Good Laboratory Practice for optimization research

Good Laboratory Practice has been a part of non-clinical research for over 40 years. Optimization Research, despite having many papers discussing standards being published over the same period of time, has yet to embrace standards that underpin its research. In this paper we argue the need to adopt standards in optimization research. Building on previous papers, many of which have suggested that the optimization research community should adopt certain standards, we suggest a concrete set of recommendations that the community should adopt. We also discuss how the proposals in this paper could be progressed.     

Arsinophosphonium cations from arsenium-phosphine and -bisphosphine coordination chemistry

A new 14pi-electron tricyclic organoarsenium cation (5-hydrophenarsazinium, AN, C12H9AsN+) has been prepared in situ and used as a Lewis acceptor with trimethylphosphine, triphenylphosphine, bis(diphenylphosphino)methane (dppm), bis(dimethylphosphino)methane (dmpm), and 1,4-bis(diphenylphosphino)benzene (dppb) ligands. Solid-state structures and spectroscopic characterization data are reported for complexes of the general formula [AN-PMe3]+, [AN-PPh3]+, [AN-dppm]+, [AN-dppm-AN]2+, [AN-dmpm-AN]2+, and [AN-dppb-AN]2+ as tetrachlorogallate salts. Depending on reaction stoichiometry, dppm forms adducts at one or both of the donor sites. Structural comparisons with analogous complexes of phosphenium cations provide interesting similarities and differences.     

Recent and potential developments in the analysis of urine: a review

Analysis of urine is a widely used diagnostic tool that traditionally measured one or, at most, a few metabolites. However, the recognition of the need for a holistic approach to metabolism led to the application of metabolomics to urine for disease diagnostics. This review looks at various aspects of urinalysis including sampling and traditional approaches before reviewing recent developments using metabolomics. Spectrometric approaches are covered briefly since there are already a number of very good reviews on NMR spectroscopy and mass spectrometry and other spectrometries are not as highly developed in their applications to metabolomics. On the other hand, there has been a recent surge in chromatographic applications dedicated to characterising the human urinary metabolome. While developments in the analysis of urine encompassing both classical approaches of urinalysis and metabolomics are covered, it must be emphasized that these approaches are not orthogonal - they both have their uses and are complementary. Regardless, the need to normalise analytical data remains an important impediment.     

Chiral Phosphoric Acid Dual-Function Catalysis: Asymmetric Allylation with α-Vinyl Allylboron Reagents

We report a dual function asymmetric catalysis by a chiral phosphoric acid catalyst that controls both enantioselective addition of an achiral α-vinyl allylboronate to aldehydes and pseudo-axial orientation of the α-vinyl group in the transition state. The reaction produces dienyl homoallylic alcohols with high Z-selectivities and enantioselectivities. Computational studies revealed that minimization of steric interactions between the alkyl groups of the diol on boron and the chiral phosphoric acid catalyst influence the orientation of α-vinyl substituent of the allylboronate reagent to occupy a pseudo-axial position in the transition state.     

Control of all‐conjugated block copolymer crystallization via thermal and solvent annealing

Control of the crystallization of conjugated polymers is of critical importance to the performance of organic electronics, such as organic photovoltaic devices, due to the effect on charge separation and transport, particularly for all‐polymer devices. The block copolymer poly(3‐dodecylthiophene)‐block‐poly(9,9‐dioctylfluorene) (P3DDT‐b‐PF), which has matched crystallization temperatures for each block, is used to study the effects of processing history on resulting crystallization. For longer annealing times and rapid quenching to room temperature, P3DDT crystals are preferred whereas for shorter annealing times and slower quenching, PF crystals are preferred. Both crystal forms are evidenced for long annealing time and slow quenching. Additionally, for room temperature annealing in the presence of a chloroform vapor, PF crystals are found in the PF β phase with the predominant crystal peak oriented perpendicular to the thermally annealed case. These results will provide guidance for optimizing annealing strategies for future donor/acceptor block copolymer photovoltaic devices. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 900–906     

Interpretation of chromatographic retentions of simple solutes with an amylose-based sorbent using infrared spectroscopy and DFT modeling

The interactions of amylose tris(3,5-dime- thylphenylcarbamate) (ADMPC, commercially “Chiralpak AD”) with 10 simple solutes—1-propanol, heptane, heptanol, benzene, propylbenzene, benzyl alcohol, pyridine, tetrahydrofuran, diethylamine, and aniline—are studied using attenuated total reflection infrared spectroscopy (ATR-IR) of thin polymer films, DFT modeling, and high performance liquid chromatography (HPLC). ATR-IR is used to determine the changes in the hydrogen bonding states of the C=O and NH groups of the polymer amide I and II bands upon absorption of each of the solutes at 25^∘C. DFT modeling with B3LYP/6-311+g(d,p) level of theory is used to predict the IR wavenumbers, the H-bonding interaction energies, and the hydrogen bonding distances of the polymer side-chains with certain solute molecules. The capacity factors of these solutes with ADMPC have been measured at 25^∘C in hexane/isopropanol (95/5, v/v) solvent. From IR data and DFT modeling, we conclude that the C=O and NH are key binding sites of the polymer and interact with the functional groups of various solutes. The capacity factors are understood on the basis of hydrogen bonding, hydrophobic, and dipole-dipole interactions of the C=O, NH, and phenyl groups of the sorbent with OH, NH, NH₂, O, phenyl, and N functional groups of the solutes.