Extraction and coordination studies of carbamoyl methyl sulfoxide (CMSO) with uranyl bis(β-diketonates). Synthesis and molecular structure of [{UO2(DBM)2}2C6H5CH2SOCH2CONHC6H5]

The carbamoyl methyl sulfoxide compounds of uranyl bis(β-diketonate) of the types [UO₂(DBM)₂CMSO] and [{UO₂(DBM)₂}₂CMSO] (where HDBM = C₆H₅COCH₂COC₆H₅; CMSO = C₆H₅CH₂SOCH₂CONHC₆H₅ or C₆H₅SOCH₂CONⁱPr₂) have been synthesized and characterized by IR and NMR spectroscopic techniques and elemental analysis. Spectral studies show that CMSO acts as a monodentate ligand in [UO₂(DBM)₂CMSO] compounds and bonds through the sulfoxo oxygen atom to the uranyl group. It acts as a bridging bidentate ligand in [{UO₂(DBM)₂}₂CMSO] compounds and bonds through both the sulfoxo and carbamoyl oxygen atoms to two different uranyl groups. The structure of the compound [{UO₂(DBM)₂}₂C₆H₅CH₂SOCH₂CONHC₆H₅] confirms the bridging bidentate mode of coordination for the CMSO ligand. Extraction studies show an enhancement in solvent extraction for the uranyl ion from nitric acid medium when a mixture of thenoyl trifluoroacetone (HTTA) and CMSO was employed.     

Recognition of anions and monocarboxylic acids by a fluorescent guanidine-based receptor

A guanidine-based fluorescent receptor has been synthesised to study its binding behaviour towards anions (F^? , Cl^? , Br^? , I^?  and AcO^? ). The two donor N–H bonds of the receptor do not point in the same direction; rather, one N–H bond is intramolecularly hydrogen-bonded with the carbonyl oxygen atom. The nature of the donor–acceptor (DA) arrangement induces moderate binding properties. The binding behaviour towards monocarboxylic acids (benzoic acid and phenylacetic acid) is also compared. The binding behaviour of receptor 1 towards the F^?  anion is higher among the anions studied, whereas in the case of monocarboxylic acid, the binding constant with phenylacetic acid is higher than benzoic acid.     

Crystal Structure Investigations of Inclusion Complexes Between β-cyclodextrin and Alkyl(aqua)cobaloximes (Alkyl=Butyl,Hexyl and Cyclohexyl)

The crystal and molecular structures of alkylcobaloxime/ g -cyclodextrin ( g -CD) inclusion complexes: butyl(aqua)cobaloxime/ g -CD ( 1 ). hexyl(aqua)cobaloxime/ g -CD ( 2 ) and cyclohexyl(aqua)cobaloxime/ g -CD ( 3 ) were determined by X-ray diffraction analyses. Crystal data for 1 14H 2 O: P 2 1 2 1 2 1 , a =15.1335(3), b =18.9630(2), c =28.1545(5) Å, Z =4; 2 12H 2 O: P 2 1 2 1 2 1 , a =15.1135(4), b =19.1477(5), c =28.2715(7) Å, Z =4; 3 10H 2 O: P 2 1 2 1 2 1 , a =15.6898(2), b =16.9094(2), c =28.9762(2) Å, Z =4. The structural and conformational comparisons for the three g -CD inclusion complexes with their guest molecules as well as other CD inclusion analogs are discussed.     

Synthesis and performance characterization of PS-PPEES nanoporous membranes with nonwoven porous support

The present work describes about the synthesis and characterization of Polysulfone blend nanoporous membrane with nonwoven support. This Nonwoven support provides mechanical strength to membrane while filtration process and minimizes membrane fouling. Hence it helps in better membrane performance in terms of salt rejection, improved flux, thermal stability and fairly increases in proton conductivity. In this work we have used K.C.270 nonwoven material consisting of fine polyester fibers and has a thickness of below 110 μm.     

Synthesis,characterization and antibacterial activity of some new pyrazole based Schiff bases

In the present study a series of new Schiff bases were synthesized. All the synthesized compounds were characterized by IR, ¹H NMR, mass spectral and elemental analyses. Newly synthesized compounds were screened for their antibacterial (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa) activity. The results revealed that, compounds 3f and 3c have exhibited significant biological activity against the tested microorganisms.     

From Nongelating to Gelating: Synthesis and Structural Self‐Assembling Property Relationships of a Homologous Series of Oligo(amide–triazole)s

A homologous series of oligo(amide–triazole)s (OAT) [ OAT‐CO₂H‐2 n and OAT‐COPrg‐(2 n +1) ] with an increasing number of primary amide (CONH) and triazole hydrogen‐bonding functionalities was prepared by an iterative synthetic procedure. It was found that their self‐assembly and thermoreversible gelation strength had a strong correlation to the number of hydrogen‐bonding moieties in the oligomers. There also existed a threshold value of the number of CONH units, above which all the oligomers became organogelators. Hence, oligomers with ≤4 CONH units are devoid of intermolecular hydrogen bonding and also non‐organogelating, whereas those that contain >4 CONH units show intermolecular association and organogelating properties. For the organogelators, the T_gel value increases monotonically with increasing number of CONH units. On the basis of FTIR measurements, both the CONH and triazole C? H groups were involved in the hydrogen‐bonding process. A mixed xerogel that consisted of a 1:1 weight ratio of two oligomers of different lengths ( OAT‐CO₂H‐6 and OAT‐CO₂H‐12 ) was found to show microphase segregation according to differential scanning calorimetry, thus indicating that oligomers that bear a different number of hydrogen‐bonding units exhibited self‐sorting to maximize the extent of intermolecular hydrogen bonding in the xerogel state.