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Chiral and achiral Pd(II)‐NNN pincer complexes (1–3) containing acetonitrile as an ancillary ligand were synthesized and characterized by spectroscopic (UV‐visible, FT‐IR, NMR and mass) techniques. Polarimetric experiments were employed... more
Chiral and achiral Pd(II)‐NNN pincer complexes (1–3) containing acetonitrile as an ancillary ligand were synthesized and characterized by spectroscopic (UV‐visible, FT‐IR, NMR and mass) techniques. Polarimetric experiments were employed to measure the specific rotation values of the chiral complexes {[α]D27= +135° (2) and −136° (3)}. The structures resolved through single crystal X‐ray diffraction technique disclosed the distorted square planar geometry of the complexes. Transfer hydrogenation (TH) reactions of ketones were carried out in order to appraise the catalytic efficiency of the complexes. Remarkably, the TH results were promising for all the complexes, however, the chiral complexes (2 and 3) failed to induce chirality. Further probe led us to believe that the pincer complexes turned into Pd particles in situ and the later acted as an active catalyst. The scope of TH was extended to various substituted aromatic and heterocyclic ketones (Conversions=75–99%).
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Abstract Formulating high sensitivity and resolution in Extreme Ultraviolet (EUV) resists is a serious concern regarding the adaptation of EUV lithography. The incorporation of a high optical density Sn compound in MAPDST-co-ADSM... more
Abstract Formulating high sensitivity and resolution in Extreme Ultraviolet (EUV) resists is a serious concern regarding the adaptation of EUV lithography. The incorporation of a high optical density Sn compound in MAPDST-co-ADSM (4-(methacryloyloxy)phenyl) dimethylsulfoniumtrifluoromethane sulfonate-co-acetyldibutylstannyl methacrylate, a non-CAR photoresist, exhibits lithography resolution for sub-15 nm node when patterned under e-beam and Helium ion irradiation. The synthesized resists were irradiated at 103.5 eV (~92 eV) using monochromatic synchrotron radiation. After EUV irradiation and oxidation, the resists were investigated using XPS, NEXAFS and by theoretical calculations (FEFF9 modeling program). It was observed significant changes in the labile CF3SO3– moiety, but interestingly its total dissociation or desorption was not observed after long exposure times. Bonds rearrangements of formation of SnO2 and new S–C/C–F functionalities after irradiation were detected. Those complex processes suggested the existence of important sinks for the high photon energy absorbed, which in turn increased the lithography resolution. The present results highlight the importance of the incorporation of a heavy metal covalently linked to the main polymer structure. The enhanced resolution observed in the MAPDST-co-ADSM resist formulation using standard processing conditions, establishes its potential candidature as a EUVL resist for rapid prototyping of semiconductor devices.
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Abstract Stimuli-responsive organic-inorganic mesoporous silica hybrid materials have attracted significant attention because of their tuning properties that enable a wide range of applications. The characteristic properties of... more
Abstract Stimuli-responsive organic-inorganic mesoporous silica hybrid materials have attracted significant attention because of their tuning properties that enable a wide range of applications. The characteristic properties of nanohybrids can be further manipulated by various external stimuli, such as pH, temperature, light, magnetic and electrical fields, redox, and enzymes. The tuning of the properties leads to the alternating nature of the hybrids and exhibition of on-off behaviour under different stimulations. Stimuli-responsive mesoporous silica hybrid materials find applications in diverse fields, such as catalysis, drug delivery, gene delivery, sensing, and imaging. In this review, we discuss the synthetic techniques, physicochemical properties, and behaviour of various responsive materials, along with the potential applications of mesoporous silica hybrids in a wide range of fields. In addition, the scope and future development of stimuli-responsive mesoporous silica hybrids are examined in detail.
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The use of polyvinyl acetal (PVA) brushes is one of the most effective and prominent techniques applied for the removal of chemical mechanical planarization (CMP) contaminants. However, the brush can be a source of defects by entrapping... more
The use of polyvinyl acetal (PVA) brushes is one of the most effective and prominent techniques applied for the removal of chemical mechanical planarization (CMP) contaminants. However, the brush can be a source of defects by entrapping the abrasives inside its porous structure during brush scrubbing. In this study, the effect of brush top skin layer was extensively studied on contamination, cross-contamination, and cleaning performance by comparing brushes with and without skin layer. The presence of a dense top skin layer resulted in larger contact areas and high ceria particle adsorption on the skin layer. This leads to higher cross-contamination of the wafers during scrubbing along with high cleaning performances. Conversely, the brushes without skin layer showed lower contamination and negligible cross-contamination with a reduced cleaning performance (removal of ceria particles from oxide surface). Therefore, the role of the brush skin layer is significant and needs to be considered while designing a post-CMP cleaning process.
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We developed a novel method to obtain a temperature-responsive switchable polymer–silica nanohybrid system without any surface functionalization for catalytic action control.
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A water-soluble binuclear organometallic Ru-p-cymene complex [Ru(η6-p-cymene)(η2-L)]2 (1) was prepared from (E)-2-((1H-indol-3-yl)methylene)-N-phenylhydrazine-1-carbothioamide (HL) and [RuCl2(p-cymene)]2 in methanol at room temperature... more
A water-soluble binuclear organometallic Ru-p-cymene complex [Ru(η6-p-cymene)(η2-L)]2 (1) was prepared from (E)-2-((1H-indol-3-yl)methylene)-N-phenylhydrazine-1-carbothioamide (HL) and [RuCl2(p-cymene)]2 in methanol at room temperature under inert atmosphere. The structure of binuclear complex was analyzed by UV-Visible, FT-IR, NMR and mass spectroscopic methods. The solid-state structure of the complex was ascertained by single crystal X-ray diffraction technique. The complex exhibited pseudo-octahedral (piano-stool) geometry around Ru(II) ion. The cytotoxic property of the ligand and complex along with cisplatin was investigated against A549-lung, MCF7-breast, HeLa-cervical, HepG-2-liver, T24-urinary bladder and EA.hy926-endothelial cancer cells, and Vero-kidney epithelial normal cells. The complex exhibited superior activity than cisplatin against A549, HeLa and T24 cancer cells with the IC50 values of 7.70, 11.2, and 5.05 µM, respectively. The complexes were cytotoxic specifically to the cancer cells. Molecular docking studies showed good binding potential of the ligand and complex with the spike protein and main protease of SARS-CoV-2, indicating the promising role of these compounds as antiviral compounds.
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Research Interests: Chemistry, Organic Chemistry, Catalysis, Medicine, Multidisciplinary, and 13 moreMetal Nanoparticles, Silver Nanoparticles, Silver, Plastics, Industrial chemistry, Particle Size, Surface Properties, Silver Nanoparticle, Langmuir, Cationic polymers, Cations, Oxidation-Reduction, and Molecular Structure
We developed a novel method to obtain a temperature-responsive switchable polymer–silica nanohybrid system without any surface functionalization for catalytic action control.
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The increase in the demand of sub-10 nm feature size in semiconductor industries necessitates a new kind of resist material development which can absorb a large fraction of irradiation and retains the small size cluster distribution (1-2... more
The increase in the demand of sub-10 nm feature size in semiconductor industries necessitates a new kind of resist material development which can absorb a large fraction of irradiation and retains the small size cluster distribution (1-2 nm). In this context, we developed a novel nickel-based organo-metallic cluster comprising high optical density inorganic nickel as metal building units (MBU), and 3,3-Dimethylacrylic acid as an organic ligand to form Ni-DMA clusters. The synthesised clusters have ~1 nm size with narrow size distribution. The formulated resist shows the negative tone pattern when exposed with a focused helium ion (He+) beam and e-beam. The high-resolution line patterns of ~8 nm at the dose of ~40 μC cm-2 were obtained with the minimum line edge roughness (LER) and line width roughness (LWR) of 2.16 ± 0.04 nm and 3.03 ± 0.06 nm, respectively.
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Herein, we develop an efficient and novel catalytic system, i.e. silver nanoparticles (AgNPs) incorporated mesoporous silica SBA‒15/copolymer hybrid material, for selective oxidation of different alcohols to aldehydes or ketones under... more
Herein, we develop an efficient and novel catalytic system, i.e. silver nanoparticles (AgNPs) incorporated mesoporous silica SBA‒15/copolymer hybrid material, for selective oxidation of different alcohols to aldehydes or ketones under ‘mild’ conditions. The copolymer of N,-N-dimethylaminoethyl methacrylate and 2-hydroxyethyl acrylate (p(DMAEMA-co-HEA)) was used to graft the surface-modified SBA‒15 (MS) using free radical polymerization method. Then AgNPs were decorated on the polymer grafted SBA‒15. The dual (thermal and pH) responsive behaviors of the AgNPs/p(DMAEMA-co-HEA)/MS catalyst were investigated using the dynamic light scattering technique. The lower critical solution temperature (LCST) of the copolymer was found to be approximately 30–35 °C. The catalytic activity of AgNPs/p(DMAEMA-co-HEA)/MS was investigated for the selective oxidation of different alcohols to aldehydes or ketones. The conversion of catalytic products and selectivity were calculated using gas chromatograp...
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In the present work, a temperature and pH-responsive hybrid catalytic system using copolymer-capped mesoporous silica particles with metal nanoparticles is proposed. The poly(2-(dimethylamino)ethyl methacrylate)(DMAEMA)-co-N-tert-butyl... more
In the present work, a temperature and pH-responsive hybrid catalytic system using copolymer-capped mesoporous silica particles with metal nanoparticles is proposed. The poly(2-(dimethylamino)ethyl methacrylate)(DMAEMA)-co-N-tert-butyl acrylamide) (TBA)) shell on mesoporous silica SBA-15 was obtained through free radical polymerization. Then, copper nanoparticles (CuNPs) decorated SBA-15/copolymer hybrid materials were synthesized using the NaBH4 reduction method. SBA-15 was functionalized with trimethoxylsilylpropyl methacrylate (TMSPM) and named TSBA. It was found that the CuNPs were uniformly dispersed in the mesoporous channels of SBA-15, and the hybrid catalyst exhibited excellent catalytic performance for the selective oxidation of different substituted benzyl alcohols in water using H2O2 as an oxidant at room temperature. The dual (temperature and pH-) responsive behaviors of the CuNPs/p(DMAEMA-co-TBA)/TSBA catalyst were investigated using the dynamic light scattering techniq...
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Palladium nanoparticles-anchored dual-responsive SBA-15-copolymer nanoreactor was developed as a novel heterogeneous catalyst for green Suzuki–Miyaura cross-coupling reaction.
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ABSTRACT a b s t r a c t New six coordinated tris-chelate cobalt(III) complexes of the type [Co(L) 3 ] (1–4) {where HL = N-[di(alkyl/aryl)carbamothioyl]benzamide derivatives}were prepared from the reaction between CoCl 2 ·6H 2 O and... more
ABSTRACT a b s t r a c t New six coordinated tris-chelate cobalt(III) complexes of the type [Co(L) 3 ] (1–4) {where HL = N-[di(alkyl/aryl)carbamothioyl]benzamide derivatives}were prepared from the reaction between CoCl 2 ·6H 2 O and N-[di(alkyl/aryl)carbamothioyl]benzamide in ethanol and characterized by elemental analysis and spectral data (UV/Vis, IR, 1 H & 13 C NMR). The molecular structure of a representative complex [Co(L1) 3 ] (1) [where HL1 = N-(diisopropylcarbamothioyl)benzamide], was determined by single crystal X-ray diffraction method and reveals a distorted octahedral geometry and a facial configuration of S atoms around the Co(III) center. These complexes act as efficient catalysts for the oxidation of alcohols to their corresponding aldehydes or ketones in presence of tert-butyl hydroperoxide (TBHP) at 80 • C.