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To conduct rapid microscope observations with the excitation spectral measurement for photosynthetic organisms, a wavelength-dispersive line-focus microscope was developed. In the developed system, fluorescence signals at multiple positions on a sample excited with different wavelengths can be detected as a two-dimensional image on the EMCCD camera at the same time. Using the developed system, one can obtain excitation spectra at every pixel over the excitation wavelength range from 635 to 695 nm, which covers the full range of the Qy bands of both chlorophyll-a and chlorophyll-b. Recording the reference laser spectra at the same time ensures robust measurement against the moderate spectral fluctuation in the excitation laser. Using an objective lens with a numerical aperture of 0.9, the lateral and axial resolutions of 0.56 and 1.08 μm, respectively, were achieved. The theoretically limited and experimentally estimated spectral resolutions of the excitation spectral measurement were 0.86 and 1.3 nm, respectively. The validity of the system was demonstrated by measuring fluorescent beads and single cells of a model alga, Chlamydomonas reinhardtii. Intrachloroplast inhomogeneity in the relative intensity of the chlorophyll-b band could be visualized in Chlamydomonas cells. The inhomogeneity reflects the intrachloroplast variation in the local peripheral antenna size.

The motivation behind this empirical investigation comes from the inconclusive evidence produced by a flurry of previous empirical studies on foreign direct investment (FDI)-growth nexus. The study recognises the fact that the treatment of FDI inflows in an aggregate form instead of a sector-specific approach while correlating it with economic growth remains the most tenuous assumption of the previously conducted studies. Driven by the impetus of filling this gap, this study applies a time-varying parameter model with vector autoregressive specification to examine as to how sector-wise FDI inflows can affect the growth of respective sectors in the context of an emerging economy like India. The study uses a number of econometric tests, such as Johansen’s cointegration test, vector error correction model, Granger causality test, variance decomposition analysis and impulse response analysis, to arrive at robust results. The study evidences the inward FDI to be non-contributive to the agricultural output growth. However, a reverse causality is evidenced wherein agricultural output is found to be attracting more FDI into the sector. It also documents interesting evidence for manufacturing sector where the FDI inflow is found to affect its output positively for a couple of years. Regarding service sector, the study confirms a bidirectional causality between FDI and growth both for the short and long run. On the basis of the findings, the study suggests economic policymakers to rejuvenate the primary sector of India so that it can attract and absorb more FDI and ensure sustainable economic growth. Besides, the agriculture-led economic growth policy might be more reliant than service which is largely vulnerable to external shocks.

Driven by the need of an economic model that can explain the foreign direct investment (FDI)–export relationship, especially in post-liberalized context, we make a special inquiry on whether FDI has a significant export-promoting impact in India under a time-varying parameter model with vector autoregressive specification. The Johansen’s co-integration test suggests a significant and positive long-run co-movement between FDI and export. The vector error correction model (VECM) confirms a unidirectional long-run causality from export to FDI. However, the Granger causality test establishes a bi-directional causal relationship between these variables in short run. Further, the foreign trade (FT) is found to be a strongly exogenous variable as per the variance decomposition analysis. Again, the impulse response function analysis suggests that the responses generated from a positive shock of FT to FDI and vice versa are small and initially negative, afterward remain steadily positive at a constant level. The study finally recommends the policymakers to channelize the inward-FDI into tradable goods industries rather than only linking it to service sector growth to reap the long-term benefit. In this regard, China’s effort to channelize inward-FDI into manufacturing sectors and the resultant momentous success in export performance can be taken as a classic example for FDI-led foreign trade promotion.

Efficient light harvesting in a photosynthetic antenna system is disturbed by a ragged and fluctuating energy landscape of the antenna pigments in response to the conformation dynamics of the protein. This situation is especially pronounced in Photosystem I (PSI) containing red shifted chlorophylls (red Chls) with the excitation energy much lower than the primary donor. The present study was conducted to clarify light-harvesting dynamics of PSI isolated from Synechocystis sp. PCC6803 by using single-molecule spectroscopy at liquid‑nitrogen temperatures. Fluorescence emission at around 720 nm from the red Chls in single PSI trimers was monitored at 80–100 K. Intermittent variations in the emission intensities, so-called blinking, were frequently observed. Its time scale lay in several tens of seconds. The blinking amplitude depended on the redox state of the phylloquinone (A1). Electrochromic shifts of Chls induced by the negative charge on A1 were calculated based on the X-ray crystallographic structure. A Chl molecule, Chl-A839 (numbering according to PDB 5OY0 ), bound near A1 was found to have a large electrochromic shift. This Chl has strong exciton coupling with neighboring Chl (A838) whose site energy was predicted to be determined by interaction with an arginine residue (ArgF84) [Adolphs et al., 2010]. A possible scenario of the blinking was proposed. Conformational fluctuations of ArgF84 seesaw the excitation-energy of Chl-A838, which perturbs the branching ratio of excitation-energy between the red Chl and the cationic form of P700 as a quencher. The electrochromic shift of Chl-A839 enhances the effect of the conformation dynamics of ArgF84.

Over the past few decades, the structure, functions, properties, and molecular mechanisms of retinal proteins have been studied extensively. The newly studied retinal protein Gloeobacter rhodopsin (gR) acts as a light-driven proton pump, transferring a proton from the cytoplasmic region to the extracellular region of a cell following light absorption. It was previously shown that gR can bind the carotenoid salinixanthin (sal). In the present study, we report the effect of pH on the binding of retinal to the apo-protein of gR, in the presence and absence of sal, to form the gR pigment. We found that binding at different pH levels reflects the titration of two different protein residues, one at the lower pKa 3.5 and another at the higher pKa 8.4, that affect the pigment’s formation. The maximum amount of pigment was formed at pH 5, both with and without the presence of sal. The introduction of sal accelerates the rate of pigment formation by a factor of 190. Furthermore, it is suggested that occupation of t...

The compartmental ligand 2,6-bis[2-(N-ethyl)thiopheneiminomethyl]-4-chlorophenol (HL) undergoes Cu(ClO4)2 induced partial hydrolysis to yield a monoamine ligand 4-chloro-2-formyl-6-[2-(thiophen-2-yl)ethyliminomethyl]phenol (HL′). On further reaction with Cu(ClO4)2, HL′ produces a dinuclear complex, [Cu2(L′)2(ClO4)2] (2), which has been characterized in solution by UV/Vis, ATR, NMR, and ESI-MS spectral techniques and in the solid state by X-ray single-crystal structure analysis. The in situ generated 2 is highly fluorescent. On reaction with sodium acetate it transforms to a fluorescence inactive tetranuclear species, [Cu4(L)2(OAc)4(O)] (3), and thereby acts as an excellent chemodosimeter for selective detection of the acetate anion via fluorescence “turn-off” signalling. The direct reaction of HL and copper(II) acetate dihydrate yielded another fluorescence inactive tetranuclear species, [Cu4(L)2(OAc)4(O)] (1), which is a diastereoisomer of 3 as is evident from X-ray single-crystal structural analyses.

This review contains extensive application of anion sensing ability of salicylidene type Schiff bases and their reduced forms having various substituents with respect to phenolic OH group. Some of these molecular systems behave as receptor for recognition or sensing of various anions in organic or aqueous-organic binary solvent mixture as well as in the solid supported test kits. Development of Schiff base or reduced Schiff base receptors for anion recognition event is commonly based on the theory of hydrogen bonding interaction or deprotonation of phenolic -OH group. The process of charge transfer (CT) or inhibition of excited proton transfer (ESIPT) or followed by photo-induced electron transfer (PET) lead to naked-eye color change, UV-vis spectral change, chemical shift in the NMR spectra and fluorescence spectral modifications. In this review we have tried to discuss about the anion sensing properties of Schiff base or reduced Schiff base receptors.

The binding affinity of cationic DNA-staining dye, propidium iodide, with transport protein, bovine serum albumin, has been explored using UV–vis absorption, fluorescence, and circular dichroism spectroscopy. Steady state and time resolved fluorescence studies authenticate that fluorescence quenching of bovine serum albumin by propidium iodide is due to bovine serum albumin–propidium iodide complex formation. Thermodynamic parameters obtained from temperature dependent spectral studies cast light on binding interaction between the probe and protein. Site marker competitive binding has been encountered using phenylbutazone and flufenamic acid for site I and site II, respectively. Energy transfer efficiency and distance between bovine serum albumin and propidium iodide have been determined using Forster mechanism. Structural stabilization or destabilization of protein by propidium iodide has been investigated by urea denaturation study. The circular dichroism study as well as FT-IR measurement demonstrates some configurational changes of the protein in presence of the dye. Docking studies support the experimental data thereby reinforcing the binding site of the probe to the subdomain IIA of bovine serum albumin.

Excited state intramolecular charge transfer (ICT) process in a donor–chromophore–acceptor system 5-(4-dimethylamino-phenyl)-penta-2,4-dienoic acid ethyl ester (DMAPPDE) has been investigated spectroscopically in combination with quantum chemical calculations. The molecule DMAPPDE shows dual fluorescence corresponding to emission from the locally excited as well as charge transfer states in polar solvents. Large solvatochromic shift of emission band (Δν = 8504 cm−1), high excited state dipole moment (18 D), quantum chemically calculated potential energy curves by Density Functional Theory (DFT) method and HOMO–LUMO pictures support the occurrence of excited state ICT process. Variation of acceptor strength in this molecular system shows prominent effect on the spectroscopic and molecular properties like absorption and emission band maxima, Stokes’ shift, quantum yields, and dipole moment which are found to be controlled by the ICT process.

In this work, we report intramolecular charge transfer (ICT) suppressed excited state intramolecular proton transfer (ESIPT) process in 4-(diethylamino)-2-hydroxybenzaldehyde (DEAHB). Photophysical properties of DEAHB have been extensively studied in different solvents with varying pH, polarity, and hydrogen bonding capability of the solvent using steady state and time-resolved spectroscopy. To establish the competition between the ICT and ESIPT processes in DEAHB, we have synthesized and studied the photophysical properties of 4-(diethylamino)-2-methoxybenzaldehyde (DEAMB) molecule where only the charge transfer process has been observed. Recently, we have reported simple Schiff base molecules (J. Phys. Chem. A 2012, 116, 10948) formed by condensation of DEAHB and hydrazine (5-(diethylamino)-2-[(4-(diethylamino)benzylidene)hydrazonomethyl]phenol (DDBHP) and N,N'-bis(4-N,N-(diethylamino)salisalidene)hydrazine (DEASH)), where charge transfer is assisted by the proton transfer process. In the present case, the DEAHB molecule shows the reverse phenomenon; i.e., charge transfer is suppressed by the proton transfer process. Comparing the photophysical properties of DEAHB with DEAMB it is also found that ICT process in DEAHB is suppressed by the ESIPT process.

Test paper coated with Schiff base [(N,N(/)-bis(5-nitro-salicylidene)hydrazine] receptor 1 (host) can selectively detect fluoride and acetate ions (guest) by developing yellow color which can be detected by naked-eye both in aqueous-acetonitrile solution and in solid supported test kit. UV-vis spectral analysis shows that the absorption peaks at 288 and 345 nm of receptor 1 gradually decrease its initial intensity and new red shifted absorption bands at 397 nm and 455 nm gradually appear upon addition of increasing amount of F(-) and AcO(-) ions over several tested anions such as H(2)PO(4)(-), Cl(-), Br(-), I(-), NO(3)(-), NO(2)(-), HSO(4)(-), HSO(3)(-), and ClO(4)(-) in aqueous-acetonitrile solvent. The colorimetric test results and UV-vis spectral analysis are in well agreement with (1)H NMR titration results in d(6)-DMSO solvent. The receptor 1 forms 1:2 stable complexes with F(-) and AcO(-) ions. However, similar kind of observation obtained from UV-vis titrations in presence of AcOH corresponds to 1:1 complexation ratio indicating the formation of H-bonding interaction between the receptor and anions (F(-) and AcO(-) ions). So, the observed 1:2 complexation ratio can only be explained on the basis of deprotonation (∼1 eqv.) and H-bonding (∼1 eqv.) interactions [1]. The ratiometric analysis of host-guest complexes corroborates well with the proposed theoretical model optimization at Density Functional Theory (DFT) level.

Photochromic Schiff bases 5-diethylamino-2-[(4-diethylamino-benzylidene)-hydrazonomethyl]-phenol (DDBHP) and N,N'-bis(4-N,N-diethylaminosalisalidene) hydrazine (DEASH) with both the proton and charge transfer moieties have been synthesized, and their photophysical properties such as excited state intramolecular charge transfer (ICT) and proton transfer (ESIPT) processes have been reported on the basis of steady-state and time-resolved spectral measurement in various solvents. The ground-state six-membered intramolecular hydrogen bonding network at the proton transfer site accelerates the ESIPT process for these compounds. Both the compounds show large Stokes-shifted emission bands for proton transfer and charge transfer processes. The hydrogen bonding solvents play a crucial role in these photophysical processes. Excited-state dipole moment of DDBHP and DEASH calculated by the solvatochromic method supports the polar character of the charge transfer excited state. Introduction of -NEt(2) groups to the reported salicylaldehyde azine (SAA) Schiff base results an increase in fluorescence lifetime from femtosecond to picosecond time scale for the proton transfer process.

We report extrinsic fluorescent probe 5-(4-dimethylamino-phenyl)-penta-2,4-dienoic acid (DMAPPDA) as a molecular reporter for studying microheterogeneous environment of protein Human Serum Albumin (HSA) via spectral modification of the probe under physiological condition. Steady state emission, fluorescence anisotropy, Red Edge Excitation Shift (REES), far-UV Circular Dichroism (CD), Atomic Force Microscopy (AFM) imaging, time resolved spectral measurements, Molecular Docking and Molecular Dynamics (MD) Simulation techniques have been used to fulfill this achievement. Interaction of the probe with HSA is signaled by the blue shift of the fluorophore emission maxima with enhancement of fluorescence intensity. The increase in steady state anisotropy, REES and fluorescence lifetime values with increasing protein concentrations indicates interaction and movement of the probe from free aqueous media to the more restricted less polar hydrophobic interior of protein. Experimental results obtained from Benesi–Hildebrand plot support the formation of 1:1 HSA–DMAPPDA complex with high binding constant and negative free energy change. Thermal denaturation of the probe bound protein has also been tracked using the spectral response of DMAPPDA. Molecular Docking studies revealed binding of the probe with in the hydrophobic cavity of subdomain IIA of HSA. MD Simulation supports greater stability of HSA–DMAPPDA complex compared to free protein.

A reduced Schiff base anionic receptor 1 [N,N'-bis-(2-hydroxy-5-nitro-benzyl)hydrazine] has been synthesized, characterized and reported as a selective chromogenic receptor for fluoride, acetate and phosphate anions over the other tested anions such as chloride, bromide, iodide and hydrogensulphite. Colorimetric naked-eye detection and UV-vis absorption spectroscopic techniques were used to distinguish the recognition behaviours towards various anions. The receptor-anion complexation mainly occurs via hydrogen bonding interactions which facile to generate the charge transfer band in the UV-vis spectra and cause large bathochromic shift as well as naked-eye colour change. Complexation stoichiometry, binding constant and free energy change due to complex formation were determined from Benesi-Hildebrand plot. The binding constant and the free energy change values are well interactive for spontaneous complexation. The experimental results have been correlated with the theoretical calculations using B3LYP hybrid functional and 6-311++G(d,p) basis set for both the receptor and complex by Density Functional Theory (DFT) method.

A molecule having ethylenediamine unit with symmetrically attached aromatic frames has been synthesized, characterized and reported as a highly selective and sensitive chemosensor for Zn2+ and Cd2+ ion. UV–vis absorption and fluorescence emission spectra, quantum yield calculation, fluorescence lifetime measurement and the observed stability constant of metal-sensor complex support 1:1 complex formation for both Zn2+ and Cd2+ ion with the sensor. Enhancement of large Stokes shifted (130 nm for Zn2+, 103 nm for Cd2+) and polarity dependent emission bands were observed for Zn2+ and Cd2+ ions, while other transition metal ions Cr3+, Fe2+, Ni2+, Co2+, Cu2+, Hg2+ quench the fluorescence emission of the sensor. Ratiometric displacement of Cd2+ ion from the complex by Zn2+ ion supports the formation of more stable sensor-Zn2+ complex over the sensor-Cd2+ complex. Scanning electron micrographs show different structural morphology of the complexes. The experimental findings have been correlated with theoretical results using B3LYP functional and 6−311++G(d,p), LANL2DZ basis set for sensor and metal ion, respectively, by Density Functional Theory (DFT) method.

Binding interaction of plasma protein bovine serum albumin (BSA) with external flexible charge transfer fluorophore 5-(4-dimethylamino-phenyl)-penta-2,4-dienenitrile (DMAPPDN) has been explored at physiological pH (7.4) by steady state absorption, emission, fluorescence anisotropy, Red Edge Excitation Shift (REES), far-UV circular dichroism (CD), time resolved spectral measurements in combination with molecular docking and molecular dynamics (MD) simulation studies. Chemical denaturation of the protein bound probe by guanidine hydrochloride (GdnHCl) has also been tracked using the spectral response of DMAPPDN. Interaction of the probe with BSA is reflected by the massive blue shift of the fluorophore emission maxima (78 nm) with the enhancement of fluorescence intensity due to change of hydrophobic micro-environment of the probe compared to a little change in protein secondary structure. Benesi–Hildebrand plot reveals spontaneous formation of 1:1 BSA–DMAPPDN complex with binding constant 8.821 ± 0.01 × 10 3 M −1 and binding free energy change −5.359 kcal mol −1 . Molecular docking study supports the binding of probe in the hydrophobic cavity of sub domain IIA of BSA. The distance for energy transfer from tryptophan of BSA to DMAPPDN measured from fluorescence resonance energy transfer (FRET) results is in good agreement with results of molecular docking study. MD simulation predicts greater stability of BSA–DMAPPDN complex compared to the free protein.

Test paper coated with reduced Schiff base 1, can selectively detect fluoride and acetate ions in aqueous medium. With such a drastic color change, detection can be achieved by just using the naked-eye, unaided by any optical instrument. Interestingly, the test paper can be re-used several times after washing with 3% HCl and distilled water respectively.

Photoinduced intramolecular charge transfer produced a polar excited state in trans-3-(4-monomethylaminophenyl)acrylonitrile (MMAPA), rendering the resulting emission sensitive to the medium polarity. Strong binding interaction of silver nanoparticles with the probe was observed, causing fluorescence quenching through the static quenching process. The probe MMAPA was found to bind to the less polar hydrophobic, restricted proteinous environment of bovine serum albumin (BSA) resulting in the blue shift of the emission maximum with an increase in emission intensity and fluorescence anisotropy. Studies using site markers of flufenamic acid and phenylbutazone coupled with molecular docking results predicted that the binding site of the probe is in between subdomains IIIA and IB of BSA and is different from the conventional Sudlow sites. The denaturation of the probe-bound BSA by urea or heat released the probe from this proteinous environment to water marked by exactly reverse spectral changes. On the interaction of silver nanoparticles with the probe bound protein, the probe was observed to move from its binding site in the protein to the Ag(0) nanoparticle surface involving conformational changes of the protein near the probe binding site.

A cleft-shaped receptor 1 was synthesized and its anion binding properties have been investigated. Receptor 1 can selectively recognize fluoride ion by naked-eye color change and UV-vis spectral changes in aqueous-acetonitrile solvent. The single crystal X-ray analysis of 1 with fluoride ion shows that there are two types of fluoride ions in the unit cell, one of which is pseudoencapsulated within the cleft-shaped cavity and the other type forms a dimer through [F2(H2O)3]2−fluoride-water cluster.

Unsymmetrical azine Schiff base 5-diethylamino-2-[(4-diethylamino-benzylidene)-hydrazonomethyl]-phenol (receptor 1) having multiple binding sites (–NEt2 and –OH group) have been synthesized. The receptor 1 exhibits color change from light yellow to purple and bright yellow in presence of Cu2+ ion and Fe3+ ion, respectively which is detectable by naked-eye. But it shows red color in presence of mixture of all metal ions. The UV–vis spectral investigation of receptor 1 shows a remarkable spectral shift from 410 nm to 527, 572 and 620 nm in presence of Cu2+ ion and 485 nm in presence of Fe3+ ion in acetonitrile solvent. Interestingly, Cu2+ ions generates a new charge transfer emission band at 532 nm in the expense of local emission of receptor at 480 nm, but Fe3+ ion only quenched the local emission. The spectral response of receptor is almost insignificant in presence of other metal ions (Mn2+, Zn2+, Co2+, Ni2+, Cd2+, Hg2+, Li+ and Na+ ions).

A symmetrical azine derivative, N,N′-Bis(imidazo[1,2-a]pyridine-2-ylmethylene hydrazine (sensor L) has been synthesized and its fluorescence sensing potential towards metal ions has been demonstrated using simple fluorometric technique. The sensor shows high fluorescence selectivity and high sensitivity towards Hg 2+ ion in aqueous-methanol media. Only Hg 2+ ion is found to effectively enhance fluorescence quantum yield of the nearly non-fluorescent sensor. The sensor can effectively distinguish Hg 2+ from Cd 2+ or Zn 2+ ion within the same group via different mechanistic pathway i.e. chelation enhanced fluorescence (CHEF) effect for Hg 2+ ion and charge transfer (CT) mechanism for Cd 2+ or Zn 2+ ion. Experimental spectral properties have been correlated with theoretical calculation based on Density Functional Theory method.

A Schiff base 2, composed with o-phenylenediamine and 5-nitro-salicylaldehyde have been synthesized as an anion receptor. It consists with conjugated imine, phenolic –OH and electron withdrawing substituent nitro (–NO2) group. Receptor 2 can recognize selectively biologically important F− and AcO− ions. The recognition properties have been investigated by naked-eye color change (colorless to yellow), followed by UV–vis spectral changes. Predicted stoichiometries of the complexes between receptor 2 and anions based on density functional theory (DFT) level calculations, corroborates well with experimental findings.

The photophysical properties of 5-(4-fluorophenyl)-2-hydroxypyridine (FP2HP) at different pH and its fluorescence response toward different transition metal ions have been studied by steady-state absorption and emission spectroscopy in combination with quantum chemical calculations. Although keto-enol tautomerization is observed in the excited state, the molecule is weakly fluorescent due to the presence of electron-rich nitrogen atom and relatively electron-deficient fluorine atom, which may lead to photoinduced electron transfer process. In the presence of the transition metal ions, such as Zn(2+) , Cd(2+) , Hg(2+) , etc., the studied molecule exhibits changes in its absorption and emission properties. The present system shows fluorescence enhancement instead of usual quenching in presence of the transition metal ions, such as Fe(2+) and Cu(2+) . Spectral observation leads to the interpretation that this structurally simple molecule can be effectively utilized as a chelation-enhanced fluorescence-based chemosensor for the detection of transition metal ions. The experimental findings corroborate well with theoretical calculations at Hartree-Fock level using 6-31G** and lanl2dz basis sets.

This review contains extensive application of anion sensing ability of salicylidene type Schiff bases and their reduced forms having various substituents with respect to phenolic OH group. Some of these molecular systems behave as receptor for recognition or sensing of various anions in organic or aqueous-organic binary solvent mixture as well as in the solid supported test kits. Development of Schiff base or reduced Schiff base receptors for anion recognition event is commonly based on the theory of hydrogen bonding interaction or deprotonation of phenolic -OH group. The process of charge transfer (CT) or inhibition of excited proton transfer (ESIPT) or followed by photo-induced electron transfer (PET) lead to naked-eye color change, UV-vis spectral change, chemical shift in the NMR spectra and fluorescence spectral modifications. In this review we have tried to discuss about the anion sensing properties of Schiff base or reduced Schiff base receptors.

The molecule methyl-2-aminonicotinate (2-MAN) does not exhibit excited state intramolecular proton transfer (ESIPT), but its derivative 4-amino-2-methylsulfanyl-pyrimidine-5-carboxylic acid ethyl ester (AMPCE), widely used in the preparation of pyrimidopyrimidines as a protein kinase inhibitor, does exhibit ESIPT. Increasing acidic and basic character at the proton donor and proton acceptor sites by adding functional groups is found to be responsible for the large Stokes shifted ESIPT emission (Δν = 12,706 cm(-1)) in AMPCE. The photophysics of AMPCE have been explored on the basis of steady state and time resolved spectral measurements, quantum yield calculation with variation of polarity, as well as hydrogen bonding ability of solvents. Experimental findings have been correlated with the calculated structure and potential energy surfaces based on the intramolecular proton transfer model obtained by density functional theory (DFT). Properties based on the calculated excited state surfaces generated in vacuo and methanol solvent using time dependent density functional theory (TDDFT) and time dependent density functional theory polarized continuum model (TDDFT-PCM), respectively, show good agreement with the experimental findings. HOMO and LUMO diagrams also support the favorable ESIPT process in the first excited state potential energy surface.

The interrelationship between flow of Foreign Direct Investment (FDI) and the volume of country's export has been a matter of controversy among economists for many decades. This study provides some empirical evidences on the short and long run dynamic relationship between FDI and Export of India for the period of 1996–97 to 2016–17. The result of Johansen's cointegration test suggests that there exist significant positive long-run comovement between the FDI and Export in India. Further, The Vector Error Correction Model and VEC granger causality test confirms a unidirectional long and short run causal relationship between these variables. In both the cases changes in export is found to be positively impacting FDI but the reverse is not found to be true. The study is highly expected to foster some basic understanding on the dynamic relationship between these variables and is targeted offer some practical insights for financial regulators and policy makers in formulating economic policies in India.

Photophysical properties of an anthracene derivative 9-methyl anthroate (9-MA) have been investigated using absorption and emission spectroscopy, in combination with quantum chemical calculations. Solvatochromic effects on the Stokes shifted emission band clearly demonstrate the highly polar character of the excited state, which is also supported by the enhancement of dipole moment of the molecule upon photoexcitation. The emission band has been found to be dependent on polarity and hydrogen-bonding ability of the solvents. Multiple linear regression analysis method has been utilized to rationalize the effect of hydrogen bonding interaction on the emissive state, which was further confirmed by the analysis of the non-radiative decay constants and urea induced H-bonding disruption study. The experimental results correlate well with theoretical predictions obtained via density functional theory (DFT).

The nature of binding of specially designed charge transfer (CT) fluorophore at the hydrophobic protein interior of human serum albumin (HSA) has been explored by massive blue-shift (82 nm) of the polarity sensitive probe emission accompanying increase in emission intensity, fluorescence anisotropy, red edge excitation shift, and average fluorescence lifetimes. Thermal unfolding of the intramolecular CT probe bound HSA produces almost opposite spectral changes. The spectral responses of the molecule reveal that it can be used as an extrinsic fluorescent reporter for similar biological systems. Circular dichrosim spectra, molecular docking, and molecular dynamics simulation studies scrutinize this binding process and stability of the protein probe complex more closely. © 2012 Wiley Periodicals, Inc. Biopolymers 97: 766–777, 2012.

were developed as materials witha set of well-defined properties, for example, porosity andmagnetism, porosity and electrical conductivity, or porosityand optical properties. This synergism, resulting from thecombinationoftwodifferentfunctionalities,opensupthewayto new multifunctional materials.In the last two years, a large number of porous covalentorganic frameworks were reported by different researchgroupsworldwideandtheyhaveshownthatinporousorganicmaterials (POMs) a degree of porosity can be achieved whichis higher than in MOFs.

A series of compounds with an amine based structural motif (ASM) have been synthesized for efficient atmospheric CO(2) fixation. The H-bonded ASM-bicarbonate complexes were formed with an in situ generated HCO(3)(-) ion. The complexes have been characterized by IR, (13)C NMR, and X-ray single-crystal structural analysis. ASM-bicarbonate salts have been converted to pure ASMs in quantitative yield under mild conditions for recycling processes.

Structural modification through binding interaction of plasma protein bovine serum albumin (BSA) with an extrinsic charge transfer fluorophore 5-(4-dimethylamino-phenyl)-penta-2,4-dienoic acid (DMAPPDA) and its response to external perturbation due to interactions with surfactant sodium dodecyl sulphate (SDS) have been explored at physiological pH by steady state absorption, emission, fluorescence anisotropy, red edge excitation shift, far-UV circular dichroism and time resolved spectral measurements in combination with Molecular Docking and Molecular Dynamics (MD) simulation. Interaction of the probe with BSA is reflected by a small change in protein secondary structure with fluorescence enhancement and blue shift of probe emission. Molecular docking studies revealed that the probe binds to the hydrophobic cavity of sub-domain IIA of BSA. The distance for energy transfer from the tryptophan of BSA to the bound DMAPPDA measured by Fluorescence Resonance Energy Transfer is in good agreement with the molecular docking results. MD simulation predicts stabilization of the complex with respect to the bare molecule. Interaction of BSA and SDS with DMAPPDA supports the movement of the probe from hydrophilic free water region to a more restricted hydrophobic zone inside the protein.

A donor acceptor substituted aromatic system 5-(4-dimethylamino-phenyl)-penta-2,4-dienoic acid (DMAPPDA) has been synthesized and its spectral properties have been explored on the basis of steady state absorption and fluorescence spectroscopy. Spectral features point largely towards a possible occurrence of photoinduced intramolecular charge transfer process from the donor NMe2 group to the acceptor acid group. Solvent dependency of the large Stokes' shifted emission band and the calculated large excited state dipole moment support the polar character of the charge transfer excited state. Quantum yield calculations and effect of addition of acid and base on the steady state spectra were also performed to further scrutinize the excited state CT character.