Structural Variations in the Complete Series of Lanthanoid Complexes of a Calix[4]arene Trisamide

Lanthanoid picrate (pic) complexes of 5,11,17,23-tetra-tert-butyl-25-hydroxy-26,27,28-tris(diethylcarbamoylmethoxy)calix[4]arene (LH) have been synthesised and structurally characterised, to complete this series for all lanthanoids (other than promethium). From cerium to lutetium, three structural types are observed: Type I, [Ln(L)(O,O'-pic)](pic), Ln = Ce-Dy; Type II, [Ln(L)(O-pic)](pic), Ln = Tb, Ho; Type III, [Ln(L)(HOEt)](pic)2, Ln = Er-Lu. With lanthanum, three different ten-coordinate complexes were characterised; [Ln(L)(O,O'-pic)(HOEt)](pic), [Ln(L)(O,O'-pic)(OH2)](pic), and [Ln(L)(O,O'-pic)(HOMe)](pic). The crystallisation of Type I and II observed for terbium shows that the stability of the different structures are sensitively poised at the transition points. Nevertheless, the structures show that the vacant space in the coordination sphere left by the trisamide L tends to reduce across the series as expected. It is occupied by a bidentate picrate anion and unidentate solvent molecule with lanthanum, a bidentate picrate anion for cerium to dysprosium (Type I), a unidentate picrate anion for terbium and holmium (Type II), and finally a unidentate solvent molecule from erbium to lutetium (Type III). The coordination number thus reduces from 10 to 8 across the series

Proline-Functionalised Calix[4]arene: An Anion-Triggered Hydrogelator

A water-soluble, chiral calix[4]arene has been found to form hydrogels when triggered by the presence of specific anions, with efficacy linked to the Hofmeister series; the gel properties are modified by the associated cations, and gelation can be reversibly switched off by increasing pH

A lanthanum picrate complex of a 1,2-bisamide substituted calix[4]arene

The synthesis and structural characterization of a lanthanum picrate complex of the proximally-substituted calix[4]arene bisamide, 5,11,17,23-tetra-tert-butyl-25,26- bis(diethylcarbamoylmethoxy)-27,28-dihydroxycalix[4] arene (L), is reported. The complex is formulated as [La(L-H)(picrate)2]2.75CH2Cl2 and crystallises with two inequivalent metal complexes in the unit cell. The differing dispositions of the picrate anions in the two complexes suggest that intramolecular interactions between the aromatic rings of the picrate and calixarene are less significant than the forces involved in the crystal packing of the complexes

A National Study of Multiple Organ Dysfunction after Trauma: Contemporary Patterns of Severity and Recovery

Background: The nature of multiple organ dysfunction syndrome (MODS) after traumatic injury is evolving as resuscitation practices advance and more patients survive their injuries to reach critical care. The aim of this study was to characterize contemporary MODS subtypes in trauma critical care at a population level. Methods: Adult patients admitted to major trauma centre critical care units were enrolled in this 4‐week point‐prevalence study. MODS was defined by a daily total Sequential Organ Failure Assessment (SOFA) score of more than 5. Hierarchical clustering of SOFA scores over time was used to identify MODS subtypes. Results: Some 440 patients were enrolled, of whom 245 (55·7 per cent) developed MODS. MODS carried a high mortality rate (22·0 per cent versus 0·5 per cent in those without MODS; P < 0·001) and 24·0 per cent of deaths occurred within the first 48 h after injury. Three patterns of MODS were identified, all present on admission. Cluster 1 MODS resolved early with a median time to recovery of 4 days and a mortality rate of 14·4 per cent. Cluster 2 had a delayed recovery (median 13 days) and a mortality rate of 35 per cent. Cluster 3 had a prolonged recovery (median 25 days) and high associated mortality rate of 46 per cent. Multivariable analysis revealed distinct clinical associations for each form of MODS; 24‐hour crystalloid administration was associated strongly with cluster 1 (P = 0·009), traumatic brain injury with cluster 2 (P = 0·002) and admission shock severity with cluster 3 (P = 0·003). Conclusion: Contemporary MODS has at least three distinct types based on patterns of severity and recovery. Further characterization of MODS subtypes and their underlying pathophysiology may lead to future opportunities for early stratification and targeted interventions

Synthesis of Distally-Bridged Chiral Resorcinarene Crowns

Our interest in the potential of chiral tetramethoxy-resorcinarene as agents for chiral recognition has led us to synthesise twelve distally-bridged chiral resorcinarene crowns. The fascinating architecture of these partially-enclosed chiral basket molecules is evident in the solid-state structures which have been determined by single-crystal X-ray crystallography. Moreover, the enantiomers of these chiral resorcinarene crowns have been resolved via diastereomeric resolution, with the absolute configuration of the diastereomers being determined by X-ray crystallography. This work enables further exploration of these enantio-pure chiral baskets as possible chiral resolving agents

Distal functionalisation of C<inf>4</inf>symmetric tetramethoxyresorcinarene by selective lithiation

© 2018, Springer Science+Business Media B.V., part of Springer Nature. Three novel C4symmetric O-substituted derivatives of tetramethoxyresorcinarene were synthesised and characterised and the selective distal lithiation of these derivatives was investigated. Lithiation of the tetraethoxy derivative, followed by quenching with dimethyldisulfide selectively afforded the distal product in 36% yield after removal of unreacted starting resorcinarene. Lithiation of the MOM derivative produced the five possible lithiated products, with the mono being the major product; the distally substituted derivative being a minor product. The benzyloxyresorcinarene appeared to be unstable under the lithation conditions. These results suggest that the selectivity of the distal lithation reaction is heavily dependent on the O-substituents of the resorcinarene