Precious particles: Dicyanoargentate(I) and dicyanoaurate(I) salts of an imidazolium cation form both crystalline (see structure and enlargement of the cation and anion) and smectic‐A phases. Electrodeposition from the ionic liquid crystals provides a novel route to silver particles and gold nanoparticles.

The preparation of chloride (1(n)) and bromide (2(n)) derivatives of 1-methyl-3-[3,4-bis(alkoxy)benzyl]-4H-imidazolium with n = 6, 12, 16, 18 is described. The two series of salts possess a rich thermotropic mesomorphism, chain-length dependent. Thus, a lamellar smectic A phase, a bicontinuous cubic Ia3d phase, and a columnar hexagonal liquid crystalline mesophase are induced as a function of increasing chain length. The mesomorphic properties were studied by polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction, and with the support of dilatometry and molecular dynamics, models for the various supramolecular arrangements of the salts are proposed. Such cationic amphiphiles were expected to be candidate molecules to design a new delivery reagent for nucleic acid transfection, particularly for short interfering RNA (siRNA). The use of an RNA interference mechanism, by introduction into cells by transfection of chemically synthesized siRNAs, is a powerful method for gene silencing studies. To exploit the potential of these amphilic imidazolium salts, these molecules were formulated with cohelper lipids and tested for their efficacy to deliver active siRNAs. Our results show high transfection efficacy of our formulated compounds and high silencing efficiency with more than 80% inhibition of the targeted gene at 10 nM siRNA concentration. Taken together our results show the potency of amphiphilic imidazolium salts as a new generation of transfection reagents for RNA interference.

The new ionic liquid crystal 1-(4-dodecyloxybenzyl)-3-methyl-1H-imidazol-3-ium bromide has been synthesized and its X-ray structure obtained; various salts containing BF 4 À , SCN À , PF 6 À , CF 3 SO 3 À Scheme 2 Synthesis of the bromide 1a. Reaction conditions: (i) DMF, K 2 CO 3 , BrC 12 H 25 , 60 1C, overnight; (ii) LiAlH 4 , THF, 4 h; (iii) SOBr 2 , DCM; dry THF, methylimidazole under inert atmosphere. Scheme 1 1-(4-Dodecyloxybenzyl)-3-methyl-1H-imidazol-3-ium salts.

SummaryThe merger of ionic liquid and liquid crystal fields, obtained by using the imidazolium ring as a common element, has allowed us to tailor a new set of materials which associate specific functionalities. These functionalities are consequences of the original properties of the component, ionic liquids, liquid crystals and their association in a single compound. The study of this interesting association led us to elaborate environment-flexible cationic architectures from which mesomorphic properties emerge. Moreover, we have also explored the influence of different anions on the mesomorphic properties.

Edle Partikel: Dicyanoargentat(I)‐ und Dicyanoaurat(I)‐Salze eines Imidazoliumkations bilden Kristallphasen (siehe Bild) und Flüssigkristallmesophasen vom Typ smektisch A. Die Elektroabscheidung der ionischen Flüssigkristalle bietet einen neuartigen Zugang zu Silber‐Partikeln und Gold‐Nanopartikeln.

No abstract

A condensation reaction involving a free base tetraarylporphyrin-2,3-dione, a macrocyclic compound containing a 1,10-phenanthroline-5,6-dione and a 1,2,4,5-tetraminobenzene as a linker affords the corresponding conjugate in good yield. The porphyrin ring and the phenanthroline fragment of the other ring are connected in such a way that mutual rotation between these two groups is prohibited. Metallation of the Porphyrins have been incorporated in rotaxanes and catenanes as electro-and photoactive components, mostly in relation to models of the photosynthetic reaction centre, to host-guest chemistry or to dynamic systems able to undergo large amplitude motions.[1] Our group has been particularly interested in energy and electron transfer studies within such rotaxanes or catenanes.[2] The porphyrin nucleus can be used as a stopper (for rotaxanes), either attached to or part of the ring.[3] Till now, limited geometrical control could be achieved as the mutual orientation between the porphyrin and the ring was not controlled, especially when the porphyrin fragment was appended to the cyclic component(s) of the rotaxane or the catenane. To have strict geometrical control over the system, it is necessary to connect the porphyrin and the ring by a rigid spacer, for which free rotation is not allowed. In the present report, we would like to describe the synthesis of such a conjugate consisting of a 30-membered ring built from 2,9-diaryl-1,10-phenanthroline and a free-base porphyrin or a zinccomplexed porphyrin. The spacer between these two components is a rigid aromatic nucleus. In addition, to demonstrate that the rigidly held porphyrin-macrocycle conjugates prepared can be used as components of interlocking structure, we have assembled a pseudorotaxane using the copper(I)-based strategy already applied in other related reactions. [2,3] The threaded species obtained by mixing the Zncontaining porphyrin-ring conjugate, copper(I) and a coordinating fragment of the 1,10-phenanthroline family, is indeed obtained in quantitative yield. porphyrinic site affords the corresponding zinc complex. By reacting this zinc porphyrin with copper(I), followed by the addition of the bidentate chelate 2,9-bis(p-anisyl)-1,10-phenanthroline, the threading reaction leading to the corresponding pseudorotaxane takes place quantitatively.

In the Report of t h e Education Reform Council, published in 1917 under the title “Education Reform,” it is suggested on page 83 that for boys of 14 to 16 years of age attending a secondary school it is desirable that the mathematical course should be directed towards an elementary use of calculus methods, so that those who remain at school to a later stage may be able to use effectively the elements of infinitesimal calculus. On the next page it is further suggested that boys of 16 to 18 years of age who take up mathematics and science may pursue the study of differential and integral calculus, including the easy parts of differential equations, and apply these with advantage to higher algebra, trigonometry, co-ordinate geometry, solid geometry and mechanics; that the co-ordinate geometry requires a muchbroader treatment than that commonly adopted—a treatment in which the calculus is freely used and in which some “geometrical” conies, when elegant and convenient, is dovetailed into the analysis.