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In this work, 5‐SIDipp [SIDipp=1,3‐bis(2,6‐diisopropylphenyl)‐imidazolin‐2‐ylidene] (1) derived Chichibabin's hydrocarbon with an octafluorobiphenylene spacer (3) has been reported. The addition of two equivalents of 5‐SIDipp with decafluorobiphenyl in presence of BF3 gives the double C−F bond activated imidazolium salt with two tetrafluoroborate anions, 2. Further reduction of 2 gives the fluorine substituted 5‐SIDipp based Chichibabin's hydrocarbon, 3. Quantum chemical calculations suggested a singlet state of 3 with a singlet–triplet energy gap (ΔES‐T) of 3.7 kcal mol−1, which is substantially lower with respect to the hydrogen substituted NHC‐based Chichibabin's hydrocarbons (10.7 kcal mol−1, B3LYP). As a result, the diradical character (y) of 3 (y=0.62) is also noticeably higher than the hydrogen substituted CHs (y=0.41–0.43). The ▵ES‐T was found to be higher in CASSCF (22.24 kcal mol−1) and CASPT2 (11.17 kcal mol−1) for 3 and the diradical character (d) is 44.6 %. [ABSTRACT FROM AUTHOR]

• Post-synthetic hooking of photocatalyst Rose Bengal and organocatalyst L-proline in an amine functionalized POF. • The modified framework works in a highly synergistic manner as dual photo-organo catalyst. • The bifunctional catalyst works under environmentally green visible light and can be recycled up to 10 cycles. • The high yield of the products in C-H functionalization is maintained for a wide range of tertiary amine substrates. • Based on experimental findings, a plausible reaction mechanism for the oxidative Mannich reaction is proposed. Photoredox and organo-catalysis denote powerful construction tools for new classes of carbon–carbon bonds, where incisive amalgamation of both the approaches over a single, recyclable platform can bring about synergic and eco-friendly reactions under mild conditions. Aiming at enamine-based photoredox catalysis for atom-economic and metal-free sp3 C H activation, an amide-based two-dimensional (2D) porous organic framework (POF) is devised. The pendent NH 2 groups are judiciously anchored with two catalytic stations viz. Rose Bengal and L-proline, through stepwise variation of solid phase peptide synthesis. The dual-catalyst engineered POF represents a fully organic material that synergistically performs visible-light triggered oxidative Mannich reaction to produce biorelevant heterocycle β-amino ketone in excellent yield at room temperature, using oxygen as clean and selective oxidant. Importantly, activity of this bi-functionalized catalyst compares favorably well to individual homogeneous counterparts. The covalently modified framework demonstrates economic viability via gram-scale synthesis besides admirable reusability, and proves to be effective for nineteen varieties of substrates. The photocatalytic path is detailed from efficient energy transfer from host polymer to substrate in light of experimental and theoretical studies, which provides proof-of-concept to the photo-organo combined mechanism. The material benefits heterogenising two homogeneous catalysts, besides excluding additional steps of conventional Mannich reactions, and offers a step-forward to smart and green cross-dehydrogenative coupling reactions. [ABSTRACT FROM AUTHOR]

The synthetically modified green fluorescent protein chromophore analogue 3,4,5‐trimethoxybenzylidene imidazolinone (1) yielded five polymorphs (I, II, III, IV, V) concomitantly irrespective of the solvent used for crystallization. The pentamorphic modification of 1 is solely due to the interplay of iso‐energetic weak intermolecular interactions in molecular associations as well as the conformational flexibility offered by a C—C single bond, which connects the electron‐deficient moiety imidazolinone with the electron‐rich trimethoxybenzylidene group. A common structural feature observed in all the polymorphs is the formation of a 'zero‐dimensional' centrosymmetric dimeric unit through a short and linear C—H...O hydrogen bond engaging phenyl C—H and imidazolinone carbonyl oxygen. However, the networking of these dimeric units showed a subtle difference in all the polymorphs. The 2D isostructurality was observed between polymorphs I, II and III, while the other two polymorphs IV and V revealed only 'zero‐dimensional' isostructurality. The different fluorescence emissions of Form I (blue) and Forms II to V (yellow) were attributed to the differences in π‐stacking interactions. It shows that one can modulate the photophysical properties of these smart materials by slightly altering their crystal structure. Such an approach will aid in developing new multi‐colour organic fluorescent materials of varying crystal structures for live‐cell imaging and fluorescent sensing applications. [ABSTRACT FROM AUTHOR]

An oxidovanadium(V) complex [VO(SGly)(bpy)]ClO4 (H2SGly=N‐(2‐hydroxybenzyl)‐L‐glycine; bpy=2,2′‐bipyridine) was synthesized and characterized by spectroscopic studies (IR, UV‐vis, ESI‐MS). The theoretical structure of the complex was optimized by density functional theory (DFT) calculations. The multifunctionality of this oxidovanadium complex was demonstrated by the application of it as a catalyst in peroxidative bromination of single‐pot conversion of phenol red to bromophenol blue, whereas its nuclease activity was established by DNA cleavage. The interaction of this oxidovanadium complex with DNA was studied by various physicochemical tools like UV‐vis, fluorescence, and viscosity measurement studies. The intrinsic binding constant of the complex with DNA was determined spectrophotometrically and calculated to be (2.3 ± 0.02) x 104 M−1. The spectroscopic studies and the viscosity measurements indicate that the complex binds to the groove of CT‐DNA, but whether to the major or minor groove that was not established. The extent of vanadium complex induced DNA cleavage was studied by gel electrophoresis techniques. The complex was found to promote cleavage of pUC19 plasmid DNA from the super coiled (SC DNA) form I to nicked coiled (NC DNA) relaxed form II. [ABSTRACT FROM AUTHOR]

This paper describes the rare use of a 6‐membered saturated N‐heterocyclic carbene (NHC) known as 1,3‐di(2,6‐diisopropylphenyl) tetrahydropyrimidine‐2‐ylidene (abbreviated as 6‐SIDipp) as a ligand in zinc chemistry. We report on the investigation of the reactions between 6‐SIDipp and ZnX2, which resulted in a range of new monomeric 6‐SIDipp⋅ZnX2 complexes (X=Et (1), Cl (2), Br (3), and I (4)). We also prepared a new NHC zinc complex where the two substituents of the zinc atom are different, 6‐SIDipp⋅Zn(Et)Br (7) through the reaction of the proligand [6‐SIDippH]Br with ZnEt2. We have observed that the reactions of complex 1 with sulfur and HBpin led to the removal of the ZnEt2 moiety, resulting in the formation of a C=S double bond and a B−H activation product, respectively. Lastly, the reaction of 1 with five‐membered NHCs led to the exchange of carbene and the formation of either 5‐IDipp⋅ZnEt2 (8) or 5‐SIDipp⋅ZnEt2 (9). [ABSTRACT FROM AUTHOR]

Designing of two dimensional surfaces and interfaces with light-active materials has been established as a versatile approach to increase their photocatalytic activity. In the present work, n-type anatase TiO 2 coupled with p-type B-doped g-C 3 N 4 nanosheet (BCN) were fabricated and Au-Cu nanoalloy with varying atomic ratio were deposited on the p-n heterojunction. The incorporation of Au-Cu on the interface of the dyad enhances light absorption over broad regime, charge separation, and migration. Au-Cu with 1:1 ratio (with an average particle size of 1.2 nm) loaded p-n hetrojunction (TBCAC-1:1) shows excellent photocurrent enhancement (approximately 4.4-folds) in the cathodic direction as compared to their monometallic plasmonic counterpart. Additionally, the catalyst shows photocurrent at zero biased potential as well as lower onset potential as compared to the other alloy. TBCAC-1:1 photocatalyst could able to produce 2150 μmol h−1g−1 of hydrogen, which is (approximately 3-folds) as compared to their monometallic counterparts. The hydrogen evolution process for Au-Cu (1:1) system was found to be governed by the charge distribution which dictates the binding preference of the Au and Cu sites leading to the water splitting as investigated by DFT calculation. The excellent hydrogen generation by the photocatalyst links to the synergistic effect between Au and Cu associated with the hot electron photochemistry due to surface plasmon resonance phenomenon. Hot electron mediated H 2 generation by a plasmonic TiO 2 /BCN/Au-Cu photocatalyst [Display omitted] • n-type TiO 2 with p-type B-doped g-C 3 N 4 nanosheet (BCN) were fabricated and Au-Cu nanoalloy were deposited on it. • Au-Cu on the interface of the dyad enhances light absorption over broad regime, charge separation, and migration. • Au-Cu with 1:1 ratio loaded p-n hetrojunction (TBCAC-1:1) shows excellent photocurrent enhancement in the cathodic direction as compared to other. • TBCAC-1:1 produced 2150 μmol h-1g-1 of hydrogen (approximately 3-folds) as compared to monometallic counterparts. • The hydrogen evolution process is governed by the charge distribution between Au and Cu sites investigated by DFT calculation. [ABSTRACT FROM AUTHOR]

Herein, we report two 2,2′-pyridylpyrrolide (PyPyrH) ligand supported magnesium complexes (1 and 2), which demonstrate bright luminescence with a quantum yield of 22% and 14% in the solid state, respectively. Theoretical calculations reveal that their emissive properties originate from the intra- and inter-ligand charge transfer. [ABSTRACT FROM AUTHOR]

In this work, naphthalimide derived functionalized silica material SiO 2 @NAPIA (2,2'((((propylazanediyl)bis(methylene))bis(2,1-phenylene))bis(oxy))bis(N-(1,3-dioxo-1H-benzo[de]isoquinoline-2(3H)-yl)acetamide)) was constructed as a dual signaling and remediation material for ferric ions from a pool of 35 common ions (cations and anions) in the aqueous system. The material Cubic SiO 2 shows a high surface area (1104 m2/g, pore volume (1.510 cm3/g), and pore diameter (6.3 nm) in the mesoporous range, which reduces further on functionalization to get the final material SiO 2 @NAPIA. The ferric ion selectivity through fluorescence quenching displays a Stern-Volmer quenching constant (K sv) of 7.8 × 108 M−1 with a LOD (Limit of detection) value of 0.11 μM for ferric-ion, which is 48 times lower than the USEPA (United States Environmental Protection Agency) maximum contaminant level (5.35 μM) in drinking water. This material also shows a very high adsorption capacity (664 mg/g) for ferric ions fitting the Langmuir model isotherm with R2 = 0.99, which can be easily stripped out, and the material can be recycled. This material was also used as a sensory probe material for biosensing of ferric ions through fluorescence imaging in living organisms like Artemia salina and quantification in the real environmental sample. Furthermore, the antibacterial activity inspired by the ferric ion chelating affinity shows good potency against several Gram-negative and Gram-positive bacterial strains. The Minimum Inhibitory Concentration (MIC) & Minimal Bactericidal Concentration (MBC) of the material against these pathogens were found to be 100 & 200 μg/mL respectively. This material signifies superior activity with respect to the ferric-ion selective materials known in the literature. This work discloses a new functionalized material showing exceptional selectivity towards ferric ions in the presence of several cations & anions with a LOD value 48 times lower than the USEPA maximum contaminant level in drinking water. The very high adsorption capacity, recyclability, quantification in the real sample, biosensing, and antibacterial activities shows its superior performances as a single platform. [Display omitted] • A fluorophore appended new functional material constructed to derive the dual functions of sensing and removal of the ferric ion with recyclability of the material. • The solid support, Cubic silica, was synthesized by an improved Stober process, where the ammonia concentration and the aging temperature were kept at the higher side to afford regular-sized cuboid mesoporous silica with improved surface area and pore size. • The material shows exceptional selectivity towards ferric ion with a very low limit of detection (LOD) and very high adsorption capacity. • This material was also used as a biosensing probe to detect the ferric ion in living organisms like artemia salina through fluorescence imaging. • Furthermore, this material with ferric ion chelating properties also shows antibacterial activities against both gram positive & negative bacterial strains. [ABSTRACT FROM AUTHOR]

A glycerol‐triazole tethered rhodamine based colorimetric and fluorimetric sensor 3′,6′‐bis(diethylamino)‐2‐(((1‐(1,3‐dihydroxypropan‐2‐yl)‐1H‐1,2,3‐triazol‐4‐yl)methylene)aminospiro [isoindoline‐1,9′‐xanthen]‐3‐one (L1) is designed and synthesized for the selective recognition of Cu2+ ion. The sensor L1 allows naked eye detection of Cu2+ ion with a fast response (<1 min). Among the various metal ions tested, the sensor L1 shows selective binding with Cu2+ through turn‐on fluorescence mechanism. The sensor shows 1 : 2 binding stoichiometry with binding constant, Ka=1.1×106 M−2 as revealed by job's plot & Benesi‐Hildebrand plot (B−H plot), respectively. The detection limit of L1 with Cu2+ ion is found to be 3.3 μM. Further, the experimental results are also validated using density functional theoretical (DFT) study. The optimized geometries indicates that the formation of the L1‐Cu2+ complex is thermodynamically favourable by ΔG=−11.7 kcal/mol. The HOMO‐LUMO gap of the ligand L1 is found to be 3.49 eV, which decreases to 1.76 eV upon complexation with copper. [ABSTRACT FROM AUTHOR]

Aluminum metal pollution is considered as a primary limiting factor that reduced crop yield in South Asian subtropical country like India. In national context, Odisha contributes around more than 40% of total ore availability. Moreover, industrial mining and smelting aid are major concern for aluminum metal toxicity in territorial vicinity affecting the soil fertility, ecosystem and human health through food chain. The aluminum metal accumulation limits the soil fertility by antagonistic regulation of photosynthetic and nitrogen fixing microbiota. The increasing concern regarding aluminum pollution enterprise critical investigations for their bioremediation in contamination sites. In this notion, the current study was hypothesized to decrypt the rate limiting factors, their explicit mode of action and intracellular detoxification in a cyanobacterium, i.e., Westiellopsis prolifica isolated from ash pond of NALCO (National Aluminum Company Limited), Angul, Odisha. In the experimental setup, treatment with different concentrations of AlCl3 (0–0.1 mM) was marked a decline in the growth of the strain due to the adverse regulation of photosynthetic pigments. However, the enforcement of catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD), guaiacol peroxidase (GPX) and glutathione reductase (GR) was critical for sustaining strain viability under oxidative imbalance. The observation of an increase in the antioxidant enzyme and MDA content was evident to sustain strain viability under such oxidative imbalance. The outcome of the anticipated study was apparent to demonstrate a colossal interlink between Al mediated induction of oxidative stress and their cellular detoxification via intracellular antioxidant enzymes and removal of H2O2 accumulation in cyanobacterium, W. prolifica. Aluminum metal toxicity renders growth of Westiellopsis prolifica via affecting photosynthesis associated pigments. Westiellopsis prolifica deploys antioxidant defense enzymes to combat against aluminum mediated oxidative upset. Intracellular antioxidant enzymes provoke cellular survival of Westiellopsis prolifica under excessive uptake of aluminum in contaminated habitats. [ABSTRACT FROM AUTHOR]

Fucoidan is a complex polysaccharide (molecular weight 10,000–100,000 Da) derived from brown algae which comprises of L-fucose and sulfate groups have potential as therapeutic diligences against several human diseases. The fucoidan has expanded a widespread range of pharmacological properties as an anti-inflammatory, anticoagulant, antiangiogenic, immunomodulatory, anti-adhesive, anticancer, antidiabetic, antiviral and anti-neurodegenerative agents owing to their diverse chemical conformation and potent antioxidant activity. The antioxidant and immunomodulatory activities of the fucoidan contribute towards their disease preventive potency through dynamic modulation of key intracellular signalling pathways, regulation of ROS accumulation, and maintenance of principal cell survival and death pathways. Additionally, it also reduces cancer-associated cachexia. Despite the wide range of therapeutic potency, the fucoidan is heavily regarded as an unexplored plethora of druggable entities in the current situation. The isolation, screening, biological application, pre-clinical, and clinical assessment along with large scale cost-effective production remain a foremost task to be assessed. Moreover, the chemical synthesis of the present bioactive drug with confirmational rearrangement for enhanced availability and bioactivity also need tenacious investigation. Hence, in the present review, we give attention to the source of isolation of fucoidan, their principle strategic deployment in disease prevention, and the mechanistic investigation of how it works to combat different diseases that can be used for future therapeutic intervention. [ABSTRACT FROM AUTHOR]

In this paper, we have used two N,O‐ketiminato ligands (L1 and L2) with biphenyl and terphenyl substituent on the nitrogen atom. Deprotonation of L1 with KN(SiMe3)2 and subsequent reaction with MgI2 led to a homoleptic dinuclear magnesium complex (1) with a Mg2O2 four‐membered ring. Deprotonation with nBuLi and subsequent reaction with MgI2 afforded a unusual dinuclear magnesium complex (2) with a Mg2O2 ring. Extension of the ligand for calcium resulted in a trinuclear calcium complex (3) with six four‐membered Ca2O2 rings. We could not isolate any chelating complex when L2 was used as a ligand, and only oxygen bound magnesium (4) and calcium (5) adducts were isolated. DFT studies were performed to understand this dissimilar behavior. More diverse results were obtained when lithiated L1 and L2 were treated with germanium dichloride. We were able to stabilize a monomeric germylene monochloride (7) with L1. However, with L2, an unusual ligand scrambling, and a C−C coupling take place, leading to the formation of a secondary carbocation with GeCl3‐ as a counter‐anion (8). Besides, a germanium dichloride adduct (9) bound to the oxygen center of the ligand was obtained as the minor product. [ABSTRACT FROM AUTHOR]