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The post-functionalization of porphyrins through the bromination in β position of the pyrrolic rings is a relevant transformation because the resulting bromoderivatives are useful synthons to covalently link a variety of chemical architectures to a porphyrin ring. However, single bromination of porphyrins is a challenging reaction for the abundancy of reactive β-pyrrolic positions in the aromatic macrocycle. We herein report a synthetic procedure for the efficient preparation of 2-bromo-5,10,15,20-tetraphenylporphyrin (1) under continuous flow conditions. The use of flow technology allows to reach an accurate control over critical reaction parameters such as temperature and reaction time. Furthermore, by performing the optimization process through a statistical DoE (Design of Experiment) approach, these parameters could be properly adjusted with a limited number of experiments. This process led us to a better understanding of the relevant factors that govern porphyrins monobromination and to obtain compound 1 with an unprecedent 80% yield.

Oxide nanoparticles (oxide NPs) are advanced materials with a wide variety of applications in different fields. The use of continuous flow methods is particularly appealing for their synthesis due to the high control achieved over the reaction conditions and the easy process scalability. The present review focuses on the preparation of oxide NPs using microfluidic setups at low temperature (≤80 °C), since the employment of mild reaction conditions is crucial for developing sustainable and cost-effective processes. A particular emphasis will be put on the improvement over the final product features (e. g., size, shape, and size distribution) given by flow methods with respect to conventional batch procedures. The main issues that arise by treating NPs suspensions in microfluidic systems are product deposition or channel clogging; mitigation strategies to overcome these drawbacks will also be presented and discussed.

The room-temperature controlled crystallization of monodispersed ZnS nanoparticles (average size of 5 nm) doped with luminescent ions (such as Mn$^{2+}$, Eu$^{3+}$, Sm$^{3+}$, Nd$^{3+}$, and Yb$^{3+}$) was achieved via a microfluidic approach. The preparation did not require any stabilizing ligands or surfactants, minimizing potential sources of impurities. The synthesized nanomaterials were characterized from a structural (XRD and XAS at lanthanide L$_{3}$ edges), morphological (TEM), and compositional (XPS, ICP-MS) perspective, giving complementary information on the materials’ features. In view of potential applications in the field of optical bioimaging, the optical emission properties of the doped nanoparticles were assessed, and samples showed strong luminescent properties while being less affected by self-quenching mechanisms. Furthermore, in vitro cytotoxicity experiments were conducted, showing no negative effects and evidencing the appeal of the synthesized materials for potential applications in the field of optical bioimaging.

The controlled nucleation and crystallization of small pure sphalerite ZnS nanoparticles was achieved under batch and continuous flow conditions at low temperature, in water and without the use of any stabilizing ligand. The obtained nanoparticles displayed a narrow size distribution and high specific surface area. Moreover, the synthesis was suitable to directly obtain stable water-based suspensions and the products were found to be active photocatalysts for the hydrogen evolution reaction.

Herein we report an effective synthetic method for the direct assembly of highly functionalized tetracyclic pharmacophoric cores. Coumarins and chromones undergo diastereoselective [4 + 2] cycloaddition reactions with light-generated photoenol intermediates. The reactions occur by aid of a microfluidic photoreactor (MFP) in high yield (up to >98%) and virtually complete diastereocontrol (>20:1 dr). The method is easily scaled-up to a parallel setup, furnishing 948 mg of product over a 14 h reaction time. Finally, a series of manipulations of the tetracyclic scaffold obtained gave access to valuable precursors of biologically active molecules.

Thanks to their unique properties, such as (i) renewability, (ii) high aspect ratios, (iii) low density, (iv) biodegradability, (v) high strength, and (vi) stiffness, there have been many reports in recent years detailing the isolation and functionalization of cellulose nanowhiskers from cellulose. Moreover, nanocellulose can be produced in large quantities in a cost-effective manner and can be easily functionalized due to its high density of hydroxy groups. In the present work, alkynyl-dendrons of the PAMAM family were covalently attached to azide-functionalized cellulose nanocrystals by click chemistry (Huisgen cycloaddition). The resulting cycloadducts were then used as templates for the preparation of stable and monodispersed gold nanoparticles in aqueous media. The catalytic capabilities of these hybrid materials were studied in the sodium borohydride mediated reduction of 4-nitrophenol to 4-aminophenol, which served as a model reaction.

Light-driven reactions of 2-methylbenzophenones (2-MBPs) occur with improved yields (up to >98%) and reaction rates (up to 0.240 mmol h−1) by using a tailored microfluidic photoreactor (MFP). For the first time, coumarins were converted into 4-benzylated chromanones in high yields (50–93%) and diastereoselectivity (up to >20 : 1 dr), thus by-passing their photo-dimerisation end-reaction.

The coupling of a polycationic Mn(III)-porphyrin, with a dinuclear Mn2(II,II)L2 core (HL = 2-{[[di(2-pyridyl)methyl](methyl)amino]methyl}phenol), results in a dual Superoxide Dismutase (SOD) and Catalase (CAT) functional analogue, Mn2L2Pn+, enabling a detoxification cascade of the superoxide anion and hydrogen peroxide into benign H2O and O2. The SOD/CAT artificial manifolds, joined in one asset, exhibit a peak catalytic performance under physiological conditions, with log kcat(O2• –) ≥ 7 and kcat(H2O2)/KM = 1890. The dual-enzyme (dizyme) concept allows for a built-in self-protection against the irreversible bleaching of the porphyrin unit (>75% protection), readily induced by H2O2 (200 μM, 20 equiv, in buffer solution, pH 7.8). We show herein that incubation of the photosynthetic green algae, Chlamydomonas reinhardtii, with the synthetic dizyme (as low as 0.1 μM), prevents H2O2 accumulation under high-light illumination conditions, thus providing antioxidant surveillance and photoprotection.

The covalent chemistry of carbon nanostructures has put forth a wide variety of interesting derivatives that widen their potential as functional materials. However, the synthetic procedures that have been developed to functionalize the nanostructures may require long reaction times and harsh conditions. In this paper, we study the continuous flow processing of single-wall carbon nanotubes with azomethine ylides and diazonium salts and demonstrate that this approach is effective to reduce reaction times and tune the properties of the functionalized carbon materials.

The covalent grafting of two amino-fullerene C60 derivatives (C60-LC-NH2 and C60-SC-NH2, LC = long chain and SC = short chain) onto the surface of TEMPO oxidized nanocrystalline cellulose (NCC-COOH) has been reported for the first time. These hybrids (NCC-LC-C60 and NCC-SC-C60) form stable colloidal suspensions at concentrations up to 0.5 mg/mL and act as effective photosensitizers for singlet oxygen production as demonstrated by the oxidation of L-methionine-methyl ester to the corresponding sulphoxide. Using the same approach, in a one-pot reaction both a fluorescent target molecule (FITC-LC-NH2) and the C60-LC-NH2 derivative have been successfully attached covalently onto the NCC-COOH surface. These hybrids, which showed no cytotoxicity on MCF-7 human breast cancer cells could be good candidates in photodynamic cancer therapy.

Functional hydroxyazobenzene dyes for optically monitoring pH in the range from 6 to 10 were synthesised. The p K a values of the dyes have been tailored by appropriate choice of substituents in position para to the hydroxy group, resulting in lower p K a values for electron acceptor substituents and higher p K a for electron donors. Furthermore, substituent effects on absorbance spectra have been evaluated, with expected shifts to longer wavelength in the case of electron donors. For immobilisation, the indicator dyes were covalently linked to cellulose films via vinylsulfonyl chemistry. Mechanical stabilization of the cellulose films was achieved by lamination onto polyethylene terephthalate foils. In order to obtain patterned sensor layers with geometrical defined sensing areas a laser-structured adhesive tape was used as protective mask in the dyeing step.

A novel two-step bottom-up approach to construct a 2D long-range ordered, covalently bonded fullerene/porphyrin binary nanostructure is presented: in the first place, reversible supramolecular interactions between C60 and 5,15-bis(4-aminophenyl)-10,20-diphenylporphyrin are exploited to obtain large domains of an ordered binary network, subsequently a reaction between fullerene molecules and the amino-groups residing on porphyrin units, triggered by thermal treatment, is used to freeze the supramolecular nanostructure with covalent bonds. The resulting nanostructure resists high temperature treatments as expected for an extended covalent network, whereas very similar fullerene/porphyrin nanostructures held together only by weak interactions are disrupted upon annealing at the same or at lower temperatures.

A straightforward, "one-pot" approach to the construction of a new class of molecular tweezers and their heterogenization onto various aminated materials is reviewed here. It is based on nucleophilic substitution of the cyanuric chloride scaffold with tailored aminoporphyrin subunits. The molecular recognition properties of these porphyrinic materials for diamine sensing are also discussed.

In this paper we report the fabrication of thiolene-based microstructured reactors (MRs) that have been specifically designed to include solid-supported reagents within the microchannels network. We propose a convenient solution to realize reversible press-fit, leak-proof interconnects that greatly simplify the MR coupling to the external environment such as capillary tubing, sample reservoirs and pumps. The MRs have been used to carry out the oxidation of alpha-terpinene and methionine using [60]fullerene, covalently linked to Tentage](R) and silica gel matrices, as a singlet oxygen sensitizer. High conversions have been observed for both substrates although, in the case of a-terpinene, a partial photodegradation of the endo-peroxide product was detected. Interestingly, in the case of methionine, a quantitative conversion to the corresponding sulfoxides was achieved in about 40 seconds, using lowpower, white LED illumination. The reaction time is considerably shorter when compared to the batch procedure that requires, for the same process, about one hour illumination and the use of a 300-W tungsten halogen lamp.

Several catalytic protocols for the oxidation of hydro-soluble substrates are presented that employ totally inorganic and robust polyoxometalate-based catalysts as well as porphyrin sensitizers, fullerenes and hybrid conjugates. Strategies for the implementation of the system stability and efficiency are discussed.

An amino-trisulfonate tetraphenylporphyrin was conjugated to carboxylate cellulose nanocrystals giving rise to a new nanomaterial with interesting binding properties.

The Phormidium sp. ETS-05 thermophile blue-green alga is one of the most typical and widespread species of cyanobacteria of the thermal muds of the Euganean hot springs, the therapeutic properties of which have been known since ancient times. The polar diacylglycerolipids of this cyanobacterium consists of monogalactosyldiacylglycerol, digalactosyldiacylglycerol, sulfoquinovosyldiacylglycerol and phosphatidylglycerol. We have isolated and purified these four diacylglycerolipids from ETS-05, and then analysed them for their quantitative and structural features and fatty acid contents. The monogalactosyldiacylglycerol and digalactosyldiacylglycerol show a marked presence of polyunsaturated fatty acids, of which C18 : 4 is the most common. We propose that these glycoglycerolipids can be used as markers for monitoring the thermal mud colonisation process.

A sixteen component array of acid–base and metal ion sensors was synthesized and covalently immobilized onto a transparent cellulose-based membrane. Dye synthesis and cellulose dyeing were carried out in one-pot, parallel, microscale reactions not requiring any isolation or purification steps. In addition, pH and metal ion optical sensing properties of the sixteen component array have been tested using a high-throughput screening based on digital imaging analysis.

Stepwise amination of cyanuric chloride (1) with 5-(4-aminophenyl)-10,15,20-triphenylporphyrin (2) and/or its zinc(II) complex (3) enables the synthesis of porphyrin-porphyrin dyads with predetermined free base-free base forms or free base-zinc and zinc-zinc metalation states. Furthermore, the use of aminopropyl-silanized silica gel as a scavenger for unwanted byproducts allowed the one-pot synthesis of title porphyrin compounds in high yield and purity with minimum use of preparative column chromatography.

beta-Cyclodextrin-poly(ethylene glycol)-folic acid conjugate (CD-PEG-FA) was synthesized according to a two-step procedure: (1). synthesis of CD-PEG-NH(2) by reaction of monotosyl-activated beta-cyclodextrin with excess of 700 Da diamino-PEG; (2). synthesis of CD-PEG-FA by reaction of CD-PEG-NH(2) with succinimidyl ester-activated folic acid. The CD-PEG-NH(2) intermediate was purified by precipitation in acetone, and the CD-PEG-FA by gel permeation and C-18 reversed-phase chromatography. Both CD-PEG-NH(2) and CD-PEG-FA were analyzed by mass spectrometry, (1)H NMR, and UV-vis spectroscopy. All analytical methods confirmed the theoretical composition of the conjugates: the CD-PEG-NH(2) intermediate was composed of CD and PEG in the molar ratio of 1:1, and the CD-PEG-FA was composed of beta-cyclodextrin, PEG, and folic acid in the molar ratio of 1:1:1. The CD-PEG-FA conjugate was highly soluble in buffer (>42 mM) as compared to the unmodified beta-cyclodextrin (16.3 mM). Phase solubility diagrams of beta-estradiol revealed that drug solubility increases from 11 microM in buffer to 600 microM in the presence of beta-cyclodextrins and 5900 microM with CD-PEG-FA. However, the affinity of beta-estradiol for beta-cyclodextrins decreased about 4 times with PEG and folic acid conjugation. Stability studies carried out using chlorambucil confirmed that the conjugate partially prevents drug degradation in buffer, although this effect was considerably lower than that obtained with beta-cyclodextrin. Computer modeling studies showed that the folic acid linked to the beta-cyclodextrins through a PEG spacer could partially interact with the cyclodextrin cavity. Finally, CD-PEG-FA displayed reduced hemolytic effect as compared to unmodified beta-cyclodextrin.

Lipoic acid is a naturally occurring compound which is being widely investigated for its therapeutic effects in the treatment or prevention of a variety of diseases associated with oxidative injury, particularly diabetes. The diversity of therapeutic applications of lipoic acid requires an appropriate formulation to control its bioavailability, site-targeting delivery and to overcome its inherent chemical instability. In this regard, cyclodextrins (CDs) are ideally suitable due to their well-documented ability to include in their cavity proper guest molecules and protect them from physical or chemical damages. Lipoic acid forms 1:1 inclusion complexes with betaCD as shown in a previous report of an extended investigation that also indicated the suitability of capillary zone electrophoresis (CZE) for the study of such host-guest interactions. In view of these possible applications, we extended the CZE analysis to determine the strength of binding, in a pH 9 phosphate buffer, of lipoic acid with other CD derivatives such as alphaCD, gammaCD and the alkylated derivatives of betaCD, namely (2-hydroxypropyl)-beta-CD (HPbetaCD), and heptakis(2,3,6-tri-O-methyl)-beta-CD (TMbetaCD). Once established that the easily available betaCD is the most suitable receptor for lipoic acid, we set up and here describe a simple and reliable procedure for the quantitative determination of lipoic acid in commercial dietary supplement tablets containing also other active substances and excipients.

We explore a photochemical approach to achieve an ordered polymeric structure at the sub-monolayer level on a metal substrate. In particular, a tetraphenylporphyrin derivative carrying para-amino-phenyl functional groups is used to obtain extended and highly ordered molecular wires on Ag(110). Scanning tunneling microscopy and density functional theory calculations reveal that porphyrin building blocks are joined through azo bridges, mainly as cis isomers. The observed highly stereoselective growth is the result of adsorbate/surface interactions, as indicated by X-ray photoelectron spectroscopy. At variance with previous studies, we tailor the formation of long-range ordered structures by the separate control of the surface molecular diffusion through sample heating, and of the reaction initiation through light absorption. This previously unreported approach shows that the photo-induced covalent stabilization of self-assembled molecular monolayers to obtain highly ordered surface covalent organic frameworks is viable by a careful choice of the precursors and reaction conditions.

A pH-sensitive azo-dye covalently grafted onto cellulose nanocrystals yields nanostructured optodes in the form of membranes, sticks, and water-based inks for optical pH detection.

The electrophoretic behavior of water-soluble anionic porphyrins, such as meso-tetrakis(4-carboxyphenyl) porphyrin (TCPP), meso-tetrakis(4-sulfonatophenyl) porphyrin (TSPP) and its zinc(II) and copper(II) complexes (ZnTSPP and CuTSPP, respectively) has been studied by capillary zone electrophoresis using fused-silica capillaries. The selectivity of the separation is strongly dependent on the type and concentration of betacyclodextrin (betaCD) or the O-methylated derivatives added to the background electrolyte. CuTSPP and TSPP can be separated using a pH 2.5 aqueous sodium phosphate buffer in the presence of 1 mM betaCD. Resolution is poorer or absent employing alkylated betaCDs, such as the heptakis (2,6-di-O-methyl)-beta-cyclodextrin or the heptakis(2,3,6-triO-methyl)-beta-cyclodextrin, as additives. On the other hand, separation of TSPP from its copper and zinc complexes has been achieved using a pH 7.0 aqueous sodium phosphate buffer, in the presence of 0.75 mM betaCD and 20% dimethyl sulfoxide (DMSO) as organic modifier. Under such conditions, the calibration curve for quantitative analysis of copper(II) was obtained. A rationale for the observed behavior will be presented and discussed on the basis of binding and protonation equilibria and a simple mathematical model.

Reductive amination of 6-deoxy-6-formyl-β-cyclodextrin, 1 , with 5-( p -aminophenyl)-10,15,20-tris( p -sulfonatophenyl)porphyrin, 2 , in the presence of an excess of sodium cyanoborohydride, affords the water-soluble compound 3 (23% yield) as confirmed by NMR spectroscopy and mass spectrometry techniques.

A microfluidic setup for the photochemical nucleation and growth of silver nanoparticles with controlled morphologies is described. The combination of microstructured reactors and efficient LED illumination speeds the growth process up and enhances the shape-wise homogeneity of the produced nanostructures.

The UV-stabilizer 2-(2′-hydroxy-5′-methylphenyl)benzotriazole (Tinuvin P, LH) has been used as a monoanionic bidentate ligand for complexing oxocations. Displacement of acacH from [VO(acac) 2 ] and [MoO 2 (acac) 2 ] gave [∗VO(acac) 2 ∗(μ-L)] ( 2 ) and [ cis - O 2 Mo(acac)L] ( 3 ) respectively, as crystalline compounds. Their structure has been determined by an X-ray analysis showing the structural changes occurring upon coordination. The UV spectrum of Tinuvin P is significantly affected by complexation.

Among the most potent inhibitors of human cytomegalovirus protease identified by random screening of a chemical library was 1,4-dihydro-7,8-dimethyl 6H-pyrimido[1,2-b]-1,2,4,5-tetrazin-6-one (1) (PTH2). The oxidized form (2), PT, which is present in solutions of PTH2, was shown to be the actual inhibitory species which irreversibly inactivates the protease; recycling of PTH2 by dissolved oxygen results in complete inhibition of the protease at substoichiometric amounts of compound. No evidence for a covalent adduct between the protease and the inhibitor was obtained, and protease activity was restored by incubation of the inactivated enzyme with the reducing agent bismercaptoethyl sulfone, suggesting that disulfide bond formation was responsible for the observed inhibition. The five cysteines of the protease are normally in the reduced state; analysis of tryptic peptides from inhibited protease indicated that disulfide bonds Cys84-Cys87 and Cys138-Cys161 were formed. Using site-directed mutagenesis, the disulfide pair induced between Cys138 and Cys161 disulfide is dependent upon interaction of PT with the protease and does not form spontaneously, unlike that of the Cys84-Cys87 pair which can form in the absence of inhibitor. The inhibitor's redox chemistry is analogous to that of flavin, and, in fact, flavin inhibits the protease by the same mechanism, causing formation of a disulfide bond between Cys138 and Cys161. That the cysteines are dispensable, but can regulate protease activity by formation of a unique disulfide pair, suggests a plausible mechanism for control of proteolysis during the viral life cycle.

A post functionalization method for the control of the wettability of thiolene resins of the NOA family is presented. Treatment of open model surfaces or closed microchannels with chlorosilane derivatives resulted in dramatic changes in the behaviour of droplets and streams contacting the surfaces. The experimental findings are confirmed by the fabrication of a Y-junction device that works as a passive valve for water streams.

The use of microelectrode voltammetry in the study of host-guest complexation is described. A digital simulation approach to describe the complexation as a second-order CE mechanism for any kinetic condition is proposed. For a completely mobile equilibrium, the constant can be determined by the very simple relationship (I1/I1,0) = (1 + DrK[L]b)/(1 + K[L]b), where I1/I1,0 is the ratio of the limiting current in the presence and absence of the host species, Dr is the ratio of the diffusion coefficients of the complex and the guest species, K is the equilibrium constant and [L]b is the bulk equilibrium concentration of the host species. Advantage is gained from the linear dependence of the limiting current on the diffusion coefficient of the reactant which allows an enlargement of the measurement range. The potential applicability of the method to electroinactive guest species was also explored by using it in a competitive procedure. Agreement was found between the theoretical results and those relative to the ferrocenecarboxylic acid + β-cyclodextrin and ferrocenecarboxylic acid + p-nitrophenol + β-cyclodextrin systems in aqueous solution at pH 9.2.

[reaction: see text] The 2:1 inclusion complex between (2,3,6-tri-O-methyl)-beta-cyclodextrin (TMbetaCD) and 5,10,15,20-tetrakis(4-sulfonatophenyl)-porphyrin (TPPS(4)) behaves as a supramolecular sensitizer in water providing photooxygenation with turnover numbers up to 30,000 with a very minor sensitizer bleaching (10%). The protocol, which employs only 4 equiv of the cyclodextrin additive with respect to the porphyrin sensitizer (5 x 10(-7) M), leads to high yield oxidation of model biomolecules such as l-methionine methyl ester and uracil and is also effective for phenol degradation in aqueous solution.

A straightforward, "one-pot" approach to the construction of a new class of molecular tweezers and their heterogenization onto various aminated materials is reviewed here. It is based on nucleophilic substitution of the cyanuric chloride scaffold with tailored aminoporphyrin subunits. The molecular recognition properties of these porphyrinic materials for diamine sensing are also discussed.

Self-assembled molecular thin films of melamine-bridged bis-porphyrin dyad, both in free form, P(H2)P(H2), or as Zn(II) metallated complex, P(Zn)P(Zn), were deposited on crystalline Si(100) by soaking or drop-casting techniques. The influence of the adopted preparation methodology, the substrate surface pre-activation procedure and the used solvent (THF or CHCl3) on the morphology and surface coverage of the resulting films was investigated by FE-SEM (Field Emission-Scanning Electron Microscopy) and AFM (Atomic Force Microscopy). The chemical composition and electronic structure of the most promising systems were also addressed by XPS (X-ray Photoelectron Spectroscopy). The results pointed out that an accurate tuning of porphyrin-porphyrin, porphyrin-substrate and porphyrin-solvent molecular interactions allow to tailor the morphogenesis and chemico-physical properties of the final self-assembled films. In addition, preliminary gas sensing tests evidenced the potential of the present porphyrin-based films for the development of new molecular sensing devices.

We report on a three-step, continuous-flow synthesis of [6,6]-phenyl-C(61)-butyric acid tert-butyl ester (PCBtB), a promising electron-acceptor methanofullerene for solution-processed bulk-heterojunction solar cells, through the integrated use of three elements in a microstructured flow-reactor that eliminate the need of isolation steps, with a definite safety and environmental advantage.

The kinetics of the cyclopropanation reaction of diethyl malonate with [60]fullerene were assayed to optimize the continuous flow synthesis of the methanofullerene monoadduct. Experiments were carried out under both batch and flow conditions, by sampling the reaction mixture at different times and separating the components by means of HPLC in a way that resembles a stop/quenched flow system with the addition of a chromatographic step before analysis. The observed concentration profiles of the fullerene species in the reaction mixture were used to calculate the pertinent rate constants and to optimize the selectivity towards the monoaddition product.

We report on the implementation of a modified methanofullerene PCBtB ([6,6]-phenyl-C(61) butyric acid tert-butylester) as electron acceptor for solution-processable bulk-heterojunction (BHJ) solar cells based on P3HT (poly(3-hexylthiophene)). The results demonstrate how a small modification of the steric hindrance of the benchmark molecule PCBM, leaving the electronic structure unchanged, significantly influences the main properties of the BHJ active layer. In particular, we investigate the effect of the replacement of the PC(61)BM methyl end-group with a tert-butyl substituent on the optical properties, OPV parameters, nanoscale morphology, D: A phase segregation, and charge carrier mobility in bulk-heterojunction with P3HT. We find that the PCBtB-based blends present a finer self-organization, higher D: A phase segregation and good charge carrier mobility, affording interesting photovoltaic responses and highlighting a marked potential of PCBtB to tailor the active BHJ layer. The best BHJ solar cells based on as-cast P3HT: PCBtB blend films exhibit power conversion efficiencies (PCEs) of similar to 3.1%, under a simulated AM1.5G illumination of 100 mW cm(-2), which are greater than the analogous as-cast P3HT: PCBM based devices.

Allylstannanes of the type Bun3Sn(C3H3) ((C3H3 = allenyl and propargyl) Me3Sn(C4H7), Bun3Sn(C4H7), Ph3Sn(C4H7), Me3Sn(C4H7)2 and Bun3Sn(C4H7)2 [C4H7 = (E)-but-2-enyl, (Z-but-2-enyl, and but-1-en-3-yl] were prepared via Grignard reactions as isomeric mixtures whose compositions can be directly determined by 119Sn and 13C NMR spectrometry. The 119Sn and 13C δ-values of all possible isomers together with the isomeric compositions of freshly prepared compounds and after isomerization in dry methanol under reflux are reported. The course of isomerization of some compounds in anhydrous methanol at room temperature or in the presence of Bu3SnCl was followed by 119Sn NMR spectrometry.

The reaction of TiCl 4 with different isocyanides did not lead to any insertion of the isocyanide functionality into the Ti-Cl bond but to simple adducts such as {[TiCl 3 (2,6-Me 2 C 6 H 3 NC)] 2 (μ 2 -Cl) 2 }, [(TiCl 4 ) 2 (μ 2 -O=P-(OEt 2 CH 2 NC) 2 ], and [(TiCl 4 ) 2 (μ 2 -O=C(OEt)CH 2 NC) 2 ]. This ruled out any organometallic pathway in the Passerini reaction assisted by TiCl 4 . The present mechanism is proposed on the basis of the isolation and structural characterization of the key intermediate [TiCl 3 (μ 3 -OC(Me,Ph)C(Cl)=NCH 2 C(OEt)=O] derived from the reaction of PhCOCH 3 and CNCH 2 COOEt assisted by TiCl 4

Heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin in a pH=7.0 aqueous solution binds meso -tetrakis(4-carboxyphenyl) porphyrin and its zinc complex to yield 2:1 complexes with exceptionally high binding constants. The mode of binding, involving the inclusion of two opposite aryl groups in the cyclodextrin cavity, is clearly defined by a detailed NMR analysis.

Multicomponent supramolecular self-assemblies of exceptional long-range order and low defectivity are obtained if C(60) and 5-(4-aminophenyl)-10,15,20-triphenylporphyrin (TPP-NH2) are assembled on Ag(110) by sequential evaporation in the submonolayer range of TPP-NH2 and fullerene on the substrate surface and subsequent annealing. A (+/-2 -3, 6 +/- 3) array consisting of supramolecular stripes of a 1:1 C(60)/TPP-NH2 2D adduct develops at 410 K (the low temperature, LT, phase). If the LT phase is annealed at 470 K, then a 3:1 fullerene/TPP-NH2 (+/-3 -5, 5 +/- 5) nanoporous array (the HT phase) forms, with each pore containing a single porphyrin molecule. Phase separation occurs by annealing the HT phase at 520 K. Structural models are proposed and discussed on the basis of the experimental scanning tunneling microscopy results.

A melamine-bridged bis-Zn(II) porphyrin dyad covalently attached onto amino-functionalized TentaGel polymer beads or controlled pore glass (CPG) undergoes a reversible and marked colour change from purple to green upon exposure to a biogenic diamine such as cadaverine both in organic and aqueous media.

Dimeric metalloporphyrin hosts with tweezer-like structures have been synthesized by reacting the cyanuric chloride scaffold, CC, with 5-(4-aminophenyl)-10,15,20-triphenylporphyrin, P, and 5-(4-aminophenyl)-10,15,20-trimesitylporphyrin, M, to yield the homoconjugates free bases PP and MM and the heterodyad PM. Metalation with Zn(II), gives three structurally related ditopic receptors P(Zn)P(Zn), P(Zn)M(Zn), and M(Zn)M(Zn) with differential steric hindrance and conformational rigidity. The solution structure and supramolecular properties of these porphyrin dimers have been investigated as isolated molecules and in the presence of aliphatic alpha,omega-diamines of general formula H(2)N-(CH(2))(n)-NH(2) (n = 4-8) by spectroscopic and theoretical studies including multidimensional NMR, UV-vis, molecular modeling, and computational NMR methods. Binding constants in the range 4.2 x 10(6) to 3.4 x 10(7) M(-1) are observed in dichloromethane at 298 K, with a 3 orders of magnitude increase as compared to monodentate nBuNH(2), thus indicating the occurrence of a host-guest ditopic interaction. Linear correlation graphs are obtained by plotting the Soret band shift (Delta nu, cm(-1)) of the complex as a function of the diamine chain length. Combined NMR evidence and OPLS 2005 Force Field conformational analysis point to a mutual adaptation of both the binding partners in the host-guest complex, whose geometry is mainly dictated by the steric impact of the bulky substituents at the porphyrin periphery.

Eight new acidochromic dyes have been synthesised that can be used for optically monitoring pH in the range from 3 to 12. Their corresponding pK a values have been both measured and calculated theoretically by means of density functional theory. The synthesis of these new dyes is facile without the need for chromatographic purification. The dyes can be covalently linked to polymers containing hydroxyl functions such as cellulose, polyurethane hydrogel, and hydroxyalkyl methacrylate. The resulting sensor layers exhibit significant colour changes both in the UV and in the visible spectral range.

A new fabrication process is described allowing rapid prototyping of multilayer microfluidic chips using commercial thiolene optical adhesives. Thiolene monomer liquid is photopolymerized across transparency masks to obtain partially cured patterns supported on thin polyethylene sheets. The patterns are easily laminated and transferred to a substrate due to the elastomeric nature and adhesiveness of partially cured thiolene. The process characteristics are evaluated by realizing several test structures and fluidic chips. As an example of application, the operation of a microfluidic bead array sensor for pH measurements is then described in some detail.

Covalent functionalization with a reactive azo-dye of tentagel resin beads bearing hydroxyl linkers led to a micro-sized optical sensor for pH detection. A PDMS/glass microfluidic cell has been constructed using replica molding combined with a fast prototyping procedure based on commercially available thiolene-based photocurable adhesives and used for studying the acid-base and time-response properties of the bead sensor under flow conditions. (C) 2007 Elsevier B.V All rights reserved.

A straightforward procedure for supporting porphyrin-derivatives onto resin beads has been developed by reacting the commercially available 4,6-dichloro-1,3,5-triazene polymer-bound, with 5-(4-aminophenyl)-10,15,20-triphenylporphyrins as free base and as Zn (II) and Co (II) complexes. The supported porphyrins have been characterized by on-resin UV-vis spectroscopy. Kinetic and Hammett LFER studies have shown that the S N Ar reaction with the triazine-bound reagent occurs at a similar rate for free and metalated complexes, with a nucleophilic strength comparable to that of the unsubstituted aniline (σ p + = 0.07-0.08).

Microfluidics is a powerful tool for the smart management of chemical reactions. It has been shown that the flow chemistry approach allows for precise control over process parameters, ease of optimization and even simplified scale-up from lab-scale to production modules. These features come in especially handy when dealing with complex systems, where reagents are not molecular in nature. Such is the case of many materials, like metal nanoparticles, carbon nanotubes and graphene, whose chemical functionalization represents a way to produce nano-sized components for a wide range of applications. After our previous experience with the development of flow chemistry method for the functionalization of fullerenes and carbon nanotubes, we have extended our study to graphene-like materials. In the presentation we will propose a general method to control the functionalization of graphene materials, as a mean to prepare derivatives with tailored properties.