Papers by Shankara Radhakrishnan
Agronomy
One of the challenges in agriculture practices is guaranteeing an adequate and bioavailable phosp... more One of the challenges in agriculture practices is guaranteeing an adequate and bioavailable phosphorus supply for plants on phosphorus-deficient soils. A promising alternative lies in the utilization of phosphate nano-fertilizers (NFs) through spray applications. Therefore, this short-term study aimed to investigate the yet undetermined widespread impact of P-NFs on crops characterized by broad leaves, an intensive rate of photosynthesis, and belonging to the oilseed plant, sunflower (Helianthus annuus L.). To achieve this, NFs were applied at lower concentrations of various phosphate-based NFs, including (i) nano-hydroxylapatite (nano-Hap) and (ii) a mixture of nano-calcium zinc phosphate and macro-sized parascholzite (nano/macro-ZnPhos), in comparison to the NF-free control. The study was carried out under authentic field conditions during the 2022 vegetation season at the Dolná Malanta site within the Central European Region. The empirical evidence presented herein indicates that...
Social Science Research Network, 2022
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Journal of Dispersion Science and Technology, 2018
We report herein, the aggregation behavior of 3, 4-di(dodecyloxy)benzoic acid-4-hydroxy phenyl es... more We report herein, the aggregation behavior of 3, 4-di(dodecyloxy)benzoic acid-4-hydroxy phenyl ester (DDBE), a synthetic amphiphile and a true non-ionic surfactant system as per the geometrical considerations. The true surfactant nature of the system stems from its hydrophilic-lipophilic-balance (HLB ¼ 4.7), comparable to that of Span-60, also a true non-ionic surfactant. This compound undergoes spontaneous vesicle formation in THF:water binary solvent mixtures which further underwent fission at lower DDBE concentrations and fusion at higher concentrations, leading to giant vesicles of the order of 3000 nm. These vesicles are sensitive to the polarity of their environment. The predominant mode of interaction as observed from the molecular dynamics simulations were found to be p-p stacking with the phenyl rings of the molecule. Further, the system, upon complete extraction into water, formed spherical aggregates of size 50 nm based on the good solvent-poor solvent combination as the necessary condition for the vesicle formation.
Dalton Trans., 2017
Syntheses, spectroelectrochemistry and molecular orbital analyses of mono- to multimetal Re(0) an... more Syntheses, spectroelectrochemistry and molecular orbital analyses of mono- to multimetal Re(0) and Re(i) Fischer carbene complexes with condensed thienothienyl substituents.
mme.iitm.ac.in
... S. Shankara Gayathri and Archita Patnaik Department of Chemistry Indian Institute of Technolo... more ... S. Shankara Gayathri and Archita Patnaik Department of Chemistry Indian Institute of Technology-Madras, Chennai 600 036 ... of the surface network leading to aggregate formation at the air-water interface were obtained from the prominent red shifts in the UV absorption features ...
Sustainable Energy & Fuels, 2020
Co-electrolysis of formic acid and water using an indium oxide cathode catalyst yields a mixture ... more Co-electrolysis of formic acid and water using an indium oxide cathode catalyst yields a mixture of methanol, ethanol and iso-propanol with a Faraday efficiency up to 82.4%. The reaction of aqueous carbon dioxide occursviaa competing pathway.
Journal of Porphyrins and Phthalocyanines, 2016
Two bis-tetraphenylporphyrin tweezers-like conjugates bearing different linkers have been charact... more Two bis-tetraphenylporphyrin tweezers-like conjugates bearing different linkers have been characterized by means of electrochemical and photophysical methods. The thrust of this work was the complexation of these bis-porphyrins with C[Formula: see text] and metallic nitride endohedral fullerenes (MNEF) like Sc3N@C[Formula: see text] in organic and in aqueus media — studied by a combination of steady-state and time-resolved spectroscopies. In the context of charge separation evidence for the formation of the 1a[Formula: see text]-Sc3N@C[Formula: see text] and 1c[Formula: see text]-Sc3N@C[Formula: see text] charge separated states in organic and aqueous media, respectively, came from transient absorption spectroscopy. Multi-wavelength analyses afforded charge separated state lifetimes of around 400 ps.
Catal. Sci. Technol., 2016
CO and NO react on hydrogen-covered 13-atom Pt clusters, O2 does not, and the hydrogenation of et... more CO and NO react on hydrogen-covered 13-atom Pt clusters, O2 does not, and the hydrogenation of ethene shows structure sensitivity.
Chemical Society Reviews, 2016
Living organisms and materials produced in the laboratory form ordered non-equilibrium states whe... more Living organisms and materials produced in the laboratory form ordered non-equilibrium states when part of the required energy is dissipated as heat.
Langmuir, 2007
The mechanism of formation and the stability of spontaneously formed vesicles upon self-assembly ... more The mechanism of formation and the stability of spontaneously formed vesicles upon self-assembly of a partially ground-state charge-separated, nonpolar-polar-nonpolar fullerene(C 60)-didodecyloxybenzene (DDB) dyad in binary solvent mixtures requiring a critical dielectric constant of ∼30 are reported. Molecular interactions giving rise to defined vesicles with in-plane bilayer packing are detailed from the predominant van der Waals and electrostatic interactions existing on the dyad's framework. The vesicles are formed with a large bending rigidity of 18k B T, which on further extraction into a polar water medium resulted in uniform spheres that corroborated well with the theoretical predictions. Furthermore, the water-extracted spherical dyad aggregates at an increased dyad concentration, leading to the formation of giant micrometer-sized fractals following diffusion-limited cluster aggregation. These dyad aggregates act as efficient quenchers of fluorescent dyes with a quenching rate of 4.6 × 10 13 M-1 s-1 .
Journal of the American Chemical Society, 2008
Quantum chemical calculations and various photophysical techniques, ranging from steadystate abso... more Quantum chemical calculations and various photophysical techniques, ranging from steadystate absorption and steady-state as well as time-resolved fluorescence to femtosecond pump-probe experiments, were employed to examine ground-and excited-state interactions in a set of novel doubledecker buckyferrocenes (i.e., Fe 2 (C 60 Me 10)Cp 2): C 2v and D 5d isomers. When compared to the individual reference systems, the intimate fullerene/ferrocene contacts reflect appreciable ground-state interactions, namely, substantial redistribution of charge density between the two electron donors (i.e., ferrocenes) and the electron acceptor (i.e., fullerene). Furthermore, an intervalence charge-transfer transition (i.e., ferrocene-ferrocenium interaction) was established, but only in the C 2v isomer. The first insight into the electron donor-acceptor interactions came from inspecting the fullerene-centered fluorescence. Relative to the reference compounds that contain no ferrocene, which exhibit quantum yields of up to 0.1, and knowing that the fluorescence of the investigated doubledecker type conjugates is quenched to 10-3 , transient absorption measurements prove unequivocally the rapid formation of the radical ion-pair states as the dominant products of excited-state deactivation in the doubledecker buckyferrocenes. Despite these products having much higher lying radical ion-pair states relative to the corresponding single-decker buckyferrocene, their lifetimes, which vary between 12 and 39 ps, are slightly shorter.
Journal of the American Chemical Society, 2010
Stable donor-acceptor conjugates (2, 3) involving an endohedral metallofullerene, La(2)@I(h)-C(80... more Stable donor-acceptor conjugates (2, 3) involving an endohedral metallofullerene, La(2)@I(h)-C(80), and pi-extended tetrathiafulvalene (exTTF) have been synthesized by highly regioselective 1,3-dipolar cycloadditions of exTTF-containing azomethine ylides to the endofullerene, yielding exclusively [5,6] metallofulleropyrrolidines with C(1) symmetry in high yields (68-77%). The cyclic voltammograms (CVs) of the conjugates reveal the redox active character of the system due to the presence of both donor and acceptor groups, that is, exTTF and La(2)@I(h)-C(80), respectively. Furthermore, the electrochemically reversible character of the endofullerene confirms the presence of the [5,6] adduct. Despite the relatively close proximity between the exTTF and the endohedral metallofullerene (EMF), only a weak electronic interaction was observed in the ground state, as evidenced by absorption spectroscopy and CV measurements of 2 and 3. On the other hand, in the excited state the fast formation of a radical ion-pair state (i.e., 6.0 x 10(10) s(-1)), that is, the reduction of the electron accepting La(2)@C(80) and the oxidation of exTTF, evolves with lifetimes as long as several ns (3.0 x 10(8) s(-1)) in toluene. Transient absorption spectroscopy experiments confirmed these observations.
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Papers by Shankara Radhakrishnan