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The present study was aimed at preparing and evaluating levocetirizine (LCZD) loaded emulgel containing tamanu oil and sericin for atopic dermatitis (AD) therapy. The emulgel envisaged topi...

Previously synthesized novel chalcone oxime ethers (COEs) were evaluated for inhibitory activities against monoamine oxidases (MAOs) and acetylcholinesterase (AChE). Twenty-two of the 24 COEs synthesized, except COE-17 and COE-24, had potent and/or significant selective inhibitory effects on MAO-B. COE-6 potently inhibited MAO-B with an IC50 value of 0.018 &micro, M, which was 105, 2.3, and 1.1 times more potent than clorgyline, lazabemide, and pargyline (reference drugs), respectively. COE-7, and COE-22 were also active against MAO-B, both had an IC50 value of 0.028 &micro, M, which was 67 and 1.5 times lower than those of clorgyline and lazabemide, respectively. Most of the COEs exhibited weak inhibitory effects on MAO-A and AChE. COE-13 most potently inhibited MAO-A (IC50 = 0.88 &micro, M) and also significantly inhibited MAO-B (IC50 = 0.13 &micro, M), and it could be considered as a potential nonselective MAO inhibitor. COE-19 and COE-22 inhibited AChE with IC50 values of 5.35 and 4.39 &micro, M, respectively. The selectivity index (SI) of COE-22 for MAO-B was higher than that of COE-6 (SI = 778.6 vs. 222.2), but the IC50 value (0.028 &micro, M) was slightly lower than that of COE-6 (0.018 &micro, M). In reversibility experiments, inhibitions of MAO-B by COE-6 and COE-22 were recovered to the levels of reference reversible inhibitors and both competitively inhibited MAO-B, with Ki values of 0.0075 and 0.010 &micro, M, respectively. Our results show that COE-6 and COE-22 are potent, selective MAO-B inhibitors, and COE-22 is a candidate of dual-targeting molecule for MAO-B and AChE.

Two new copper(II) complexes; [Cu(temed)(p-nitro-cinnamate)2] (1), [Cu(temed)(p-methoxy-cinnamate)2] (2), where temed = N,N,N′,N'-tetramethylethylenediamine, have been synthesized by reacting appropriate starting materials using methanol-water (4:1 v/v) as solvent at room temperature. Both newly synthesized copper(II) cinnamate complexes have been characterized on the basis of elemental analyses, spectroscopic techniques (FT-IR, UV–visible, EPR) and single crystal X-ray structure determination. X-ray structure determination of both complexes revealed the existence of neutral structure of both complexes. p-Nitrocinnamate and p-methoxycinnamte exhibited similar (asymmetric chelating) coordination mode of carboxylate ligand towards copper(II) metal centre. Various non-covalent intermolecular interactions such as C-H∙∙∙O have also been observed that play an important role in crystal lattice stabilization of complexes 1 and 2. The EPR spectroscopy on the basis of axial symmetry of g tensor components suggested tetragonally elongated octahedral geometry of the complexes which is consistent with X-ray structure determination.

Two transition metal complexes containing copper (II) ion, dye methyl red (H-MR) and nitrogen donor ligands β/γ-picoline (β/γ-pic) have been synthesized for the first time using appropriate starting materials in methanol-water (4:1 v/v) as solvent and characterized by spectroscopic methods (UV–Vis, FT-IR) and thermogravimetric analyses. The crystal structures of both complexes have been unambiguously determined by single crystal X-ray analysis as [Cu(MR)2 (β-pic)2] for 1 and [Cu(MR)2 (γ-pic)2 (MeOH)0.5(H2O)0.5]∙0.5MeOH∙1.5H2O for 2. Whereas in complex 1 Cu(II) coordinated by carboxylate oxygen atoms of two MR and nitrogen atoms of two β-pic molecules adopts an almost ideal square planar geometry, in complex 2 Cu(II) additionally coordinated by methanol/water exhibits a distorted square pyramidal structure. Both complexes are packed in layers stabilized by intermolecular C/O H⋯O hydrogen bonds. DFT calculations provided insight into the existence of the six possible relevant complexes. The relative stabilities are in the order Cu(MR)2 (γ-pic)2(H2O) 2w ≈ Cu(MR)2 (β-pic)2(H2O) 1w > Cu(MR)2 (γ-pic)2 (MeOH) 2m ≈ Cu(MR)2 (β-pic)2 (MeOH) 1m » Cu(MR)2 (γ-pic)2 2b ≈ Cu(MR)2 (β-pic)2 1, suggesting the significant role of solvent's coordination in enhancing the thermodynamic stability of metal coordination complexes.

We report a novel nanohybrid shish-kebab (NHSK) architecture of cellulose nanofibers (CNFs) and a block copolymer, (polyethylene-b-polyethylene glycol) (PE-b-PEG). Cellulose microfibers were ultrasonically dispersed to generate cellulose nanofibers in the size range of 50 ± 10 nm in diameter, while the block copolymer was crystallized using a solution crystallization approach to prepare NHSK. This unique approach allows the flocculated NHSK product to transfer quickly from toluene to ethanol, in order to shorten the preparation time. Morphological analysis reveals, for the first time, that nanocellulose can be used to induce crystallization of a block copolymer to generate NHSK and trans-crystalline structure. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results reveals the crystal morphology and crystallinity changes by virtue of crystallization. The ordered periodic growth and alignment of polymer crystals is recognized as the virtue of molecular origin of extended polymer chains. The proposed hypothesis affords elucidation of NHSK architecture and promotes the designing of novel nanohybrids with controllable functionality.

A new anionic copper(II) complex, (MeImH)(2) Cu(pfbz)(4)] (1) where, MeImH = 2-methylimidazolium and pfbz = pentafluorobenzoate has been isolated by reacting copper(II) sulfate pentahydrate, pentafluorobenzoic acid and 2-methylimidazole in ethanol: water mixture in 1:2:2 molar ratio. This complex 1 has been characterized by elemental analysis, thermogravimetric analysis, spectroscopic techniques (U-VVis, FT-IR) and conductance measurements. The complex salt crystallizes in monoclinic crystal system with space group C2/c. Single crystal X-ray structure determination revealed the presence of discrete ions: Cu(pfbz)(4)](2-) anion and two 2-methylimidazolium cation (C4H7N2)(+). The crystal lattice is stabilized by strong hydrogen bonding and F center dot center dot center dot F interactions between cationic-anionic and the anionic -anionic moieties respectively, besides pi-pi interactions. (C) 2016 Elsevier B.V. All rights reserved.

A new hybrid inorganic-organic compound [Cu(Hdien)2(H2O)2](pnb)4·4H2O (1) (where pnb = p-nitrobenzoate), in which the tridentate ligand diethylenetriamine (dien) shows an unusual coordination behavior acting as a bidentate ligand when present in its monoprotonated form (Hdien+) has been synthesized by the reaction of copper(II) p-nitrobenzoate and slight excess of dien in methanol-water mixture (4:1v/v). Re-crystallization of the violet precipitated product from hot water gave single crystals suitable for X-ray diffraction studies. The newly synthesized compound 1 has been characterized by spectroscopic techniques (UV–Vis, FT-IR, EPR), and theoretical methods (DFT and MRCI/SORCI). Single crystal X-ray structure determination revealed the existence of the cationic species [Cu(Hdien)2(H2O)2]4+, four p-nitrobenzoate as counter anions and four water molecules are present as solvent of crystallization. Packing analyses of title compound as well as of the structurally similar [Cu(en)2(H2O)2](pnb)2, 2 has shown similarities in the crystalline architecture that both hybrid inorganic-organic compounds is stabilized by various non-covalent interactions such as N-H⋯O, C-H⋯O, O-H⋯O etc.

An efficient unprecedented Pd-catalyzed rapid 2-fluoroethoxylation of bromo-chalcones has been unveiled. The oxygen nucleophiles (fluoroalcohols) experience the rapid C O bond forming reaction for the first time, albeit the alcohols are known to be a weak nucleophile and have greater competing β–hydride elimination in the transition-metal-catalyzed (especially Pd and Cu) C O cross-coupling reaction. The higher fluoroalcohols have also been effectively coupled with bromo-chalcones with relatively lower rate.

Using metal ions thallium(I), copper(II), silver(I) and lead(II) and ligand 2-chloro-5-nitrobenzenesulfonate(cnb), four new metal complexes [Tl(cnb)]n(1), [Cu(en)2(H2O)2](cnb)2.2H2O(2), where en = ethylenediamine, [Ag(cnb)]n(3) and [Pb(cnb)2]n(4) have been synthesized and characterized by elemental analyses, spectroscopic methods (FT-IR, multinuclear NMR), single crystal X-ray structure analyses (except 4) and TGA analyses. Complexes 1 and 3 crystallize in monoclinic crystal system in P21/c space group having unit cell dimensions, a = 13.849(2) A, b = 9.449(2) A, c = 7.506(2)A, β = 105.3°, V = 947.1 A3, Z = 4 and a = 15.197(13)A, b = 5.136(4)A, c = 24.058(18)A, β = 106.86°, V = 1797.1 A3, Z = 4 respectively. Complex 2, crystallizes in triclinic crystal system with P I ¯ having unit cell parameters; a = 6.888 A, b = 7.835 A, c = 13.227 A, α = 80.20°, β = 83.15°, γ = 78.18°, V = 945.6 A3, Z = 1. X-ray structure determination revealed that complexes 1 and 3 are polymeric in nature, whereas complex 2 has ionic structure. Remarkably, cnb ligand is coordinating through sulfonato oxygen atoms and nitro oxygen atoms in thallium complex but coordinates through sulfonato oxygen atoms and chloro group in silver complex, thereby showing the flexible/versatile coordinating behaviour of anionic ligand. This is unusual.

Synthesis of Schiff bases linked to organopropylsilatranes were performed by condensation reaction of post-functionalized silatranes such as aminopropylsilatrane (4), aminopropyl-3,7,10-trimethylsilatrane (5) and N-substituted aminopropylsilatrane (10) with two different aldehydes viz. pyrrole-2-carboxaldehyde and 2-hydroxy-1-napthaldehyde. The resulting Schiff base substituted silatranes were well characterized by elemental analysis, spectroscopic studies [IR, (1H, 13C) NMR, and MS]. The structures of two silatranes were confirmed by single crystal X-ray diffraction analysis.

Reaction of hydrated copper(II) 2-chloro-benzoate with β-/γ-picoline in methanol: water mixture (4:1 v/v) yielded polymeric [Cu(2-chlorobenzoate) 2 (β-picoline) 2 (μ-H 2 O)] n ; 1 and monomeric [Cu(2-chlorobenzoate) 2 (γ-picoline) 2 (H 2 O)]; 2 . The newly synthesized complexes have been characterized by elemental analyses, FT-IR spectroscopy, UV–Visible spectroscopy, TGA and single crystal X-ray structure determination. X-ray crystallographic analysis revealed that both complexes crystallize in the monoclinic crystal system with space group and unit cell dimensions: C 2/ c ; a = 51.71 A, b = 10.58 A, c = 10.02 A and β = 100.5° for 1 and P 2 1 / c ; a = 11.81 A, b = 16.33 A, c = 13.79 A and β = 90.77° for 2 . Whereas in 1 the presence of constituent and mediating water molecules running along a -axis gives rise to 1-dimensional zig-zag polymer chains, in complex 2 , the presence of square pyramidal arrangement of ligands around copper(II) center results in monomeric structure. Various non-covalent interactions like O H⋯O, C H⋯O and C H⋯л have been observed to play a decisive role in the stabilization of crystal lattices in both complexes.

Reaction of hydrated copper (II) 2-iodobenzoate with β/γ-picoline in methanol:water mixture (4:1, v/v) yielded two rare aqua bridged zig-zag polymers [Cu(2-iodobenzoate) 2 (β-picoline) 2 (μ-H 2 O)] n ; 1 and [Cu(2-iodobenzoate) 2 (γ-picoline) 2 (μ-H 2 O)] n ; 2 . The newly synthesized complexes have been characterized by elemental analysis, FT-IR spectroscopy, UV–Vis spectroscopy and single crystal X-ray structure determination. Complex 1 crystallized in monoclinic crystal system with C2/c space group, and complex 2 crystallized in triclinic crystal system with P 1 ‾ space group. X-ray structure determination revealed the presence of 1-dimensional chains of constituent molecules running along a -axis in both complexes. Water molecules act as bridges between constituent molecules and hence play a crucial role in 1-dimensional chain propagation in zig-zag manner. Empty channels have been observed between the zig-zag chains of complexes. Non-covalent interactions interactions such as O–H⋯O, C–H⋯O and C–H⋯π have been observed, which play a decisive role in the stabilization of crystal lattices in both complexes 1 and 2 .

A new tetranuclear thallium complex, [Tl4(H2O)2(anthracene-9-carboxylate)4] was isolated by reaction of hot aqueous solution of thallium(1)sulphate with sodium salt of anthracene-9-carboxylic acid in water taken in appropriate stoichiometric ratio. The newly synthesized complex was characterized by elemental analysis, thermogravimetric analysis, spectroscopic studies (FT-IR, UV–Visible, and multinuclear NMR). Complex crystallizes in monoclinic crystal system with P21/n space group. X-ray crystal structure determination revealed the presence of neutral centrosymmetric tetranuclear complex which contains two symmetry independent thallium cations. Tl1 is four-coordinate and bonded to three different anthracene-9-carboxylate anions. The other thallium cation, Tl2, is three-coordinate, being surrounded by two carboxylate oxygen atoms from two different ligands; anthracene-9-carboxylate and a water molecule. The crystal lattice is stabilized by C H/O H⋯O hydrogen bonding and cation⋯π interactions.

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.

In an effort to study the binding of substituted arylsulphonates by cationic cobalt(III) complex [Co(phen) 2 CO 3 ] + , two complex salts [Co(phen) 2 CO 3 ](4-chlorobenzenesulphonate)⋅3H 2 O, 1 and [Co(phen) 2 CO 3 ] (2,4-dinitrobenzenesulphonate)⋅H 2 O, 2 have been synthesized. These complex salts were characterized by elemental analysis, solubility product, conductivity measurements, thermal and spectroscopic studies. The crystal structures of 1 and 2 have been determined by single-crystal X-ray structure determination. Both complex salts crystallize in triclinic system (space group P 1 ¯ ) with cell dimensions a = 10.215(5) Ǻ, b = 12.013(5) Ǻ, c = 12.822(5) Ǻ, α = 69.497(5), β = 88.855(5), γ = 78.430(5)°, Z = 2, V = 1441.6(11) Ǻ 3 for 1 and a = 7.730(5) Ǻ, b = 13.958(5) Ǻ, c = 14.020(5) Ǻ, α = 73.763(5), β = 88.352(5), γ = 81.035(5)°, Z = 2, V = 1434.5(11) Ǻ 3 for 2 . The hydrogen bonding (C H⋯O and O H⋯O) and π–π stacking interactions result in the formation of bi-layered and zig–zag structures in 1 and 2 respectively. The facile formation of complex salts with small K sp values and detailed packing analysis suggests that the [Co(phen) 2 CO 3 ] + complex ion may be effective as a binding agent for substituted arylsulphonates in an aqueous medium.

1-Isothiocyanato-3,7,10-trimethyl-5-aza-2,8,9-trioxa-1-silabicyclo[3.3.3.0]undecane 3 , containing transannular N → Si bond, has been synthesized by transesterification reaction of trisisopropanolamine and triethoxyisothiocyanato silane. To study the reactivity of exocyclic NCS group, 3 was treated with methyliodide, triethylsilane and aniline. All synthetic compounds have been characterized by spectroscopic methods and elemental analysis and by an X-ray crystal structure determination in the case of 3 . Single crystal X-ray studies have shown that the asymmetric unit contains two crystallographically independent molecules. It has depicted the distorted trigonal bipyramidal coordination at the silicon atom with N → Si av. bond distance of 2.0385 A. The structural investigations were complemented by quantum chemical studies of the structure.

A new mixed ligand cobalt(III) complex salt [Co(phen)(H2biim)2]Cl3 (1) (where phen = 1,10-phenanthroline, H2biim = 2,2′-biimidazole) has been synthesized for the first time. In an effort to explore this new cationic complex [Co(phen)(H2biim)2]3+ as binding agent for fluoroanions, complex salt [Co(phen)(H2biim)2](PF6)2Cl·2H2O(2) has been synthesized and characterized. Single crystal X-ray structure determination has revealed that complex salt 2 crystallizes in monoclinic crystal system with space group P21/c and consist of one complex cation, one chloride, two hexafluorophosphate anions and two water molecules of crystallization. The packing analyses revealed that the complex cations are arranged in such a way that N–H groups of biimidazole moiety are involved in N–H⋯Cl interaction with chloride ion while C–H groups of phen/H2biim are involved in C–H⋯F interaction with hexafluorophosphate to keep these groups in close proximity. A strong network of hydrogen bond interactions C–H⋯F, N–H⋯O, N–H⋯Cl, C–H⋯O (water) and O–H⋯O (water) are responsible for the stabilization of 3D supramolecular architecture. To the best of our knowledge, this is the first crystal structure of any salt containing the cation [Co(phen)(H2biim)2]3+.

The syntheses, physical, spectroscopic characterizations and crystal structures of [Co(phen) 2 CO 3 ]ClO 3 , [Co(phen) 2 CO 3 ]BrO 3 ·3.5H 2 O and [Co(phen) 2 CO 3 ]IO 4 are described (phen = 1,10-phenanthroline, C 12 H 8 N 2 ). The crystal structures feature “synergistic” directional bonding interactions including cation-to-anion C–H⋯O(anion) bonds and anion-to-cation Cl⋯π and I–O⋯π bonds, as well as cation-to-cation C–H⋯O(carbonato) and π – π stacking interactions. The bromate structure also features distinctive O–H⋯O hydrogen bonding networks involving the water molecules. The facile formation of this series of complex salts with relatively small K sp values suggests that the [Co(phen) 2 CO 3 ] + complex ion may be effective as a binding agent for oxo-anions containing halogen atoms(halates) in an aqueous environment.

In an attempt to formulate spectra–structural relationship to provide information on coordination around copper(II) ion in aqueous solution, two novel copper(II) complexes were investigated. [Cu(py)2(H2O)4](p-toluenesulfonate)2, 1 and [Cu(β-pic)2(H2O)4](p-toluenesulfonate)2, 2(py = pyridine, β-pic = β-picoline) were isolated by addition of py and β-pic respectively to the hydrated Cu(p-toluenesulfonate)2 suspended in water–methanol (1:4) mixture. The newly isolated complexes have been characterized by elemental analyses, TGA, spectroscopic techniques (EPR, IR and UV/Visible), conductance, magnetic susceptibility studies and single crystal X-ray structure determination. X-ray structural studies revealed the presence of uncoordinated p-toluenesulfonate anions in both of the crystal structures. The copper cations coordinate to two py/β-pic and four water molecules; the six donor atoms span as a distorted octahedron in both case. The crystal packing in both the complexes 1 and 2 are stabilized by C H O, C H π and π π stacking interactions besides electrostatic forces of attraction.

In an effort to utilize the cationic cobalt(III) complex as a binding agent for fluoroanions, the reaction of carbonatobis(1,10-phenanthroline)cobalt(III) chloride with sodium tetrafluoroborate and sodium hexafluorophosphate in water (1:1 M ratio) leads to the formation of [Co(phen)2CO3]BF4 (1) and [Co(phen)2CO3]PF6·3H2O (2). These cobalt(III) complex salts have been characterized by elemental analyses, spectroscopic techniques (multinuclear NMR, UV/Visible and FT-IR), solubility product and conductance measurements. X-ray structure determination of these complex salts revealed the presence of ionic structures i.e., one complex cation [Co(phen)2CO3]+ and one BF 4 - anion in 1 and one complex cation [Co(phen)2CO3]+, one PF 6 - anion and three water molecules of crystallisation in 2. The packings in both complex salts are stabilized by C H⋯F, C H⋯O(carbonato) hydrogen bonds and anion⋯π interactions beside electrostatic forces of attraction. In addition to these non-covalent interactions, O H⋯O(water) and π–π stacking interactions are also observed in 2. The formation of complex salts of definite composition with tetrafluoroborate and hexafluorophosphate ions suggest that [Co(phen)2CO3]+ may be used as binding agent for weakly coordinating fluoroanions i.e. BF 4 - and PF 6 - .

The present work aims at the synthesis of various novel silatranes bearing substituted urea functionality. Nucleophilic addition of various amines (morpholine, aniline, ethylenediamine and 3-aminopropyltriethoxysilane) to 3-isocyanatopropyltriethoxysilane resulted in the four triethoxysilanes; N-[3-(triethoxysilyl)propyl]morpholine-4-carboxylic acid amide (1), 1-[3-(triethoxysilyl)propyl]-3-phenylurea (2), 1,2-bis{N′-[3-(triethoxysilyl)propyl]ureido}-ethane (3) and N-[3-(triethoxysilyl)propyl]-N′-[3-(triethoxysilyl)propyl]urea (4), respectively. In the presence of a base the resulting silanes undergo transesterification reaction with triethanolamine, thus forming the corresponding silatranes, N-(3-silatranylpropyl)morpholine-4-carboxylic acid amide (5), 1-(3-silatranylpropyl)-3-phenylurea (6), 1,2-Bis[N′-(3-silatranylpropyl)ureido]-ethane (7) and N-(3-silatranylpropyl)-N′-(3-silatranylpropyl)urea (8), respectively. Among these are four novel compounds (5–8), which were characterized by elemental analysis, IR, multinuclear (1H, 13C and 29Si) NMR and mass spectroscopy. Structures of compounds 5 and 6 were deduced by X-ray crystallography. Single crystal X-ray studies revealed distorted trigonal bipyramidal coordination about Si in 5 and 6 with Si–N bond distance of 2.121(1) A and 2.189(2) A, respectively.

Two novel copper(II) complexes, [Cu(2-Cl-5-FC7H3O2)2(β-pic)2(H2O)2] 1 and [Cu(en)2(H2O)2] (2-Cl-5-F-C7H3O2)2 2 (where β-pic = β-picoline, en = ethylenediamine) were isolated by addition of β-picoline and ethylenediamine respectively to the hydrated copper(II) aryl carboxylate, Cu(2-Cl-5-F-C7H3O2)2 suspended in water–methanol (1:4) mixture. The newly isolated complexes have been characterized by elemental analyses, TGA, spectroscopic techniques (EPR, IR and UV/Vis), conductance, magnetic susceptibility studies and single crystal X-ray structure determination. Single crystal X-ray structure determinations revealed the presence of covalently bonded 2-Chloro-5-fluorobenzoate groups in the complex, viz: [Cu(2-Cl-5-FC7H3O2)2(β-picoline)2(H2O)2] 1 and ionic 2-Chloro-5-fluorobenzoate groups in [Cu(en)2(H2O)2] (2-Cl-5-FC7H3O2)2 in 2. In 1, two β-picoline, two unidentate carboxylate groups and two water molecules are coordinated to copper(II) ion. In 2, two ethylenediamine molecules (4 N) and two oxygen from water molecules are coordinated to copper(II) ion. Hexacoordination around copper(II) is achieved with distorted octahedral geometry in both the cases. The crystal network in complex 1 is stabilized by O–H⋯O, C–H⋯π, Cl⋯F, and Cl⋯H–C and in complex 2 cationic and anionic layers are held together by the N–H⋯O, O–H⋯O, C–H⋯F, C–H⋯O interactions.

The partially fluorinated HF soluble intermediates formed during the electrochemical perfluorination of propionyl chloride (PC) and n-butyryl chloride (n-BC) were analyzed after passing 0%, 25%, 50%, 75% and 100% of theoretical charge required for the fluorination of PC and n-BC. The acid fluorides formed were converted to their corresponding sodium salt by alkali treatment and were separated by methanol extraction. The methanol was subsequently removed from the extract by vacuum distillation and the residue containing partially fluorinated sodium carboxylates was analyzed using 19 F and 1 H NMR spectra. Initial perfluorination on activated electrode surface indicates the operation of ‘zipper-mechanism’. Formation of partially fluorinated product mixture, initial selectivity towards primary and secondary carbon, carbon chain isomerization and formation of cleaved and coupled products support the general operation of free radical pathway in the overall electrochemical process.

Chitosan-functionalized graphene oxides (FGOCs) were successfully synthesized. FGOCs were found to significantly improve the solubility of the GO in aqueous acidic media. The presence of organic groups was confirmed by means of XPS and TGA. Restoration of the sp2 carbon network and exfoliation of graphene sheets were confirmed by Raman spectroscopy, UV-visible spectroscopy and WAXD. The SEM and AFM investigations of the resultant FGOCs showed that most of the graphene sheets were individual and few were layered. Controlled release behavior of Ibuprofen and 5-fluorouracil was then investigated. We found that FGOCs are a promising new material for biological and medical applications.

We report the synthesis of biomimetic nanocomposites based on carboxymethyl cellulose (CMC) and hydroxyapatite (HA) nanoparticles via a co-precipitation method. Physico-chemical characterization was performed before and after calcination by Fourier transform infrared (FTIR) spectroscopy, solid state 31P nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (TGA). The formation of nanocomposites was observed by wide angle X-ray diffraction (WAXD), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM). The spectral and crystallographic data indicated the formation of hydroxyapatite in the presence of CMC. They were observed as aggregates of HA nanoparticles and CMC, whose sizes were approximately ∼ 260 ± 40 nm. The crystallite size of the hydroxyapatite particles decreased (with 2 wt% 18 ± 3 nm) with increasing CMC content. The morphological aspects of the calcined samples revealed the sintering ability of HA nanoparticles. Nanocomposites of hydroxyapatite nanoparticles that mimic the process of nucleation and growth in nature can be prepared using biomacromolecules such as CMC.

Reaction of 3-chloropropyltriethoxysilane ( 1 ) with sodium azide ( 2 ) in the presence of phase transfer catalyst, tert-butylammonium bromide provided 3-azidopropyltriethoxysilane ( 3 ). This undergoes transesterification reaction with triethanolamine in the presence of KOH to form a new silatrane 3-azidopropylsilatrane ( 4 ). Multinuclear NMR ( 1 H, 13 C and 29 Si), IR and elemental analyses support the structure of novel silatrane 4 . 29 Si NMR indicates the presence of penta-coordinated silicon atom, which is supported by X-ray studies. It revealed that Si is present in distorted trigonal bipyramidal environment with three O atoms in equatorial positions and N atom at one of the apical positions. The second axial position is occupied by long alkyl chain bearing azide moiety. The interaction of Si with N forms a transannular bond having 2.176 A bond length.

Utility of second sphere interactions for the isolation of a new polycadmate(II) anion is demonstrated through the synthesis of [Co(NH 3 ) 6 ] 2 [Cd 3 Br 10 (H 2 O) 2 ]Br 2 ·2H 2 O. The anion is stabilized through the unison of large number of N–H⋯Br second sphere interactions. The packing analysis delineates that the polycadmate(II) anion is not discrete but form polymeric ribbons of repeated formula, [Cd 3 Br 10 (H 2 O) 2 ] 4− that run along a axis of the unit cell. The complex cations, bromide ions and lattice water molecules are between and in the offsets between the corrugated anion ribbons. The study also advances the cooperative role of second sphere interactions amid electrostatic forces that stabilize the crystal lattice.

Chitosan films with various compositions of silver nanoparticles were prepared by solution casting with an aqueous solution of chitosan and l-lactic acid. The chitosan/Ag nanocomposites were characterized by wide angle X- ray diffraction (WAXD) and UV-vis spectroscopy. An analysis of the surface topography and size of the Ag nanopar- ticles (≤100 nm) were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Thermogravimetric analysis (TGA/DTA) confirmed the increase in thermal stability with increasing Ag nanoparticle content in the nanocomposites. Dynamic thermal analysis (DMA) was used to examine the phase relax- ation behavior of chitosan and its nanocomposites. The conductivity of chitosan/Ag nanocomposites was considered with respect to the frequency. Contact angle measurements were used to characterize the surface twistability, surface cleanliness, and hydrophilic/hydrophobic nature of the surface.

Two new copper(II) complexes of composition [trans-Cu(en)2(H2O)2](L1)2, 1 and [trans-Cu(en)2(H2O)2](L2)2, 2 (L1 = 3-methoxybenzoate, L2 = 3,4,5-trimethoxybenzoate) were obtained by the addition of ethylenediamine to hydrated Cu(II) benzoates, Cu(L1/L2)2·H2O in methanol–water mixture. The newly synthesized complexes have been characterized by elemental analyses, spectroscopic techniques (electronic and FT-IR), magnetic moment determination and molar conductance studies. The complex 1 crystallizes in the triclinic system with space group P 1 ¯ and complex 2 crystallizes in the monoclinic system with space group P21/c. X-ray structure determination revealed ionic structures consisting of one complex cation [Cu(en)2(H2O)2]2+ and two respective aryl benzoate anions in 1 and 2. There is a slight difference in the interplanar (plane passing through the Cu centers) distance between two cationic layers of both the complexes due to presence of two more OCH3 groups on the anionic moiety in 2. A three dimensional hydrogen bonding network formed by N H⋯O and O H⋯O through second sphere and C H…π interactions besides electrostatic forces of attraction stabilizes crystal lattice in both the complexes.

In an attempt to synthesize [Co(NH 3 ) 6 ][Hg 2 I 7 ], a new cobalt(III) complex salt, [Co(NH 3 ) 6 ][HgI 4 ]I·H 2 O ( 1 ) was crystallized from a solution of hexaamminecobalt(III) bromide and potassium heptaiodatodimercurate(II) in aqueous medium in 1:1 M ratio. It has been characterized by elemental analyses, spectroscopic techniques (e.g. UV/visible, IR), solubility product and conductance measurements. The complex salt crystallizes in trigonal crystal system with space group R3c. Single crystal X-ray structure determination revealed the presence of discrete ions: [Co(NH 3 ) 6 ] 3+ cation, one [HgI 4 ] 2− , one I − anions and one lattice water molecule. The crystal structure of complex salt, consist of a bilayered structure demonstrating “rosette structure” arrangements involving N H…I and N H…O hydrogen-bond interactions through second sphere coordination. The crystal lattice is stabilized by these non-covalent interactions besides electrostatic interaction.

Three new mercury(II) halide complex salts, [C7H6N3O2] HgX3·H2O (1: X = Cl, 2: X = Br, 3: X = I) synthesized by reacting stoichiometric quantities of appropriate reactants in aqueous medium, have been investigated by FT IR, NQR spectroscopies, and single crystal X-ray diffractions. The crystal structures of 1 and 2 are isostructural with orthorhombic system (Pnma); a = 15.943(5), b = 6.357(6), c = 12.733(7) A, Z = 4 at 296(2) K for 1 and a = 16.104(4), b = 6.539(4), c = 13.059(4) A, Z = 4 at 296(2) K for 2, respectively. In the crystal Structures, a planar cation of C 7 H 6 N 3 O 2 + , a planar trigonal anion of HgX3– [X = Cl, Br] and water molecule are arranged through the hydrogen bonds of X⋯H–O, O⋯H–N, and X⋯H–N into 2D sheets which are parallel to ac plane. The sheets are connected by double chains of Hg⋯X interionic bonds, which run along the b directions. In contrast, 3 crystallizes in monoclinic (P21/n) space group with a = 7.321(6), b = 16.205(5), c = 13.113(4) A, β = 96.94(4)°, and Z = 4 at 298(2) K. The crystal structure of 3 consists of a pair of 5-nitrobenzimidazolium cations associated through hydrogen bonds with water molecules and a Hg 2 I 6 2 - dimer in which Hg atoms are tetrahedrally coordinated. In accordance with the crystal structures, three NQR lines due to 81Br and 127I(m = ± 1/2 ↔ ± 3/2) were observed at room temperature for 2 and 3, respectively, while two 35Cl NQR lines being assignable to the terminal Cl atoms were observed for 1. The splitting into two 81Br NQR lines of each line below around 160 K shows an occurrence of a phase transition followed by a slight structural change into a structure with lower crystal symmetry. A corresponding disappearance of 35Cl NQR lines below about 110 K may indicate an occurrence of a phase transition in 1. The effects of secondary bonding of interionic Hg⋯X and hydrogen bonds on the coordination of Hg atoms as well as the crystal structures have been discussed.

Novel unsaturated esters of sucrose were synthesised directly and in good yields from sucrose using a simple, mild, and selective Mitsunobu procedure. These regioisomerically pure vinyl sugars have been copolymerised with styrene by a free radical process, yielding unbranched linear polymer materials with pendant sucrose moieties. Their physical properties indicate that these polymers have potential technological relevance as amphiphilic and biodegradable materials. Biodegradation tests on the copolymer samples by a fungal (Aspergillus niger) culture method showed a fungal growth ⩾60%, indicating good biodegradability and that the copolymers were partially bio-assimilated during microbial attack.

The syntheses, physical characterization and crystal structures of two new molecular copper(II) complexes of composition [Cu(C 5 H 5 N) 2 (C 7 F 5 O 2 ) 2 ] ( 1 ) and [Cu(C 5 H 5 N) 2 (C 7 F 5 O 2 ) 2 (H 2 O)] ( 2 ) (C 5 H 5 N = py = pyridine and C 7 F 5 O 2 − = pfb = pentafluorobenzoate) are reported. Single-crystal X-ray structure determinations revealed that in 1 , the Cu 2+ ion, which lies on a crystallographic inversion centre, is coordinated to two py molecules and two oxygen atoms from two monodentate pfb anions, resulting in a trans -CuN 2 O 2 square planar geometry. In 2 , the Cu 2+ ion is also coordinated to two py and two pfb species in addition to a water molecule in the apical site of a distorted CuN 2 O 3 square pyramid. In the crystal packing, both 1 and 2 show segregated aromatic π–π stacking interactions in which (py + py) and (pfb + pfb) ring-pairings are seen, but no (py + pfb) pairings occur. Crystal data: 1 : C 24 H 10 CuF 10 N 2 O 4 , M r = 643.88, space group P 1 ¯ , a = 8.0777 (3) A, b = 8.0937 (3) A, c = 10.5045 (5) A, α = 90.916 (3)°, β = 93.189 (2)°, γ = 118.245 (3)°, V = 603.36 (4) A 3 , Z = 1. 2 : C 24 H 12 CuF 10 N 2 O 5 , M r = 661.90, space group P 1 ¯ , a = 7.5913 (5) A, b = 15.6517 (6) A, c = 21.1820 (14) A, α = 95.697 (4)°, β = 94.506 (2)°, γ = 91.492 (4)°, V = 2495.2 (3) A 3 , Z = 4.

A novel silatrane containing Si ← N bond (2.160 A), has been synthesized by the reaction of 3-aminopropylsilatrane (1), dicyclohexylcarbodiimide (2) and CS2. The structure was established by elemental analysis, spectroscopic methods (IR, 1H NMR, 13C NMR and Mass spectroscopy) and X-ray crystallography. It was correlated with theoretical studies such as semiempirical (AM1, PM3, PM3MM and MNDO), Density Functional Theory (B3LYP) and Hartree–Fock at 3-21+G∗ and 6-31G∗(d) levels. The reactivity of compound 3 was studied with some Lewis acids and bases that showed the formation of corresponding adducts (4–7), which were characterized by elemental analysis, IR and NMR (1H, 13C) spectroscopy.

In this work, an attempt was made to synthesize a novel Chitosan-Mesoporous silica (CS-MS) hybrid composite to design a drug delivery system based on ultrasound triggered stimuli-responsive smart release. The in-vitro drug release properties of both the Mesoporous Silica (MS) and Chitosan (CS) hybrids were investigated. Ibuprofen (Ibu) was used as a model drug. The results from powder X-Ray diffraction (XRD) patterns, and BET N 2 adsorption isotherms exhibited that MS can accommodate drug molecules into the lumen of the channels and pores. Drug release, stimulated by temperature and pH of the release media was also investigated. We studied the Ultrasound (US) triggered release of Ibu in a simulated body fluid (pH 7 . 4 ). The results exhibited that US can be used as a non-invasive technique for drug release from polymeric materials. The enhancing effect of ultrasound on drug release is due to the Cavitation effect, without causing any significant destruction on the polymer morphology.

The complex salt [Co(phen)3]2[Hg(SCN)4]3·3H2O was synthesized by mixing the separately dissolved tris(1,10-phenanthroline)cobalt(III) chloride, mercury(II) chloride and ammonium thiocyanate in aqueous medium in 2:3:12 molar ratio. The newly synthesized complex salt was characterized by elemental analyses, spectroscopic studies (IR, 1H, 13C and 59Co NMR). Single-crystal X-ray structure determination of [Co(phen)3]2[Hg(SCN)4]3·3H2O revealed that the complex salt crystallizes in the monoclinic crystal system with space group P21/n where a = 12.0150(4), b = 20.1916(5), c = 36.1151(9) A, β = 94.408(2)°, V = 8735.7(4) A3, Z = 4. The asymmetric unit consists of two complex cations, three anions and three lattice water molecules. Crystal lattice is stabilized by hydrogen bonding interactions of type C–H…O, C–H…N through second sphere coordination and O–H…O interactions besides the electrostatic forces of attraction. The structural studies suggest that [Co(phen)3]3+ is a potential anion receptor for the [Hg(SCN)4]2− ion.

In an effort to study role/effect of non-covalent interactions in anion binding, the cobalt(III) complex salts, [Co(phen) 3 ](SCN) 3 ·2H 2 O ( 1 ) and [Co(phen) 2 CO 3 ](SCN)·3H 2 O ( 2 ) were synthesized by reacting appropriate reactants in aqueous medium and characterized by UV/Visible, IR, NMR, conductance and solubility product measurements. The molecular structure of complex salt 1 and 2 were determined by single crystal X-ray crystallography which revealed the presence of discrete ions and lattice water molecules in the solid state. A strong network of hydrogen bond interactions through the weak second sphere interactions (C–H…O), strong interactions of type O–H…O (water) and π…π stacking interaction besides the electrostatic interactions play a very important role in stabilization of crystal lattice. The solubility product measurements, X-ray structure analysis and formation of these salts of definite composition suggest that cationic cobalt(III) complexes, [Co(phen) 3 ] 3+ and [Co(phen) 2 CO 3 ] + are promising anion receptors for the thiocyanate ion and presence of hydrogen bond acceptor/hydrogen bond donor groups increase the magnitude of non-covalent (hydrogen bond) interactions.

To explore the potential of cationic cobaltammine as anion receptor, single crystals of cis-diazidobis(ethylenediamine)cobalt(III) saccharinate have been obtained by slowly mixing separately dissolved solutions of [cis-Co(en)2(N3)2]NO3 and NaC7H4SO3N in aqueous medium in nearly 1:1 molar ratio. Elemental analyses, solubility product measurement, molar conductance studies and spectroscopic techniques (IR, UV/Visible, 1H and 13C NMR) were employed for characterizing the complex salt. The complex salt crystallized in the triclinic space group P 1 ¯ with cell dimensions a = 7.2638 (15) A, b = 11.424 (2) A, c = 11.953 (2) A, Z = 2, V = 894.8 (3) A3, R1 = 0.0401 and wR2 = 0.0910. Single crystal X-ray structure determination revealed supramolecular assemblies via hydrogen bonding network between ionic groups and N H groups of coordinated ethylenediamine molecules i.e., second-sphere coordination.

To explore the anion receptor potential of [Co(phen) 2 (CO) 3 ] + for the pentafluorobenzoate ion, [Co(phen) 2 (CO) 3 ](Pfbz)·6H 2 O (where phen = 1,10-phenanthroline and Pfbz = pentafluorobenzoate) was synthesized by reacting appropriate salts in aqueous medium. A detailed packing analysis has been undertaken to delineate the role of second sphere C–H⋯F interactions amid other heteroatom interactions. The complex salt has been characterized by elemental analyses, spectroscopic studies (IR, UV/Vis, multinuclear NMR) and solubility product measurement. The complex salt crystallizes in the monoclinic crystal system with space group P 2 1 / n having the cell dimensions a = 13.377(3) A, b = 17.204(3) A, c = 15.408(3) A, β = 108.11(3)°, V = 3370.1(12) A 3 and Z = 4. Single crystal X-ray structure determination revealed ionic structure consisting of complex cation, [Co(phen) 2 (CO) 3 ] + , Pfbz anion and six lattice water molecules. In the crystal lattice, discrete ions [Co(phen) 2 CO 3 ] + are forming rectangular voids in which the Pfbz anions are entrapped. Crystal lattice is stabilized by electrostatic forces of attraction and hydrogen bonding interactions, i.e. O–H⋯O, C–H⋯O, and C–H⋯F, involving second sphere coordination besides π⋯π interactions.

To explore the potential of [Co(phen)2CO3]+ as anion receptor, the complex salt [Co(phen)2CO3](4-aminobenzenesulphonate).6H2O was synthesized and characterized by X-ray crystallography, elemental analyses, spectroscopic studies (IR, UV/Visible, 1H, 13C and 59Co NMR), solubility product and conductance measurements. The complex salt crystallizes in the triclinic space group P 1 ¯ with unit cell constants: a = 10.803(2), b = 11.758(2), c = 15.190(3) A, α = 99.66(3)°, β = 103.53(3)°, γ = 113.54(3)°. X-ray structure determination revealed the presence of one [Co(phen)2CO3]+, one 4-aminobenzenesulphonate ion and six lattice water molecules per asymmetric unit. Two 1,10-phenanthroline and one carbonato ligands (each bidentate) showed distorted octahedral geometry around the central Co(III) metal ion. Supramolecular hydrogen bonding networks formed by C–H···O, O–H···O and N–H···O interactions besides electrostatic forces of attraction stabilize crystal lattice. The structural studies suggest that [Co(phen)2CO3]+ is a potential anion receptor for the 4-aminobenzenesulphonate ion in aqueous medium.

Two new copper(II) complex salts of composition [trans-Cu(en) 2 (H 2 O) 2 ](p-hydroxybenzoate) 2 · 2H 2 O (1) and [cis-Cu(p-hydroxybenzoate) 2 (3-picoline) 2 ] (2) have been prepared. The newly synthesized complex salts have been characterized by elemental analyses, spectroscopic techniques (UV/visible, IR and EPR) and conductance measurements. The complex salt 1 crystallizes in the monoclinic space group P 2 1 / c having cell dimensions a = 11.8907 (2), b = 9.4443 (2), c = 10.8489 (3)A, β = 100.340 (1)°, V = 1198.54 (5) A 3 , Z = 2 and complex salt 2 crystallizes in the monoclinic space group P 2/ c having cell dimensions a = 9.9924 (3), b = 10.6862 (4), c = 11.6493 (3)A, β = 108.588 (2)°, V = 1179.03 (6)A 3 , Z = 2. X-ray structure determination revealed an ionic structure consisting of one complex cation [trans-Cu(en) 2 (H 2 O) 2 ] 2+ , two [C 7 H 5 O 3 ] − ions, two lattice water molecules in 1 and coordinated structure consisting of two p-hydroxybenzoate and two 3-picoline units attached to copper center in 2 . In complex salt 1 central metal ion, copper(II) is coordinated to four nitrogen atoms, originating from two chelating ethylenediamine ligands and two oxygen atoms of two coordinated water molecules, showing distorted octahedral geometry around copper metal ion while in complex salt 2 Cu(II) is coordinated to four oxygen atom originating from two p-hydroxybenzoate (bidentate) and two nitrogen atoms of the 3-picoline molecule.

The present study firstly describes the synthesis of novel, thermo-latent initiators based on xanthenyl phosphonium salts with different counter anions and phosphine moieties and secondly examines their efficiency in the bulk polymerization of glycidyl phenyl ether (GPE). The polymerization was performed with phosphonium salt initiators (I SbF6 ,I PF6 ,I AsF6 andI BF4 ) at ambient temperature to 200 °C for 1 h. The order of initiator activity wasI SbF6 >I PF6 >I AsF6 >I BF4 . To examine the effect of the phosphine moiety on the initiator activity, polymerization was carried out withI SbF6 (Ph3P) andII SbF6 (Bu3P) at ambient temperature to 170 °C for 1 h. The order of reactivity wasI SbF6 >II SbF6 . In general, the conversion percentage increased with increasing polymerization temperature. The thermal stability of these salts was measured by thermo gravimetric analysis (TGA). The solubility of phosphonium salts in various organic solvents and epoxy monomers was also investigated.

To explore the potential of [Co(phen)2CO3]+ as anion receptor, red coloured single crystals of [Co(phen)2CO3](dnb)·5H2O (dnb = 3,5-dinitrobenzoate) were obtained by recrystallizing the red microcrystalline product synthesised by the reaction of carbonatobis (1,10-phenanthroline)cobalt(III)chloride with sodium salt of 3,5-dinitrobenzoic acid in aqueous medium (1:1 molar ratio). The newly synthesized complex salt has been characterized by elemental analysis, spectroscopic studies (IR, UV/visible, 1H and 13C NMR), solubility and conductance measurements. The complex salt crystallizes in the triclinic crystal system with space group P 1 ¯ , having the cell dimensions a = 10.3140(8), b = 12.2885(11), c = 12.8747(13), α = 82.095(4), β = 85.617(4), γ = 79.221(4)°, V = 1585.6(2) A3, Z = 2. Single crystal X-ray structure determination revealed ionic structure consisting of cationic carbonatobis(1,10-phenanthroline)cobalt(III), dnb anion and five lattice water molecule. In the complex cation [Co(phen)2CO3]+, the cobalt(III) is bonded to four nitrogen atoms, originating from two phenanthroline ligands and two oxygen atoms from the bidentate carbonato group showing an octahedral geometry around cobalt(III) center. Supramolecular networks between ionic groups [ CH phen + ⋯ X anion - ] by second sphere coordination i.e. C H⋯O (benzoate), C H⋯O (nitro), C H⋯O (water) besides electrostatic forces of attraction alongwith π−π interactions stabilize the crystal lattice.

Polypropylene (PP)/layered double hydroxide (LDH) nanocomposites were prepared via melt intercalation using dodecyl sulfate anion modified LDH and maleated PP as compatibilizing agent. Evidently the interlayer anions in LDH galleries react with maleic anhydride groups of PP-g-MA and lead to a finer dispersion of individual LDH layers in the PP matrix. The nanostructure was characterized by XRD and TEM; the examinations confirmed the nanocomposite formation with exfoliated/intercalated layered double hydroxides well distributed in the PP matrix. The nonisothermal crystallization behavior of resulting nanocomposites was extensively studied using differential scanning calorimetry (DSC) technique at various cooling rates. In nonisothermal crystallization kinetics, the Ozawa approach failed to describe the crystallization behavior of nanocomposites, whereas the Avrami analysis and Jeziorny method well define the crystallization behavior of PP/LDH nanocomposite. Combined Avrami and Ozawa analysis (Liu model) also found useful. The results revealed that very small amounts of LDH (1%) could accelerate the crystallization process relative to the pure PP and increase in the crystallization rates was attributed to the nucleating effect of the nanoparticles. Polarized optical microscopy (POM) observations also support the DSC results. The effective crystallization activation energy was estimated as a function of the relative degree of crystallinity using the isoconversional analysis. Overall, results indicated that the LDH particles in nanometer size might act as nucleating agent and distinctly change the type of nucleation, growth and geometry of PP crystals.

In an effort to capture fluoroanions by cationic cobalt(III) complex, two new cobalt(III) complex salts of composition [Co(phen) 3 ](BF 4 ) 3 ·H 2 O ( 1 ) and [Co(phen) 3 ](PF 6 ) 3 ·CH 3 COCH 3 ( 2 ) have been synthesized by the reaction of tris(1,10-phenanthroline)cobalt(III)chloride with sodium salts of tetrafluorborate and hexafluorophosphate (1:3 molar ratio) in aqueous medium. Single crystals of 1 were obtained directly from the reaction mixture when the solution was allowed to evaporate slowly at room temperature and single crystals of 2 were obtained by recrystallizing the precipitated product from acetone and water solution by slow evaporation. The newly synthesized complex salts were characterized by elemental analyses, TGA spectroscopic studies (IR, UV/Visible, 1 H, 13 C, 19 F and 11 B NMR), solubility product and conductance measurements. X-ray structure determination revealed ionic structures consisting of one [Co(phen) 3 ] 3+ , three [BF 4 ] − ions and one lattice water molecule in complex salt 1 , one [Co(phen) 3 ] 3+ , three [PF 6 ] − anions and one acetone molecule as solvent of crystallization in complex salt 2 . The three 1,10-phenanthroline ligands (each bidentate) coordinated to cobalt(III) showed distorted octahedral geometry around the central metal ion. Supramolecular hydrogen bonding networks between ionic groups [Co-phenCH δ+ ⋯ F anion δ - ] by second sphere coordination have been observed that stabilize crystal lattice besides electrostatic forces of attraction. The structural studies suggest that [Co(phen) 3 ] 3+ is a promising anion receptor for the fluoroanions (BF 4 ) − and (PF 6 ) − in aqueous medium.

Orange coloured single crystals of [Co(phen)3]Cl[(CH3)3C6H2SO3]2·11H2O were obtained, when the solution obtained by mixing separately dissolved, tris(1,10-phenanthroline)cobalt(III)chloride and sodium salt of mesitylenesulphonic acid in aqueous medium in 1:3 molar ratio was allowed to evaporate slowly at room temperature. The newly synthesized complex salt was characterized by elemental analyses, TGA, spectroscopic studies (IR, UV/Visible, 1H, 13C and 59Co NMR), conductance and solubility product measurements. Single crystal X-ray structure determination of [Co(phen)3]Cl[(CH3)3C6H2SO3]2·11H2O revealed that complex salt crystallizes in the monoclinic crystal system with space group P21/c where a = 17.7628(4), b = 15.7546(3), c = 20.8338(5)A, β = 104.691(1), V = 5639.65 A3, Z = 4. The asymmetric unit consists of one cation, one chloride, two mesitylenesulphonate ions and eleven lattice water molecules. Crystal lattice is stabilized by hydrogen bonding interactions of type C H⋯O, C H⋯Cl through second sphere coordination and O H⋯O interactions besides the electrostatic forces of attractions. The solubility product measurements indicated that the affinity of cationic metal complex tris(1,10-phenanthroline)cobalt(III), [Co(phen)3]3+ is greater for mesitylenesulphonate ion than for chloride ion in aqueous medium. The structural studies suggest that [Co(phen)3]3+ is a potential anion receptor for the mesitylenesulphonate ion. This is the first crystal structure report of [Co(phen)3]3+ complex cation with any arylsulphonate ion.

In an effort to utilize [Co(phen)2CO3]+ cation as a new host for mono-, di- and tri-substituted nitrophenolate anions, red coloured crystals of composition [Co(phen)2CO3](onp)·2H2O, [Co(phen)2CO3](pnp), orange coloured precipitated product of [Co(phen)2CO3](dnp)·4.5H2O (which gave red coloured crystals from acetone–water mixture) and orange-yellow coloured precipitated product of [Co(phen)2CO3](tnp) were obtained in good yields by reacting sodium salts of o-nitrophenol, p-nitrophenol 2,4-dinitrophenol and 2,4,6-trinitrophenol with [Co(phen)2CO3]Cl·5H2O, respectively in 1:1 molar ratio in aqueous medium. These cobalt(III) complex salts have been characterized by elemental analyses, spectroscopic techniques (UV/Visible, IR and NMR) and conductance measurements. Single crystal X-ray structure determination of [Co(phen)2CO3](onp)·2H2O and [Co(phen)2CO3](dnp)·4.5H2O revealed the presence of discrete ions and lattice water molecules in the solid state. A strong network of hydrogen bond interactions through the weak second sphere coordination (C H…O (phenolate), C H…O (nitro), and strong interactions of type O H…O (water) besides the electrostatic interactions play a very important role in stabilizing the crystal lattice. The studies indicated that complex cation, [Co(phen)2CO3]+ may preferentially bind nitrophenolate ions in the aqueous medium.