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Suitable functionalization on Si94− Zintl core makes superhalogen nona-silicide cluster.

Herein a successful chemoselective either functionalization of the nucleophilic sites of prolinol by exploiting the relative acidity difference and inverted nucleophilicity of the corresponding conjugate bases, employing a suitable base is reported. An elaborate investigation into the overlooked sensitivity of reaction conditions to a highly utilized protocol has been reported. As an example, mono-Boc functionalization of prolinol for the exclusive synthesis of either NBoc/OBoc/Oxazolidinone derivatives is reported. Failing to emulate the former protocols, a mechanistic investigation was initiated which revealed that the rudimentary steps can be controlled by: a) a requisite base to recognize the differently acidic sites (NH and OH) for the formation of the conjugate base reacting to the electrophile, b) the disparity in nucleophilicity of the completely formed conjugate basic sites. This protocol has been extended to be successful with various other substrates, which might prove to be applicable as suitable catalysts in asymmetric reactions. Never-reported-before substrates such as O-Boc, O-CBz, O-Bz and O-ethyl carbonate derivatives of prolinol were synthesized in good to excellent yields along with other substrates.

In quest of a Zintl ion-based Lewis superacids, Al(Ge9L3)3 {L= H, CH3, CHO and CN} compounds have been designed and their properties have been studied within the framework of conceptual density functional theory-based reactivity descriptors. Superacid property has been identified for these complexes as per the fluoride ion affinity (FIA) values. Studies reveal that Al[Ge9(CN)3]3 and Al[Ge9(CH3)3]3 behave like superacids as their FIA exceeds the value of SbF5, which is considered as the strongest Lewis acid. It has been observed that the ligand plays an important role in reactivity as well as in Lewis acidic property.

India has a wide range of agro climates and soil types. The highly diverse agriculture and farming systems are beset with different types of weed problems. Weeds reduces 10-80% crop yield, impairing, product quality and causes health and environmental hazards. Weeds are a major constraint to agriculture, forestry and aquatic environment. A field experiment was laid out at Crop Research Station, Ghaghraghat, (ANDUAT), Bahraich, U.P. to evaluate long term trial on weed dynamics in mono or double cropped rice system under different establishment methods. The treatments consisted of 3 main plots M1 – Mechanised planting/transplanting, M2 – Puddled direct seeding, M3 – Unpuddled dry direct seeding and four sub plots T1 – Weed free, T2 – Weedy check, T3 – Mechanical weeding using weeder and T4 – Chemical weed control of pre and post emergence herbicide application. NDR 359 medium duration rice variety was sown in spilt plot design with three replications. The results revealed that the grain yield loss was found 3.22% in mechanical weeding using weeder followed by chemical weed control (pre & post emergence herbicide application) 15.96%. The highest grain yield was found in weed free of M1 –Transplanting, (4.08 t/ha) followed by M2 – Puddled direct seeding (3.22t/ha). The study showed that yield of rice increased under transplanting along with mechanical weeding using weeder.

Submergence is a major threat in rice growing areas of South and South-East Asia. Investigation were undertaken at Crop Research Station, (ANDUAT) Ghaghraghat, Bahraich during 2018 and 2019 under AICRIP experiment to study the performance of deep water rice line NDGR 706 for submergence, yield and yield characters under the agro-ecological conditions of Eastern Uttar Pradesh. The experiment was laid out in Split Plot Design (SPT) with having three replications. The mean value of survival % of NDGR 706 (85%) compared to national check (65%), regional check (73%) and local check (75%). The mean value of grain yield kg/ha was recorded maximum was NDGR 706 (3093 kg/ha) compared to national check CR Dhan 500 (2167 kg/ha), regional check Dinesh (2486 kg/ha) and local check Jal Nidhi (2138kg/ha). The increase yield over check of CR Dhan 500, Dinesh and Jal Nidhi (42.73, 24.41 & 44.67%). The mean value of plant height of NDGR 706 was 176 cm, days to 50% flowering 119. Highest number of panicle/m2 was observed of NDGR 706 (200) compared to national check, regional check and local check 175,175 and 151. NDGR 706 can be used as commercial cultivars in deep water rice of Uttar Pradesh.

Field experiment was carried out to assess the influence of various levels of NPK fertilizers (F1: 50-30-20 & F2: 100-60-40 kg/ha) on yield 5 new rice cultures namely IET 26767, IET 26803, IET 26477, IET 24914, IET 25713 and 4 national checks (Sahbhagi, Varalu, NDR 97 and Govind) and one local check (Shushk Smart) in split plot design with three replications at Crop Research Station, (ANDUAT), Masodha, Ayodhya. Results revealed that application of the highest grain yield was recorded with IET 25713 (4.87 t/ha). At higher level of RDF i.e. 150% followed by IET 26477 (4.55 t/ha). The increase level of NPK increase up to (150% RDF). The highest grain yield was recorded at 150% RDF/ha (3.84 t/ha). The lowest grain yield was recorded with recommended level of RDF (100%/ha) (3.69 t/ha). Shabhagi dhan recorded lower mean grain yield of RDF and higher level of RDF.

To evaluate the suitable and promising irrigation management practices in different crop establishment methods, Field experiment was carried out Crop Research Station, (ANDUAT), Masodha, Ayodha. To assess the agronomic efficiency, plant water potential and water use efficiency under irrigation management practices along with Split plot design was adopted with 3 main plots of irrigation management {i1: Flooding throughout crop growth (3 +/- 2 cm), i2: Saturation maintenance up to PI and (3 +/- 2 cm) after PI and i3: Alternate wetting and drying (irrigation at 5-7 days interval with 5 cm/ha of water (5 cm irrigation at 3 DADPW) up to PI and (3 +/- 2 cm) after PI} and 6 subplots of crop establishment methods {T1: Mechanical Transplanting method on puddled soil (crop management methods same as for puddled transplanted rice), T2: Direct wet seeding on puddled soil (Use of Drum seeder/ dibbling of sprouted seed at 25 x 25 cm) fb crop management practices as per direct wet seeded rice, T3: Normal hand transplanting (20 x15 cm with flooding water management, 3-4 seedlings transplanted at 25-30 days old seedlings), T4: Aerobic rice T5: Direct broadcast dry seeding on well prepared unpuddled soil fb crop management practices for direct dry drill seeded rice and T6: Optional- Location specific} of three replication. The highest grain yield was recorded at saturation with use of drum seeder 5.44 t/ha, followed by transplanting 4.38 t/ha crop establishment. The different method of irrigation recorded maximum mean highest garin yield (3.98 t) followed by alternate waiting and drying.

Density functional theory (DFT) is one of the popular methods to understand the electronic structure of molecular systems based on electronic density. On the basis of this theory, several conceptual DFT descriptors have been developed which can deal with the stability, reactivity, and several other physicochemical properties of molecules. Here, we have taken a nine-atom-functionalized deltahedral Zintl cluster of germanium (Ge) to examine the alkylation reaction mechanism. The study showed that the Zintl cluster having a methyl group as a ligand, [Ge9(CH3)3-], acts as a better nucleophile than the cyanide (-CN)-substituted cluster [Ge9(CN)3-] in terms of different thermodynamic parameters like free energy, enthalpy of activation, reaction energy, etc. A detailed reaction electronic flux analysis reveals the nature of the electronic activity throughout the reaction pathway. The reaction force, Wiberg bond indices, and dual descriptor lend additional support to the reaction mechanism. It has been found that the alkylation reaction between the Zintl ion and the alkyl halide follows a SN2-like mechanism.

The cycloaddition of ethylene, cyanoethylene, and propylene to a five-membered P/B frustrated Lewis pair (FLP) is shown to be highly favorable under normal conditions, as confirmed by the computed thermodynamic and kinetic data. All of these cycloaddition reactions are concerted as highlighted by the intrinsic reaction coordinate (IRC) and Wiberg bond index calculations. Almost 70% of the reaction force is required for structural orientation to initiate electronic activity. The reactions are interpreted by the frontier molecular orbital (FMO) analysis and conceptual density functional theory (DFT)-based reactivity descriptors. It appears that ethylene and propylene will act as nucleophiles, while the FLP will act as an electrophile throughout the cycloaddition reaction, however, cyanoethylene will act as an electrophile and the FLP as a nucleophile. Regioselectivities of the cycloadditon of cyanoethylene and propylene to the FLP are further verified through philicity and dual descriptors. It is demonstrated that an FLP can be forced to act as an electrophile or a nucleophile by intelligently selecting its partner in a cycloaddition reaction. Even the P and B centers would behave differently within the same FLP. This strategy may be properly exploited by the experimentalists in designing a suitable reaction for the synthesis of any useful molecule possessing the desired property.

A field experiment was laid out at Crop Research Station, Ghaghraghat, (ANDUAT), Bahraich, U.P. to evaluate the effect of different nutrients (N) level on agronomic traits of newly developed rainfed shallow lowland rice varities. The experiment was comprised of five rice genotypes viz., IET 26692, Dhanrasi, Pooja, Savithri and Sambha-Sub 1 and two levels of NPK viz., 60:30:30 and 90:45:45 kg/ha. In this trial, 150% of recommended dose of fertilizer (RDF) was found to be promising and also exhibited higher nutrient recovery efficiency. IET 26692 was found to be promising in terms of grain yield and nutrient response at the location. Among the genotypes maximum grain yield was recorded for IET 26692 (3.63t/ha RDF & 3.94 t/ha of 150% RDF) followed by Sambha-Sub1 (3.22t/ha RDF & 3.28 of 150% DF). The study showed that yield of rice. Increases under elevated 150% of recommended dose of fertilizer (RDF).

In quest for efficient Lewis base an in-silico investigation on NH3 and its structurally similar different molecules have been carried out. It has been observed that the ionization energy of the groups attached to N-centre play an important role in determining their stability and reactivity. Among different groups, superalkali ligands make better Lewis base. Several conceptual DFT descriptors like electrophilicity, nucleophilicity, dual descriptors have been used to analyse the stability and reactivity of proposed Lewis base. Calculated charge transfer descriptor describes the efficiency of the designed Lewis base to form an adduct with Lewis acid. nc-2e (n=1,2) AdNDP calculation lend additional support to the bonding of the studied molecules.

Imidazole and benz-imidazole based different NHC ligands have been designed to synthesize a Cu(I)@NHC complex. Calculated vertical electron affinity suggests that all the ligands belong to a special type of molecule, superalkali, and shows a very good non linear optical activity. All of them form Cu(I)@NHC complexes having a trinuclear Cu3 core. Canonical Molecular Orbital contribution towards nucleus-independent chemical shift values suggest that the Cu3 ring is both σ- and π-aromatic. Aromaticity and other reactivity parameters like electrophilicity and hardness change with different ligand environments. It has been found that pyrazine based NHC synthesizes a more reactive complex than pyridine. Natural localized molecular orbitals of these complexes suggest that they have sp2 hybridization like BH3.

Boron compounds usually exhibit Lewis acidity at the boron center due to the presence of vacant p-orbitals. We show that this chemistry can be altered by an appropriate choice of ligands to decorate the boron center. To elucidate this effect, we studied the interactions of boron with two classes of ligands, one based on penta-substituted phenyl species (C6X5, X = F, BO, CN) and the other based on Zintl-ion-based groups (Ge9Y3, Y = H, CH3, BO, CN). An in-depth analysis of the charges and Fukui function values at the local atomic sites of the substituted boron derivatives B(C6X5)3 and B[Ge9Y3]3 shows that the B-center in the former is electrophilic, while it is nucleophilic in the latter. The chemical stability of the B[Ge9Y3]3 species is shown to be due to the presence of strong 2c-2e bonds between the B and Ge centers. Thus, the general notion of the Lewis acid nature of a boron center depends upon the choice of the ligand.

In this work, we report a new cyclic molecule, [8] Cyclo-1, 4-naphthylene ([8]-CN), that can act as an effective hole transport molecule. Based on First principle calculation we have quantified the reorganization energy of the compound to explore its efficiency as a hole transport molecule. Further, the molecule was functionalized with several electron donating (ED)/withdrawing(EW) groups to investigate the effect on the hole/electron transport property. We have found that the energy difference between indium tin oxide (ITO) work function and HOMO energy of ED group substituted ([8]-CN) are almost comparable while the situation is not suitable for EW group substituted [8]-CN.

Superalkalis and superhalogens are atomic clusters that mimic the chemistry of alkali and halogen atoms, respectively; the ionization energies of the superalkalis are less than those of alkali atoms, while the electron affinities of superhalogens are larger than those of the halogen atoms. These superions can serve as the building blocks of a new class of supersalts with applications in solar cells, metal-ion batteries, multiferroic materials, and so on. While considerable progress has been made in the design and synthesis of superhalogens, a similar understanding of superalkalis is lacking. Using density functional theory with hybrid exchange-correlation functional and Gaussian basis sets, we have systematically studied the role of size and composition on the properties of two different classes of clusters whose stabilities are governed by the Wade-Mingos polyhedral skeletal electron pair theory. One class belongs to the closo-borane family LimBnXn (m = 1, 2, 3; n = 6, 12; X = H, F, CN), while the other to the Zintl ions Lim[Be@Ge9]. We show that Li3BnXn and Li3[Be@Ge9] clusters are superalkalis with ionization energies as low as 2.84 eV in Li3B6H6. However, contrary to expectation, the ionization energies do not decrease with increasing cluster volume. Instead, ionization energies are linked to the X ligands' electron affinities; the larger the electron affinity, the higher is the ionization energy. The understanding gained here will help in the discovery of superalkalis and, hence, enrich the library of supersalts.

School of Applied Science and Humanities, Haldia Institute of Technology, Haldia 721657, India Department of Chemistry, Cooch Behar Panchanan Barma University, Cooch Behar 736101, India Department of Chemical Engineering, Haldia Institute of Technology, Haldia 721657, India Energy decomposition analysis(EDA) of Py-M+ (Py = Pyridazine, Pyrimidine, Pyrazine & M=Li, Na, K) and pyrazine-2M+ (M=Li, Na, K ) building blocks have been carried out to evaluate the bonding nature after metal doping with C4H4N2(Pyridazine, Pyrimidine, Pyrazine) isomers. To show what type of interaction occurred between building blocks and adsorbed H2 molecules, a topological analysis has been performed.

Confinement causes drastic changes in bonding, reactivity and dynamics. Alkali metal atoms are excellent reducing agents due to their low ionization energies. On the other hand, high electron affinity values allow the halogen atoms to behave as powerful oxidizing agents. In this article, we have shown that those properties get changed in a confined environment created by two fullerenes differing in size.

School of Applied Science, Haldia Institute of Technology, Haldia-721 657, West Bengal, India bDepartment of Chemistry, Jadavpur University, Kolkata-700 032, India Department of Chemistry, Utkal University, Bhubaneswar-751 004, Odisha, India S-Inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, Brazil Department of Chemistry, School of Basic Science, SRM University Sikkim, Gangtok-737 102, Sikkim, India E-mail: gourisankar1978@gmail.com, rana_bidyut@yahoo.com, joydevdinda@gmail.com Manuscript received online 02 December 2020, revised and accepted 27 December 2020 A new Ru-N-heterocyclic carbene (Ru-NHC) complex (3a), chloro(p-cymene)-1-methyl-3-pyrimidylimidazolideneruthenium(II)- hexafluorophosphate was synthesized from a non-annulated NHC precursor,1-methyl-3-pyrimidylimidazoli um­hexafluorophosphate (3). The half-sandwich geometry of the molecule is established with single crystals X-ray diffraction. The absorption spectra and electrochemical nature of the complex are also investigated, supported by DFT analysis. Compound 3a is applied on lung (A549), colon (HCT116), and breast (MCF7) cancer cells to examine their in vitro cytotoxicity activity, and results are summarized and compared with a recent report for Ru(II)-NHC complexes containing annulated NHC ligands.

Two fluorescence active bromoaniline-based Schiff base chemosensors, namely, (E)-4-bromo-2-(((4-bromophenyl)imino)methyl)phenol (HL1) and (E)-2-(((4-bromophenyl)imino)methyl)phenol (HL2), have been employed for the selective and notable detection of Cu2+ and Zn2+ ions, respectively, with the simultaneous formation of two new metal complexes [Cu(L1)2] (1) and [Zn(L2)2] (2). X-ray single crystal analyses indicate that complexes 1 and 2 are tetra-coordinated systems with substantial CH...π/π...π stacking interactions in the solid-state crystal structures. These two complexes are exploited for the next step detection of Al3+ and Hg2+ where complex 2 exhibits impressive results via turn-off fluorescence quenching in (DMSO/H2O) HEPES buffer medium. The sensing phenomena are optimized by UV–vis spectral analyses as well as theoretical calculations (density functional theory and time-dependent density functional theory). The combined detection phenomena of the ligand (HL2) and complex 2 are exclusively utilized for the first time to construct a molecular memory device, intensifying their multisensoric properties. Furthermore, the DNA- and human serum albumin (HSA)-binding efficacies of these two complexes are examined by adopting electronic and fluorometric titration methods. Complex 2 shows a higher DNA-binding ability in comparison with complex 1, whereas in the case of HSA, the reverse situation is observed. Finally, the binding modes of both the complexes with DNA and HSA have been investigated through molecular docking studies, suggesting good agreement with the experimental results.

The cycloaddition of ethylene, cyanoethylene, and propylene to a five-membered P/B frustrated Lewis pair (FLP) is shown to be highly favorable under normal conditions, as confirmed by the computed thermodynamic and kinetic data. All of these cycloaddition reactions are concerted as highlighted by the intrinsic reaction coordinate (IRC) and Wiberg bond index calculations. Almost 70% of the reaction force is required for structural orientation to initiate electronic activity. The reactions are interpreted by the frontier molecular orbital (FMO) analysis and conceptual density functional theory (DFT)-based reactivity descriptors. It appears that ethylene and propylene will act as nucleophiles, while the FLP will act as an electrophile throughout the cycloaddition reaction, however, cyanoethylene will act as an electrophile and the FLP as a nucleophile. Regioselectivities of the cycloadditon of cyanoethylene and propylene to the FLP are further verified through philicity and dual descriptors. It is demonstrated that an FLP can be forced to act as an electrophile or a nucleophile by intelligently selecting its partner in a cycloaddition reaction. Even the P and B centers would behave differently within the same FLP. This strategy may be properly exploited by the experimentalists in designing a suitable reaction for the synthesis of any useful molecule possessing the desired property.

Induced chirality (achiral target in chiral matrix such as proteins) sometimes play a useful role in evaluating supramolecular systems involving biomolecules. Enzymatic fuel cells, which generate electricity via enzymatic redox reactions at electrodes hold a significant potential for sustainable power. Bacterial laccase, a multi-copper oxidase, was used in the cathodic compartment of the enzymatic biofuel cells because of its low redox potential. Three new salen Cu(II) complexes were designed and investigated as mediators. The Schiff base ligands consisted of both a redox-active (anthraquinone) and a photochromic (azobenzene) moiety. The interaction between laccase and a mediator was examined with induced circular dichroism (CD) and the docking tool to observe in which of the laccase domains the mediators bind as well as study the photo-induced tuning of both the cis-trans photoisomerization and orientation by the Weigert effect. Both the electrochemical and photochromic properties are also discussed and compared using density functional theory (DFT), time-dependent (TD)-DFT, and docking simulations.

Differentially selective molecular sensors that exhibit differential response toward multiple analytes are cost-effective and in high demand for various practical applications. A novel, highly differentially selective electrochemical and fluorescent chemosensor, 5, based on a ferrocene-appended coumarin-quinoline platform has been designed and synthesized. Our designed probe is very specific toward Fe3+ via a reversible redox process, whereas it detects Cu2+ via irreversible oxidation. Interestingly, it exhibits differential affinity toward the Cu+ ion via complexation. High-resolution mass spectrometry, 1H NMR titration, and IR spectral studies revealed the formation of a bidentate Cu+ complex involving an O atom of the amide group attached to the quinoline ring and a N atom of imine unit, and this observation was further supported by quantum-chemical calculations. The metal binding responses were further investigated by UV-vis, fluorescence spectroscopy, and electrochemical analysis. Upon the addition of Fe3+ and Cu2+ ions, the fluorescence emission of probe 5 shows a "turn-on" signal due to inhibition of the photoinduced electron transfer (PET) process from a donor ferrocene unit to an excited-state fluorophore. The addition of sodium l-ascorbate (LAS) as a reducing agent causes fluorescence "turn off" for the Fe3+ ion because of reemergence of the PET process but not for the Cu2+ ion because it oxidizes the ferrocene unit to a ferrocenium ion with its concomitant reduction to Cu+, which further complexes with 5. Thermodynamic calculations using the Weller equation along with density functional theory calculations validate the feasibility of the PET process. A unique combination of Fe3+, LAS, and Cu2+ ions has been used to produce a molecular system demonstrating combinational "AND-OR" logic operation.

The increase in the use of bactericides is a matter of grave concern and a serious threat to human health. The present situation demands rapid and efficient detection and elimination of antibiotic-resistant microbes. Herein, we report the synthesis of a simple C3-symmetric molecular system (TGP) with an intrinsic positive charge through a single-step Schiff base condensation. In a water-dimethyl sulfoxide (DMSO) solvent mixture (80:20 v/v), TGP molecules self-aggregate to form spherical nanoparticles with a positively charged surface that displays efficient fluorescence owing to the aggregation-induced emission (AIE) phenomenon. Both Gram-positive and Gram-negative bacteria could be effectively detected through "turn-off" fluorescence spectroscopy as the electrostatic interaction of the resultant nanoaggregates with the negatively charged bacterial surface induced quenching of fluorescence of the nanoparticles. The fluorescence analysis and steady-state lifetime studies of TGP nanoparticles suggest that a nonradiative decay through photoinduced electron transfer from the nanoparticles to the bacterial surface leads to effective fluorescence quenching. Further, the TGP nanoaggregates demonstrate potent antimicrobial activity against microbes such as multidrug-resistant bacteria and fungi at a concentration as low as 74 μg/mL. A combination of factors including ionic surface characteristics of the nanoparticles for strong electrostatic binding on the bacterial surface followed by possible photoinduced electron transfer from the nanoaggregates to the bacterial membrane and enhanced oxidative stress in the membrane resulting from reactive oxygen species (ROS) generation is found accountable for the high antimicrobial activity of the TGP nanoparticles. The effective disruption of membrane integrity in both Gram-positive and Gram-negative bacteria upon interaction with the nanoaggregates can be observed from field emission scanning electron microscopy (FESEM) studies. The development of simple pathways for the molecular design of multifunctional broad-spectrum antimicrobial systems for rapid and real-time detection, wash-free imaging, and eradication of drug-resistant microbes might be crucial to combat pathogenic agents.

Zintl ions constitute a special type of naked anionic clusters, mainly consisting of Group 13, 14, and 15 elements of the Periodic Table. Due to the presence of multiple negative ions, the chemistry of Zintl ions is unique. They not only form Zintl phases with alkali and alkaline-earth metal cations, but also form organo-Zintl clusters with distinct properties. By first-principles calculations based on density functional theory, we have designed a new deltahedral organo-Zintl cluster with Ge94- as the core and aromatic heterocyclic compounds as ligands. Calculations on such complexes show that they form a special class of system known as a superhalogen (SH), with a high vertical detachment energy of 4.9 eV. The density of states (DOS), partial DOS, and different molecular orbitals give additional information about the bonding features of the complexes.