The structure of a potassium salt of the polyether ionophore antibiotic Lasalocid A has been determined by single–crystal X–ray crystallography. A dimeric structure is revealed in which two antibiotic molecules present hemispheric oxygen co–ordination environments for two potassium centres. Co–ordination for both cations is further fulfilled by contact with the oxygen atoms of two discrete dimethylformamide molecules that bridge the two potassium centres. Close analysis using directional statistics of the conformation of the backbone of the Lasalocid A molecule in all previously reported crystal structures, as well as the potassium salt reported here, reveals that conformation is substantially conserved throughout the series, aside from some variation in the twist of the carboxylate group with respect to the plane of the aromatic ring, and the orientation of the tetrahydrofuran ring. The Lasalocid A molecule in the potassium complex presented here is the closest fit to the averaged Lasalocid structure, derived from the family of known complexes,

The crystal structures of six cobalt sandwich complexes-four in the eta(5)-cyclopentadienyl/eta(4)-cyclobutadiene family, two from the related eta(5)-cyclopentadienyl/eta(4)-cyclopentadienone family-are presented and discussed alongside related structural precedents. In each of the complexes an undecorated cyclopentadienyl ligand is present whereas the partner cyclobutadiene or cyclopentadienone ligand bears four identical aromatic substituents (phenyl, p-tolyl, p-fluorophenyl, 2-thienyl or 2,2 '-bithienyl). This range of substituents allows for detailed structural comparison between members of the families of sandwich complexes presented here, and with previously reported structures. Graphic Crystal structures of members of the eta(5)-cyclopentadienyl/eta(4)-tetraarylcyclobutadiene (left) and eta(5)-cyclopentadienyl/eta(5)-cyclopentadienone (right) families of sandwich complexes are presented.

Poly(1‐methylpyrol‐2‐ylsquaraine) particles can be prepared in a one‐pot reaction by refluxing equimolar amounts of squaric acid (3,4‐dihydroxycyclobut‐3‐ene‐1,2‐dione) and 1‐methylpyrrole in butan‐1‐ol and precipitate from the reaction as porous micrometer‐sized spheres that have potential use as molecular adsorbents in chromatography and sensors, as well as ion batteries. Previous papers that have examined the electrical, photophysical, and adsorption properties of these particles have reported their size and shape, with appropriate proof in the form of electron microscope images but have paid little attention as to the actual limits of the particle size and spherical formation. Thus, a range of experiments have been undertaken to examine the robustness, in terms of reaction variation, of the construction of these spheres. Reaction characteristics such as solvent, sequence in which reactants are added, reaction time, reactant concentration, and mode of reaction agitation have all been examined to determine the optimal conditions for the production of these spheres. Fortuitously, butan‐1‐ol remains the most suitable solvent, but reactant concentration is important to produce uniformly sized spherical particles with minimal interparticle growth.

Sixty-four elements from the periodic table, mainly in the form of metal oxides or chloride/sulfate salts dissolved in either HCl or H2SO4, have been adsorbed into tetraethyl orthosilicate treated poly(1-methylpyrrol-2-ylsquaraine) particles and then heat treated to remove the polysquaraine core to produce core-shell materials. Powder X-ray diffraction techniques were utilised as the primary means of identification for each inorganic compound/mixture inside the amorphous silica shells. In twelve cases (B, Al, Ca, Ti, Ga, As, Se, Mo, Sb, Os, Hg, and Tl) no crystalline material was identified within the shells but analysis of these sample powders (except B) using X-ray fluorescence techniques identified the presence of all bar three elements (Ga, Se, and Hg). The colour of each resultant powder has been reported and in several cases indicated the creation of new physical characteristics. The process was shown to also work with a selected mixture of starting materials with the production of 2% Eu doped YVO4 inside the silica shells. Further results have been presented for the previously published Fe2O3 core – SiO2 shell sample plus additional electron microscopic analysis of the Ag core - SiO2 shell and Au core - SiO2 shell samples. This paper demonstrates a proof-of-concept methodology for the production of new core-shell materials.

The crystal structures of six cobalt sandwich complexes—four in the η5-cyclopentadienyl/η4-cyclobutadiene family, two from the related η5-cyclopentadienyl/η4-cyclopentadienone family—are presented and discussed alongside related structural precedents. In each of the complexes an undecorated cyclopentadienyl ligand is present whereas the partner cyclobutadiene or cyclopentadienone ligand bears four identical aromatic substituents (phenyl, p-tolyl, p-fluorophenyl, 2-thienyl or 2,2′-bithienyl). This range of substituents allows for detailed structural comparison between members of the families of sandwich complexes presented here, and with previously reported structures. Crystal structures of members of the η5-cyclopentadienyl/η4-tetraarylcyclobutadiene (left) and η5-cyclopentadienyl/η5-cyclopentadienone (right) families of sandwich complexes are presented.

Pyrrol‐3‐yl squaraine dyes are prepared by the condensation of 3,4‐dihydroxycyclobut‐3‐ene‐1,2‐dione with two‐molar equivalence of a 2,5‐disubstituted pyrrole possessing a free β‐position, or substituted indoles with a similarly free β‐position. From the first reported syntheses of two indol‐3‐yl squaraines in 1966, numerous pyrrol‐3‐yl squaraines (including indol‐3‐yl squaraines) have been reported in both the scientific and patent literatures. This microreview highlights the synthesis, history, spectroscopy, and applications of pyrrol‐3‐yl squaraines from their first preparation to the present date.

The dual-pendant sulfonate bis(indolenine)squaraines with 1,8-diazabicyclo[5.4.0]undec-7-enium cations has been prepared and examined with reference to the previously studied bis-piperidinium analogue. The X-ray crystal structure of the bis-(1,8-diazabicyclo[5.4.0]undec-7-enium) dye (crystals from the reaction solution) revealed that this compound crystallizes with two molar equivalence of toluene. The fluorescence intensities of the dye in the presence of an equimolar amount of BSA in both water and 10 mM Tris/HCI buffer were comparable to those of the bis-piperidinium compound. The dye also proved comparable to the bis-piperidinium compound as a colorimetric stain for gel electrophoresis, but unlike the bis-piperidinium compound, the dye did not fluoresce in the stained gel upon irradiation with 300 nm light. An additional experiment examined the use of the bis-piperidinium compound as both colorimetric and fluorimetric stain for bacterial cells. (C) 2017 Elsevier B.V. All rights reserved.

We report that poly((2,5-bis(1-methylpyrrol-2-yl)thiophene)squaraine) can be synthesized as a dark green insoluble powder which when subjected to shear force and pressed as a disk exhibits a gold-green near optical quality surface with semi-metallic behaviour. Reflectivity measurements at a wavelength of 819 nm reveal a high (72 degrees) pseudo-Brewster angle and non-zero p-reflectivity whilst electrical measurements using a four-point probe return a conductivity of 1 x 10(-5) S cm(-1). Unexpectedly the disks also exhibit magneto-optic (MO) activity which it appears must arise from a weak magnetic component intrinsic to the samples. In both the longitudinal and transverse Kerr configurations large fractional changes in reflectivity(Delta I/I approximate to 2.5 x 10(-2)) are observed across a wide range of angles of incidence for wavelengths between 400 nm and 1064 nm on application and reversal of a magnetic field. Anomalously for these configurations all the MO effects observed are quadratic in the applied field and no first-order effects linear in applied field are observed for any state of incident polarisation. Examined using conventional magnetometry, disk samples return saturation magnetization values of 4.13 x 10(-3) emu g(-1) on a vibrating sample magnetometer and smaller samples similarly processed and prepared for examination by Squid magnetometer confirmatory values of 4.9 x 10(-3) emu g(-1). Magnetization curves from both instruments have a similar form, saturating at about 1.14 kOe, and are also in close correspondence with curves derived by plotting the magneto-optic signal as a function of field after allowance for the quadratic nature of the observed MO response. Similarly, both the magnetic and magneto-optic behaviour of all samples is isotropic in plane.Taken together, all experimental observations on this fully organic polymer appear, surprisingly, to be commensurate with the development at room temperature of some form of magnetic state throughout very limited regions of the material. A very tentative model able to reconcile the magnetic and MO observations on the supposition that the magnetic state may be of a reduced dimensional nature is presented. We are very aware that the appearance of an intrinsic room temperature magnetism in the material studied is highly unlikely and that this interpretation of the results presented is strongly dependent on using MO evidence to support chemical analysis, which included multi-elements scans on an ICP and ESR, in precluding contamination. (c) 2013 Elsevier B.V. All rights reserved.

The adsorptive properties of poly(1-methylpyrrol-2-ylsquaraine) (PMPS) particles were investigated in batch and column adsorption experiments as alternative adsorbent for the treatment of endocrine-disrupting chemicals in water. The PMPS particles were synthesised by condensing 3,4-dihydroxycyclobut-3-ene-1,2-dione (squaric acid) with 1-methylpyrrole in butanol. The results demonstrated that PMPS particles are effective in the removal of endocrine disrupting chemicals (EDCs) in water with adsorption being more favourable at an acidic pH, and a superior sorption capacity being achieved at pH 4. The results also showed that the removal of EDCs by the PMPS particles was a complex process involving multiple rate-limiting steps and physicochemical interactions between the EDCs and the particles. Gibbs free energy of −8.32 kJ/mole and −6.6 kJ/mol, and enthalpies of 68 kJ/mol and 43 kJ/mol, were achieved for the adsorption E2 and EE2 respectively The removal efficiencies of the EDCs by PMPS particles were comparable to those of activated carbon, and hence can be applied as an alternative adsorbent in water treatment applications.

A statistical analysis of carbonyl bond lengths both with and without O-H hydrogen-bonding interactions has been undertaken using data from the Cambridge Structural Database. Only structures with Csp(3)-C(=0)-Csp(3) were considered to rule out any resonant or inductive effects. All structures were subdivided into five groups based on the carbon ring structure supporting the carbonyl bond. The carbon ring structures involved 4-, 5-, 6-, and 7-membered rings with the fifth sub-category being 8-membered rings or higher out to alkyl chains. It was found that carbonyl bond lengths from the 4-membered rings were statistically shorter than the remainder but in all cases the carbonyl bond length increased with involvement of a single O-H hydrogen-bonding interaction. The overall average of carbonyl bond length was 1.210 angstrom whereas the overall average carbonyl bond length involved in a hydrogen bond was 1.217 angstrom. (C) 2018 Elsevier B.V. All rights reserved.

In the 50+ years since the first squaraine dye, made by using 3,4-dihydroxycyclobut-3-ene-1,2-dione (squaric acid), was reported, numerous analogues have not only been made and published, but similarly, a number of good review articles on squaraine dyes has also been published. In contrast, for the majority of this time, reports of croconaine dyes, made by using 4,5-dihydroxy-4-cyclopentene-1,2,3-trione (croconic acid), have also been published, but they have not received the same attention as squaraine dyes. Furthermore, the only known review of croconaine dyes, which was recently published, is written in Chinese. This current review aims to document the history of croconaine dyes since their first report in a German patent in 1970. This review sources both the scientific literature and published patents, and attention is given to both synthesis and spectroscopic details.

The synthesis of the first azulenyl squaraine dye was reported in 1966 and the paucity of activity in the scientific literature since that time has given the false impression that they have remained relatively unexplored as organic dyes. In contrast, a wealth of research activity on azulenyl squaraines has been recorded in the patent literature and it is the purpose of this review to bring these reports to the attention of scientists that have an interest in the chemistry and applications of squaraine dyes. This review shows that it is possible to prepare, via targeted substitution of the azulene ring, a dye with an absorption maximum value ranging from 650 to 840 nm.

The study of ternary systems is interesting because it introduces the concept of molecular preference/competition into the system where one molecule may be displaced because the association between the other two is significantly stronger. Current definitions of a tertiary system indicate that solvent molecules are excluded from the molecule count of the system and some of the latest definitions state that any molecule that is not a solid in the parent form at room temperature should also be excluded from the molecule count. In the structure of the quinoline adduct hydrate of tryptaminium 3,5-dinitrobenzoate, 3C10H13N2+·3C7H3N2O6-·2C9H7N·2H2O, the asymmetric unit comprises multiple cation and anion species which are conformationally similar among each type set. In the crystal, a one-dimensional hydrogen-bonded supramolecular structure is generated through extensive intra- and inter-unit aminium N-H...O and N-H...N, and water O-H...O hydrogen bonds. Within the central-core hydrogen-bonding associations, conjoined cyclic R44(10), R53(10) and R44(12) motifs are generated. The unit is expanded into a one-dimensional column-like polymer extending along [010]. Present also in the crystal packing of the structure are a total of 19 π-π interactions involving both cation, anion and quinoline species [ring-centroid separation range = 3.395 (3)-3.797 (3) Å], as well as a number of weak C-H...O hydrogen-bonding associations. The presence of the two water molecules in the crystal structure is considered to be the principal causative factor in the low symmetry of the asymmetric unit.

The article reports an experimental study of the metal uptake properties of poly(1-methylpyrrol-2-ylsquaraine) particles, in the context of 51 elemental metal complexes. Vagaries of the experimental results meant that the final analysis took place for 43 of these metals. After an initial descriptive analysis, an Analysis of Variance model was fitted. This revealed that several factors, some intrinsic to the metals themselves, others relating to the experimental conditions, have an important influence on the adsorption characteristics of the poly(1-methylpyrrol-2-ylsquaraine) particles. Of these, the most important is the ratio of the number of moles of the metal to the number of moles of the adsorbent particles. X-ray mapping of the poly(1-methylpyrrol-2-ylsquaraine) particles treated with contrast agent revealed that, although adsorption was all throughout the particles, the majority of the agent was adsorbed within 10–15% (diameter distance) of the surface of the particles.

A water-soluble dual pendent squaraine with tryptaminium cations has been mixed with mononitroaromatics in solution to create ternary complexes with the aim of creating indole-nitroaromatic charge-transfer pairs. Examination of the X-ray crystal structures of two tryptamine-nitroaromatic complexes, without the squaraine moiety, revealed that neither demonstrated charge-transfer pair or stacking associations between the indole and nitroaromatic rings. Examination of the fluorescence performance upon illumination with 300 nm light of each ternary squaraine complex, particularly in the presence of an equimolar amount of protein, showed that the levels across the series were no more than that observed for the base bis-tryptaminium squaraine, as was observed in a previous study. However, electrophoresis gels stained with the base bis-tryptaminium squaraine, whose X-ray crystal structure is also reported, were found to fluorescence; the only other squaraine dye of this type to do so in addition to the bis-piperidinium squaraine of previous studies. (C) 2016 Elsevier B.V. All rights reserved.

The morpholinium (tetrahydro-2H-1,4-oxazin-4-ium) cation has been used as a counter-ion in both inorganic and organic salt formation and particularly in metal complex stabilization. To examine the influence of interactive substituent groups in the aromatic rings of benzoic acids upon secondary structure generation, the anhydrous salts of morpholine with salicylic acid, C4H10NO(+)·C7H5O3(-), (I), 3,5-dinitrosalicylic acid, C4H10NO(+)·C7H3N2O7(-), (II), 3,5-dinitrobenzoic acid, C4H10NO(+)·C7H3N2O6(-), (III), and 4-nitroanthranilic acid, C4H10NO(+)·C7H5N2O4(-), (IV), have been prepared and their hydrogen-bonded crystal structures are described. In the crystal structures of (I), (III) and (IV), the cations and anions are linked by moderately strong N-H...Ocarboxyl hydrogen bonds, but the secondary structure propagation differs among the three, viz. one-dimensional chains extending along [010] in (I), a discrete cyclic heterotetramer in (III), and in (IV), a heterotetramer with amine N-H...O hydrogen-bond extensions along b, giving a two-layered ribbon structure. With the heterotetramers in both (III) and (IV), the ion pairs are linked though inversion-related N-H...Ocarboxylate hydrogen bonds, giving cyclic R4(4)(12) motifs. With (II), in which the anion is a phenolate rather than a carboxylate, the stronger assocation is through a symmetric lateral three-centre cyclic R1(2)(6) N-H...(O,O') hydrogen-bonding linkage involving the phenolate and nitro O-atom acceptors of the anion, with extension through a weaker O-H...Ocarboxyl hydrogen bond. This results in a one-dimensional chain structure extending along [100]. In the structures of two of the salts [i.e. (II) and (IV)], there are also π-π ring interactions, with ring-centroid separations of 3.5516 (9) and 3.7700 (9) Å in (II), and 3.7340 (9) Å in (IV).

Summary Pharmacogenomics (PGx) guided warfarin dosing, using a comprehensive dosing algorithm, is expected to improve dose optimisation and lower the risk of adverse drug reactions. As a complementary tool, a simple genotype-dosing table, such as in the US Food and Drug Administration (FDA) Coumadin drug label, may be utilised for general risk assessment of likely over- or under-anticoagulation on a standard dose of warfarin. This tool may be used as part of the clinical decision support for the interpretation of genetic data, serving as a first step in the anticoagulation therapy decision making process. Here we used a publicly available warfarin dosing calculator (www.warfarindosing.org) to create an expanded gene-based warfarin dosing table, the CPMC-WD table that includes nine genetic variants in CYP2C9, VKORC1, and CYP4F2. Using two datasets, a European American cohort (EUA, n=73) and the Quebec Warfarin Cohort (QWC, n=769), we show that the CPMC-WD table more accurately predicts therapeutic dose than the FDA table (51 % vs 33 %, respectively, in the EUA, McNemar’s two-sided p=0.02; 52 % vs 37 % in the QWC, p<1×10−6). It also outperforms both the standard of care 5 mg/day dosing (51 % vs 34 % in the EUA, p=0.04; 52 % vs 31 % in the QWC, p<1×10−6) as well as a clinical-only algorithm (51 % vs 38 % in the EUA, trend p=0.11; 52 % vs 45 % in the QWC, p=0.003). This table offers a valuable update to the PGx dosing guideline in the drug label. Supplementary Material to this article is available at www.thrombosis-online.com.

The anhydrous salts of the Lewis base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) with 4-aminobenzoic acid [1-aza-8-azoniabicyclo[5.4.0]undec-7-ene 4-aminobenzoate, C9H17N2+·C7H6NO2− (I)], 3,5-dinitrobenzoic acid [1-aza-8-azoniabicyclo[5.4.0]undec-7-ene 3,5-dinitrobenzoate, C9H17N2+·C7H3N2O6−, (II)] and 3,5-dinitrosalicylic acid (DNSA) [1-aza-8-azoniabicyclo[5.4.0]undec-7-ene 2-hydroxy-3,5-dinitrobenzoate, C9H17N2+·C7H3N2O7−, (III)] have been determined and their hydrogen-bonded structures are described. In both (II) and (III), the DBU cations have a common disorder in three of the C atoms of the six-membered ring moieties [site-occupancy factors (SOF) = 0.735 (3)/0.265 (3) and 0.686 (4)/0.314 (4), respectively], while in (III), there is additional rotational disorder in the DNSA anion, giving two sites (SOF = 0.72/0.28, values fixed) for the phenol group. In the crystals of (I) and (III), the cation–anion pairs are linked through a primary N—H...Ocarboxyl hydrogen bond [2.665 (2) and 2.869 (3) Å, respectively]. In (II), the ion pairs are linked through an asymmetric three-centre R12(4), N—H...O,O′ chelate association. In (I), structure extension is through amine N—H...Ocarboxyl hydrogen bonds between the PABA anions, giving a three-dimensional structure. The crystal structures of (II) and (III) are very similar, the cation–anion pairs being associated only through weak C—H...O hydrogen bonds, giving in both overall two-dimensional layered structures lying parallel to (001). No π–π ring associations are present in any of the structures.

The anhydrous salts of 2-(1H-indol-3-yl)ethanamine (tryptamine) with isomeric (2,4-dichlorophenoxy)acetic acid (2,4-D) and (3,5-dichlorophenoxy)acetic (3,5-D), both C10H13N2+·C8H5Cl2O3−[(I) and (II), respectively], have been determined and their one-dimensional hydrogen-bonded polymeric structures are described. In the crystal of (I), the aminium H atoms are involved in three separate inter-species N—H...O hydrogen-bonding interactions, two with carboxylate O-atom acceptors and the third in an asymmetric three-centre bidentate carboxylateO,O′chelate [graph setR12(4)]. The indole H atom forms an N—H...Ocarboxylatehydrogen bond, extending the chain structure along theb-axis direction. In (II), two of the three aminium H atoms are also involved in N—H...Ocarboxylatehydrogen bonds similar to (I) but with the third, a three-centre asymmetric interaction with carboxylate and phenoxy O atoms is found [graph setR12(5)]. The chain polymeric extension is also alongb. There are no π–π ring interactions in either of the structures. The aminium side-chain conformations differ significantly between the two structures, reflecting the conformational ambivalence of the tryptaminium cation, as found also in the benzoate salts.