NJC Blog

Scientists from the Universities of Rennes and Nancy in France have developed dual-role biphotonic chromophores for photodynamic therapy (PDT) applications that retain fluorescence properties, thus enabling their 3-D localization and the selective irradiation of cancer cells when combined with targeting.

In their paper selected as ‘Hot Article’, the collaboration led by Mireille Blanchard-Desce presents the synthesis and photophysical study of “banana-shaped” chromophores where the nature of the conjugated backbone is modified by playing with the aromatic units (a complementary approach to that based on the incorporation of heavy atom substituents).

By optimizing the chromophore structure of a series of fluorene derivatives, the researchers were able to design photosensitizers exhibiting large two-photon adsorption (TPA) cross section in the biologically useful spectral region combined with singlet oxygen production.

‘This route allows to combine in a single biphotonic chromophore several features highly desirable for two-photon PDT: fluorescence (for localisation and subsequent localized irradiation), large and broad TPA responses in the spectral range of interest for bio-oriented applications (700-1000 nm), as well reasonable singlet oxygen sensitization ability’, says Mireille Blanchard-Desce.

The team is now working on developing nano-objects with very high TPA, that incorporate the biphotonic sensitizers.

Banana-shaped biphotonic quadrupolar chromophores: from fluorophores to biphotonic photosensitizers
Cédric Rouxel, Marina Charlot, Youssef Mir, Céline Frochot, Olivier Mongin and Mireille Blanchard-Desce
New J. Chem., 2011, Advance Article
DOI: 10.1039/C1NJ20073A, Paper

Interested? Why not read the full article now, FREE to access for a period of 4 weeks!

Why not submit your high impact research to us today or alternatively email us your suggestions.

In this NJC Hot Article, Richard Compton and co-workers at the University of Oxford highlight novel electro-synthetic applications of ionic liquids.

The team has decorated carbon nanotubes with Palladium nanoparticles and used the composite material for the efficient electrochemical deprotection of common functional groups in ionic liquids (IL), thus demonstrating that Pd nanoparticles can be used for clean, efficient, safe electro- chemical hydrogenolysis in IL media.

This NJC article will be of interest to synthetic organic and inorganic chemists, electrochemists, material chemists, pharmaceutical chemists and process chemists alike.

• Why not take a look and read the article now, FREE to access for a period of 4 weeks!

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Palladium nanoparticle-modified carbon nanotubes for electrochemical hydrogenolysis in ionic liquids
Yao Meng, Leigh Aldous, Ben S. Pilgrim, Timothy J. Donohoe and Richard G. Compton
New J. Chem., 2011, Advance Article
DOI: 10.1039/C1NJ20070D, Paper

Ferrocene units confer a set of interesting properties to ligands for transition metal complexes, such as reversible redox- properties, planar chirality, or strong electron donating ability. While there are numerous examples of ferrocenylphosphines in which the ferrocene unit is directly bonded to the active coordination center – therefore maximizing its impact – attempts at stabilizing a carbene center using one or two ferrocenyl substituents had yet to prove successful.

Now, Guy Bertrand and colleagues at the University of California, Riverside, have successfully prepared the first stable carbene featuring a ferrocenyl unit directly bonded to the electron-deficient center, by using a pi-electron-donating substituent in the form of an amino group. The team was able to spectroscopically characterize and chemically trap the novel (amino)(ferrocenyl)carbene compound.

Such work is envisioned to open perspectives for the synthesis of new types of carbene ligands, and will be of high relevance to researchers in fundamental chemistry, organometallics, supramolecular chemistry, catalysis and beyond. Challenges ahead now include the further stabilization of such carbenes, via the preparation of cyclic ferrocenylaldiminium systems.

A persistent (amino)(ferrocenyl)carbene
Alan DeHope, Daniel Mendoza-Espinosa, Bruno Donnadieu and Guy Bertrand
New J. Chem., 2011, Advance Article
DOI: 10.1039/C1NJ20170K, Paper

Interested? Why not read this NJC Article selected as Hot, FREE to access until 6th of June 2011.
Let us know what you think and leave us a comment below!

This article will be part of the themed issue of NJC honouring the life and work of Prof. Didier Astruc, on the occasion of his 65th birthday – Coming soon.

A new facet of Phosphole chemistry is being uncovered it this NJC Letter by François Mathey et al. at the Nanyang Technological University, Singapore. Phosphole rings have been known for a long time to dimerize via [4+2] cycloaddition whenever the phosphorus lone pair is oxidized or complexed. The [2+2] dimerization, on the contrary, is almost unknown.

Now, the authors show that a minor change in the structure of the bisphospholes derivative – i.e. P-O-P vs. P-S-P – completely suppresses the familiar (4+2)-cycloaddition in favour of the thermally forbidden (2+2) -cycloaddition despite considerable steric constraint.

Under solar light at room temperature, the tungsten pentacarbonyl complex of the P–S–P-linked biphosphole undergoes a [2+2] intramolecular cycloaddition. Then, this [2+2] dimer gives the original [4+4] dimer via a Cope rearrangement. This sequence stands in sharp contrast with the behavior of the corresponding P–O–P-linked biphosphole which undergoes a classical [4+2] cycloaddition.

This NJC Letter has been rated as Hot, and will be FREE to access for 4 weeks. Read it now and let us know what you think!

Intramolecular [4+2] versus [2+2] cycloadditions in P–X–P-linked biphospholes (X = O, S)
Matthew P. Duffy, Yuhan Lin, Liow Yu Ting and François Mathey
New J. Chem., 2011, Advance Article
DOI: 10.1039/C1NJ20087A, Letter

This article will be part of the themed issue of NJC honouring the life and work of Prof. Didier Astruc, on the occasion of his 65th birthday – Coming soon.

Here are the latest Hot Articles published in NJC, selected by the journal editorial team and highly commended by the reviewers. All are FREE to access for 6 weeks, so why not take your pick and have a read now?

• Heterolytic cleavage of ammonia N–H bond by bifunctional activation in silica-grafted single site Ta(V) imido amido surface complex. Importance of the outer sphere NH3 assistance, Eric Gouré, Priscilla Avenier, Xavier Solans-Monfort, Laurent Veyre, Anne Baudouin, Yasemin Kaya, Mostafa Taoufik, Jean-Marie Basset, Odile Eisenstein and Elsje Alessandra Quadrelli, New J. Chem., 2011, Advance Article, DOI: 10.1039/C1NJ20032A, Paper

The work by this international collaboration shows how the outer-sphere NH3 assistance lowers the energy barrier of H+ transfer in the reaction of NH3 with silica-supported single site TaV amido–imido complex.

• A binaphthol-substituted tetrathiafulvalene with axial chirality and its enantiopure TCNQF4 charge-transfer salts, Ali Saad, Olivier Jeannin and Marc Fourmigué, New J. Chem., 2011, Advance Article
  DOI: 10.1039/C1NJ20034H, Paper

Fourmigué et al. (University of Rennes, France) report on the TCNQF4 oxidation of an original chiral tetrathiafulvalene bearing a binaphthol moiety on one side, affording the very first enantiomeric salts of chiral TTFs with axial chirality, characterised with segregated, dimerised stacks.

• Stirring-induced aggregation of graphene in suspension, Wenzhi Yang, Erika Widenkvist, Ulf Jansson and Helena Grennberg, New J. Chem., 2011, 35, 780-783, DOI: 10.1039/C0NJ00968G

Helena Grennberg et al. (Uppsala University, Sweden) investigate how graphene in suspension undergoes stirring-induced aggregation, leading to reversible agglomeration and irreversible folding/scrolling, all of which affects the Raman spectra.

• Rapid purification/oxidation of multi-walled carbon nanotubes under 300 kHz-ultrasound and microwave irradiation, Giancarlo Cravotto, Davide Garella, Emanuela Calcio Gaudino, Francesco Turci, Serena Bertarione, Giovanni Agostini, Federico Cesano and Domenica Scarano, New J. Chem., 2011, 35, 915-919, DOI: 10.1039/C0NJ00892C

300 kHz ultrasound and microwaves strongly accelerate the oxidation and purification of MWCNTs, preserving the typical tubular shape, as discussed in this hot article by Giancarlo Cravotto and colleagues, from the University of Torino, Italy.

These four hot articles have been made freely available until April 28th, so why not download the ones that interest you today and let us know what you think in our blog below.

If you have some of your own exciting, high impact research to publish then consider submitting your manuscript to NJC, via our online submission system.

Since the 1950’s, synthetic organic polymers have been widely used as consolidants for the preservation of historic stones, altered by the weather conditions. Although still in use, their conservation efficiency has been drastically reconsidered due to their fugitiveness, thermo- and photo-degradation, limited removability, and incompatibility with the stone matrix. Synthetic organic polymers are thus believed to be harmful in the long term and unsuitable materials for the consolidation of historic stone.

Inorganic materials such as alkaline earth hydroxides are better suited for the task due to their higher physicochemical compatibility with the rocks, but mostly exist as isolated particles acting as fillers only, rather than offering a continuous medium that would ensure an optimal adhesion between the newly produced carbonate and the weathered stone.

Now, Bingjian Zhang and his team at the University of Zhejiang and Tianshui (China) have solved the adhesion issue and developed for the first time a biomimetic approach for the reinforcement of weathered stones. Their strategy was to mimic the growth of bones, by introducing calcium and phosphore sources in the pores of the damaged stone, and then let them mineralize in the presence of collagen at ambient temperature. This biomimetic mineralization process allows a porous and interlinked reinforcing phase of apatite to be formed, which can bind the grains of loose weathered calcareous stone together and provide substantial reinforcement. The team also showed that the breathing function of the stones was retained, due to the porous nature of bone-like apatite. With the highly positive results achieved, this method is promising for the conservation of historic stones, say the researchers, while further challenges lie towards a reinforcement method aimed at non-calcareous rocks.

Biomimic conservation of weathered calcareous stones by apatite
Fuwei Yang, Bingjian Zhang, Yan Liu, Guofeng Wei, Hui Zhang, Weixiang Chen and Zhude Xu
New J. Chem., 2011, Advance Article
DOI: 10.1039/C0NJ00783H, Paper

A native enzyme, which catalyzes stereoselective aldol reactions, was successfully encapsulated in an inorganic support by Forano, Lemaire, and co-workers. This biocatalyst maintains 100% of enzyme activity through a series of different condensation reactions. In addition, the immobilized enzyme is stable under storage and can be reused several times without a notable loss of activity, highlighting its suitability for organic synthesis.

Efficient immobilization of fructose-6-phosphate aldolase in layered double hydroxide: improved stereoselective synthesis of sugar analogues
Christine Guérard-Hélaine, Bertrand Légeret, Carlos Fernandes, Vanessa Prévot, Claude Forano and Marielle Lemaire
New J. Chem., 2011, Advance Article
DOI: 10.1039/C0NJ00956C, Letter

Curious? Why not read all about it here. This NJC paper has been rated as ‘hot’ and is FREE to access to all for a period of four weeks, after a simple registration process at: http://pubs.rsc.org/en/account/register. Let us know your thoughts and comments below!

Meisel and co-workers (University of Florida, USA) report on the elaboration of thin films of a series of Prussian Blue analogs, together with their magnetic behaviour. These films were shown to exhibit magnetic anisotropy by investigating the magnetic susceptibility, and specifically the difference between parallel and perpendicular orientations of the films with respect to the applied magnetic field. The degree of anisotropy is largely explained by demagnetizing effects, and a simple model is discussed. This paper represents a first step towards the understanding of the anisotropy of thin films of coordination polymer systems, of importance if films are to be used in device applications. Furthermore, this manuscript casts light on the origin of the anisotropy of photomagnetic systems.

Anisotropic magnetism in Prussian blue analogue films
Daniel M. Pajerowski, Justin E. Gardner, Daniel R. Talham and Mark W. Meisel
New J. Chem., 2011, Advance Article
DOI: 10.1039/C0NJ00841A, Paper