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We report the use of a ditopic molecular probe bispentadecylphenol substituted perylenediimide (PBI–PDP) to examine the molecular level self-assembly of polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) in tetrahydrofuran (THF). A series of complexes were prepared between PS-b-P4VP copolymers with varying lengths of the 4-vinylpyridine chain and PBI–PDP. Light scattering and NMR spectroscopic studies reveal that the self-assembled structures of the solid complexes are not fully disrupted when the complexes are dissolved in THF. NMR experimental parameters measured for the small probe molecule provide detailed insights into the structure of the assemblies in solution as well as the interaction between the small molecule and the block copolymer. Such insights can have important implications in manipulating the nanostructure of block copolymer micelles to suit various application requirements. The dynamics and distribution of the PBI–PDP molecules within the assemblies in solution show a dependence on the leng...

Allylic amination, directly from alcohols, has been demonstrated without any Lewis acid activators using an efficient and regiospecific molecular iron catalyst. Various amines and alcohols were employed and the reaction proceeded through the oxidation/reduction (redox) pathway. A direct one-step synthesis of common drugs, such as cinnarizine and nafetifine, was exhibited from cinnamyl alcohol that produced water as side product.

This study focused work-exposure to particulate matter ≤ 10 µm (PM10), volatile organic compounds (VOCs) and biological monitoring of major VOCs (BTEX) to observe the significant effects of traffic related pollutants on respiratory and hematological systems of workers engaged in two occupational settings, petrol pumps and traffic areas of Kolkata metropolitan city, India. PM10 was assessed by personal sampling and particle size distribution by 8-stage Cascade Impactor. VOCs were analysed by gas chromatography-flame ionization detector (GC-FID) and five urinary metabolites, trans trans- mercapturic acid (tt-MA), S-phenyl mercapturic acid (SPMA), hippuric acid (HA), mandelic acid (MA) and methyl hippuric acid (MHA) of VOCs, benzene, toluene, ethyl benzene and xylenes (BTEX) by reverse phase high performance liquid chromatography (HPLC). Pulmonary functions test (PFT) was measured Spirometrically. ∂-aminoleavulinic acid (ALA) and porphobilinogen (PBG) in lymphocytes were measured spectrophometrically following column chromatographic separation. High exposure to PM10, having 50% of particles, ≤ 5.0 µm in both the occupational settings. Exposure to toluene was highest in petrol pumps whereas benzene was highest (104.6 ± 99.0 μg m-3) for traffic police personnel. Workplace Benzene is found many fold higher than the National ambient standard. Air-benzene is correlated significantly with pre- and post-shift tt-MA (p < 0.001) and SPMA (p < 0.001) of exposed workers. Blood cell counts indicated benzene induced hematotoxicity. ALA and PBG accumulation in lymphocytes indicated alteration in heme-metabolism, especially among traffic police. Significant reduction of force exploratory volume in one second (FEV1) and forced vital capacity (FVC) of fuel fillers are observed with increased tt-MA and SPMA. Study revealed PFT impairments 11.11% (6.66% restrictive and 2.22% obstructive and combined restrictive and obstructive type, each) among petrol pumps and 8.3% obstructive type among traffic police.

Allylic amination, directly from alcohols, has been demonstrated without any Lewis acid activators using an efficient and regiospecific molecular iron catalyst. Various amines and alcohols were employed and the reaction proceeded through the oxidation/reduction (redox) pathway. A direct one-step synthesis of common drugs, such as cinnarizine and nafetifine, was exhibited from cinnamyl alcohol that produced water as side product.

The sulfonoquinovosyldiacylglyceride (SQDG) isolated from the leaves of Azadirachta indica showed significant anti-leukemic activity in human leukemic cell lines U937 and K562 with IC50 of 9 μg/ml. SQDG treated leukemic cells showed chromatin condensation, apoptotic body formation, and increased caspase 3 production indicating apoptosis. Cell cycle study revealed that the treated leukemic cells accumulated in the sub-G1 phase; the cell cycle was halted in this phase and the DNA content decreased in other phases.

Chloromethylated polystyrene supported ionic liquid is used as catalyst in the aldol-type coupling of a variety of aldehydes with ethyl diazoacetate in water. Moderate to excellent yields of the corresponding α-diazo-β-hydroxy esters were obtained. The catalyst was separated by filtration and reused in five consecutive cycles without any appreciable loss of activity.

Oxidative Heck reactions of arylboronic acids and alkenes are carried out in the presence of polyaniline-supported palladium catalysts using air as a co-oxidant to afford the Heck products with excellent yields and selectivities under base- and ligand-free conditions. The catalyst was recovered by simple filtration and used for several cycles with consistent activity.

Layered-double-hydroxide-supported nanorhodium catalyst (LDHRh(0)) was employed in the Heck-type coupling of alkenes 1 with arylboronic acids 2 to afford the corresponding substituted alkenes 3 in good to high yields (Table 1). The catalyst was separated by simple filtration and reused for five cycles with consistent activity.

Polyaniline supported CuI catalyst was prepared, characterized and effectively used in the N -arylation of N (H)-heterocycles and benzylamines with aryl halides and arylboronic acids and in aza-Michael reaction of amines with activated alkenes. The catalyst was recovered by simple filtration and reused for several cycles with consistent activity.

Silica-supported tetramethylguanidine catalyst was prepared and effectively used in the aldol-type coupling of aldehydes with ethyl diazoacetate to afford the corresponding α-diazo-β-hydroxy esters in good to excellent yields. The catalyst was quantitatively recovered from the reaction by a simple filtration and reused for a number of cycles with almost consistent activity.

Pd/C is used as an efficient catalyst for the copper-free Sonogashira coupling of acid chlorides and terminal alkynes to afford ynones in high yields (Tables 1 and 3). Cyclization of (2-methoxyaryl)-substituted ynones induced by I2/ammonium cerium(IV) nitrate (CAN) at room temperature gave 3-iodochromenones (=3-iodo-4H-1-benzopyran-4-ones) in excellent yield (Table 4).

Layered double hydroxides supported rhodium(0) catalyst was prepared, characterized and effectively used as a catalyst in the Heck, Suzuki and Stille cross-coupling of haloarenes. The catalyst can easily be removed by simple filtration and reused for several cycles with consistent activity.

Polyaniline supported palladium catalysts were prepared from different palladium precursors and all the catalysts are well characterized using ICP-AES, FTIR, TGA–DTA, SEM-EDX and XPS analysis. All the catalysts were tested for Suzuki–Miyaura coupling of bromo- and chloroarenes in water and the catalyst prepared from PdCl2 precursor was found to be the most effective catalyst. The catalyst can easily be recovered by simple filtration and reused for several cycles with almost consistent activity.

Silica tethered copper complexes are effectively used as reusable catalysts in the N-arylation of N(H)-heterocycles and benzyl amines with aryl halides and arylboronic acids. N-Arylated products were isolated in good to excellent yields, demonstrating the versatility of the protocol. Moreover the Cat2 was easily recovered by simple filtration and reused for several cycles with consistent activity.

Nanocrystalline magnesium oxide supported palladium(0) catalyst [NAP-Mg-Pd(0)], prepared by the counter-ion stabilization of PdCl 4 2- followed by reduction with hydrazine hydrate, was effectively used in the Heck olefination of haloarenes (chloro, bromo, and iodo) to afford good to excellent yields of substituted olefins. This ligand-free heterogeneous NAP-Mg-Pd(0) catalyst was quantitatively recovered from the reaction by a simple filtration and reused for a number of cycles with almost no loss of activity. Moreover, NAP-Mg-Pd(0) efficiently catalyzed the Sonogashira coupling of haloarenes with terminal alkynes without any copper co-catalyst under milder conditions to afford excellent yields of substituted alkynes.

Polyaniline-supported Sc, In, Pd, Os and Re catalysts were prepared by using a simple protocol and the thus prepared catalysts were well characterized using FTIR, XPS, UV-Vis/DRS, TGA-DTA. All the catalysts were successfully employed in a wide range of organic transformations such as cyanation and allylation of carbonyl compound, Suzuki coupling of aryl halides and boronic acids, and, most importantly, in asymmetric dihydroxylation of olefins to afford optically active vicinal diols. All the catalysts were separated from the reaction mixture by simple filtration and reused with consistent activity for five cycles without noticeable leaching of metal from the support.

Layered double hydroxide (LDH)-supported nanoplatinum(0) and nanopalladium(0) catalysts were prepared by a simple ion exchange technique and subsequent reduction with hydrazine hydrate and used for the allylation of aldehydes to give moderate to good yields of homoallylic alcohols. Detailed mechanistic studies of LDH-Pd(0)-catalyzed allylation using XPS and TGA-MS reveal that a monoallyl-palladium complex is the key intermediate for the catalytic cycle.

New bifunctional catalysts composed of PdCl 4 2- , OsO 4 2- and OsO 4 2- , WO 4 2- designed and prepared by a counterionic stabilization technique involving the reactions of Na 2 PdCl 4 -K 2 OsO 4 and K 2 OsO 4 -Na 2 WO 4 with nanocrystalline MgO are well characterized. These bifunctional catalysts, NAP-Mg-PdOs and NAP-Mg-OsW perform tandem Heck asymmetric dihydroxylation and asymmetric dihydroxylation-N-oxidation reactions, respectively, in the presence of the chiral ligand 1,4-bis(9-o-dihydroquinidinyl)phthalazine [(DHQD) 2 PHAL] in a single pot. It is quite impressive to note that H 2 O 2 is used as a terminal oxidant to provide N-methylmorpholine N-oxide (NMO) in situ by the oxidation of N-methylmorpholine (NMM) in the asymmetric dihydroxylation-N-oxidation catalyzed by NAP-Mg-OsW.

Silica-supported copper catalysts were effectively used in the three-component coupling of aldehydes, amines and alkynes to afford the corresponding propargylamines in moderate to excellent yields. The catalyst was quantitatively recovered from the reaction by a simple filtration and reused for a number of cycles with almost consistent activity.

A layered double hydroxide-supported nanoplatinum catalyst is employed in the Heck and Stille cross-coupling of a wide range of iodoarenes to give the corresponding cross-coupled products in good to excellent yields. The catalyst is recovered by centri-fugation and reused over a number of cycles with consistent activity.

Layered double hydroxide-supported nanopalladium (LDH-Pd°) is an effective catalyst for Suzuki cross-coupling of a wide range of aryl iodides and bromides with arylboronic acids at room temperature. The catalyst is reused for four cycles with consistent activity.

Layered-double-hydroxide-supported nanorhodium catalyst (LDHRh(0)) was employed in the Heck-type coupling of alkenes 1 with arylboronic acids 2 to afford the corresponding substituted alkenes 3 in good to high yields (Table 1). The catalyst was separated by simple filtration and reused for five cycles with consistent activity.

Silica-supported tetramethylguanidine catalyst was prepared and effectively used in the aldol-type coupling of aldehydes with ethyl diazoacetate to afford the corresponding α-diazo-β-hydroxy esters in good to excellent yields. The catalyst was quantitatively recovered from the reaction by a simple filtration and reused for a number of cycles with almost consistent activity.

A 3-aminopropyl-functionalized silica-supported rhodium(0) catalyst (SiO2–Rh0) was prepared and employed in the Heck-type coupling of arylboronic acids and alkenes, affording good-to-excellent yields of substituted alkenes; the catalyst was recovered by filtration and reused for several cycles.

Polyaniline supported palladium catalysts were prepared from different palladium precursors and all the catalysts are well characterized using ICP-AES, FTIR, TGA–DTA, SEM-EDX and XPS analysis. All the catalysts were tested for Suzuki–Miyaura coupling of bromo- and chloroarenes in water and the catalyst prepared from PdCl2 precursor was found to be the most effective catalyst. The catalyst can easily be recovered by simple filtration and reused for several cycles with almost consistent activity.

A 3-aminopropyl-functionalized silica-supported rhodium(0) catalyst (SiO2–Rh0) was prepared and employed in the Heck-type coupling of arylboronic acids and alkenes, affording good-to-excellent yields of substituted alkenes; the catalyst was recovered by filtration and reused for several cycles.