Poly(ethylene glycols) (PEGs) and room-temperature ionic liquids (ILs) are both projected as possible alternatives to volatile organic compounds (VOCs). Their potential usage in chemical applications, however, is often hampered by their limited and, in some cases, undesired individual physicochemical properties. Properties of mixtures of PEG with a common IL 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) are assessed via responses of three fluorescence probes: pyrene (Py) and pyrene-1-carboxaldehyde (PyCHO) are the dipolarity sensing probes and 1,3-bis-(1-pyrenyl) propane (BPP) is the probe for microfluidity. All three probes demonstrate anomalous fluorescence behavior within the mixture of [bmim][PF6] with four different PEGs of average molecular weight (MW) 200, 400, 600, and 1500 g.mol−1, respectively, across complete composition range. Cybotactic region dipolarity of the probe Py within the mixtures is observed to be higher than that expected from ideal additive behavior. PyCHO lowest energy fluorescence maxima implying the static dielectric constant around the cybotactic region shows values within the mixtures to be even higher than that in neat PEG, the component having higher static dielectric constant of the two, clearly indicating the milieu to have anomalously high dipolarity. "Hyperpolarity" inherent to the PEG + [bmim][PF6] mixture is confirmed. Intramolecular excimer-to-monomer fluorescence intensity ratio of BPP indicates the microfluidity within the mixture to be even lower than that within neat [bmim][PF6], the component with lowest microfluidity. Presence of strong solvent−solvent interactions within the mixture is proposed to be the major reason for the anomalous fluorescence probe responses. Specifically, extensive hydrogen-bonded network involving termini hydroxyls of PEGs and PF6− as well as ethoxy/hydroxyl oxygens of PEGs and the C2−H of bmim+ is proposed to be responsible for the unusual outcomes. Fluorescence probe responses are shown to be adequately predicted by a four-parameter simplified combined nearly ideal binary solvent/Redlich−Kister (CNIBS/R-K) model. Unusually altered physicochemical properties are demonstrated to be the key feature of the "hybrid green" PEG + IL systems.
Hybrid "green" solvent systems composed of room-temperature ionic liquids (ILs) and poly(ethylene glycols) (PEGs) may have enormous future potential. Solvatochromic absorbance probe behavior is used to assess the physicochemical properties of the mixture composed of IL 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF(6)]) and PEG (average molecular weights of 200, 400, 600, and 1500) at ambient conditions. Lowest energy intramolecular charge-transfer absorbance maxima of a betaine dye, i.e., E(T)(N), indicates the dipolarity/polarizability and/or hydrogen-bond donating (HBD) acidity of the [bmim][PF 6] + PEG mixtures to be even higher than that of neat [bmim][PF(6)], the solution component with higher dipolarity/polarizability and/or HBD acidity. Dipolarity/polarizability (pi*) obtained separately from the electronic absorbance response of probe N, N-diethyl-4-nitroaniline shows a trend similar to E(T)(N ) thus confirming the unusually high dipolarity/polarizability of the [bmim][PF(6)] + PEG mixtures. Similar to E(T)(N ) and pi*, the HBD acidity (alpha) of [bmim][PF(6)] + PEG mixtures is also observed to be anomalously high. Contrary to what is observed for E(T)(N ), pi*, and alpha, the hydrogen-bond accepting (HBA) basicity (beta) of the [bmim][PF(6)] + PEG mixtures is observed to be lower than that predicted from ideal additive behavior indicating diminished HBA basicity of the mixture as compared to its neat components. A four-parameter simplified combined nearly ideal binary solvent/Redlich-Kister (CNIBS/R-K) equation is shown to satisfactorily predict the solvatochromic parameters within [bmim][PF(6)] + PEG mixtures. It is demonstrated that [bmim][PF(6)] + PEG mixtures possess physicochemical properties that are superior to those of either the neat IL or the neat PEG.
A hybrid, potentially green solvent system composed of tetraethylene glycol (TEG) and the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF(6)]) was investigated across all mole fractions with regard to the solvent properties of the mixture. For this purpose, a suite of absorbance- and fluorescence-based solvatochromic probes were utilized to explore solute-solvent and solvent-solvent interactions existing within the [bmim][PF(6)] + TEG system. These studies revealed an interesting and unusual synergistic solvent effect. In particular, a remarkable "hyperpolarity" was observed in which the E(T) value, comprising dipolarity/polarizability and hydrogen bond donor (HBD) acidity contributions, at intermediate mole fractions of the binary mixture well exceeded that of the most polar pure component (i.e., [bmim][PF(6)]). Independently determined dipolarity/polarizability (pi*) and HBD acidity (alpha) Kamlet-Taft values for the [bmim][PF(6)] + TEG mixtures were also observed to be anomalously high at intermediate mole fractions, whereas hydrogen bond acceptor (HBA) basicities (beta values) were much more in line with the ideal arithmetic values predicted on a mole fraction basis. Two well-established fluorescent polarity probes (pyrene and pyrene-1-carboxaldehyde) further illustrated notable hyperpolarity within [bmim][PF(6)] + TEG mixtures. Moreover, the steady-state fluorescence anisotropy of the molecular rotor rhodamine 6G and the excimer-to-monomer fluorescence ratio exhibited by the fluidity probe 1,3-bis-(1-pyrenyl)propane demonstrated that solute rotation and microfluidity within the [bmim][PF(6)] + TEG mixture were significantly reduced compared with expectations based on simple solvent mixing. A solvent ordering via formation of HBD/HBA complexes involving the C-2 proton of the [bmim(+)] cation and oxygen atoms of TEG, as well as interactions between [PF(6)(-)] and the terminal hydroxyl groups of TEG, is proposed to account for the observed behavior. Further spectroscopic evidence of strong intersolvent interactions occurring within the [bmim][PF(6)] + TEG mixture was provided, inter alia, by substantial frequency shifts in the [PF(6)(-)] asymmetric stretching mode observed in the infrared spectra as TEG was incrementally added to [bmim][PF(6)]. Overall, our observations contribute to a growing literature advocating the notion that ionic liquids and certain organic solvents form ordered, nanostructured, or microsegregated phases upon mixing.
The harmful effect of acid deposition is considered as one of the most serious environmental problems in the modern world. It has reached alarming proportions mainly in the industrialized countries which affected global ecology vastly. Acid rain creates several health problems to the human body like eye, nose, and throat irritations, lung disorders such as dry coughs, asthma, headaches, and bronchitis. The excessive presence of sulfur dioxide and oxides of nitrogen in rainwater is the main reason behind acid rain. Emissions of these gases have increased in the atmosphere due to human activities, such as combustion of fossil fuels in thermal power plants, burnable wastes, automobiles and airplanes etc. To reduce and protect the world from acid rain it is necessary to identify the causes and find suitable strategies for the eradication of those causes. Probable remedies for the reduction of acid deposition have been discussed here for the welfare of global ecology.
: Ionic Liquids (ILs) in their neoteric form have emerged to be a potential ‘green’ alternative to traditional Volatile Organic Compounds (VOCs) as solvents in different fields of industries and academia. Recent investigations on the development of multi-faceted applications of ionic liquids have revealed that they really stand for “environmentally-benign” solvents as far as their impact on the ecology is concerned. This caused them to be an exciting and lucrative subject to explore more and more, and many research groups are involved in the manifestation of their inherent undisclosed legacy. Recently, there has been a huge jump in search of an alternative to conventional metal catalysts in academia as well as in industries due to their pollution-evoking roles. Scientists have explored multiple numbers of homogeneous or heterogeneous mixtures of catalysts incorporating ionic liquids to reduce the extent of contamination in our global environment produced due to catalytic synthesis and chemical transformations. In this review, we have put our concentration on some beneficial and recently explored aspects of the successful implementation of Ionic Liquids in different forms in several fields of catalysis as a ‘green’ alternative catalyst/co-catalyst/solvent for catalysis to replace or minimize the lone and hazardous use of metal and metallic compounds as catalysts as well as chemicals like mineral acids or VOCs as solvents. Here, our study focuses on the inevitable role of ILs in several catalytic reactions like cycloaddition of CO2, electrolytic reduction of CO2, biocatalytic or enzymatic reactions, some of the important organic conversions, and biomass to biofuel conversion as catalysts, cocatalysts, catalyst activator, and solvents.
The developmental process in the field of chemical and biological sciences is continuously undergoing changes in search of further developments in efficiency, productivity, and profitability.Information-guided design strategies and tools could unveil the creativity of a wide range of scientists and engineers by combining expertise from implementation.This book "Modern Approaches in Chemical and Biological Sciences" discusses ways to promote the developing academic paradigm of the chemistry-biology continuum to advance this discovery and developmental process.Through a series of chapters this book tries to identify significant areas and opportunities in chemical biological sciences.The different chapters of this book are contributed by different authors.The articles discuss about ionic liquids as the appropriate replacement for the Volatile Organic Compounds (VOCs) in the industrial and academic sectors as the solvents.The gradual probe desolvation may be another cause for thermosolvatochromism.Determining the structure of small molecule like environment sensitive fluorophoresare is enormously important in bio-chemical and bio-physical research.In this chapters the researcher tries to find out the synthesis and photo-physical studies of a new family of fluorophores with keto-tetrahydrocarbazole (KTHC) framework.Photophysics of such fluorophores have been thought-provoking up to now.Such studies will therefore help to determine this new family of fluorophores as a potential biomarker.Antibiotic resistance is a growing public health issue that may lead to epidemics of drugresistant bacterial species.So researchers tries to review the synthesis of ruthenium complexes with 2,3,5,6-tetrakis-(2-pyridyl)pyrazine (tppz) ligand to make its application easy.The biological application of ruthenium has augmented in the past few years, particularly after the understanding of the important of this bioactive metal as anticancer, antimicrobial, and antiviral agent.Hypervalent iodine reagents have been used extensively in numerous oxidative transformations in organic synthesis due to their low toxicity, commercial accessibility, ease of handling and being environmentally friendly.The unique desulfurizing abilities of hypervalent iodine reagents have put forward a significant green synthetic device to synthesize a varied range of nitrogen containing bioactive heterocycles with a diverse application in medicinal chemistry.Organic-inorganic hybrid fluorescent materials are getting immense attention in the scientific community and the industry due to their high performance and multifunctionality for numerous applications.Significant use of this novel materials includes high specific surface area, particularly well-controlled size, homogeneous distribution, and strong attachment to the interfacial surfaces.Researcher have prepared novel fluorescent organic-inorganic hybrid MCM-41 type materials, characterized for the detection of nitroaromatic explosives.C-reactive protein (CRP) is a substance produced by the liver in response to inflammation.It is a highly conserved plasma homopentameric acute-phase inflammatory protein.Previously it was only considered to be a biomarker for inflammation.But now the future prospect shows the applicability of CRP molecule in diagnosis and monitoring of disease biology.Rumen flukes causes pathogenic disease of domesticated ruminants, causing massive economic loss in dairy industry and meat production.It is regarded as a neglected tropical disease with maximum prevalence all over tropical and subtropical regions.A study on the medicinal plant Justicia adhatoda reported noteworthy anthelmintic effect in traditional procedure and was found to be anti-cestoidal activity against Paramphistomum sp.More studies are required based on the viability assays of these pathogens.Climate change includes changes in environmental conditions which will disturb the distribution and biological performance of species.Worldwide patterns of marine biodiversity are immensely driven by ocean temperature.Global warming and acidification lessen the chances of survival of certain species of fish.Every developed and developing countries should decrease CO release to save marine biodiversity from altering the 2 environment of the sea water.Sex determination, in contrast to numerous developmental procedures, is considered by a lack of conservation throughout the vertebrates.The Nile tilapia, a gonochoristic teleost fish with an XX/XY sex-determining system, offers an excellent prototype for studying gonadal sex differentiation because genetic all-females and all-males are available.Different expression outline of miRNA was observed during development of testis and ovary which determine their role in the controlling the ovarian and testicular development and function.The adaptive immune system (AIS) is captivating to both scientists and laymen.The AIS is specific yet immensely varied system that can combat innumerable pathogens and has a 'memory' that allows a quick response to pathogens encountered earlier.Many questions still need to be addressed in the field of Immunology, Evolutionary biology.Genetics and Molecular biology have presented deep understandings into the latest developments in this field and speculated the selective pressures that led to the development and conservation of the AIS.This book elucidates new information, advances and outlook in research in chemical and biological sciences.This array of chapters facilitates exchange of ideas and tries to answer many current necessity and future perspective in different interdisciplinary research problems.
Limitations of the properties of water, the most common 'green' solvent, may be overcome by adding small amounts of ionic liquids (ILs). Important physical properties, such as density, viscosity and refractive index, of dilute aqueous IL 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF6) are shown to be significantly different than those of pure water at different temperatures. Up to 2.00 wt% bmimPF6 behaves like a strong electrolyte in water. Solvatochromic absorbance probe investigation indicates sensitive spectral behavior of a water-soluble betaine dye upon bmimPF6 addition to water. With considerably modified physicochemical properties, dilute aqueous IL solutions may find use in a variety of chemical applications.
'%3e%3ccircle r='20' fill='%23008'/%3e%3ccircle r='17.5' fill='%23fff'/%3e%3ccircle r='3.5' fill='%23008'/%3e%3cg id='d'%3e%3cg id='c'%3e%3cg id='b'%3e%3cg id='a' fill='%23008'%3e%3ccircle r='.875' transform='rotate(7.5 -8.75 133.5)'/%3e%3cpath d='M0 17.5.6 7 0 2l-.6 5L0 17.5z'/%3e%3c/g%3e%3cuse xlink:href='%23a' transform='rotate(15)'/%3e%3c/g%3e%3cuse xlink:href='%23b' transform='rotate(30)'/%3e%3c/g%3e%3cuse xlink:href='%23c' transform='rotate(60)'/%3e%3c/g%3e%3cuse xlink:href='%23d' transform='rotate(120)'/%3e%3cuse xlink:href='%23d' transform='rotate(-120)'/%3e%3c/g%3e%3c/svg%3e)
