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The components of the title compound, [Ni(C10H24N4)(H2O)2]2[Ni(C10H24N4)(C27H24O9P3)2]·10H2O are two centrosymmetric [Ni(C10H24N4)(H2O)2]2+ dications, a centrosymmetric [Ni(C10H24N4)(C27H24O9P3)2]4− tetra-anion and five crystallographically unique water molecules of crystallization. All of the nickel ions are coordinated by the four secondary N atoms of the macrocyclic cyclam ligands, which adopt the most energetically stable trans-III conformation, and the mutually trans O atoms of either water molecules in the cations or the phosphonate groups in the anion in a tetragonally distorted NiN4O2 octahedral coordination geometry. Strong O—H...O hydrogen bonds between the protonated and the non-protonated phosphonate O atoms of neighboring anions result in the formation of layers oriented parallel to the bc plane, which are linked into a three-dimensional network by virtue of numerous N—H...O and O—H...O hydrogen bonds arising from the sec-NH groups of the macrocycles, phosphonate O atoms and coordinated and non-coordinated water molecules.

A novel DPyDB-CN-18C6 compound was synthesised by linking a pyrene moiety to each phenyl group of dibenzo-18-crown-6-ether, the crown ether, through –HCN– bonds and characterized by FTIR, 1H-NMR, 13C-NMR, TGA, and DSC techniques. The quantitative 13C-NMR analysis revealed the presence of two position isomers. The electronic structure of the DPyDB-CN-18C6 molecule was characterized by UV-vis and fluorescence spectroscopies in four solvents with different polarities to observe particular behavior of isomers, as well as to demonstrate a possible non-bonding chemical association (such as ground- and excited-state associations, namely, to probe if there were forming dimers/excimers). The interpretation of the electronic structure was realized through QM calculations. The TD-CAM-B3LYP functional, at the 6-311+G(d,p) basis set, indicated the presence of predominant π → π* and mixed π → π* + n → π* transitions, in line with the UV-vis experimental data. Even though DPyDB-CN-18C6 computational studies revealed a π-extended conjugation effect with predominantly π → π* transitions, thorough fluorescence analysis was observed a weak emission, as an effect of PET and ACQ. In particular, the WAXD analysis of powder and thin films obtained from n-hexane, 1,2-dichloroethane, and ethanol indicated an amorphous organization, whereas from toluene a smectic ordering was obtained. These results were correlated with MD simulation, and it was observed that the molecular geometry of DPyDB-CN-18C6 molecule played a defining role in the pyrene stacking arrangement.

Four novel ditopic ligands that have a pyrazole ring in their central unit and are useful for the generation of coordination polymers have been synthesized. Two of these ditopic ligands present two carboxylate functions as coordinating groups, while the other two are hybrid ligands having only one carboxylate function and either tetrazolate or imidazole as the remaining coordination site. The ligands have been obtained through a multi-step reaction sequence that begins with the Claisen condensation of either 4-acetylbenzonitrile or 4-(1H-imidazol-1-yl)acetophenone with diethyl oxalate and has the Knorr pyrazole ring closure as its key step. Subsequently, the tetrazolate in one of the ligands is constructed through a [3 + 2] cycloaddition of azide anion to the cyano group, while hydrolysis of the ester and the cyano substituents generates the carboxylate function(s). The structure of the intermediates and of the target ligands has been investigated by solution NMR, special attention being given to keto–enol and pyrazole tautomerism when present. The structure of two ligands and a key intermediate has also been established by single-crystal X-ray diffraction.

Three new 3D-metal–organic frameworks based on 2′,3′,5′,6′-tetramethyl-[1,1′:4′,1′′-terphenyl]-4,4′′-dicarboxylic acid (H2L) and Co, Cu, and Cd nodes have been synthesized. The complexes were characterized by elemental, thermogravimetric analysis, IR spectroscopy, single crystal, powder X-ray diffraction and gas sorption experiments. The crystal structure of [Cu2L2(H2O)2]n (1) corresponds to a two-dimensional coordination polymer, in which the metal nodes are two crystallographically equivalent Cu(II) atoms linked by four μ2-O,O′ carboxylate ligands in a centrosymmetric {Cu2O10} paddle-wheel building block. The structure of compound [CoL(dmso)]n (2) has a 3D metal–organic coordination lattice, in which the metal centers are connected by the linear organic ligand to generate a dense three-dimensional coordination polymer. Also, a three-dimensional coordination network was identified in the case of compound [Cd2L2(dmf)]n (3), whose structure is very similar to that of compound 2. In compound 3, the carboxylate groups of the linear L2− spacers behave as μ2-κ3O, O′:O tridentate bridging ligands. The compounds have a high thermal stability. Polymers 3 and 1 have moderate porosity (specific surface areas of approximately 900 m2/g and 600 m2/g, respectively), while polymer 2 has a dense structure.

Two synthetic approaches towards 4′-(2H-tetrazol-5-yl)-[1,1′-biphenyl]-4-carboxylic acid, a valuable organic ligand for the preparation of metal-organic frameworks, are reported. The first reaction sequence leading to the target compound comprises the iodination of [1,1′-biphenyl]-4-carboxylic acid, formation of the methyl ester of 4′-iodo-[1,1′-biphenyl]-4-carboxylic acid, nucleophilic substitution of iodine with cyano, ring closure of tetrazole, and hydrolysis of the ester function. The second synthetic pathway starts from 4-bromobenzonitrile, which is converted through Suzuki coupling with 4-carboxyphenylboronic acid into 4′-cyano-[1,1′-biphenyl]-4-carboxylic acid, which in turn leads to the desired compound after ring closure of tetrazole. All of the synthesized compounds have been fully characterized by IR and 1H- and 13C-NMR spectroscopy. Single crystal X-ray structures are reported for the target compound and for methyl esters of 4′-iodo-[1,1′-biphenyl]-4-carboxylic acid and 4′-cyano-[1,1′-biphenyl]-4-carboxylic acid. The target compound and the intermediates showed no antimicrobial activity against Escherichia coli, Staphylococcus aureus and Candida albicans.

A novel DPyDB-C[double bond, length as m-dash]N-18C6 compound was synthesised by linking a pyrene moiety to each phenyl group of dibenzo-18-crown-6-ether, the crown ether, through -HC[double bond, length as m-dash]N- bonds and characterized by FTIR

Efficient tools are still being searched for to substitute the viral vectors in nucleic acid delivery applications. One of the most severe constraints in producing them is related to the strict reproducibility of their molecular characteristics, which is ensured through the synthesis. In this work, we report an original route to obtain polycationic nanoentities with low variability, which are able to act as cooperating carriers for dsDNA complexation and transport. The carriers are synthesized by rigorous conjugation of β-cyclodextrin (β-CD) with precise ratios of 2 kDa branched poly(ethyleneimine) (b-PEI) and 0.75 kDa poly(ethylene glycol) (PEG). Low cytotoxicity was the key parameter of the carrier design, besides the highest possible transfection ability, and both of these features were proven by HeLa cell culture assays. A reporter gene which induces the expression of green fluorescent protein (GFP), inserted in a plasmid, was used to perform the necessary quantitative measurements. In silico molecular modelling guided the carrier design and confirmed the functional mimicry of histones in the tight and compact nucleosome-like spiral packaging of dsDNA. The carrier molecules, synthesized with high reproducibility, are expected to be feasible for application in gene transfection.

Three symmetric azomethine dimers having dibenzo-18-crown-6-ether as internal moiety and halogens (F, Cl, Br) as terminal functional groups were synthesized and characterized by FTIR and 1 H NMR spectroscopy. Their thermal behavior was investigated by polarized optical microscopy (POM) and DSC techniques. Interesting textures have been observed at cooling by POM as being representative for a soft crystalline smectic phase. X-ray diffraction measurements in powder at room temperature exhibited a map of reflections corresponding to crystal E phase. The influence of molecular parameters (interdigitation parameter γ, dipole moment, molecular polarizability, halogen radius) on thermal behavior was discussed. The UV–Vis investigations allowed evaluation of photostability and a bathochromic effect was noticed with the increasing of halogen atom radius. Also the values of optical band gap (E g ) are higher than those corresponding to conjugated Schiff bases.

This paper describes the philosophy to design, and a procedure to construct polyrotaxane-type gene carriers, together with the proof of their ability to conjunctively cooperate in order to generate cargo-complexes with dsDNA, able to efficiently transfect cultured cells. The main feature of these entities is their functionality as a cargo-complex that chemomimic the histones, and morphomimic the nucleosome. The polyrotaxane contains a PEG axle end-capped with silatrane cages, allowing the threading of nine cyclodextrin units, functionalized with polyethylenimines (PEI, 2 kDa). The obtained ROT-PEI multivalent architecture is similar to a giant PEI polycation, but devoid of the toxicity of large PEIs. To increase the cargo-complexes’ versatility and to reduce their cytotoxicity, the study has been complemented with two other types of carriers: (i) including a mixture of PEI and short PEG molecules (ROT-PEI-PEG750), and (ii) with PEI branches post-decorated with guanidine or arginine (ROT-PEI-G; ROT-PEI-Arg). The molecular geometry and the overall interactions of the synthesized carriers were investigated in silico. The experimental DNA binding capacity of these carriers in relationship with size, morphology and electrical charge was evaluated. The in vitro tests, showing the cytotoxicity and transfection efficiency of the investigated carriers, provided new information on gene vector design.

The straightforward and facile synthetic approaches towards four coordination polymers, {[CdL(H2O)]·0.5H2O}n, {[Cd2L2(H2O)2(4,4′-bipy)]·4H2O}n, {[Cd2L2(H2O)2(4,4′-azpy)]·3H2O}n and {[CoL(H2O)3]·2.5H2O}n (4,4′-bipy = 4,4′-bipyridine; 4,4′-azpy = 4,4′-azopyridine), based on the polydentate ligand 1-(4-carboxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carboxylic acid (LH2) and Cd(II) and Co(II) ions are reported. In addition, two mononuclear complexes, [Cu(HL)2(DMA)] and [Cu(HL)2(H2O)2], derived from the same ligand and the Cu(II) ion have been prepared. The coordination compounds have been characterized by infrared spectroscopy, thermogravimetry, powder X-ray diffraction and elemental analysis. Single crystal X-ray structures for each of these coordination compounds have been established. The specific surface of the 3D Cd(II)- and Co(II)-derived coordination polymers, determined through nitrogen adsorption, is negligible (SBET

New photoactive copolysulfones carrying azo crown ether moieties in the main chain were prepared by polycondensation reaction of 4,4′-bis(4-hydroxyphenylazo)dibenzo-18-crown-6, bisphenol A, and bis(4-chlorophenyl)sulfone. The azo polysulfones were characterized via FTIR and 1H NMR spectra, thermogravimetrical analysis, and differential scanning calorimetry. The products showed good thermal stability, with 10% weight loss temperatures ranging from 366 to 426 °C, while the glass transition temperatures varied from 137 to 158 °C. A kinetic study of trans–cis–trans isomerization process based on the evolution of the electronic absorption spectra during UV irradiation was conducted.

A series of 3D metal–organic frameworks derived from 2′,3′,5′,6′-tetramethyl-[1,1′:4′,1′′-terphenyl]-4,4′′-dicarboxylic acid (H2L) as organic linker and various lanthanides have been prepared. The resulting coordination polymers [Ln3L4(NO3)(DMF)x(H2O)]n (where x = 2 or 3) were characterized by elemental analysis, thermogravimetric investigations, IR and TG-FTIR spectroscopy, as well as powder X-ray diffraction measurements. The crystal structure for six of these isostructural networks based on La(III), Ce(III), Nd(III), Sm(III), Tb(III) and Dy(III) was established using single crystal X-ray crystallography. As an example, the asymmetric part of [La3L4(NO3)(DMF)3(H2O)]n consists of two deprotonated ligand molecules L2- and two La(III) ions, one of them occupying a general position with full site occupancy, while the other one has a fractional occupancy of 0.5. Investigation of the luminescence of these coordination polymers showed that compounds containing La3+, Nd3+ and Gd3+ possess only the emission associated with the anion of the organic ligand (L2-), polymers containing Eu3+ and Tb3+ show pure metal-centered radiation, while networks containing Dy3+ and Sm3+ display dual metal- and ligand-centered luminescence. The organic linker acts as a good antenna for Tb3+, Eu3+, Dy3+ and Sm3+ ions.

New soluble and thermally-resistant copoly(ether sulfone)s, containing both azo-crown-ether and fluorene units, have been synthesized by using the Williamson reaction. In this respect the 4,4′-sulfonylbis( p -chlorophenyl) monomer was reacted with two bisphenols, namely 9,9-bis(4-hydroxyphenyl)fluorene and 4,4′-bis(4-hydroxyphenylazo)dibenzo-18-crown-6. The polymers synthesized were confirmed as chemical structures by FTIR and 1 H NMR spectra and characterized by X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, solubility and solution viscosity. The copolymers have been complexed with KSCN and the atomic potassium content was determined by EDX. A study of the photoisomerization process as well as the thermal relaxation of azoaromatic chromophores in the copoly(ether sulfone)s in dimethyl sulfoxide solution and of the corresponding complexes with KSCN was also presented.

An ionic liquid based on polydimethylsiloxane with imidazolium salt brushes was synthesized as a good solvent for β-cyclodextrin-polydimethylsiloxane rotaxane. As expected the PDMS-Im/Br ionic liquid had a liquid-like non-Newtonian behavior with rheological parameters dependent on frequency and temperature. The addition of rotaxane to the ionic liquid strengthened the non-Newtonian character of the sample and a type of stable liquid-like network was formed due to the contribution of weak ionic interactions. The structure is stable in the 20 to 80 °C domain as proved by the oscillatory and rotational rheological tests.

The discovery of a remarkable class of plastics that can conduct electricity has opened a new era of plastics science and technology that has just been recognized by the award of the 2000 Nobel prize for chemistry. They can be used to make a wide range of electronic devices such as transistors, light-emitting diodes, solar cells and even lasers, through much simpler manufacture than conventional inorganic materials, increasing flexibility, reducing cost, and opening up new markets. Polysilanes are subject of an intensive research work aiming to various optoelectronic applications. Through this work the chemical structure of polydiphenylsilane was modified to obtain both solubility in common solvents and to induce new properties by attaching of various organic segments.

A new polysilane with pendant metal complex segments was synthesized and characterized. For this purpose a macroligand has been prepared starting from a iodopropyl-functionalized polysilane and a bis(salicylideneimine) derivative. Under mild reaction temperature this polymeric ligand was able to form crosslinked structures. The material was then doped with metal cations and was investigated to observe the system behavior near the gelation point. The UV-vis spectrum of the new material indicated that the electronic structures of the conjugate polysilane chain and metal complex remained unaffected by the condensation reaction process. Similar polymeric structures could be useful to build new organic electroconductive devices.

New polysilane-metal complexes structures were obtained by the polycondensation reaction of α,ω-bis(chloromethyl)-polymethylphenylsilane with the Ni (II) complex of bis(salicylidene)ethylenedia-mine (salen). The chloro-functionalized polysilane was obtained by a modified Wurtz coupling procedure at low temperatures. To obtain the polymer-metal complex the resulted macroligand was complexed with metal cations. This structure is characterized by a highly localized electroactivitry in the redox moiety combined with a specific σ conjugative effect in the polysilane chain. Infrared, 1H NMR and UV-vis spectral analysis as well as gel permeation chromatography and thermogravimetric analysis were used to investigate the new chemical structures.

This paper presents the structural influence of the Si-H functionality on the physicochemical properties of polysilanes. New low-temperature restructuring processes were discovered using thermal analysis (TGA, DSC). Photo-luminescent (FL) and X-ray photoelectron specttoscopy (XPS) measurements revealed the optoelectronic properties- chemical structure relationship of the synthesized polymers.

N,N’-Bis(4-hydroxysalicylidene)ethylendiamine (salen) was attached to a poly[iodopropyl(methyl)-co-diphenylsilane)chain. Due to intermolecular crosslinking reactions, a high molecular weight polymer formation was observed. The resulted material was doped with metal cations through complexation reactions. The chemical structure of the polysilane-Schiff base metal complex was investigated by spectral analysis (IR, 1H-NMR, 13C-NMR, UV), thermogravimetric analysis (TGA) and gel permeation chromatography (GPC).

A new segmented polysiloxaneimide was synthesized by solution polycondensation of N, N bis(hydroxyethyl)benzophenontetracarboxylic diimide with siloxane diacid chloride. The copolymer was obtained with good yield and high molecular weight. The characterization by IR and 1H-NMR spectrometry and a study of the properties such as solubility and thermal behaviour of this copolymer are presented. A corona poling study was performed to obtain information about the piezoelectric behaviour of polysiloxaneimide. The remanent dielectric constants of the polarized samples were compared with those of well-known piezoelectric polymers.

A hybrid polymeric network was prepared through encapsulation of a new ruthenium complex within a poly(methylsilsesquioxane) matrix. The Ru(III) complex was obtained using a tridentate bis‐amide derivate of the 2,6‐pyridinedicarboxylic acid. The synthesis of the tridentate ligand and the entrapping procedure of the Ru(III) complex were presented. The polycondensation process of methyl triethoxysilane in the presence of the Ru(III) complex was studied in order to obtain information concerning the evolution of the gelation process. All products and intermediates were characterized using IR, UV‐VIS, 1H‐NMR spectral techniques, and elemental and thermogravimetric analyses.

This work presents the first synthesis of a new polymer obtained by catalytic addition of the Si-H groups of a poly[methyl(H)silane-co-methylphenylsilane] backbone to an N-(allyl)cycloimmonium salt. This hybrid polymer was characterized by spectrascopic analysis, thermogravimetric analysis and gel-permeation chromatography (GPC). The pendant N-(allyl)cycloimmonium segments lead to the formation of molecular dipoles, as evidenced by electrical polarization experiments.

This paper presents the synthesis of new polysilane with pendant crown ether groups. The polymer was obtained through the addition reaction of 4′-allylbenzo-15-crown-5 to poly[methyl(H)-co-methylphenylsilane] copolymer in anhydrous toluene solution using hexachloroplatinic acid as a catalyst. The allyl functionalization of the crown ether was achieved by the coupling of the crown ether bromide with allyl magnesium chloride. The availability of the crown ether sites in complexation reactions with Cu(II) cations was tested. The chemical structures of all products and intermediates were studied using spectral methods (IR, 1H-NMR, 13C-NMR, UV), gel permeation chromatography (GPC) and thermogravimetric analysis (TGA).

This paper describes the synthesis of a new coordination polymer prepared through the polycondensation reaction of α,ω-bis(chloromethyl)-polymethylphenylsilane with the Ni(II) complex of bis(salicylidene)ethylenediamine (salen). For this purpose, a new preparation method of the chloromethylated polysilane was presented along with the synthesis and characterisation of the polymer–metal complex. IR, 1 H-NMR and UV–Vis spectral analyses as well as GPC and TGA were used to investigate the new chemical structures.

This paper presents the synthesis procedure of new photosensitive siloxane–crown ether copolymers using the polycondensation reaction of an oligosiloxane with COCl end groups and bisazo derivatives of dibenzo-18-crown-6 polyether. The azodiphenol compounds were prepared via the coupling reaction of 4,4 0 -diamine-DB18C6 diazonium salt with phenol or 1-naphthol. The polymers were characterized by IR absorption and 1 H-NMR spectra as well as by thermal analysis and GPC. A study of the photoisomerization process as well as the thermal relaxation of azoaromatic chromophores in the polysiloxane–crown ether copolymer in dimethyl sulfoxide solution and of the corresponding complexes with KSCN was also presented. 2002 Elsevier Science Ltd. All rights reserved.

The complexation ability of some linear crown ether-siloxane copolymers of ester or amide type with cations as K + and NH + 4 was investigated spectrophotometrically in order to select the polysiloxane receptors that achieve good ion transport ability by bulk liquid membrane systems. The transport properties of the potasium picrate through a liquid membrane using siloxane-crown ether polyamide as carrier were discussed.

A polysilane copolymer with reactive Si-H side groups was obtained through a homogeeous coupling reaction of dichlorodiphenylsilane with dichloromethylsilane. The reaction was carried out in a tetrahydrofuran (THF) solution of a sodium-potasium alloy complex with 18-crown-6 with a well defined composition of alkali metal ion pairs (Mt + /crown ether, Mt ― ) at -75°C. The product was characterized using 1 H NMR, 13 C NMR, FT-IR and UV/Visible spectroscopies and gel permeation chromatography. The result were compared with those obtained by the heterogeneous coupling reaction of the same monomers.

Silnaphthalene-siloxane copolymers with reactive Si-H pendant groups were synthesized through the cohydrolysis reaction of 1,4-bis(hydrochlorosilyi)naphthalene with dimethyl-methyl-(phenyl)-, and diphenylchlorosilanes. Allproducts were characterized by IR, H-NMR, Si and H elemental analysis, and molecular weights estimations.