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Four salts of an anionic iron(III) bis-complex, [Fe(L L -thr)2]1−, were synthesized from water or methanol. H2L L -thr is a tridentate ligand derived from the L -threonine amino acid, and the cations used are Li+ (1), Na+ (2), K+ (3), and Ba2+ (4). Single-crystal X-ray diffraction showed that all the complexes are coordination polymers of different dimensionalities. The iron(III) complex binds to cations through its coordinated phenolate and non-coordinated carboxylate oxygen atoms. While Li+ forms a linear chain, all others have a pair of bridged cations intervening the iron(III) complexes. The 3D network of Ba2+ salt has a sizeable solvent-accessible space occupied by aquated chloride ions. The differences in circular dichroism (CD) spectra and significantly lower conductance values in water and methanol support partial retention of the polymeric nature in methanol. The visible spectra of 4 in methanol or water showed an ∼10 nm shift of the charge transfer bands from 3. However, the addition of Al3+ salt to 2 showed a significant colour shift. Further investigation confirmed that the colour shift is due to partial protonation of the complex with protons generated from salt hydrolysis. Most reports on visual aluminium detection consider aluminium's binding as the shift's source. The present results show that protonation due to hydrolysis of aluminium salt can skew the observation. [ABSTRACT FROM AUTHOR]

We analyzed data from a long-term rice-wheat cropping sequence to evaluate the effects of integrated nutrient management (INM) on yield trends and sustainability, nutrient balance and soil fertility of the system. After 30th cycle, grain yield of both the crops significantly declined under control and highest rice and wheat grain yields were obtained when 50% N supplied through green manure and farm yard manure, respectively. The magnitude of yield slope under INM was found considerably higher than 100% recommended fertilizer (RDF). Sustainable yield index (SYI) for both the crops were found lower in control but considerably higher with the 100% RDF and under INM. The soils under all the treatments suffered an apparent loss of K and N (except where organics replacing 50% N). Correlation study also reveals K is the sole factor for the yield sustainability as apparent K balance was negatively correlated with SYI and yield slope. [ABSTRACT FROM AUTHOR]

We are reporting structural characterization of two new hexanuclear cages (H3O)2[Cu3(μ3-OH)-(μ3-NH3)0.5(L)3]2·8H2O (1) and (H3O)2[Cu3(μ3-OH)(μ3-H2O)0.5(L)3]2·8H2O (1a) where L2- is the dianionic form of the Schiff base of L-alanine and salicylaldehyde. The complex 1 has two C3 symmetric hydroxo bridged trinuclear halves joined by an ammonia or water molecule at the center through H-bonding. Each of the trinuclear halves is enantiopure but of opposite chirality to the other half, making the hexanuclear unit a meso isomer. Temperature dependent magnetic measurements showed the presence of ferromagnetic interactions among trinuclear Cu(II) units, a rare occurrence among trinuclear Cu(II) complexes. Characterization of the LiHL showed it to be enantiopure. Addition of a base, monitored using optical rotation, showed that racemization occurs as a result of base addition. The racemization depends on the base as well as the temperature. Base or Cu(II) induced racemization of amino acid derivatives has been indicated in a number of cases in the past but structural characterization of the products or formation of this type of chiral hexanuclear architecture was never reported. Structures of the complex and the ligand have a number of interesting H-bonding situations. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three versions of polymer, each version in acid salt and free base form. • Different versions have different surface properties due to the orientation of the functional group. • Hydrophilic salt forms showed a 20-fold increase in removal than the hydrophobic counterpart. • Salt forms remove 95%-98%, chromate concentrations 10–100 mg/L, dose 4 g/L. Aniline formaldehyde condensate (AFC) is a polymer with an amine functional group. It can exist in either an acid salt or free amine form. AFC Polymers in salt form, Poly-1s, and Poly-2s, were synthesized by switching the ratio between isopropanol to an aqueous solution in the reaction medium from 3:1 to 1:3. Another Poly-3s was prepared in a reduced volume using an intermediate solvent ratio. All three were hydrophilic with a contact angle of 0°. Treatment with a base produced the corresponding polymers in a free base form. Elemental analysis, FTIR, and MALDI mass analyses confirmed the formulation of the salt form and free base form without significant changes in the chemical identity of the polymers. Contact angle measurements showed that Poly-1b (from Poly-1s) was superhydrophobic (contact angle 154°), whereas Poly-2b (from Poly-2s) was hydrophilic (contact angle 0°). The reversal in hydrophobicity between Poly-1b and Poly-2b indicated a significant change in the orientation of the amine group. FESEM imaging and surface area measurements from the BET isotherm reflected the differences between them. In chromate removal experiments, all three salt forms showed 80%-93% chromate removal (initial chromate concentration 10–100 mg/L, adsorbent dose 1 g/L, pH 4). The adsorption capacity of salt forms, between 131 and 149 mg/g (dose 0.5 g/L, removal 66%-75%), is the highest reported for AFC. In contrast, the uptake of hydrophobic Poly-1b at 3.87 mg/g (dose 4 g/L, C i 100 mg/L) was the lowest found for AFC. This work demonstrates that the relationship between surface property and site accessibility profoundly impacts chromate binding property. [ABSTRACT FROM AUTHOR]

The use of caesium is a less trodden path in terms of the synthesis of coordination polymers. The chemical similarity and mild toxic nature of caesium salts does not provide much impetus to work with these compounds compared to their potassium analogues. However, are the potassium and caesium salts really close in terms of coordination polymer formation? The result presented in this manuscript shows that while neither potassium halides or potassium nitrate inhibit the formation of a trinuclear chiral assembly of a copper(ii) complex from a mononuclear Cu(ii) complex, caesium chloride preferentially forms a coordination polymer while keeping the Cs–Cl bond intact. Under the same conditions, caesium nitrate does not inhibit the assembly formation. Structural characterization of {[CsCl{Cu(HLl-leu)2}(H2O)]}n (2) showed it to be a two-dimensional coordination polymer in the ab plane, where penta-coordinated Cu(HLl-leu)2 complex units (HLl-leu = reduced Schiff base of l-leucine and the salicylaldehyde condensation product) were interconnected through the formation of Cu–Cl–Cs bonds. Multitudes of intermolecular H-bonds were observed as well. The use of KCl, KBr, KI or CsNO3 in lieu of CsCl to the [Cu(HLl-leu)2(CH3CN)] (1) facilitated the formation of the trinuclear assembly, [M{Cu(HLl-leu)2}3]X, where M = K+ or Cs+ and X = Cl, Br, I or NO3 depending on the salt used. The Cu(HLl-leu)2 units in these assemblies are hexacoordinated Cu(ii) complexes. [ABSTRACT FROM AUTHOR]

Abstract: An amine-based polymer, aniline formaldehyde condensate (AFC) was coated on silica gel and used as an adsorbent for removal of trivalent chromium [Cr(III)] in aqueous environment. A comparative study with mixed metal solutions containing Cu(II), Cd(II), Pb(II), Cr(III) and Ni(II) showed that adsorption was in the order of Cu(II)>Ni(II)>Cr(III)>Pb(II)>Cd(II). Comparative adsorption of mixed metal ions by AFC was according to preferences dictated by the hard–soft theory of acids and bases and ligand exchange rate of metal ions. It was observed that in mixed metal solution Cr(III) adsorption by AFC though thermodynamically favoured with high binding constant, however, limited kinetically. Cr(III) adsorption by AFC increased with pH achieving maximum removal of 80% at pH 6. Formation of multidentate coordinate bond between [CrOH]2+ and [Cr(OH)2]1+ and deprotonated amine group (–NH2) of AFC was probable mechanism for removal of Cr(III) in aqueous environment. Adsorption of Cr(III) on AFC followed Lagergren’s second order kinetic model and Langmuir–Freundlich’s isotherm model with maximum monolayer coverage of 30.77mg/g (0.57mmol/g). Electromagnetic paramagnetic resonance and energy dispersive X-ray spectra confirmed the presence of trivalent chromium ion on surface of AFC coated silica gel. [Copyright &y& Elsevier]

Earlier we reported the tendency of ferrocenylmethyl substituted amino acids to organize around Cu(II) in a C2 symmetry. In this paper we have utilized this property to form a chiral cavity using a L-tyrosine derivative. Structural characterization of [CuII(S-fTyr)2(MeCN)2] (1), where S-fTyr1- is ferrocenylmethyl-L-tyrosinate, showed that the alignment of two tyrosine aromatic rings around the fifth coordination site generates a narrow cavity. Structural characterization of [Cu(S-fTyr)2(pyrazine)] (2), [Cu(S-fTyr)2(pyridine)] (3), [Cu(S-fTyr)2(bpy)] (4) and [Cu(S-fTyr)2(H2O)] (5) revealed that planar heterocyclic N-donors as guests stabilized the cavity, while polar water molecules destroyed it. Electrochemical properties of the complexes showed a shift of CuII/CuI potentials depending on the strength of the guest binding inside the cavity. [ABSTRACT FROM AUTHOR]

A resinous polymer, aniline formaldehyde condensate (AFC) coated on silica gel was used as an adsorbent in batch system for removal of hexavalent chromium from aqueous solution by considering the effects of various parameters like reaction pH, dose of AFC coated silica gel, initial Cr(VI) concentration and aniline to formaldehyde ratio in AFC synthesis. The optimum pH for total chromium [Cr(VI) and Cr(III)] adsorption was observed as 3. Total chromium adsorption was second order and equilibrium was achieved within 90–120min. Aniline to formaldehyde ratio of 1.6:1 during AFC synthesis was ideal for chromium removal. Total chromium adsorption followed Freundlich''s isotherm with adsorption capacity of 65mg/g at initial Cr(VI) 200mg/L. Total chromium removal was explained as combinations of electrostatic attraction of acid chromate ion by protonated AFC, reduction of Cr(VI) to Cr(III) and bond formation of Cr(III) with nitrogen atom of AFC. Almost 40–84% of adsorbed chromium was recovered during desorption by NaOH, EDTA and mineral acids. AFC coated silica gel can be effectively used for treatment of chromium containing wastewaters as an alternative. [Copyright &y& Elsevier]

Examines the synthesis and characterization of low-spin iron(III) peptide complexes. Magnetism and Mossbauer spectra of iron(III) complexes; Identification of oxidized complexes from iron(III) compounds; Determination of ligand oxidation in the iron(III) complexes; Classification of oxidized complexes as a diamagnetic specie.

Determines the structure and magnetic properties of trigonal bipyramidal iron nitrosyl complexes. Formation of stable nitrosyl adducts from non-heme Fe(II) proteins; Synthesis with tripodal ligands from the 3,5-dimethylphenyl groups; Use of X-ray diffraction methods on iron nitrosyl; Rhombic spectrum through EPR measurements.

Initiates a program to explore the coordination chemistry of a simple, easily synthesizable, tridentate dianioic bis-amide ligand L(2-) [H2L=2,6-bis(N-phenylcarbamoyl)pyridine]. Description of several complexes; Experiments conducted; Results of experiments; Detailed information on study.

Presents a study which synthesized and characterized, a series of trigonal monopyramidal (TMP) complexes of the tripodal ligand tris((N-tert-butylcarbamoyl-methyl)aminato, [But]3-. Indication of the structural studies; Examination of crystallographic structural determination; Discussion on the design considerations and syntheses.

Quinoxalines are heterocyclic compounds with potential application as drugs or fluorophores. However, few quinoxalinylium salts have been reported in the literature. This manuscript describes the synthesis and structural characterization of a previously unknown quinoxalinylium derivative, 2-aminopyrido[1,2-a]quinoxalin-11-ylium ([1]+), as perchlorate and thiocyanate salts from the CuII-mediated reaction of a Schiff base. The reaction is most efficient with CuII. The formation of a small quantity was observed spectroscopically in the presence of either a strong oxidizer or MnII. No product formation was observed with ZnII, CdII, FeII, or NiII. [1]+ emits at 580 nm, with a quantum yield estimated as 0.23, upon excitation at 470 nm. [ABSTRACT FROM AUTHOR]

• Schiff base of (S)-(-)-1-phenylethylamine resolved from racemic mixture. • Enantiomeric enhancement in crystalline state ~91%. • Enantiomeric enhancement without crystallization ~59%. Racemic 1-phenylethylamine was converted to bidentate Schiff base ligand by condensing with imidazole-2-carboxaldehyde (rac -L2). The reaction between Ni(II)(ClO 4) 2 , rac -L2 and another Schiff Base S -L1 (ratio:1:2:2) yielded crystals of fac -Δ-[Ni(S -L1) 2 (S -L2)](ClO 4) 2 (1). The ligand S -L1 is a condensation product of S -1-phenylethylamine and pyridine-2-carboxaldehyde. Enantiomeric excess (ee) of bulk crystals of 1 was found to be ~91%. The values were calculated from from Circular dichroism (CD) spectra and optical rotation experiments. The ee measured on a non-crystalline form of 1 , isolated by rapid precipitation, was found to be ~59%. The value supports the presence of chiral enhancement without the crystallization. Compared to this, only 40–60% ee in crystals and 0% in precipitated form was achieved in our earlier report. Substituting rac -L2 with R -L2, in the reaction did not yield the [Ni(S -L1) 2 (R -L2)](ClO 4) 2 diastereoisomer. The solid from the reaction contains [Ni(S -L1) 3 ](ClO 4) 2 complex among others. The enantiomer, fac -Δ-[Ni(R -L1) 2 (R -L2)](ClO 4) 2 (2) , has been synthesized and structurally characterized. Cyclic voltammetry (CV) of the complexes were analyzed for a probable method for electrochemical detection of enantiomers. [ABSTRACT FROM AUTHOR]

Background: Inclusion of legume with cereal as an intercrop ensure crop nutrition and enhanced soil quality. Combine application of organic manure with inorganic fertilizer minimizes the soil hazard and improves crop productivity in a significant manner. Methods: The experiment on Kharif maize +cowpea intercropping system was carried out at 'Jaguli Instructional Farm' of Bidhan Chandra Krishi Viswavidyalaya, Nadia, under the New Alluvial Zone of West Bengal in 2019-2020 to investigate the influence of crop geometry and nutrient management practices on growth and yield responses of legume (cowpea). The experiment was laid out with a split-plot design. The main plot had five crop geometry and a sub plot comprised five nutrient management practices, which were replicated thrice. Result: From the pooled data of two years experiment, the intercropping system of 1M:1C (Maize: Cowpea) (C3) perform better in respect of growth attributes, viz., leaves plant-1, LAI, branches plant-1 and CGR; yield reflecting attributes viz., pods plant-1, pod length, pod and forage yield of cowpea (1.30 and 5.49 t ha-1) and crop (maize) equivalent yield of cowpea (1.76 t ha-1) although the maximum values were attained from sole cowpea treatment (C2). Nutrient management practices with the application of 75% N as chemical + 25% N as organic with seaweed application (N2) recorded greater growth and yield viz., pod, forage and crop (maize) equivalent yield (1.51, 6 and 2.01 t ha-1), respectively. Total nodules plant-1 were significantly influenced by crop geometry and nutrient management, whereas the total chlorophyll content of cowpea was significantly varied with nutrient management. Regression studies depicted the negative functional relationship between pod yield and canopy temperature, whereas the relationship between intercepted photosynthetic active radiation (PAR) and pod yield was positive. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Change in ligand changes crystallization path to conglomerate formation. • Using benzoate almost doubled the chiral enhancement. • Weak interactions responsible for recognition were identified. Abstract Chiral recognition is an important phenomenon. Identifying factors those influences recognition and resolution have significance in multiple areas. Earlier, we had reported recognition and resolution (30% ee) of 1-phenylethylammonium cation using an anionic binuclear Ni(II) complex of a l -histidine derived ligand. We have now synthesized its l -methionine analogue and also substituted the bridging acetate to benzoate. Substitution of amino acid and subsequent reaction with racemic 1-phenylethylamine resulted in isolation of crystals of both possible diastereoisomers (1 and 2) as a conglomerate. This is different from l -histidine analogue which showed pseudo racemate formation. HPLC experiments on the bulk of the crystals showed 30% ee. On the other hand, substitution of both the amino acid and bridging ligand resulted in isolation of crystals of single diastereoisomer (3). HPLC experiment on the bulk of the crystals showed an improved 58% ee. Thus, changes in amino acid changed the mechanism of crystal formation without improving the enantiomeric excess (ee) but the changes in bridge almost doubled the % ee. To understand the reasons, the complexes 1 – 3 were structurally characterized and compared with previously reported l -histidine analogue. Comparison showed, the absence of strong imidazole-carboxylate H-bonding in the present system narrowed the solubility difference between diastereomers, which may have resulted in the formation of conglomerate. On the other hand, changing the bridging acetate to benzoate increase the number of inter molecular non-covalent interactions which may have influenced the improved chiral enhancement. [ABSTRACT FROM AUTHOR]

We analyzed data from a long-term rice-wheat cropping sequence to evaluate the effects of integrated nutrient management (INM) on yield trends and sustainability, nutrient balance and soil fertility of the system. After 30th cycle, grain yield of both the crops significantly declined under control and highest rice and wheat grain yields were obtained when 50% N supplied through green manure and farm yard manure, respectively. The magnitude of yield slope under INM was found considerably higher than 100% recommended fertilizer (RDF). Sustainable yield index (SYI) for both the crops were found lower in control but considerably higher with the 100% RDF and under INM. The soils under all the treatments suffered an apparent loss of K and N (except where organics replacing 50% N). Correlation study also reveals K is the sole factor for the yield sustainability as apparent K balance was negatively correlated with SYI and yield slope. [ABSTRACT FROM AUTHOR]

Removal of hexavalent chromium by aniline-formaldehyde condensate polymer coated on silica gel, in the past, showed poor removal at low concentration range with high adsorbent dose (∼30% removal at 10 mg/L with a adsorbent dose of 8 g/L). We have now synthesized a new form of the support less polymer which brings down residual concentration to less than 1 mg/L with a 2 g/L dose. The maximum removal of total chromium was observed between pH 3–8 (94–98% removal at 2 g/L dose). Removal is susceptible to processing of the polymer and batch to batch variation has been observed. Field emission scanning Electron microscope (FESEM) showed polymer consists of micron-sized (1–2 µm diameter) clusters. Phosphate and nitrate strongly inhibited total chromium uptake while effect of sulphate and chloride were less. Desorption was 86% with 1 N HCl and reuse of the micron sized AFC was possible for four cycles. Ion exchange as well as redox interaction between chromate ion and protonated amine group of polymer was found to be the key factor for adsorption. [ABSTRACT FROM AUTHOR]

• Irrigation and nutrient management are key factors for a desirable yield of potato;. • Water use efficiency and potassium were linked to the productivity of potato;. • Infrared thermometry-based stress indices help to predict potato yield under moisture stress;. • Stress monitoring tools are useful as non-destructive tools in the production system of potato. As the demand for food continues to rise and water availability challenges intensify, the delicate equilibrium between efficient water usage and sustainable agricultural production has become increasingly pivotal. Recognizing the significance of water stress monitoring and nutrient management in the country's agricultural landscape, two years of field trials (2018–2019 and 2019–2020) were conducted at the Regional Research Station, Bidhan Chandra Krishi Viswavidyalaya, Gayeshpur, Nadia, to demonstrate the efficiency of canopy temperature-based indices for monitoring crop water stress in potato (cv. Kufri Jyoti) under varied irrigation (IW:CPE = 0.4, 0.8, 1.2 and 1.6) and potassium doses (K 2 O @ 100, 150 and 200 kg ha−1). The seasonal evapotranspiration of potato plants ranged from 121.0 mm to 320.9 mm during the crop growth period, and it exhibited a quadratic relationship with both the total dry biomass and the tuber yield. In 2019–2020, the highest water use efficiency (WUE) of 12.74 kg m−3 was obtained from the application of IW; CPE= 1.20 with the application of K 2 O @ 200 kg ha−1. In the following year, the highest WUE of 9.78 kg m−3 was obtained from irrigation at IW:CPE= 1.60, along with K 2 O application @ 200 kg ha−1. During a major part of the growth period, the canopy air temperature difference (CATD) was greater in the treatments in which irrigation was applied at IW:CPE = 0.4 and 0.8 than in those in which irrigation was applied at higher levels, i.e., IW:CPE = 1.2 and 1.6, implying the effectiveness of CATD as a stress indicator. The stress indices, stress degree days (SDD) and crop water stress index (CWSI) accumulated over the crop growing season showed decreasing trends with increasing irrigation and potassium doses. Both the accumulated SDD and accumulated CWSI showed a strong inverse relationship with tuber yield. The significant linear relationship between tuber yield and the seasonal accumulation of both infrared thermometry-based stress indices (i.e., SDD and CWSI) may help to predict crop yield in response to seasonal moisture stress and thus aid in strategic crop planning under the limited availability of irrigation. [ABSTRACT FROM AUTHOR]

A long-term experiment was initiated in a sub-humid tropical Indian rice-wheat system to identify suitable soil quality indicators for determining yield and sustainability of the system as influenced by chemical fertilizers (NPK) alone or in combination with organic amendments viz. farmyard manure (FYM), paddy straw (PS) and green manure (GM). Soil samples were analysed for physical, chemical and biological indicators after 30 crop cycles and the soil quality index (SQI) was calculated by nonlinear scoring functions following the methodology of principal component analysis and multiple regression analysis-based minimum data set selection. Application of NPK fertilizers in combination with FYM and GM significantly increased systems yield and sustainability (sustainable yield index or SYI) as well as improved soil properties compared to the control and other combinations. The value of the dimensionless SQI varied from 2.0 in the control plot to 3.1 in the NPK+FYM. A greater SYI and SQI in the NPK+FYM treatment suggested that FYM in combination with chemical fertilizers has an edge over GM and PS. Among all the indicators (30) under study, available-N, soil organic carbon, available-B and aryl-sulfatase were screened as suitable indicators which contributed 24, 29, 24, 22%, respectively to the SQI in NPK+FYM treatment. [ABSTRACT FROM AUTHOR]

Chiralrecognition through noncovalent interaction occurs in manybiological systems. Structural characterization of chiral host–guestcomplexes can enhance the understanding of recognition mechanism.but such examples are relatively few. Chiral recognition and resolutionof 1-phenylethylamine was studied where a binuclear Ni(II) complexacts as chiral host. Structural characterization showed that (R)-1-phenylethylamine forms a triangular assembly of threehost–guests adducts through both H-bond and CH···πinteractions. In contrast, use of (S)-1-phenylethylamineleads to formation of ∼11 Å wide one-dimensional channelsby the binuclear Ni(II) anionic complex where the chiral guest cationhas been organized inside the channels in a zigzag fashion. Use ofracemic amine yielded crystals having identical channel structurewhere S-amine and R-amine are insidethe channels in a 55:45 ratio. HPLC results of the isolated aminesfrom bulk of the crystals show that the S:Risomer ratio is 65:35, supporting the structural observation.HPLC on the isolated amine from amorphous precipitate of host–guestadduct showed minor (4% ee) chiral enhancement, indicating that thisenhancement is mostly due to noncovalent interactions in the crystallinestate. Resolution of enantiomers through crystallization is a resultof solution thermodynamics, nucleation, and other factors pertainingto the crystalline state. Results presented attempted to show theextent of this interdependence within a chiral metallo-organic hostand an amine. [ABSTRACT FROM AUTHOR]

Cropping system diversification under integrated nutrient management is an important tool for enhancing crop productivity, maintaining soil nutrient and energy balance while restoring environmental quality and sustainability. A field experiment was conducted for seven consecutive cycles with three rice-based cropping systems (C 1 : rice-mustard-jute; C 2 : rice-wheat-maize+greengram; C 3 : rice-lentil-sesame) under multiple irrigated conditions and four nutrient management practices (NPK fertilizers and biogas slurry (BGS) in various combinations). Comprehensive assessment of system productivity as well as sustainability, nutrient balance, energy and carbon footprint (CF) of different cropping systems under the influence of inorganic-organic fertilization were analysed to know the possible environmental impact. Irrespective of the cropping systems, the highest system rice equivalent yield (REY) (7.78 t ha−1) was recorded with 100% NPK fertilizers, whereas, substitution of chemical fertilizers with BGS for supplying a part of N, P and K requirement of different crops in the cropping system resulted in higher sustainable yield index (SYI). Positive apparent soil N and P balance were observed irrespective of cropping systems and nutrient management practices, however, the soils under all the treatments suffered an apparent loss of K. The rice-wheat-maize+green gram (C 2) system dominated in terms of productivity and soil fertility, over the others, whereas substitution of NPK fertilizers by BGS resulted in a significant increase of available N, P, K, S, B and cationic micronutrient (Fe, Mn, Cu and Zn) content in the soil over 100% NPK fertilizers. However, sole application of BGS resulted in higher build-up of soil organic carbon. The energy ratio was higher in the rice-mustard-jute cropping system with 100% NPK fertilizers application (6.57 and 6.13 kg MJ−1 respectively) due to higher energy output to input balance, however, the specific energy was higher in the rice-lentil-sesame system with sole BGS application (6.13 and 6.25 kg MJ−1 respectively). In contrast to the C output and carbon footprint (CF), the carbon sustainability index (CSI) was reported highest in the rice-mustard-jute system (12.28) while the lowest was recorded in the rice-wheat-maize+green gram system (9.14). Therefore, legume inclusive cropping along with organic nutrient sources could be considered as an effective option to maintain crop productivity, soil nutrients and energy balance while reducing carbon footprints in the areas where intensive cultivation is predominated. • Integrating slurry with fertilizers and legume inclusion was found more sustainable. • Inclusion of legume and slurry maintained positive soil apparent N and P balance. • Rice-mustard-jute with fertilizers showed higher energy ratio and specific energy. • Rice-lentil-sesame with sole slurry showed higher energy ratio and specific energy. • Low footprint and high C sustainability in rice-mustard-jute reduces global warming. [ABSTRACT FROM AUTHOR]

Abstract: Four pentacoordinated square-pyramidal Cu(II) complexes with the general formula [Cu(L)(X)], where L is a l-histidine derived tetradentate ligand and X is either 3-hydroxypyridine or 2-methylpyridine, has been synthesized. Structural analysis showed that the presence of water filled one dimensional chiral channel in the lattices. The interiors of the channels were varied using aromatic ring substitution on the ligand as well as on the monodentate ligand. The dimensions of the channels range from ∼7 to 9Å. [Copyright &y& Elsevier]

L-Leucine derived ligand (H2LL-leu), KOH, and Ni(ll) salt iv 2:2:1 ratio self-assembled into a rather large (∼13 Å) supramolecular assembly with the formula [K(Ni(HLL-leu)2)3]+ (1). Struclural chatacterizalion showed three [Ni(HLL-leu)2] units encapsulated K+ similar to organic crown ethers/cryptand. Substituting Ni(ll) with Cu(ll) and K+ with Na+ in the above reaction resulted in a set of structurally identical assemblies with the general formula [M'(M(HLL-leu)2)3]+, where M' is either K+ or Na+ and M is ether Cu(lI) or Ni(ll); [Na(Ni(HLL-leu)2)3]ClO4 (2), Na(Ni(HLL-leu)2)3]OTf (3), (K(Cu(HLL-leu)2)3]ClO4 (4) [Na(Cu(HLL-leu)2)3]ClO4 (5), [K(Cu(HLL-leu)2)3]NO3 (6). Electrospray Ionization (ESI)-mass spectra of the assemblies in MeOH showed the retention of assemblies in solution. Viable spectroscopic studies showed retention of assembly 1 in N,N-dimethylformamide (DMF) whim is stable even after the addition of 5 equiv of [18]-crown-6. The assemblies in 2-6 show various degrees of dissociation lo [M(HLL-leu)2] and M', in stronger H-bonding methanol. The dissociation can be reversed upon addition of excess KNO3/NaNO3 salt. Structural characterization of [Cu(HLL-leu)2(MeCN)] (7) along with its transformation to [K(Cu(HLL-leu)2)3]+ in the presence of K+ salt demonstrated thaI the assembly formation proceeds through an alkali metal ion induced ligand reorientation within the [Cu(HLL-leu)2] units whets is further stabilized by six strong H-bonds holding the assembly. Interestingly, visible spectra of 1 and 2 shows that minor structural changes caused by replacing K+ with Na+ is sufficient to shift the d-d transition 01 Ni(ll) by ∼70 nm, thereby providing an indirect way of distinguishing K+ and Na+ none of whim have specfrostsspix signature in the visible range. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, short chain polyaniline (PANI), a polymer was synthesized on the surface of jute fiber and was used as an adsorbent to remove hexavalent chromium (Cr(VI)). Experiments were conducted in batch mode with the variables such as amount of jute fiber on PANI, chain length of PANI, solution pH, initial concentration of Cr(VI), dose of PANI-jute and temperature. The PANI formed was found to be short chain polyaniline (oligoaniline). Optimum amount of jute fiber and chain terminating agent 1,4-phenylenediamine were observed as 5g and 3.05mmol, respectively, for 21.5mmol of aniline. Maximum adsorption of total chromium (Cr(VI), Cr(III) and its other forms) was observed at reaction pH of 3 by electrostatic attraction of acid chromate ion with protonated PANI-jute. Adsorption equilibrium was achieved within 40–120min for initial Cr(VI) of 50–500mg/L. Maximum monolayer capacity of PANI-jute was observed as 62.9mg/g at pH 3 and temperature 20°C. Total chromium adsorption decreased with rise in temperature suggesting an exothermic adsorption of chromium. During desorption almost 83% efficiency was achieved within 10min by 2M NaOH. By ignition of chromium bounded PANI-jute, 94% Cr(VI) were able to recover as Cr(III) along with reduction in weight by 95%. PANI-jute can be used effectively to remove chromium from wastewater. [Copyright &y& Elsevier]

A H-bond capable chiral tetradentate ligand, Fe3+, and acetate ion assembles into a hydroxo-bridged binuclear complex with the formula [FeIII2(μ-OH)(μ-OAc)(S-L)2]·4H2O (1) where H2S-L = S-2-(2-hydroxy-benzylamino)-3-(1H-imidazol-4-yl)-propionic acid. The crystal of 1 contains right-handed one-dimensional (1D) helical channels with 7.3–9.8 Å diameter. A similar reaction with a ligand having opposite chirality forms the complex with left-handed helical channels (1a). Heating the crystals of 1 at 95 °C under reduced pressure selectively removes three waters from the channel forming an enantiopure porous crystal with empty channels (solvent accessible voids 18% v/v). Intermolecular hydrogen bonding between the imidazole N-H and phenolate oxygen in 1–2 forms a C6 symmetric helix with bridging hydroxo groups pointing inside the channels. All the H-bond capable atoms in the ligand along with one water molecule form an extended H-bonded network throughout the crystal. Exposing the empty channels of 2 to iodine vapor indicates partial filling of the channels with iodine. Crystal data for 1·4H2O include the following: hexagonal, P61, a = b = 13.164(3) Å, c = 36.305 (11) Å, α = β = 90°, γ = 120°, z= 6, R1 = 0.0387, wR2 = 0.0842. Crystal data for 1a·2H2O include the following: hexagonal, P65, a = b = 13.151(4) Å, c = 36.558(2) Å, α = β = 90°, γ= 120°, Z = 6, R1 = 0.0416, wR2 = 0.1190. Crystal data for 2·H2O include the following: hexagonal, P61, a = b = 13.160(7) Å, c = 36.559 (4) Å, α = β = 90°, γ = 120°, z = 6, R1 = 0.0574, wR2 = 0.1423. [ABSTRACT FROM AUTHOR]

Abstract: Four different mononuclear octahedral Ni(II) complexes with protonated and deprotonated form of the same ligand have been synthesized by controlling reaction conditions and structurally characterized. The complexes are [Ni(HL l-his)(benzoate)(MeOH)] (1), [Ni(HL l-his)(SCN)(MeOH)] (2), [Ni(HL l-his)2] (3) and [Ni(L l-his)(imidazole)2] (4) where H2L l-his is (S)-2-(2-hydroxybenzylamino)-3-(1H-imidazol-4-yl)-propionic acid. The ligand behaves as a monobasic tetradentate ligand in 1 and 2, monobasic tridentate ligand in 3 and dibasic tetradentate ligand in 4. Ni(II) coordinated phenolic proton of the ligand in the complexes 1–2 shows strong intra-molecular H-bonding with benzoate in 1 and lattice water in 2, whereas 3 shows intermolecular H-bonding between uncoordinated phenols with neighbouring carboxylate. The pH titration of the complexes revealed that metal coordination and H-bond in complexes 1 and 2 considerably lowers the acidity of ligand phenol (pKa 6.8 and 7.0 respectively) compared to phenol (pKa 10). The complex 4 does not show any proton loss due to the absence of phenolic proton. All the complexes show extensive H-bonded network in the crystals including narrow (7.8×5.2Å) water filled one dimensional channel in 2. [ABSTRACT FROM AUTHOR]

Abstract: A resinous functionalized polymer, aniline formaldehyde condensate (AFC) coated on silica gel was used as an adsorbent to remove copper (Cu2+) from aqueous solution under conditions of different initial Cu2+ concentration, adsorbent loading, pH and adsorption time. Coordination bond formation between amine group and Cu2+ ion was the main mechanism of copper removal. Adsorption increased from 20% at pH 4 to 71% at pH 6 due to less competition from proton. Adsorption equilibrium was achieved within 120–150min. The kinetics of adsorption followed second order model with rate constant of 0.0021g/mgmin. The adsorption data gave good fit with Langmuir isotherm and yielded Langmuir monolayer isotherm uptake of 76.33mg/g and adsorption equilibrium parameter of 0.022L/mg at solution pH of 5.4–5.7 and temperature of 22–25°C. During desorption studies 97–100% of adsorbed copper ion released in solution in presence of 1N strength of mineral acids HCl, H2SO4 and HNO3. Dynamic study shows that column breakthrough was achieved at 264 bed volume at initial Cu2+ of 25mg/L. Further studies are recommended on regeneration and reuse of AFC coated silica gel after desorption of copper ion. [Copyright &y& Elsevier]

Examines the role of carboxylate bridges in modulating nonheme diiron(II)/O[sub 2] reactivity. Crystal structure; Physical properties of diiron(II) complexes; Generation and characterization of the dioxygen adducts; Implications for the oxidation mechanisms of nonheme diiron enzymes.