Synthesis and Crystal Structure of N—（1‘’‘’—Phenyl—2‘’‘’—hydroxyethyl）—2,3—naphthylenedicarboximide

IntroductionThe design and the synthesis of new chiral ox-azoline[1,2 ] and C2 symmetric bis( oxazoline) ligandsand the application of their metal complexes inasymmetric catalytic reactions have inspired manyscientists to great exertions in recent years[3— 8] .Our interest has been focussed on the studies ofenantioselective transition metal catalysis ofhetero-cyclic ligands[9— 11] . In the synthesis of our new de-signed ligands,what is crucial is to select a rigidcyclic backbone. Bis( oxazo…     

On the boundary between laboratory ‘givens’ and laboratory ‘tangibles’

From the 4-part Procedure/Observations/Data/Analysis structure of a laboratory report (generalized from Italian, Chinese and US sources), we distill a fifth flavor, the givens, whose flip side is the freedoms or tangibles of an experiment. (Stated in terms of computer science, we are trying to find inputs and outputs, but these turn out to be surprisingly vague in chemistry.) Then, in the service of a white-boxing ethos (which sounds less severe than ‘anti black-boxing’), we establish a movable boundary between givens and tangibles, with implications for ‘ontological attitudes’ and for the future of chemistry. Next, in revisiting a 2002 exchange between Schummer and Laszlo, which might be paraphrased as the chemist-as-philosopher versus chemist-as-artisan, we apply a second kind of sliding scale which seems to harmonize the discussion. Finally, on a possibly quixotic note, we look briefly at a third kind of sliding scale, now aimed squarely at ontology itself. For illustrative purposes, we adopt an atomocentric viewpoint (as distinct from atomistic), and assign it the provisional name ‘Fuzzy CH₄ Ontology’.     

The meaning of ‘concentration’

Terminology within a small laboratory community can be informal without danger of misunderstanding, but communication with a wider audience and not least in publications, needs unequivocal terms for defined concepts. As an example, the many meanings of “concentration” are explored to present a systematic nomenclature, including a concept diagram.

Molecular ‘OR’ and ‘AND’ logic gates integrated in a single molecule

Based on the N electrodes elastic scattering quantum chemistry (NESQC) technique, an intramolecular circuit simulator is presented for the design of electronic logic functions integrated inside a single molecule interconnected to the N electrodes. Using molecular rectifier groups, a molecule-OR and a molecule-AND are designed, their current-voltage characteristics calculated and their logic response presented. Both the OR and AND molecules have approximatively the targeted function. The running current of the OR gate, 10 fA, is quite low and the AND gate works only in an output voltage mode. This forbids the design of larger logic functions inside a single molecule with molecular rectifiers.     

‘Apples’ and ‘oranges’: comparing the structural aspects of biomineral- and ice-interaction proteins

The title of this review describes structural comparisons of protein classes whose task is to identify and interact with biological solids (minerals and ice). To date, the following trends have been noted: (1) biomineral-interaction proteins typically adopt unfolded, open conformations, and, where mineral binding motifs have been identified, these sequences exhibit structural trends towards extended, random coil, or other unstable secondary structures; (2) ice-interaction proteins typically adopt folded structures, featuring stable secondary structure preferences (α-helix, β-sheet, β-helix, etc.) and stable, planar ice binding motifs that exploit hydrophobicity and van der Waals’ interactions for ice binding.     

Thermal investigation of ‘molten starch’

Detailed thermal analysis studies have shown that a ‘molten starch’ phase is obtained during controlled heating of starch. Before the ‘molten’ stage, depolymerisation of starch produces lower molecular weight compounds like dextrins, oligo, di- and monosaccharides, as well as other types of compounds. These compounds should have ideal properties for plasticizing starches because of the similarities of the molecules, helping lower phase changes in collaboration with molecular weight decrease. Interestingly, it was found previously that these materials only act as adhesives in a narrow temperature range around 523 K (250 °C) (Shuttleworth et al. J Mater Chem 19(45):8589–8593, 2009). Materials were investigated using thermal and mechanical analyses of single lap joints.     

Lead-free relaxor ferroelectrics with ‘TTB’ structure

Preparation and dielectric characterisations of a great number of TTB-type ceramics have allowed us to show that some of them present relaxor behaviour, due to the occupation of the same crystallographic site by two different cations or anions. One of the cation in the octahedral site has to be ferroelectrically active. The relaxor effect is correlated to either cationic distribution disorder in the same site or dilution of the ferroelectric character.     

Low generational polyamidoamine dendrimers to enhance the solubility of folic acid:A‘‘dendritic effect’’investigation

Low generational(G0–G2,G for generation) polyamidoamine(PAMAM) dendrimers were investigated as enhancers to improve the aqueous solubility of folic acid at pH 11 and pH 5.In these two cases,the solubility of folic acid increases with both the dendrimer concentration and generation.However,the solubilization mechanism is different.The electrostatic interaction between the primary amines of dendrimers and the ionized carboxylic groups of folic acid dominates the dissolution process at pH 11 while the increase of the solubility of folic acid at pH 5 is attributed to the hydrophobic encapsulation inside the dendrimer molecules.In addition,for comparison ethylenediamine was used as a small molecule control to examine the ‘‘dendritic effect' in the dendrimer-related solubilization process.Interestingly,PAMAM dendrimers exhibit,at pH 5,a significant superiority over ethylenediamine in enhancing solubility,whereas this ‘‘dendritic effect' cannot be observed under the basic condition.     

‘Purposive’ Molecular Design for Multifunctional Artificial Receptors

This account describes recent examples of multifunctional artificial receptors, which demonstrates our approach to purposive molecular design. The paper is divided into two parts. The first deals with novel crowned spirobenzopyrans as dual-mode signal transducers. The new crowned spirobenzopyrans complement previous crowned spirobenzopyrans from the viewpoint of molecular devices, and a detailed comparison between them is given. The second part is concerned with polypyridine-macrocyclic structures as ribofuranoside receptors. The design of the ribofuranoside receptors was based on the multipoint hydrogen bond complementarity between the receptors and methyl -(d)-ribofuranoside. The binding affinity of the receptors was very high, so that even native ribose was extracted by them into nonpolar solvents.     

Report On ‘Chemistry in a Biological Context’

The American Chemical Society has started its first large-scale project related to opening up new options for undergraduate majors. Tentatively titled Chemistry in a Biological Context, the work has only just begun. Participants are invited to provide early feedback into the nature and shape of the project.     

A Simple Short Synthesis of Isotachin ‘C’

A short simple synthesis of Isotachin ‘C’ a sulphur containing aromatic ester isolated from New-Zealand Liver worts, Balantiopsis rosea has been described.     

Multi-responsive cyclodextrin vesicles assembled by ‘supramolecular bola-amphiphiles’

Multi-responsive cyclodextrin vesicles (CDVs) self-assembled by ‘supramolecular bola-amphiphiles’, consisting of a guest (N,N′-bis(ferrocenylmethylene)-diaminohexane, 1) and a host (γ-hydroxybutyric-β-cyclodextrin, γ-HB-β-CD), were prepared and investigated for the first time. The morphologies and sizes of these novel vesicles in water were observed by transmission electron microscopy (TEM), scanning electron microscopy and dynamic light scattering. The effects of the host–guest ratio, the concentration and the solvent composition are also discussed. The host–guest interactions, complex stoichiometry and structures of 1·γ-HB-β-CD in water were investigated by cyclic voltammetry, UV and NMR spectroscopy. According to the complex stoichiometry, TEM observations and Chem3D estimation, the ‘supramolecular bola-amphiphiles’, made from 1·γ-HB-β-CD and assumed for the first time, formed the membranes of the CDVs. The CDV system was responsive to an oxidising agent, which is the first report on redox-responsive systems in this field. The CDVs are also responsive to pH and the presence of metal ions, such that they disassemble upon addition of acetic acid or Cu²⁺ ions, providing possible routes to drug delivery systems.     

An improved synthesis of ‘octa-acid’ deep-cavity cavitand

An improved synthesis of a water-soluble deep-cavity cavitand (octa-acid, 1) is presented. Previously (Gibb, C.L.D.; Gibb, B.C. J. Am. Chem. Soc. 2004, 126, 11408–11409), we documented access to host 1 in eight (non-linear) steps starting from resorcinol; a synthesis that required four steps involving chromatographic purification. Here, we reveal a modified synthesis of host 1. Consisting of seven (non-linear) steps, this new synthesis involves only one chromatographic step, and avoids a minor impurity observed in the original approach. This improved synthesis is therefore useful for the laboratories that are investigating the properties of these types of host.     

Generic division of ‘quantity’ and related terms

In the slow evolution of the International vocabulary of metrology (VIM), the first concept of ‘quantity’ has now been divided generically into ‘ordinal quantity’ and a coordinate primitive without definition and term. An analysis of the concepts by their characteristics is made, and the nature of inheritance is discussed in response to a recent communication in this journal. A completion of the initiated generic division of ‘quantity’ is suggested, and a neoterm for the sister of ‘ordinal quantity’ is offered on the basis of two proposals.     

Report On ‘Technology and Assessment in Chemistry’

The Multimedia Instruction workshop examined a variety of uses for multimedia in instruction. Marco Molinaro, Director of Multimedia Development for the Modular Chemistry Consortium based at the University of California at Berkeley, presided. The session consisted of developing a common language used in describing multimedia, exploring demonstration programs, and using hands-on experience to create, adapt, or critique available software.     

‘Pincer’ pyridyl- and bipyridyl-N-heterocyclic carbene analogues of the Grubbs’ metathesis catalyst

The ‘pincer’ pyridine-dicarbene and bipyridyl-carbene ruthenium benzylidene complexes, Ru(C–N–C)Cl₂(CHPh) and Ru(C–N–N)Cl₂(CHPh), (C–N–C) = 2,6-bis(DiPP-imidazol-2-ylidene)pyridine, (C–N–N) = (DiPP-imidazol-2-ylidene)bipyridine, have been prepared and characterised by spectroscopic and diffraction methods. They exhibit moderate metathesis activity. Non-symmetrical linear tridentate ether-functionalised N-heterocyclic carbene pro-ligands are also described.     

Syntheses and Crystal Structures of 4,4‘—Diformyl—diphenoxyethane and 4,4’,4‘’—Triformyl—triphenoxytriethylamine

Two title compounds, 4,4'-diformyl-diphenoxyethane (compound 1, C16H14O4)and 4,4',4'-triformyl-triphenoxytriethylamine (compound 2, C27H27NO6), were synthesized by condensation of 4-hydroxybenzaldehyde with 1,2-dichloroethane and tris2-chloroethylamine, respectively in dimethyl formamide in the presence of anhydrous potassium carbonate. The crystal data are: monoclinic, P21/c, a = 7.571(2), b = 12.608(3), c = 7.357(2) ', = 105.823(6)o, V = 675.7(2)'3, Mr = 270.3, Z = 2, Dc = 1.328 g/cm3, F(000) = 284, (MoK = 0.096 mm-1, R = 0.0537 and wR = 0.2189 for compound 1; and monoclinic, P21/n, a = 11.7162(6), b = 9.0042(6), c = 22.908(2) ', = 99.505(1)°, V = 2383.5(3) '3, Mr = 461.50, Z = 4, Dc = 1.286 g/cm3, F(000)= 976, (MoK = 0.091 mm-1, R = 0.0464 and wR = 0.1462 for compound 2. The molecule of compound 1 dialdehyde is located at the crystallographic inversion center nearby the midpoint of C8-C8A single bond. The three chains in the molecule of compound 2 trialdehyde are of non-crystallographic pseudo-C3 symmetry, and each of them is quite planar.