Rahul Sakla | National Institute Of Technology Kurukshetra (original) (raw)

Papers by Rahul Sakla

Inorganic Chemistry, Aug 1, 2019

ACS applied energy materials, Jan 27, 2021

Durable multifunctional electrocatalysts with zero emission and high catalytic activity are desir... more Durable multifunctional electrocatalysts with zero emission and high catalytic activity are desirable for environmentally benign clean energy technologies such as water-splitting devices, fuel cell...

Methods, Sep 1, 2019

Fluorescent nanoprobes for the sensing of gasotransmitters hydrogen sulfide (H 2 S), nitric oxide... more Fluorescent nanoprobes for the sensing of gasotransmitters hydrogen sulfide (H 2 S), nitric oxide (NO) and carbon monoxide (CO),

ACS Sensors, Jun 1, 2018

A new approach for the detection of hydrogen sulfide (HS) was constructed within vesicles compris... more A new approach for the detection of hydrogen sulfide (HS) was constructed within vesicles comprising phospholipids and amphiphilic copper complex as receptor. 1,2-Distearoyl- sn-glycero-3-phosphocholine (DSPC) vesicles with embedded metal complex receptor (1.Cu) sites have been prepared. The vesicles selectively respond to HS in a buffered solution and show colorimetric as well as spectral transformation. Other analytes such as reactive sulfur species, reactive nitrogen species, biological phosphates, and other anions failed to induce changes. The HS detection is established through a metal indicator displacement (MIDA) process, where Eosin-Y (EY) was employed as an indicator. Fluorescence, UV-vis spectroscopy, and the naked eye as the signal readout studies confirm the high selectivity, sensitivity, and lower detection limit of the vesicular receptor. The application of vesicular receptors for real sample analysis was also confirmed by fluorescence live cell imaging.

ACS Sensors, Nov 9, 2020

A fluorescent probe for the monitoring of H 2 S levels in living cells and organisms is highly de... more A fluorescent probe for the monitoring of H 2 S levels in living cells and organisms is highly desirable. In this regard, nearinfrared (NIR) fluorescent probes have emerged as a promising tool. NIR-I and NIR-II probes have many significant advantages; for instance, NIR light penetrates deeper into tissue than light at visible wavelengths, and it causes less photodamage during biosample analysis and less autofluorescence, enabling higher signal-to-background ratios. Therefore, it is expected that fluorescent probes having emission in the NIR region are more suitable for in vivo imaging. Consequently, a considerable increase in reports of new H 2 Sresponsive NIR fluorescent probes appeared in the literature. This review highlights the advances made in developing new NIR fluorescent probes aimed at the sensitive and selective detection of H 2 S in biological samples. Their applications in real-time monitoring of H 2 S in cells and in vivo for bioimaging of living cells/animals are emphasized. The selection of suitable dyes for designing NIR fluorescent probes, along with the principles and mechanisms involved for the sensing of H 2 S in the NIR region, are described. The discussions are focused on small-molecule and nanomaterialsbased NIR probes.

ACS Applied Materials & Interfaces, Jul 18, 2017

Colorimetric sensors based on Sudan-III (1) and Alizarin red S (2) have been developed for the de... more Colorimetric sensors based on Sudan-III (1) and Alizarin red S (2) have been developed for the detection of a trace amount of water in organic solvents such as THF, acetone, acetonitrile, and DMSO. The deprotonated (anionic) forms of 1 and 2 namely 1.F and 2.F are reprotonated by using a trace amount of water. Deprotonation of 1 and 2 was obtained by using fluoride anion. Test papers of 1.F and 2.F in organic solvents with and without moisture showed dramatic changes in color. Receptor 1.F exhibits high sensitivity for water in acetone and THF with the detection limit as low as 0.0042 and 0.0058 wt %. Remarkably, probes 1.F and 2.F are reversible in nature both in solution and in test strips. 1.F and 2.F are reversible and reusable for sensing moisture in the organic solvents with high selectivity, high sensitivity, and fast response. The reversible moisture sensor 1.F has also been used for application in inkless writing.

Journal of Organometallic Chemistry, Feb 1, 2022

Recent papers in this series (1) illustrated that, besides the highly active and stereoselective ... more Recent papers in this series (1) illustrated that, besides the highly active and stereoselective tungsten and molybdenum imido alkylidene metathesis catalysts, extensively developed by Schrock and coworkers (2, 3), a large class of ruthenium complexes have been successfully applied in organic and polymer syntheses (4-9). These include arene 1, alkylidene 2, vinylalkylidene 3, vinylidene 4, allenylidene 5 and indenylidene 6 complexes; where R are phenyl (Ph), isopropyl (i-Pr) or cyclohexyl (Cy) and R' are phenyl (Ph) or tert-butyl (t-Bu) groups. This variety of 16-and 18-electron ruthenium complexes, and specifically the 'first generation' catalysts (or pre-catalysts) of diphosphane ruthenium alkylidene type 2 and 3 (5, 6), displayed a set of appealing properties such as good to excellent metathesis activity and high tolerance towards many organic functionalities, various impurities, air and moisture (10). The main inconveniences during their utilisation, however, consist of a limited stability in the course of metathesis reactions and particularly decomposition upon heating, due to a pronounced lability of the phosphane ligands. Type of NHC Ruthenium Complexes, Syntheses and Catalytic Properties A remarkable development in the chemistry of ruthenium alkylidene complexes occurred subsequently when three independent research teams reported the design and synthesis of a novel class of ruthenium pre-catalysts containing alkylidene

ACS Applied Materials & Interfaces, Mar 30, 2018

In this paper, a new type of methodology to deliver carbon monoxide (CO) for biological applicati... more In this paper, a new type of methodology to deliver carbon monoxide (CO) for biological application has been introduced. Amphiphilic manganese carbonyl complex (1.Mn) incorporated into the DSPC lipid vesicles have been reported first time for the photo induce release of CO. The liposomes (Ves-1.Mn) gradually released CO under light at 365 nm over a period of 50 min with half-time of 26.5 min. The CO-releasing ability of vesicles appended 1.Mn complexes have been confirmed by myoglobin assay and IR study. The vesicles appended with 1.Mn have the advantages of biocompatibility, water solubility, steady and slow CO release. This approach could be a rational approach for applying various water-insoluble photoinduced CO donors in aqueous media by using vesicles as a nanocarrier for CO release. ASSOCIATED CONTENT Supporting Information. Supporting Information [ 1 H-NMR and ESI mass spectrum, SEM-EDX data, Uv-Vis spectrum for MB assay are available] is available. This material is available free of charge via the Internet at http://pubs.acs.org.

Applied Organometallic Chemistry, Aug 31, 2022

We present the syntheses of ruthenium (II) complexes bearing an N‐heterocyclic carbene (NHC)‐base... more We present the syntheses of ruthenium (II) complexes bearing an N‐heterocyclic carbene (NHC)‐based C^N donor set and an NCS ligand and evaluate their use as photosensitizers in dye‐sensitized solar cells (DSSCs). These complexes deploy a monocarboxylic acid‐functionalized terpyridine (tpy)/phenyl‐tpy to anchor with the TiO2 of the photoanodes. Results show that the complexes devoid of the phenyl spacer between the acid anchor and the tpy harvest the visible light more effectively. Absorption of the visible light transfers the electron density from the ruthenium, NHC, and the NCS donors to the tpy acceptor (1MRuLdonorLacceptorCT). Stronger MRuLdonor σ‐bonds in the complexes with opposite NHC and tpy ligand configuration render facile ruthenium‐centered oxidation. In contrast, the metal‐centered oxidation of complexes with trans‐oriented NHC and NCS ligands is relatively difficult. However, these complexes display higher photon conversion efficiency (PCE) in DSSCs. One of them shows PCE of 3.44%, which is ~70% of the standard N3 dye, under similar conditions. A longer electron lifetime and the lowest charge transfer resistance at the TiO2/electrolyte interface derived from the electrochemical impedance spectra accounts for the enhanced PCE. Insights into the oxidized dye regeneration in a DSSC setup, obtained from the computed Hirshfeld charges and spin density, depict the essential role of iodide anion in dye regeneration. This report summarizes our investigation of photophysics, electronic structure calculations, and the electrochemical study of all newly prepared complexes and their use as photosensitizers in DSSCs.

European Journal of Inorganic Chemistry, Nov 3, 2022

This report presents ruthenium (II) complexes featuring bis‐imidazole‐2‐ylidene donors and carbox... more This report presents ruthenium (II) complexes featuring bis‐imidazole‐2‐ylidene donors and carboxylic acid‐functionalized terpyridine ligands (tpy−COOH or tpy4′−phenyl−COOH). We introduced the monodentate −NCS or pyridine carboxylate ligands into the coordination sphere to render sizeable changes in photo‐functional attributes. The coordination of the thiocyanate ligands to these ruthenium centers extends their absorption tails up to 800 nm. In contrast, the absorption bands of complexes featuring isonicotinic acid last only until 600 nm. Even though phenyl spacers at the acceptor end rendered a bathochromic shift in the λmax, in their absence, complexes exhibited a longer electron lifetime at the TiO2 photoanode. The complexes devoid of phenyl spacers show lower charge transfer resistance at the TiO2/electrolyte interface giving improved photon conversion efficiency (PCE) in Dye‐Sensitized Solar Cells (DSSCs). Herein, we analyze the relationship between the structure and the light‐harvesting efficiency via a combined experimental and computational approach.

Molecular Pharmaceutics, Dec 6, 2022

Current bionanotechnology, Jan 5, 2017

New Journal of Chemistry, 2020

A polyoxometalate (POM) cluster [Mo72Fe30O252(CH3COO)12{Mo2O7(H2O)}2 {H2Mo2O8(H2O)} (H2O)91]. ca.... more A polyoxometalate (POM) cluster [Mo72Fe30O252(CH3COO)12{Mo2O7(H2O)}2 {H2Mo2O8(H2O)} (H2O)91]. ca. 150 H2O (catalyst I) has been explored as a light-driven water oxidation catalyst. The catalyst is stable and could be reused/recycled several times.

ChemPlusChem

Cyanine dye‐based new amphiphilic compound NIR‐Amp has been synthesised. NIR‐Amp was embedded wit... more Cyanine dye‐based new amphiphilic compound NIR‐Amp has been synthesised. NIR‐Amp was embedded with phospholipids DOPC and DPPC to form liposomes based nanoscale chemical sensors NIR‐Lip1 and NIR‐Lip2. Here, two different phospholipids were used to demonstrate the influence of lipid structure, composition and fluidity on sensing of nanosensors. Both the probes show NIR absorption maximum at 790 nm and emission maximum at 815 nm. H2S‐triggered thiolation resulted a remarkable change in color from green to pale yellow. A decrease in UV‐Vis absorption and emission in the NIR region was observed only with H2S. NIR‐Lip1 and NIR‐Lip2 are highly selective for H2S with a LOD of 0.57 μM and 1.24 μM, respectively. It was observed that in a solid‐like gel state, NIR‐Lip1 is slightly more sensitive towards H2S than fluid‐like NIR‐Lip2. The H2S sensing mechanism was confirmed by ESI‐mass and infrared (IR) spectroscopic analysis. Based on the high sensitivity and selectivity, NIR‐Lip1 was employed...

European Journal of Inorganic Chemistry

European Journal of Inorganic Chemistry, 2021

Heteroleptic ruthenium (II) complexes featuring donor functionalized phenyl‐terpyridine (ph‐tpy) ... more Heteroleptic ruthenium (II) complexes featuring donor functionalized phenyl‐terpyridine (ph‐tpy) and a monocarboxylic‐(ph‐tpy)/(tpy) are synthesized and characterized. Reactions of ruthenium (II) precursors at 80 °C favored heteroleptic complexes formation over the homoleptic side products. Visible light excitation of these complexes resulted in the metal‐to‐ligand charge transfer (MLCT) transitions. The inter‐planar torsional angle between the atoms of donor functionalized phenyl ring and the central pyridine (py) of the tpy core strongly influences visible light absorption and photovoltaic properties. The lower inter‐ring py‐ph torsion in the acceptor end of the MLCT structures and its increase in the oxidized doublets could prevent the back electron transfer. The ruthenium atom and the acceptor functionalized tpy host the triplet‐MLCT spin density. Ambient temperature excited‐state decay followed the energy gap law and occurred in the order of a few nanoseconds. Herein, we evalua...