with M@C20 fullerenes. The frontier molecular orbital analysis demonstrates enhanced stability of complexes, attributed to widened Eg gaps during EB adsorption onto M@C20 fullerenes. The notable shift in λmax values in the visible region suggests using M@C20 fullerenes as UV–visible-based naked-eye sensors. The infrared analysis showed a red shift in the carbonyl bond stretching frequency of ethyl butyrate upon adsorption onto M@C20 fullerenes. The red shift resulted from charge transfer from ethyl butyrate to M@C20. These findings establish the foundation for utilizing M@C20 fullerenes in IR-based handheld sensing devices. The minimum recovery time (6.8 s) demonstrates Ca@C20 fullerene as a promising, reusable sensor for detecting ethyl butyrate at human body temperature. Our results pave the way to design rapid, reusable sensors for detecting ethyl butyrate.

Chromene meroterpenoids from Rhododendron dauricum L. and their anti-inflammatory effects

Rhododendron dauricum L. is a perennial herb belonging to the genus Rhododendron, commonly utilized in formulations for treating coughs and bronchitis, as well as in herbal teas for enhancing immunity and preventing tracheitis. In this study, fifteen previously undescribed chromene meroterpenoids (1a/1b-4a/4b, 5–8, 9b, 10a, 11b), along with twenty-one known compounds were isolated from the dried twigs and leaves of Rhododendron dauricum L. Of these, (−)-rhodonoid E (9b), (+)-confluentin (10a), and (−)-rubiginosin D (11b) were separated for the first time by chiral HPLC separation. The elucidation of their structures, including absolute configurations, was achieved through a combination of techniques such as NMR, HRESIMS, modified Mosher's method and quantum-chemical calculation of electronic circular dichroism (ECD) spectra. Seven pairs of enantiomers, compounds 1a/1b-4a/4b and 9a/9b-11a/11b, were initially obtained in a racemic manner and were further separated by chiral HPLC preparation. The biological assessment of these compounds against NO production was conducted in the LPS-induced RAW264.7 macrophage cells model. Compounds 9a, 9b, and 11a displayed inhibitory rates exceeding 80%, with IC50 values ranging from 8.69 ± 0.94 to 13.01 ± 1.11 μM. A preliminary examination of the structure-activity relationship (SAR) for these isolates indicated that chromene meroterpenoids with α, β-unsaturated ketone carbonyl and Δ12(13) double bond functionalities exhibited enhanced anti-inflammatory properties.

Atomically dispersed Zn-NxCy sites on N-doped carbon for catalytic transfer hydrogenation of ethyl levulinate into γ-valerolactone

Catalytic transfer hydrogenation (CTH) of biomass-derived carbonyl compounds provides a viable strategy to synthesize high value-added chemicals and biofuels, for which the development of efficient catalysts still remains a formidable challenge. Here, we report a Zn-based single-atom catalyst (Zn/NC-950), prepared by pyrolysis of ZIF-8 at 950 °C, for the CTH of ethyl levulinate to γ-valerolactone (GVL). This catalyst exhibited excellent performance, affording a GVL selectivity of 95.3 % at an ethyl levulinate conversion of 100 %, using isopropanol as the hydrogen source at 200 °C and autogenous pressure. The structural characterization and theoretical calculation demonstrate that such extraordinary efficacy of the Zn/NC-950 catalyst is attributed to the dual Zn-N3C1 and Zn-N2C2 sites of low Zn oxidation states, which work synergistically to generate the active hydrogen species and activate the carbonyl bonds, respectively. This work provides a rationale for the precise design of the non-noble metal single-atom catalysts efficient for the biomass valorization.

Bis(acyl)phosphide Complexes of U(III)/U(IV): A Case of a Hidden Redox-Active Ligand.

The recently reported tris(bis(2,4,6-triisopropylbenzoyl)-phosphide)uranium (UIII(trippBAP)3, 2) complex (Inorg. Chem. 2022, 61 (32), 12508-12517) demonstrated a silent 31P NMR spectrum. This complex was described as a U(III) complex with an organic radical ligand fragment. Moreover, the EPR spectrum of 2 was indicative of an organic radical in the ligand framework complexed to uranium, in contrast to that of UIV(mesBAP)4, 1. Herein, with the help of relativistic density functional theory (DFT) calculations, the electronic structures of 1, 2, and U(mesBAP)3 (4) are examined in an effort to understand the unusual 31P NMR spectrum of 2. Results indicate the reduction of the carbonyl bonds and delocalization of the electrons over the ligands, indicative of U → L backbonding. Additionally, the reduced acyl carbons are found to exist as ketyl radicals [O═C• -] that are responsible for the silent 31P NMR spectra of 2. These findings demonstrate the redox noninnocent nature of BAP- in 2 and 4, causing uranium to exist in a formal oxidation state of +4.

Accumulated charge density at the interface boosts the urea oxidation reaction activity of Ni3N/Ni3S2 heterointerface

Optimizing the adsorption strength of multiple intermediates at one single active site at the same time is rather difficult. Heterointerface engineering provides more than one type of active sites to function, which may dramatically enhance the intrinsic urea oxidation reaction (UOR) activity of catalysts. Herein, a Ni3N (110)/Ni3S2 (010) heterointerface was fabricated. The electronic interactions between the two phases generates an accumulated charge density heterointerface and endows the heterointerface with more enhanced density of states, which facilitates the adsorption and desorption of more UOR intermediates, thus lowering the theoretical reaction barrier for the rate-controlling step of *CONHN to *CONN. The nickel moieties on Ni3N side tends to bond carbonyl and the nickel moieties on Ni3S2 side preferentially bond amnio. The cooperation of both nickel moieties contributes to the superb intrinsic UOR activity of Ni3N (110)/Ni3S2 (010) heterointerface. As a consequence, Ni3N (110)/Ni3S2 (010) heterointerface showcases outstanding UOR activity, reaching 105.66 mA·cm−2 at 1.6 V. This work provides an excellent UOR catalyst and helps to better understand the cooperation mechanism of the active sites at the heterointerface.

Biodegradation of low-density polyethylene film by two bacteria isolated from plastic debris in coastal beach

Low-density polyethylene (LDPE) conduces massive environmental accumulation due to its high production and recalcitrance to environment. In this study, We successfully enriched and isolated two strains, Nitratireductor sp. Z-1 and Gordonia sp. Z-2, from coastal plastic debris capable of degrading LDPE film. After a 30-day incubation at 30 ℃, strains Z-1 and Z-2 decreased the weight of branched-LDPE (BLDPE) film by 2.59 % and 10.27 % respectively. Furthermore, high temperature gel permeation chromatography (HT-GPC) analysis revealed molecular weight reductions of 7.69 % (Z-1) and 23.22 % (Z-2) in the BLDPE film. Scanning electron microscope (SEM) image showed the presence of microbial colonization and perforations on the film's surface. Fourier transform infrared spectroscopy (FTIR) analysis indicated novel functional groups, such as carbonyl and carbon-carbon double bonds in LDPE films. During LDPE degradation, both strains produced extracellular reactive oxygen species (ROS). GC-MS analysis revealed the degradation products included short-chain alkanes, alkanols, fatty acids, and esters. Genomic analysis identified numerous extracellular enzymes potentially involved in LDPE chain scission. A model was proposed suggesting a coordinated role between ROS and extracellular enzymes in the biodegradation of LDPE. This indicates strains Z-1 and Z-2 can degrade LDPE, providing a basis for deeper exploration of biodegradation mechanisms.

Biosynthesis of silver nanoparticles using Burkholderia contaminans ZCC and mechanistic analysis at the proteome level

The biogenic synthesis of silver nanoparticles (AgNPs) by microorganisms has been a subject of increasing attention. Despite extensive studies on this biosynthetic pathway, the mechanisms underlying the involvement of proteins and enzymes in AgNPs production have not been fully explored. Herein, we reported that Burkholderia contaminans ZCC was able to reduce Ag+ to AgNPs with a diameter of (10±5) nm inside the cell. Exposure of B. contaminans ZCC to Ag+ ions led to significant changes in the functional groups of cellular proteins, with approximately 5.72% of the (C-OH) bonds being converted to (C-C/C-H) (3.61%) and CO (2.11%) bonds, and 4.52% of the CO (carbonyl) bonds being converted to (C-OH) bonds. Furthermore, the presence of Ag+ and AgNPs induced the ability of extracellular electron transfer for ZCC cells via specific membrane proteins, but this did not occur in the absence of Ag+ ions. Proteomic analysis of the proteins and enzymes involved in heavy metal efflux systems, protein secretion system, oxidative phosphorylation, intracellular electron transfer chain, and glutathione metabolism suggests that glutathione S-transferase and ubiquinol-cytochrome c reductase iron-sulfur subunit play importance roles in the biosynthesis of AgNPs. These findings contribute to a deeper understanding of the functions exerted by glutathione S-transferase and ferredoxin-thioredoxin reductase iron-sulfur subunits in the biogenesis of AgNPs, thereby hold immense potential for optimizing biotechnological techniques aimed at enhancing the yield and purity of biosynthetic AgNPs.

Isolation and characterisation of lignin using natural deep eutectic solvents pretreated kenaf fibre biomass

Extraction of lignin via green methods is a crucial step in promoting the bioconversion of lignocellulosic biomasses. In the present study, utilisation of natural deep eutectic solvent for the pretreatment of kenaf fibres biomass is performed. Furthermore, extracted lignin from natural deep eutectic solvent pretreated kenaf biomass was carried out and its comparative study with commercial lignin was studied. The extracted lignin was characterized and investigated through Infrared Fourier transform spectroscopy, X-ray Diffraction, thermogravimetric analysis, UV–Vis spectroscopy, and scanning electron microscopy. FTIR Spectra shows that all samples have almost same set of absorption bands with slight difference in frequencies. CHNS analysis of natural deep eutectic solvent pretreated kenaf fibre showed a slight increase in carbon % from 42.36 to 43.17% and an increase in nitrogen % from − 0.0939 to − 0.1377%. Morphological analysis of commercial lignin shows irregular/uneven surfaces whereas natural deep eutectic solvent extracted lignin shows smooth and wavy surface. EDX analysis indicated noticeable peaks for oxygen and carbon elements which are present in lignocellulosic biomass. Thermal properties showed that lignin is constant at higher temperatures due to more branching and production of extremely condensed aromatic structures. In UV–VIS spectroscopy, commercial lignin shows slightly broad peak between 300 and 400 nm due to presence of carbonyl bond whereas, natural deep eutectic solvent extracted lignin does not show up any peak in this range. XRD results showed that the crystallinity index percentage for kenaf and natural deep eutectic solvent treated kenaf was 70.33 and 69.5% respectively. Therefore, these innovative solvents will undoubtedly have significant impact on the development of clean, green, and sustainable products for biocatalysts, extraction, electrochemistry, adsorption applications.

Pt(II) complexes bearing P,N-donor ligands as catalysts in chemoselective hydrosilylation, hydrogermylation, and hydroboration of terminal alkenes

In this report, we present the synthesis of six novel neutral platinum complexes employing readily available P,N-donor ligands through a straightforward two-step procedure. Subsequently, we investigated their catalytic activity in the hydroelementation of terminal olefins, highlighting their versatile utility in material and natural product chemistry. The efficient addition of silicon, germanium, and boron hydrides to the CC bond at low catalyst loading occurred exclusively in an anti-Markovnikov manner. Furthermore, our substrate scope encompasses a wide range of aliphatic and aromatic alkenes, featuring substituents with varying electronic properties. In contrast to many previous Pt-complexes, our catalytic system displayed exceptional chemoselectivity towards other unsaturated functional groups, such as carbonyl and internal CC bonds. Notably, it also exhibited remarkable tolerance to hydroxyl, alkoxyl, silyl, and thioether moieties. Additionally, we accentuated the prowess of our catalyst, showcasing its capability to sustain consistent activity and selectivity throughout numerous catalytic cycles.