Showing papers on "Benzophenone published in 2020"
TL;DR: In this paper, a bifunctional benzophenone-carbazole-based photoinitiator BPC was designed from its molecular structure viewpoint, which can efficiently initiate the free radical photopolymerization (FRP) of acrylates without addition of any extra hydrogen donors demonstrating a monocomponent Type II behavior.
62 citations
TL;DR: Benzophenone-carbazole PIs have a good application potential, and this work provides a rational design route for PI molecules, and other PIs without synergetic effect demonstrate unsatisfied photopolymerization profiles in the same conditions.
Abstract: In this article, different substituents (benzoyl, acetyl, styryl) are introduced onto the carbazole scaffold to obtain 8 novel carbazole derivatives. Interestingly, a benzoyl substituent, connected to a carbazole group, could form a benzophenone moiety, which composes a monocomponent Type II benzophenone-carbazole photoinitiator (PI). The synergetic effect of the benzophenone moiety and the amine in the carbazole moiety is expected to produce high performance photoinitiating systems (PISs) for the free radical photopolymerization (FRP). For different substituents, clear effects on the light absorption properties are demonstrated using UV-Visible absorption spectroscopy. Benzophenone-carbazole PIs can initiate the FRP of acrylates alone (monocomponent Type II photoinitiator behavior). In addition, fast polymerization rates and high function conversions of acrylate are observed when an amine and/or an iodonium salt are added in systems. Benzophenone-carbazole PIs have good efficiencies in cationic photopolymerization (CP) upon LED @ 365 nm irradiation in the presence of iodonium salt. In contrast, other PIs without synergetic effect demonstrate unsatisfied photopolymerization profiles in the same conditions. The best PIS identified for the free radical photopolymerization were used in three-dimensional (3D) printing. Steady state photolysis and fluorescence quenching experiments were carried out to investigate the reactivity and the photochemistry and photophysical properties of PIs. The free radicals, generated from the studied PISs, are detected by the electron spin resonance - spin trapping technique. The proposed chemical mechanisms are provided and the structure/reactivity/efficiency relationships are also discussed. All the results showed that the benzophenone-carbazole PIs have a good application potential, and this work provides a rational design route for PI molecules. Remarkably, BPC2-BPC4, C6, C8 were never synthetized before; therefore, 5 of the 8 compounds are completely new.
47 citations
TL;DR: It is revealed that the novel versatile photoinitiators based on benzophenone-triphenylamine hybrid structures have great potentials for future industrial applications (e.g., 3D printing, composites, etc.).
Abstract: In this study, a new generation of photoinitiator (PI) based on hybrid structures combining benzophenone and triphenylamine is proposed. Remarkably, these photoinitiators (noted monofunctional benzophenone-triphenylamine (MBP-TPA) and trifunctional benzophenone-triphenylamine (TBP-TPA)) are designed and developed for the photopolymerization under light-emitting diodes (LEDs). Benzoyl substituents connected with triphenylamine moiety contribute to the excellent absorption properties which results in both high final conversions and polymerization rates in free radical photopolymerization (FRP). Remarkably, TBP-TPA owning trifunctional benzophenone group exhibits a better Type II PI behavior than well-known 2-isopropylthioxanthone for photopolymerization under LED@365 and 405 nm irradiation. FRP and cationic photopolymerization of TBP-TPA-based systems are applied on 3D printing experiments, and good profiles of the 3D patterns are observed. The high molecular weight of TBP-TPA associated with it trifunctional character can also be very interesting for a better migration stability of PIs that is a huge challenge. The development of this new generation of photoinitiators based on benzophenone hybrid structures is a real breakthrough. It reveals that the novel versatile photoinitiators based on benzophenone-triphenylamine hybrid structures have great potentials for future industrial applications (e.g., 3D printing, composites, etc.).
47 citations
TL;DR: Three different electrochemical strategies for the oxidative homocoupling of benzophenone imine, a readily accessible ammonia surrogate, are evaluated, revealing low overpotentials for the copper and iodine mediated processes, but a much higher value for the proton-coupled pathway.
Abstract: Hydrazine is an important industrial chemical and fuel that has attracted considerable attention for use in liquid fuel cells. Ideally, hydrazine could be prepared via direct oxidative coupling of ammonia, but thermodynamic and kinetic factors limit the viability of this approach. The present study evaluates three different electrochemical strategies for the oxidative homocoupling of benzophenone imine, a readily accessible ammonia surrogate. Hydrolysis of the resulting benzophenone azine affords hydrazine and benzophenone, with the latter amenable to recycling. The three different electrochemical N-N coupling methods are (1) a proton-coupled electron-transfer process promoted by a phosphate base, (2) an iodine-mediated reaction involving intermediate N-I bond formation, and (3) a copper-catalyzed N-N coupling process. Analysis of the thermodynamic efficiencies for these electrochemical imine-to-azine oxidation reactions reveals low overpotentials (η) for the copper- and iodine-mediated processes (390 and 470 mV, respectively), but a much higher value for the proton-coupled pathway (η ≈ 1.6 V). A similar approach is used to assess molecular electrocatalytic methods for electrochemical oxidation of ammonia to dinitrogen.
37 citations
TL;DR: A benzophenone-derived photosensitizer combined with a nickel catalyst has been established as the catalytic system for the direct benzylic C-H acylation reaction furnishing a variety of unsymmetrical ketones.
28 citations
TL;DR: In this article, a facile route toward the preparation of PEEK membranes via traditional non-solvent-induced phase separation (NIPS) and one-step heat treatment was proposed.
27 citations
TL;DR: The complexes with non-covalent interactions between benzophenone and C=C bonds in unsaturated lipids have been successfully characterized and for the first time a [2 + 2] cy-cloaddition leading to the formation of oxetanes has been identified under visible-light irradiation.
Abstract: The [2 + 2] photocycloaddition of alkenes and carbonyls is of fundamental interest and practical importance, as this process is extensively involved in oxetane-ring constructions. Although individual carbonyl group or alkene moiety has been utilized as photoactive species for oxetane formations upon ultraviolet photoexcitation, direct excitation of the entire noncovalent complex involving alkene and carbonyl substrates to achieve [2 + 2] photocycloadditions is rarely addressed. Herein, complexes with noncovalent interactions between benzophenone and C═C bonds in unsaturated lipids have been successfully characterized, and for the first time a [2 + 2] cycloaddition leading to the formation of oxetanes has been identified under visible-light irradiation. The mechanism of this reaction is distinctly different from the well-studied Paterno-Buchi reaction. The entire complexes characterized as dimeric proton-bonded alkene and carbonyl substrates can be excited under visible light, leading to electron transfer from the alkene moiety in fatty acyls to the carbonyl group within the complex. These results provide new insight into utilizing noncovalent complexes for the synthesis of oxetanes in which the excitation wavelength becomes independent of each individual substrate.
26 citations
TL;DR: A water-stable luminescent Zn-Tb heterometallic coordination polymer was rationally designed and synthesized for rapid detection of Benzophenone and showed a high quenching effect, excellent selectivity, and fast response toward BP.
Abstract: Benzophenone (BP) is an ultraviolet filter (UVF) widely used in personal care products such as sunscreens and cosmetics. Excessive exposure to BP-type UVFs is a potential threat to human's health because of their endocrine-disrupting activity. Water stability of lanthanide compounds is crucial when they serve as luminescent sensors because of the practicality and recyclability. In this study, a water-stable luminescent Zn-Tb heterometallic coordination polymer was rationally designed and synthesized for rapid detection of BP. This material showed a high quenching effect, excellent selectivity, and fast response toward BP.
26 citations
TL;DR: Unprotected aldoses in water undergo an isomerization reaction via a radical pathway when irradiated with light in the presence of water-soluble benzophenone, which generates 2-deoxy lactones, which are often contained in bioactive compounds.
Abstract: Unprotected aldoses in water undergo an isomerization reaction via a radical pathway when irradiated with light in the presence of water-soluble benzophenone. Whereas its anomeric carbon (C1) is oxidized to a carboxy group, the hydroxy group on the C2 carbon is replaced by hydrogen. The generated 2-deoxy lactones are readily reduced to the corresponding 2-deoxy aldoses, which are often contained in bioactive compounds.
25 citations
TL;DR: The titled material would be an effective and easily regenerated adsorbent for CR removal from wastewater and exhibits the suitable adsorption ability toward CO2.
Abstract: A new metal–organic framework was prepared based on a mixed ligand system of the designed nitrogen-rich 3,6-bis(2-methylimidazole)pyrimidine (b2mpm) and benzophenone 4,4′-dicarboxylic acid (H2bpndc...
25 citations
TL;DR: This work employed benzophenone as a catalyst and exploited its S0→Tn transition in C(sp3)-H alkynylations with hypervalent iodine reagents, enabling the reaction to proceed under mild conditions.
Abstract: Benzophenone has an S0 → S1 absorption band at 365 nm. However, the rarely reported S0 → Tn transition occurs upon irradiation at longer wavelengths. Herein, we employed benzophenone as a catalyst ...
TL;DR: An oxidative ring-opening strategy to transform cyclopropylamides and cyclobutylamides into fluorinated imines is reported, giving access to a broad range of useful building blocks for medicinal chemistry.
Abstract: We report an oxidative ring-opening strategy to transform cyclopropylamides and cyclobutylamides into fluorinated imines The imines can be isolated in their more stable hemiaminal form, with the fluorine atom installed selectively at the γ or δ position Both inexpensive benzophenone with UVA light or organic and inorganic dyes with blue light could be used as photoredox catalysts to promote this process Various fluorinated amines were then obtained by nucleophilic attack on the hemiaminals in one pot, giving access to a broad range of useful building blocks for medicinal chemistry
TL;DR: In vitro tubulin polymerization inhibition assay and molecular docking study showed that compound 4u has high binding affinities with the colchicine binding site of tubulin through hydrogen bond, cation-π, and hydrophobic interaction.
TL;DR: A ketylate species NacNacAl(η 2 (C,O)-OCPh 2 ) that undergoes easy cyclization reactions with unsaturated substrates and is characterized by NMR spectroscopy and X-ray diffraction analysis.
Abstract: Reaction of NacNacAl (NacNac=[DippNC(Me)CHC(Me)NDipp]- ) with one equivalent of benzophenone affords a ketylate species NacNacAl(η2 (C,O)-OCPh2 ) that undergoes easy cyclization reactions with unsaturated substrates. The scope of substrates included benzophenone, aldimine (PhNC(Ph)H), quinoline, phenyl nitrile, trimethylsilyl azide, and a saturated cyclic thiourea. The latter substrate reacted by an unusual C-N cleavage that left the C=S functionality intact. The new products were characterized by NMR spectroscopy and X-ray diffraction analysis.
TL;DR: An orthogonal selectivity for distal meta-C-H activation of benzophenone is acheived by overriding the inherent proximal ortho-selectivity through a template assisted metalation approach.
TL;DR: A thermally stable, T‐shaped, d7 high‐spin iron(I) complex was obtained by reduction of a PNP‐supported ferrous chloride byParamagnetic NMR spectroscopy combined with DFT modeling was used to analyze the electronic structure of the coordinatively highly unsaturated complex.
Abstract: A thermally stable, T-shaped, d7 high-spin iron(I) complex was obtained by reduction of a PNP-supported ferrous chloride. Paramagnetic NMR spectroscopy combined with DFT modeling was used to analyze the electronic structure of the coordinatively highly unsaturated complex. The metalloradical character of the compound was demonstrated by the formation of a benzophenone ketyl radical complex upon addition of benzophenone. Furthermore, the compound displays a rich chemistry as an oxygen-atom abstractor from epoxides, yielding a dinuclear, diferrous [Fe2 O] complex.
TL;DR: In this paper, the photoinitiating properties of novel visible-light absorbing diphenylporphyrins (DPPs) for free-radical (FRP), cationic (CP) and thiol-ene polymerization under visible LED irradiation (405 and 530 nm) at low intensities, under air or in laminate.
TL;DR: In this paper, two series of benzophenone based acid dyes are synthesized using diazotized derivatives of amino benzene sulfonic acid and amino benzoic acid, which were characterized by 1H NMR, 13C NMR and CHN analysis and FTIR.
TL;DR: An efficient and operationally simple Ni-catalyzed amination protocol has been developed and a diverse number of (hetero)aryl halides were coupled successfully with primary and secondary alkyl amines, and anilines in good to excellent yields.
Abstract: An efficient and operationally simple Ni-catalyzed amination protocol has been developed This methodology features a simple NiII salt, an organic base and catalytic amounts of both a pyridinium additive and Zn metal A diverse number of (hetero)aryl halides were coupled successfully with primary and secondary alkyl amines, and anilines in good to excellent yields Similarly, benzophenone imine gave the corresponding N-arylation product in an excellent yield
TL;DR: A tricobalt-substituted PMCDs is synthesized by conventional aqueous solution method and employed as a catalyst for the oxidation of diphenylmethane to benzophenone, giving 96.8% yield in the presence of tert-butyl hydroperoxide and pyridine.
Abstract: POM-supported metal carbonyl derivatives (PMCDs) represent a family of tremendous potential catalysts owing to their peculiar physical and chemical properties Yet low-valence transition metal-substituted Dawson-type PMCD catalysts are uncommon Hence, we synthesized a tricobalt-substituted PMCDs by conventional aqueous solution method, [Na(H2O)5](NH4)7[P2W15O56Co3(H2O)3(OH)3Re(CO)3]·13H2O (1), and characterized by single crystal X-ray diffraction crystallography, IR, and thermogravimetric analyses (TGA), etc The obtained compound 1 was employed as a catalyst for the oxidation of diphenylmethane (DPM) to benzophenone, giving 968% yield in the presence of tert-butyl hydroperoxide (TBHP) and pyridine The control experiments indicate that Co metal ion plays an important role in the catalytic reactions As a side note, the electrospray ionization mass spectrometry (ESI-MS) and UV spectroscopy showed that 1 can retain its integrity in solution, and magnetic measurements indicated that 1 exhibited a weaker ferromagnetic interaction at low temperature
TL;DR: In this paper, the binding interaction of Ni(II) complex of Schiff base of glycine and chiral auxiliary (S)-2-[N-(N′-benzylprolyl)amino]benzophenone (Ni(II)-(S)-BPB-Gly) with bovine serum albumin (BSA) at different temperatures (293, 298, and 308) was studied using UV/Vis and fluorescence spectroscopy methods.
Abstract: Binding interaction of Ni(II) complex of Schiff base of glycine and chiral auxiliary (S)-2-[N-(N′-benzylprolyl)amino]benzophenone (Ni(II)-(S)-BPB-Gly) with bovine serum albumin (BSA) at different temperatures (293, 298, and 308 K) has been studied using UV/Vis and fluorescence spectroscopy methods. A gradual decrease in the Stern–Volmer constant with the increase in temperature showed the static mechanism of BSA fluorescence quenching in the presence of Ni(II)-(S)-BPB-Gly initiated by the formation of ground-state complex. Analysis of the binding constants, number of binding sites, and thermodynamic parameters (∆H0, ∆S0, ∆G0) suggested that Ni(II)-(S)-BPB-Gly spontaneously and exothermically binds to BSA mainly driven by hydrogen bonding and van der Waals forces. The binding distances between Ni(II)-(S)-BPB-Gly and BSA in the temperature range 293–308 K determined using Forster’s resonance energy transfer theory (found to be 2.413, 2.445, and 2.459 nm) showed that the binding properties decrease with the temperature rising.
TL;DR: An amine‐exchange reaction was revealed as a key step of the catalytic cycle, in which Ln−Si−H β‐agostic interactions are proposed to promote insertion of the carbonyl moiety into the Si−H bond.
Abstract: The rare-earth metal complexes Ln(L1 )[N(SiHMe2 )2 ](thf) (Ln=La, Ce, Y; L1 =N,N''-bis(pentafluorophenyl)diethylenetriamine dianion) were synthesized by treating Ln[N(SiHMe2 )2 ]3 (thf)2 with L1 H2 . The lanthanum and cerium derivatives are active catalysts for the hydrosilylation of benzophenone derivatives with HN(SiHMe2 )2 . An amine-exchange reaction was revealed as a key step of the catalytic cycle, in which Ln-Si-H β-agostic interactions are proposed to promote insertion of the carbonyl moiety into the Si-H bond.
TL;DR: In this article, the authors describe the use of benzophenone imine and its derivatives for synthesizing primary amines, readily achieving the selective formation of primary amine and obtaining easily deprotectable amines.
Abstract: Benzophenone imine and its derivatives are useful ammonia equivalents for synthesizing primary amines, readily achieving the selective formation of primary amines and obtaining easily deprotectable...
TL;DR: In this paper, 2-hydroxybenzophenone, S-allyl-thiosemicarbazone and 3-ally l-salicylaldehyde were condensed by template effect of iron(III) ion to yield the N2O2 type-chelate complex.
Abstract: 2-Hydroxybenzophenone-S-allyl-thiosemicarbazone and 3-allyl-salicylaldehyde were condensed by template effect of iron(III) ion to yield the N2O2 type-chelate complex. The S-allyl-thiosemicarbazone ...
TL;DR: In this article, the acridan-substituted benzophenone derivative was used as non-doped emissive layer in OLED and a green device with external quantum efficiency of 1.93% was obtained with the CIE coordinates of (0.37, 0.57).
TL;DR: In this article, the effect of benzophenone (BP) group in the main chain on the photo-alignment behavior of cinnamoyl groups was studied and a novel photosensitive polyimide (BTDA-PI-CA) was synthesized.
Abstract: In order to study the effect of benzophenone (BP) group in the main chain on the photo-alignment behaviour of cinnamoyl groups, a novel photosensitive polyimide (BTDA-PI-CA) is synthesised by 3,3ʹ,...
TL;DR: A new prenylated benzophenone, hypatulin C, was isolated from the leaves of Hypericum patulum together with a biogenetically related analog, hypelodin B, which had a tricyclic [4.3.1.03,7]-decane moiety substituted by fourPrenyl groups.
Abstract: A new prenylated benzophenone, hypatulin C (1), was isolated from the leaves of Hypericum patulum together with a biogenetically related analog, hypelodin B (2). Hypatulin C (1) had a tricyclic [4.3.1.03,7]-decane moiety substituted by four prenyl groups. The structure of 1 was elucidated by detailed spectroscopic analyses, while the absolute stereochemistries of 1 and 2 were assigned by comparison of their ECD spectra with TDDFT calculated spectra.
TL;DR: In this article, the effect of substitutions at ortho-, meta-, para-positions on photoluminescence properties of benzophenone derivatives was investigated by using FTIR, NMR, UV/Visible, and fluorescence spectroscopies and cyclic voltammetry.
TL;DR: In this article, two types of novel photoinitiaors containing phototrigger were prepared to overcome oxygen inhibition in the UV- curing system in the absence of hydrogen donor, and the structures of prepared novel photoinitiators were determined by nuclear magnetic resonance (NMR) and high resolution MS (HR MS) spectra data.
Abstract: In this work, two types of novel photoinitiaors containing phototrigger were prepared to overcome oxygen inhibition in the UV- curing system in the absence of hydrogen donor. The structures of prepared novel photoinitiators were determined by nuclear magnetic resonance (NMR) and high resolution MS (HR MS) spectra data. The photo chemical behavior and photo-reactivity were also evaluated by ultraviolet-visible (UV–vis) spectroscopy and real-time Fourier transform infrared spectroscopy (RT-FTIR), respectively. The results show the prepared photoinitiators exhibit remarkable redshift compared to the commercial BP (benzophenone) and Irgacure 907 (2-methyl-1-(4-methylsulfanylphenyl)-2-morpholin-4-ylpropan-1-one), fast photolysis by C S bond, good photo initiation and significant overcoming oxygen inhibition for some compounds, which can be used as one-component photoinitiator candidates.