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,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.     

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.     

Syntheses,crystal structures and spectroscopic properties of the novel complexes [M(MOBPT)*2 (H2O)2](ClO4)2 · 4H2O (M = CoII and NiII)

The novel cobalt(II) and nickel(II) complexes with 4-(p-methoxyphenyl)-3,5-bis(pyridin-2-yl)-1,2,4-triazole (MOBPT) have been synthesized and their molecular structures determined by X-ray analysis, i.r. and by ESI-MS spectroscopy. The metal atom is in a distorted octahedral environment. Two bidentate chelating ligands (MOBPT) coordinate to the metal center equatorially and two water molecules coordinate axially. Each MOBPT entity coordinates via one triazole nitrogen and one pyridine nitrogen atom. Magnetic measurements show that the complexes are high-spin species in the 75–300 K range.     

Diethyl 1-(p-fluoro­phenyl)-5-oxo-3-(2-thienyl)­pyrrolidine-2,2-di­carboxyl­ate

In the title compound, C₂₀H₂₀FNO₅S, the pyrrolidine ring adopts an envelope conformation. The fluoro­phenyl and thio­phene rings are individually planar. The molecular and crystal structures are stabilized by intra- and intermolecular C—H⋯O interactions.     

层状配位聚合物犤Pb(NCS)_2(bpea)_n的合成,结构和非线性光学性质(bpea=1,2-双(4-吡啶基)乙烷)(英文)

室温下Pb(OAC)2·3H2O,KNCS,和1,2-双(4-吡啶基)乙烷在甲醇中反应生成了八员环支撑的层状配位聚合物犤Pb(NCS)2(bpea)犦n。三阶非线性Z-扫描研究表明该化合物具有非线性折射行为:其非线性吸收系数α2=1.1×10-11m·W-1,非线性折射系数n2=6.055×10-18m2·W-1。     

间苯二甲酸连接的氢键导致的二维锌配位聚合物的合成及晶体结构

由于配位聚合物在催化材料,磁性材料和光学材料等领域内具有广泛的 应用价值,近年来人们已经合成了不少多维配位聚合物,并对其进行了结构鉴定和性质研究。配位聚合物一般都是通过体系内的配位键、氢键,和金属－金属间相互作用等作用力形成。在大多数的体系中,一般采用含氮基团,如4,4－联吡啶,2,4,6－三（4－吡啶基）－1,3,5－三嗪,1,4－二咪唑丁胺等作为桥连配体合成具有各种不同拓扑结构的无限伸展体系。同时,利用含氧基团作为桥基合成各类配位聚合物也是一个重要的途径,一般为多酸体系,如1,3,5－三苯甲酸,马来酸等。我们通过分子自组装作用,合成了一例由间苯二甲酸作桥基通过氢键导致的金属锌的二维配位聚合物,通过单晶X－射线衍射,研究了它的结构。     

咪唑配合物[Co(C3H4N2)6](PhCHCHCOO)2的合成及晶体结构

The complex [Co(Im)6](Cin)2 (Im=imidazole,Cin=cinnamate) was prepared by reaction of Co(PhCHCHCOO)2 with imidazole in ethanol. It has been determined by single crystal X-ray analyses. The crystals are triclinic, space group P, with a=9.7601(3),b=10.5935(3),c=11.3269(2)(A),α =69.948(1),β =71.027(1),γ =62.803(1)°, and Z=1. The crystal structure of the title complex consists of monomeric [Co(Im)6]2+ cations and cinnamate anions in which the cobalt(Ⅱ) ion assumes a centrosymmetric octahedral geometry with the CoN6 chromophore. In the solid state, the complex forms a three dimensional network through N-H… O hydrogen bonds, the intermolecular hydrogen bonds connect the [Co(Im)6]2+ cations and cinnamate anions.The cinnamate anions are nearly planar.     

Synthesis,crystal structure and two-photon property studies on a series of complexes derived from a novel Schiff base ligand

A new Schiff base ligand derived from S-benzyldithiocarbazate and 4-[N-hydroxy ethyl-N-(methyl)amino]benzaldehyde (HL, where H is a dissociable proton) and its Ni^II, Cu^II, Zn^II and Pd^II complexes were prepared and fully characterized. The structures of HL and Ni(L)₂ were determined by X-ray diffraction analysis, which revealed that the geometry of the Ni^II ion is square-planar with two equivalent Ni=N and Ni=S bonds, and that the two neighboring molecules in two layers have weak contact. The electronic spectra and solution fluorescence of the ligand and the complexes were studied, and the quantum yields of single-photon fluorescence for the compounds were determined. The compounds possess two-photon absorption (t.p.a.) character and the t.p.a. coefficient and t.p.a. cross-section were determined by the Z-scan technique. Especially, the Zn(L)₂complex and the HL ligand exhibit intensive two-photon fluorescence (t.p.f.) at 800 nm laser pulses in the femtosecond regime.