The TiO 2 thin films doped by Ni uniformly and non-uniformly were prepared on glass substrate from an aqueous solution of ammonium hexa-fluoro titanate and NiF 2 by liquid phase deposition technique. The addition of boric acid as an Fscavenger will shift the equilibrium to one side and thereby deposition of the film is progressed. The rate of the reaction and the nature of deposition depend on growing time and temperature. The resultant films were characterized by XRD, EDAX, UV and SEM. The result shows that the deposited films have amorphous background, which becomes crystalline at 500°C. The EDAX data confirms the existence of Ni atoms in TiO 2 matrix. XRD analysis reveals the peaks corresponding to Ni but no peak of crystalline NiO was found. The transmittance spectra of Ni uniformly and non-uniformly doped TiO 2 thin films show 'blue shift and red shift', respectively. Ni-doped TiO 2 thin films can be used as photocatalyst for the photodegradation of methyl orange dye. It was found that, organic dye undergoes degradation efficiently in presence of non-uniformly Ni-doped TiO 2 thin films when compared to uniformly doped films and pure TiO 2 films under visible light. The photocatalytic activity increases with increase in the concentration of Ni in case of nonuniformly doped thin films but decreases with the concentration when uniformly doped thin films were used.

Curcumin derivatives which are very potent antioxidant, free radical scavenger and known inhibitor of dioxygenases have been extensively studied to explore their potential utilization in chemoprevention. The main objective of the present work is to perform a docking analysis of curcumin derivatives: Tetrahydrocurcumin (THC), Bisdemethoxy curcumin (BDC). Docking studies of these were performed using GOLD and AutoDock into a few well validated targets of anticancer therapy (COX-2, PhenolsulphoTransferases, Matrix metalloproteinases (MMPs), P450 and TNF-alpha). A good correlation was observed in binding affi nity of THC and BDC against the targets indicating these derivatives are potent procarcinogen activating enzyme inhibitors.

For the first time fluorine has been examined as a steering group for crystal engineering. In sharp contrast to the packing and photo behaviour of unsubstituted coumarin, molecules of both 6-and 7fluorocoumarins are found to attain a packing mode which enables them to undergo [2 + 21 photodimerization in the solid state leading stereospecifically to a mirror symmetric dimer.From the pioneering work by Schmidt et al.,I4 it emerged that the crucial factor that determines the success of a [2 + 2) topochemical photo cycloaddition is a favourable juxtaposition of double bonds of incipient reactive molecules with the centreto-centre distance of the double bonds being less than ca. 4.2 A;(the @ packing mode). Ever since this discovery the most challenging problem in the area is that of 'Crystal Engineering' which aims at pre-organising the molecules of interest into a packing mode favourable for photodimerization. Efforts in this direction led to the identification of steering groups such as ~h l o r o , ~-~ bromo" and sulfur." We present here the first report on the use of fluoro-substitution to bring about a packing mode favourable for stereospecific photodimerization.Coumarin which was earlier reported' ' to be photostable in the crystalline state has in fact been found to react,13 though in a non-topochemical fashion, yielding three photodimers differing in stereochemistry; syn head-to-head, syn head-to-tail and anti head-to-head (Scheme 1). However, chloro7 and bromo" groups have already been shown to be able to steer molecules of coumarin to the @-packing mode. It was considered to be worth examining the steering capability of other halogen atoms i.e. fluorine and iodine. The results pertaining to the photo behaviour in relation to the nature of crystal packing of fluoro-substituted coumarins are discussed in this paper. ExperimentalBoth 6-fluorocoumarin 1 and 7-fluorocoumarin 2 were Paper 2/05480I

In order to achieve high colouration efficiency, MoO 3-WO 3 composite thin films have been successfully deposited on sodium silicate glass and silicon wafer (111) at 30 • C by a very simple novel wet process known as liquid phase deposition. The deposited films were annealed at different temperatures and characterized by carrying out SEM, EDAX, UV-vis and XRD analyses. The EDAX and SEM analyses support the structure and existence of peaks corresponding to Mo, W and O. X-ray diffraction studies showed that MoO 3-WO 3 is amorphous at lower temperature and turns crystalline at higher annealing temperature and suggested the mixture of two crystalline phases such as orthorhombic-monoclinic. Photochromic properties of the MoO 3-WO 3 composite films were studied in the spectral region 400-1200 nm by illuminating them in polychromatic light. The photochromic behaviour is observed to be more effective in composites films in visible region. Keywords. MoO 3-WO 3 thin films; composites; LPD technique; photochromism.

Simultaneous deposition of both nickel and chromium in the form of alloy is a subject with pronounced practical significance in automobile industries. Electroplating of Ni-Cr alloy has been carried out using suitable plating bath solution and working conditions. The alloys are partially crystalline and new phases appear on heat-treatment of the coating. Surface morphology and microstructure of the coating are closely related to the nature of the bath components, bath composition, alloy composition, and post-treatment of the coating. X-ray photoelectron spectroscopy studies indicated that the alloy contains nickel in +2 and +3 oxidation states, whereas it contains chromium in the +3 oxidation state in the deposited Ni-Cr coating. The sputtering of the coatings up to 20 min changed the nickel and chromium to metallic state. The coated alloys exhibited good corrosion resistance to acidic media, e.g., 0.5 M H 2 SO 4 , 1 M HCl, and 5% NaCl ͑pH 5͒, and heat-treatment of the coating enhanced the corrosion resistance.

The title compound, C 21 H 24 O 6 , is the reduced form of curcumin, and exhibits important cosmoceutical properties. The molecule is non-planar and the benzene rings positioned at the ends of the heptane chain are orthogonally placed, with a dihedral angle of 84.09 (7) between them. The molecular geometry and H-atom locations reveal that the`heptane-3,5-dione' moiety exists in the keto±enol form, with the hydroxy H atom disordered over two adjacent sites. The packing of the molecules in the lattice is directed by strong OÐHÁ Á ÁO intermolecular hydrogen bonds, which generate two-dimensional sheets. These sheets are linked by CÐHÁ Á ÁO hydrogen bonds and weak CÐHÁ Á Á% interactions to develop a threedimensional network. CommentTetrahydrocurcuminoids, such as the title compound, (I), are derived from curcuminoids, such as (II), and may be extracted from the roots of Curcuma longa, commonly called turmeric root (Govindarajan, 1980). Tetrahydrocurcuminoids are colourless, unlike the yellow curcuminoids. They may therefore be used in colour-free foods and cosmetic products, which currently employ conventional synthetic antioxidants such as butylated hydroxytoluene (BHT). An antioxidant used in a cosmetic application should have the capability of ef®ciently quenching any radicals on the surface of the skin. In this context, compound (I) displays a superior free-radical scavenging ability and also exhibits antioxidant, anti-in¯am-matory and skin-lightening actions (Sugiyama et al., 1996; Srihari Rao et al., 1982) and anticancer activity (Huang et al., 1995). It is thought that the p-hydroxy functional groups in (I) are responsible for the antioxidant and chemopreventive action of the compound (Rao et al., 1995; Halliwell & Gutteridge, 1985). We have established the crystal structure of (I) with the intention that it will assist in pharmocological studies of the compound.Electron delocalization and intramolecular hydrogen bonding in the keto-enol moiety ÐCOÐHC CÐOH have been studied in a number of molecules (Semmingsen, 1976) and in curcuminoid structures (Mostad, 1994;Arrieta et al., 2000;Tonnesen et al., 1982). Of the possible tautomeric forms, it appears that, in the crystal phase, -diketones prefer the cisenol arrangement stabilized by a strong intramolecular hydrogen bond.A view of (I) with the labelling scheme is shown in Fig. 1 Figure 1 The structure of (I), showing the atom-numbering scheme and 30% probability displacement ellipsoids. H atoms are shown as small spheres of arbitrary radii. Figure 2A difference map in the plane of the keto±enol system, showing the hydroxy H-atom disorder at O3 and O5 and the single H atom at C4. Contours are drawn at 0.05 e A Ê À3 .

Abstract. Different substituted diesters of thiazolopyrimidine were prepared by the treatment of 3,4 dihydropyrimidine2-thione with α-haloesters using ethanol under reflux condition affording 71-85% yield. IR, 1 HNMR, 13 CNMR and elemental analyses were used for the characterization of these compounds. The crystal and molecular structure of one of the product, 5-phenyl-3,7-dimethyl-5H-thiazolo[3,2-a]pyrimidine-2,6-dicarboxylic acid diethyl ester (3e) was verified by single crystal X-ray diffraction method. The antimicrobial activity was evaluated against four bacterial strains and one fungal species. Few of the derivatives exhibited antibacterial and antifungal activities.

In the title compound, C14H9F3N2O, the best planes of the benzimidazole group and benzene ring form a dihedral angle of 26.68 (3)°. In the crystal, N—H⋯N hydrogen bonds link the mol­ecules into infinite chains parallel to the c axis. Stacking inter­actions between the benzimidazole groups [centroid–centroid distance = 3.594 (5) Å] assemble the mol­ecules into layers parallel to (100). The trifluoro­methyl group is disordered over three sets of sites with site-occupancy factors of 0.787 (4), 0.107 (7) and 0.106 (7).