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Background: This study was undertaken to develop a simple tool for assessing risk of undernutrition for use by the primary health care team, Methods: We devised a list of 25 questions that might be predictive of nutritional risk. Community nurses administered the questions, which required only yes/no answers, to 507 patients in their care. Within 4 days a dietitian carried out a full nutritional assessment. Discriminant analysis was used to determine which questions were predictive of nutritional risk as assessed by a dietitian. Multiple regression analysis was used to derive a simple equation to assign weightings to those questions. Results: Five hundred and seven patients completed the study. Nine questions were found to be associated with nutritional risk as assessed by a dietitian. The final tool, which has three categories of scores: 0-6 = not at risk; 7-16 =possible/ probable risk; >/= 17 =malnourished, has a positive predictive value of 94.6% and a negative predictive value of 81.1%. Conclusion: This simple tool can be used to assess risk of undernutrition in patients in primary care, to increase awareness of the importance of nutrition in patients in the community and to ensure that patients are given appropriate dietary advice and/or referred to a dietitian. [ABSTRACT FROM AUTHOR]

The solvothermal reaction of FeCl 2  ⋅ 4H 2 O and H 4 TBC[4] in a basic dmf/EtOH solution affords an [Fe III 18 ] Keplerate conforming to a stellated cuboctahedron. Magnetic and heat capacity measurements reveal spin frustration effects arising from the high symmetry. A crossover between inverse and direct magnetocaloric effects is observed at ~10 K for applied-field changes lower than 3 T., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

A seventh blind test of crystal structure prediction has been organized by the Cambridge Crystallographic Data Centre. The results are presented in two parts, with this second part focusing on methods for ranking crystal structures in order of stability. The exercise involved standardized sets of structures seeded from a range of structure generation methods. Participants from 22 groups applied several periodic DFT-D methods, machine learned potentials, force fields derived from empirical data or quantum chemical calculations, and various combinations of the above. In addition, one non-energy-based scoring function was used. Results showed that periodic DFT-D methods overall agreed with experimental data within expected error margins, while one machine learned model, applying system-specific AIMnet potentials, agreed with experiment in many cases demonstrating promise as an efficient alternative to DFT-based methods. For target XXXII, a consensus was reached across periodic DFT methods, with consistently high predicted energies of experimental forms relative to the global minimum (above 4 kJ mol -1 at both low and ambient temperatures) suggesting a more stable polymorph is likely not yet observed. The calculation of free energies at ambient temperatures offered improvement of predictions only in some cases (for targets XXVII and XXXI). Several avenues for future research have been suggested, highlighting the need for greater efficiency considering the vast amounts of resources utilized in many cases., (open access.)

A seventh blind test of crystal structure prediction was organized by the Cambridge Crystallographic Data Centre featuring seven target systems of varying complexity: a silicon and iodine-containing molecule, a copper coordination complex, a near-rigid molecule, a cocrystal, a polymorphic small agrochemical, a highly flexible polymorphic drug candidate, and a polymorphic morpholine salt. In this first of two parts focusing on structure generation methods, many crystal structure prediction (CSP) methods performed well for the small but flexible agrochemical compound, successfully reproducing the experimentally observed crystal structures, while few groups were successful for the systems of higher complexity. A powder X-ray diffraction (PXRD) assisted exercise demonstrated the use of CSP in successfully determining a crystal structure from a low-quality PXRD pattern. The use of CSP in the prediction of likely cocrystal stoichiometry was also explored, demonstrating multiple possible approaches. Crystallographic disorder emerged as an important theme throughout the test as both a challenge for analysis and a major achievement where two groups blindly predicted the existence of disorder for the first time. Additionally, large-scale comparisons of the sets of predicted crystal structures also showed that some methods yield sets that largely contain the same crystal structures., (open access.)

Macrocyclic drugs can address an increasing range of molecular targets but enabling central nervous system (CNS) access to these drugs has been viewed as an intractable problem. We designed and synthesized a series of quinolinium-modified cyclosporine derivatives targeted to the mitochondrial cyclophilin D protein. Modification of the cation to enable greater delocalization was confirmed by x-ray crystallography of the cations. Critically, greater delocalization improved brain concentrations. Assessment of the compounds in preclinical assays and for pharmacokinetics identified a molecule JP1-138 with at least 20 times the brain levels of a non-delocalized compound or those reported for cyclosporine. Levels were maintained over 24 hours together with low hERG potential. The paradigm outlined here could have widespread utility in the treatment of CNS diseases.

Amide-based organic cage cavities are, in principle, ideal enzyme active site mimics. Yet, cage-promoted organocatalysis has remained elusive, in large part due to synthetic accessibility of robust and functional scaffolds. Herein, we report the acyl transfer catalysis properties of robust, hexaamide cages in organic solvent. Cage structural variation reveals that esterification catalysis with an acyl anhydride acyl carrier occurs only in bifunctional cages featuring internal pyridine motifs and two crucial antipodal carboxylic acid groups. 1 H NMR data and X-ray crystallography show that the acyl carrier is rapidly activated inside the cavity as a covalent mixed-anhydride intermediate with an internal hydrogen bond. Michaelis-Menten (saturation) kinetics suggest weak binding ( K M = 0.16 M) of the alcohol pronucleophile close to the internal anhydride. Finally, activation and delivery of the alcohol to the internal anhydride by the second carboxylic acid group forms ester product and releases the cage catalyst. Eyring analysis indicates a strong enthalpic stabilization of the transition state (5.5 kcal/mol) corresponding to a rate acceleration of 10 4 over background acylation, and an ordered, associative rate-determining attack by the alcohol, supported by DFT calculations. We conclude that internal bifunctional organocatalysis specific to the cage structural design is responsible for the enhancement over the background reaction. These results pave the way for organic-phase enzyme mimicry in self-assembled cavities with the potential for cavity elaboration to enact selective acylations.

Investigation of the analyte soaking conditions on the crystalline sponge {[(ZnI 2 ) 3 (tpt) 2 ·x(solvent)] n } method using a statistical design of experiments model has provided fundamental insights into the influence of experimental variables. This approach focuses on a single analyte tested via 60 experiments (20 unique conditions) to identify the main effects for success and overall guest structure quality. This is employed as a basis for the development of a novel molecular structure grading system that enables the quantification of guest exchange quality., (open access.)

Coordination complexes of lanthanide metals with tris-1-naphthylphosphine oxide (Nap 3 PO, L) have not been previously reported in the literature. We describe here the formation of lanthanide(III) nitrate complexes Ln(NO 3 ) 3 L 4 (Ln = Eu to Lu) and the structures of [Ln(NO 3 ) 3 L 2 ]·2L (Ln = Eu, Dy, Ho, Er) and L. The core structure of the complexes is an eight-coordinate [Ln(NO 3 ) 3 L 2 ] with the third and fourth ligands H-bonded via their oxygen atoms to one of the naphthyl rings. The structures are compared with those of the analogous complexes of triphenylphosphine oxide and show that the Ln-O(P) bond in the Nap 3 PO complexes is slightly longer than expected on the basis of differences in coordination numbers. The reaction solutions, investigated by 31 P and 13 C NMR spectroscopy in CD 3 CN, show that coordination of L occurs across the lanthanide series, even though complexes can only be isolated from Eu onwards. Analysis of the 31 P NMR paramagnetic shifts shows that there is a break in the solution structures with a difference between the lighter lanthanides (La-Eu) and heavier metals (Tb-Lu) which implies a minor difference in structures. The isolated complexes are very poorly soluble, but in CDCl 3 , NMR measurements show dissociation into [Ln(NO 3 ) 3 L 2 ] and 2L occurs., Competing Interests: The authors declare no conflicts of interest.

A series of mixed ligand, photoluminescent organometallic Ir(III) complexes have been synthesized to incorporate substituted 2-phenyl-1 H -naphtho[2,3- d ]imidazole cyclometalating ligands. The structures of three example complexes were categorically confirmed using X-ray crystallography each sharing very similar structural traits including evidence of interligand hydrogen bond contacts that account for the shielding effects observed in the 1 H NMR spectra. The structural iterations of the cyclometalated ligand provide tuning of the principal electronic transitions that determine the visible absorption and emission properties of the complexes: emission can be tuned in the visible region between 550 and 610 nm and with triplet lifetimes up to 10 μs. The nature of the emitting state varies across the series of complexes, with different admixtures of ligand-centered and metal-to-ligand charge transfer triplet levels evident. Finally, the use of the complexes as photosensitizers in triplet-triplet annihilation energy upconversion (TTA-UC) was investigated in the solution state. The study showed that the complexes possessing the longest triplet lifetimes showed good viability as photosensitizers in TTA-UC. Therefore, the use of an electron-withdrawing group on the 2-phenyl-1 H -naphtho[2,3- d ]imidazole ligand framework can be used to rationally promote TTA-UC using this class of complex.

4,4'-(Disulfanedi-yl)dipyridinium chloride triiodide, C 10 H 10 N 2 S 2 2+ ·Cl - ·I 3 - , ( 1 ) was synthesized by reaction of 4,4'-di-pyridyl-disulfide with ICl in a 1:1 molar ratio in di-chloro-methane solution. The structural characterization of 1 by SC-XRD analysis was supported by elemental analysis, FT-IR, and FT-Raman spectroscopic measurements., (© Podda et al. 2024.)

Background: Oxidative stress is a pathological feature of acute coronary syndrome (ACS), a complex disease with varying clinical outcomes. Surrogate biomarkers of oxidative stress including, peroxiredoxin-2 (PRDX2), PRDX4, thioredoxin (TRX) and thioredoxin reductase (TRXR) were measured in ACS patients at presentation and follow-up, to assess their clinical utility in diagnosis and risk stratification., Methods: Plasma from 145 participants (80 ACS and 65 healthy) at diagnosis, 1-3 month (first) and 6-month follow-up (second) was analysed by ELISA. ACS patients were monitored for 12-months., Results: ACS patients at diagnosis had significantly higher concentrations of TRX (p < 0.05), TRXR (p < 0.01) and PRDX4 (p < 0.01), compared to healthy donors. This was increase was driven by non-ST elevated myocardial infarction for TRX (p < 0.01) and PRDX4 (p < 0.05). For TRXR, ACS females were significantly higher than males (p < 0.05). TRX was also higher in older females (>55 years) at diagnosis (p < 0.05). At first follow-up, TRX had lowered, whereas PRDX4 remained significantly high (p < 0.05). Stratification of ACS patients according to percutaneous coronary intervention (PCI) revealed that TRXR was significantly higher in patients receiving PCI to the right coronary artery (p < 0.05). Whereas both TRXR (p < 0.01) and PRDX4 (p < 0.01) were significantly higher in patients receiving PCI to the left anterior descending (LAD) artery. ACS patients who had plasma TRX >13.40 ng/ml at second follow-up were at high risk of readmission (p < 0.05), as were patients with TRXR of <1000 pg/ml at diagnosis having PCI to the LAD (p < 0.05)., Conclusion: This study indicates that TRX, TRXR and PRDX4 may have clinical utility for ACS stratification., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2024. Published by Elsevier B.V.)

A series of ligands based upon a 1,3-diimino-isoindoline framework have been synthesized and investigated as pincer-type (N ∧ N ∧ N) chelates for Pt(II). The synthetic route allows different combinations of heterocyclic moieties (including pyridyl, thiazole, and isoquinoline) to yield new unsymmetrical ligands. Pt( L 1-6 )Cl complexes were obtained and characterized using a range of spectroscopic and analytical techniques: 1 H and 13 C NMR, IR, UV-vis and luminescence spectroscopies, elemental analyses, high-resolution mass spectrometry, electrochemistry, and one example via X-ray crystallography which showed a distorted square planar environment at Pt(II). Cyclic voltammetry on the complexes showed one irreversible oxidation between +0.75 and +1 V (attributed to Pt 2+/3+ couple) and a number of ligand-based reductions; in four complexes, two fully reversible reductions were noted between -1.4 and -1.9 V. Photophysical studies showed that Pt( L 1-6 )Cl absorbs efficiently in the visible region through a combination of ligand-based bands and metal-to-ligand charge-transfer features at 400-550 nm, with assignments supported by DFT calculations. Excitation at 500 nm led to luminescence (studied in both solutions and solid state) in all cases with different combinations of the heterocyclic donors providing tuning of the emission wavelength around 550-678 nm.

Integrating symmetry-reducing methods into self-assembly methodology is desirable to efficiently realise the full potential of molecular cages as hosts and catalysts. Although techniques have been explored for metal organic (coordination) cages, rational strategies to develop low symmetry organic cages remain limited. In this article, we describe rules to program the shape and symmetry of organic cage cavities by designing edge pieces that bias the orientation of the amide linkages. We apply the rules to synthesise cages with well-defined cavities, supported by evidence from crystallography, spectroscopy and modelling. Access to low-symmetry, self-assembled organic cages such as those presented, will widen the current bottleneck preventing study of organic enzyme mimics, and provide synthetic tools for novel functional material design., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Six iridium(iii) complexes of the general form [Ir(C^N) 2 (N^N)]X (where C^N = cyclometalating ligand; N^N = disubstituted 2,2'-bipyridine), and incorporating alkyl chains of differing lengths (C8, C10, C12), have been synthesised and characterised. The complexes have been characterised using a variety of methods including spectroscopies (NMR, IR, UV-Vis, luminescence) and analytical techniques (high resolution mass spectrometry, cyclic voltammetry, X-ray diffraction). Two dodecyl-functionalised complexes were studied for their behaviour in aqueous solutions. Although the complexes did not possess sufficient solubility to determine their critical micelle concentrations (CMC) in water, they were amenable for use as emissive dopants in a N -methyl C12 substituted imidazolium salt microemulsion carrier system with a CMC = 36.5 mM. The investigation showed that the metal doped microemulsions had increased CMCs of 40.4 and 51.3 mM and luminescent properties characterised by the dopant., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The reactivity between bis(pyridin-2-yl)diselane o Py 2 Se 2 and ditellane o Py 2 Te 2 (L1 and L2, respectively; o Py=pyridyn-2-yl) and I 2 /Br 2 is discussed. Single-crystal structure analysis revealed that the reaction of L1 with I 2 yielded [(HL1 + )(I - )⋅5/2I 2 ] ∞ (1) in which monoprotonated cations HL1 + template a self-assembled infinite pseudo-cubic polyiodide 3D-network, while the reaction with Br 2 yielded the dibromide H o PySe II Br 2 (2). The oxidation of L2 with I 2 and Br 2 yielded the compounds H o PyTe II I 2 (3) and H o PyTe IV Br 4 (6), respectively, whose structures were elucidated by X-ray diffraction analysis. FT-Raman spectroscopy measurements are consistent with a 3c-4e description of all the X-Ch-X three-body systems (Ch=Se, Te; X=Br, I) in compounds 2, 3, H o PyTe II Br 2 (5), and 6. The structural and spectroscopic observations are supported by extensive theoretical calculations carried out at the DFT level that were employed to study the electronic structure of the investigated compounds, the thermodynamic aspects of their formation, and the role of noncovalent σ-hole halogen and chalcogen bonds in the X⋅⋅⋅X, X⋅⋅⋅Ch and Ch⋅⋅⋅Ch interactions evidenced structurally., (© 2023 The Authors. Chemistry - An Asian Journal published by Wiley-VCH GmbH.)

We report the synthesis and structures of two transition-metal complexes involving 2-(2-hy-droxy-phen-yl)benzimidazole (2hpbi - a ligand of inter-est for its photoluminescent applications), with cobalt, namely, bis-[μ-2-(1 H -1,3-benzo-diazol-2-yl)phenolato]bis-[ethanol(thio-cyanato)-cobalt(II)], [Co 2 (C 13 H 9 N 2 O) 2 (NCS) 2 (C 2 H 6 O) 2 ], ( 1 ), and manganese, namely, bis-[μ-2-(1 H -1,3-benzo-diazol-2-yl)phenolato]bis-{[2-(1 H -1,3-benzo-diazol-2-yl)phenolato](thio-cyanato)-mang-an-ese(III)} dihydrate, [Mn 2 (C 13 H 9 N 2 O) 4 (NCS) 2 ]·2H 2 O, ( 2 ). These structures are two recent examples of a fruitful collaboration between researchers at the Laboratoire de Chimie de Coordination Organique/Organic Coordination Chemistry Laboratory (LCCO), University of Dakar, Senegal and the National Crystallography Service (NCS), School of Chemistry, University Southampton, UK. This productive partnership was forged through meeting at Pan-African Conferences on Crystallography and quickly grew as the plans for the AfCA (African Crystallographic Association) developed. This article therefore also showcases this productive partnership, in celebration of the IUCr's 75 year anniversary and the recent inclusion of AfCA as a Regional Associate of the IUCr., (© Orton et al. 2023.)

The synthesis and characterisation of eleven different 2-(thienyl)quinoxaline species that incorporate different points of functionality, including at the thiophene or quinoxaline rings, are described. These species display variable fluorescence properties in the visible region ( λ em = 401-491 nm) depending upon the molecular structures and extent of conjugation. The series of 2-(thienyl)quinoxaline species were then investigated as cyclometalating agents for Ir(III) to yield [Ir(C^N) 2 (bipy)]PF 6 (where C^N = the cyclometalated ligand; bipy = 2,2'-bipyridine). Eight complexes were successfully isolated and fully characterised by an array of spectroscopic and analytical techniques. Two Ir(III) examples were structurally characterised in the solid state using single crystal X-ray diffraction; both structures confirmed the proposed formulations and coordination spheres in each case showing that the thiophene coordinates via a Ir-C bond. The photophysical properties of the complexes revealed that each complex is luminescent under ambient conditions with a range of emission wavelengths observed (665-751 nm) indicating that electronic tuning can be achieved via both the thienyl and quinoxaline moieties.

Structurally defined graphene nanoribbons (GNRs) have emerged as promising candidates for nanoelectronic devices. Low band gap (<1 eV) GNRs are particularly important when considering the Schottky barrier in device performance. Here, we demonstrate the first solution synthesis of 8-AGNRs through a carefully designed arylated polynaphthalene precursor. The efficiency of the oxidative cyclodehydrogenation of the tailor-made polymer precursor into 8-AGNRs was validated by FT-IR, Raman, and UV/Vis-near-infrared (NIR) absorption spectroscopy, and further supported by the synthesis of naphtho[1,2,3,4-ghi]perylene derivatives (1 and 2) as subunits of 8-AGNR, with a width of 0.86 nm as suggested by the X-ray single crystal analysis. Low-temperature scanning tunneling microscopy (STM) and solid-state NMR analyses provided further structural support for 8-AGNR. The resulting 8-AGNR exhibited a remarkable NIR absorption extending up to ∼2400 nm, corresponding to an optical band gap as low as ∼0.52 eV. Moreover, optical-pump TeraHertz-probe spectroscopy revealed charge-carrier mobility in the dc limit of ∼270 cm 2  V -1  s -1 for the 8-AGNR., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Carbon, although the central element in organic chemistry, has been traditionally neglected as a target for directional supramolecular interactions. The design of supramolecular structures involving carbon-rich molecules, such as arene hydrocarbons, has been limited almost exclusively to non-directional π-stacking, or derivatisation with heteroatoms to introduce molecular assembly recognition sites. As a result, the predictable assembly of non-derivatised, carbon-only π-systems using directional non-covalent interactions remains an unsolved fundamental challenge of solid-state supramolecular chemistry. Here, we propose and validate a different paradigm for the reliable assembly of carbon-only aromatic systems into predictable supramolecular architectures: not through non-directional π-stacking, but via specific and directional halogen bonding. We present a systematic experimental, theoretical and database study of halogen bonds to carbon-only π-systems (C-I⋯π C bonds), focusing on the synthesis and structural analysis of cocrystals with diversely-sized and -shaped non-derivatised arenes, from one-ring (benzene) to 15-ring (dicoronylene) polycyclic atomatic hydrocarbons (PAHs), and fullerene C 60 , along with theoretical calculations and a systematic analysis of the Cambridge Structural Database. This study establishes C-I⋯π C bonds as directional interactions to arrange planar and curved carbon-only aromatic systems into predictable supramolecular motifs. In >90% of herein presented structures, the C-I⋯π C bonds to PAHs lead to a general ladder motif, in which the arenes act as the rungs and halogen bond donors as the rails, establishing a unique example of a supramolecular synthon based on carbon-only molecules. Besides fundamental importance in the solid-state and supramolecular chemistry of arenes, this synthon enables access to materials with exciting properties based on simple, non-derivatised aromatic systems, as seen from large red and blue shifts in solid-state luminescence and room-temperature phosphorescence upon cocrystallisation., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Ammonium N -(pyridin-2-ylmethyl)oxamate (AmPicOxam), synthesized from O -methyl- N -(pyridin-2-ylmethyl)oxamate, was spectroscopically and structurally characterized and assayed as a novel precursor for the protection and consolidation of carbonate stone substrates. An in-depth characterization of treated and untreated biomicritic limestone and white Carrara marble samples was carried out by means of SEM microscopy, X-ray powder diffraction, helium pycnometry, determination of water transport properties, and pull-off tests. The improved solubility (1.00 M, 16.5% w / w ) of the title compound with respect to ammonium oxalate (0.4 M, 5% w / w ) results in the formation of a thicker protective coating of calcium oxalate (CaOx) dihydrate (weddellite) on marble and biomicrite samples after the treatment with 5% and 12% w / w water solutions, producing a reduction in the stone porosity and increased cohesion. Theoretical calculations were carried out at the DFT level to investigate both the electronic structure of the N -(pyridin-2-ylmethyl)oxamate anion and the hydrolysis reaction leading from AmPicOxam to CaOx.

Utilization of the crystalline sponge {[(ZnI 2 ) 3 (tpt) 2 ·x(solvent)] n } method has enabled characterization of a novel family of synthetic organic oils. The systematic structural differences and diversity of functional groups offered by 13 related molecular adsorbates provide a detailed quantitative understanding of the relationship between the guest structure, its conformation, and the type of intermolecular interactions adopted with neighbouring guests and the host framework. This analysis is extended to assess the connection of these factors to the resulting quality indicators for a particular molecular structure elucidation., (open access.)

The coordination chemistry of scorpionate ligands based on borates containing the 7-azaindole heterocycle is relatively unexplored. Thus, there is a requirement to further understand their coordination chemistry. This article outlines the synthesis and characterization of a family of complexes containing anionic flexible scorpionate ligands of the type [(R)(bis-7-azaindolyl)borohydride] - ([ R Bai ] - ), where R = Me, Ph or naphthyl. The three ligands were coordinated to a series of copper(I) complexes containing a phosphine co-ligand to form the complexes, [Cu( Me Bai )(PPh 3 )] ( 1 ), [Cu( Ph Bai )(PPh 3 )] ( 2 ), [Cu( Naphth Bai )(PPh 3 )] ( 3 ), [Cu( Me Bai )(PCy 3 )] ( 4 ), [Cu( Ph Bai )(PCy 3 )] ( 5 ) and [Cu( Naphth Bai )(PCy 3 )] ( 6 ). Additional copper(II) complexes, namely, [Cu( Me Bai ) 2 ] ( 7 ) and [Cu( Ph Bai ) 2 ] ( 8 ), were obtained during attempts to obtain single crystals from complexes 4 and 2 , respectively. Complexes 7 and 8 were also prepared independently from CuCl 2 and two equivalents of the corresponding Li[ R Bai ] salt alongside an additional complex, namely, [Cu( Naphth Bai ) 2 ] ( 9 ). The copper(I) and copper(II) complexes were characterized using spectroscopic and analytical methods. Furthermore, a crystal structure was obtained for eight of the nine complexes. In all cases, the boron-based ligand was found to bind to the metal centers via a κ 3 - N , N , H coordination mode.

Cyclic porphyrin oligomers have been studied as models for photosynthetic light-harvesting antenna complexes and as potential receptors for supramolecular chemistry. Here, we report the synthesis of unprecedented β,β-directly linked cyclic zinc porphyrin oligomers, the trimer ( CP3 ) and tetramer ( CP4 ), by Yamamoto coupling of a 2,3-dibromoporphyrin precursor. Their three-dimensional structures were confirmed by nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and single-crystal X-ray diffraction analyses. The minimum-energy geometries of CP3 and CP4 have propeller and saddle shapes, respectively, as calculated using density functional theory. Their different geometries result in distinct photophysical and electrochemical properties. The smaller dihedral angles between the porphyrin units in CP3 , compared with CP4 , result in stronger π-conjugation, splitting the ultraviolet-vis absorption bands and shifting them to longer wavelengths. Analysis of the crystallographic bond lengths indicates that the central benzene ring of the CP3 is partially aromatic [harmonic oscillator model of aromaticity (HOMA) 0.52], whereas the central cyclooctatetraene ring of the CP4 is non-aromatic (HOMA -0.02). The saddle-shaped structure of CP4 makes it a ditopic receptor for fullerenes, with affinity constants of (1.1 ± 0.4) × 10 5 M -1 for C 70 and (2.2 ± 0.1) × 10 4 M -1 for C 60 , respectively, in toluene solution at 298 K. The formation of a 1:2 complex with C 60 is confirmed by NMR titration and single-crystal X-ray diffraction.

Reaction of a new ligand 6-D i PPon (6-diisopropylphosphino-2-pyridone) with 0.5 equiv of [RuCl 2 ( p -cymene)] 2 resulted in the formation of a mixture of [RuCl 2 ( p -cymene)(κ 1 - P - 6-D i PPon )] 2 ( 1 ) and [RuCl( p -cymene)(κ 2 - P,N - 6-D i PPin )]Cl ([ 2 ] Cl ) (where 6-D i PPin = 6-diisopropylphosphino-2-hydroxypyridine). The ratio between the two products can be controlled by the nature of the solvent. The similar reaction between 6-D i PPon and [RuCl 2 ( p -cymene)] 2 in the presence of AgOTf and Na[BArF 24 ] (where BArF 24 = [{3,5-(CF 3 ) 2 C 6 H 3 } 4 B] - ) resulted in the formation of the complexes [RuCl( p -cymene)(κ 2 - P,N - 6-D i PPin )]OTf, ([ 2 ] OTf ) and [RuCl( p -cymene)(κ 2 - P,N - 6-D i PPin )]BArF 24 ([ 2 ] BArF 24 ), respectively. Reactions between complex [ 2 ] Cl , [ 2 ] OTf , or [ 2 ] BArF 24 and a base (either DBU or NaOMe) resulted in the deprotonation of the hydroxyl functional group to form a novel neutral orange-colored dearomatized complex, 3 . The identity of complex 3 was confirmed as [RuCl( p -cymene)(κ 2 - P,N - 6-D i PPon * )], where 6-D i PPon * is the anionic species (6-diisopropylphosphino-2-oxo-pyridinide), which contains the deprotonated moiety. The new 6-D i PPon ligand and its corresponding air stable half-sandwich derivative ruthenium complexes 1 , [ 2 ] OTf , [ 2 ] BArF 24 , and 3 were all isolated in good yields and fully characterized by spectroscopic and analytical methods. The interconversions between the neutral and anionic forms of the ligands 6-D i PPon , 6-D i PPin , and 6-D i PPon * offer the potential for novel secondary sphere interactions and proton shuttling reactivity. The consequences for this have been explored in the activation of H 2 and the subsequent catalytic hydrogenations of CO 2 into formate salts in the presence of a base.

The synthesis and characterization of six new substituted guanidium tetrahydroxidohexaoxidopentaborate(1-) salts are reported: [C(NH 2 ) 2 (NHMe)][B 5 O 6 (OH) 4 ]·H 2 O ( 1 ), [C(NH 2 ) 2 (NH{NH 2 })][B 5 O 6 (OH) 4 ] ( 2 ), [C(NH 2 ) 2 (NMe 2 )][B 5 O 6 (OH) 4 ] ( 3 ), [C(NH 2 )(NMe 2 ) 2 ][B 5 O 6 (OH) 4 ] ( 4 ), [C(NHMe)(NMe 2 ) 2 ][B 5 O 6 (OH) 4 ]·B(OH) 3 ( 5 ), and [TBDH][B 5 O 6 (OH) 4 ] ( 6 ) (TBD = 1,5,7-triazabicyclo [4.4.0]dec-5-ene). Compounds 1 - 6 were prepared as crystalline salts from basic aqueous solution via self-assembly processes from B(OH) 3 and the appropriate substituted cation. Compounds 1 - 6 were characterized by spectroscopic (NMR and IR) and by single-crystal XRD studies. A thermal (TGA) analysis on compounds 1 - 3 and 6 demonstrated that they thermally decomposed via a multistage process to B 2 O 3 at >650 °C. The low temperature stage (<250 °C) was endothermic and corresponded to a loss of H 2 O. Reactant stoichiometry, solid-state packing, and H-bonding interactions are all important in assembling these structures. An analysis of H-bonding motifs in known unsubstituted guanidinium salts [C(NH 2 ) 3 ] 2 [B 4 O 5 (OH) 4 ]·2H 2 O, [C(NH 2 ) 3 ][B 5 O 6 (OH) 4 ]·H 2 O, and [C(NH 2 ) 3 ] 3 [B 9 O 12 (OH) 6 ] and in compounds 1 - 6 revealed that two important H-bonding R 2 2 (8) motifs competed to stabilize the observed structures. The guanidinium cation formed charge-assisted pincer cation-anion H-bonded rings as a major motif in [C(NH 2 ) 3 ] 2 [B 4 O 5 (OH) 4 ]·2H 2 O and [C(NH 2 ) 3 ] 3 [B 9 O 12 (OH) 6 ], whereas the anion-anion ring motif was dominant in [C(NH 2 ) 3 ][B 5 O 6 (OH) 4 ]·H 2 O and in compounds 1 - 6 . This behaviour was consistent with the stoichiometry of the salt and packing effects also strongly influencing their solid-state structures.

We synthesised and characterised the racemic and chiral versions of two Zn salan fluorine-based complexes from commercially available materials. The complexes are susceptible to absorbing H 2 O from the atmosphere. In solution (DMSO-H 2 O) and at the millimolar level, experimental and theoretical studies identify that these complexes exist in a dimeric-monomeric equilibrium. We also investigated their ability to sense amines via 19 F NMR. In CDCl 3 or d 6 -DMSO, strongly coordinating molecules (H 2 O or DMSO) are the limiting factor in using these easy-to-make complexes as chemosensory platforms since their exchange with analytes requires an extreme excess of the latter.

Molecular materials based on small organic molecules often require advanced structural analysis, beyond the capability of spectroscopic techniques, to fully characterise them. In such cases, diffraction methods such as single crystal X-ray diffraction (SCXRD), are one of the most powerful tools available to researchers, providing molecular and structural elucidation at atomic level resolution, including absolute stereochemistry. However SCXRD, and related diffraction methods, are heavily dependent on the availability of suitable, high-quality crystals, thus crystallisation often becomes the major bottleneck in preparing samples. Following a summary of classical methods for the crystallisation of small organic molecules, this review will focus on a number of recently developed advanced methods for crystalline material sample preparation for SCXRD. This review will cover two main areas of modern small organic molecule crystallisation, namely the inclusion of molecules within host complexes ( e.g. , "crystalline sponge" and tetraaryladamantane based inclusion chaperones) and the use of high-throughput crystallisation, employing "under-oil" approaches ( e.g. , microbatch under-oil and ENaCt). Representative examples have been included for each technique, together with a discussion of their relative advantages and limitations to aid the reader in selecting the most appropriate technique to overcome a specific analytical challenge.

Two propeller-shaped chiral Co III 3 Y III complexes built from fluorinated ligands are synthesized and characterized by single-crystal X-ray diffraction (SXRD), IR, UV-vis, circular dichroism (CD), elemental analysis, thermogravimetric analysis (TGA), electron spray ionization mass spectroscopy (ESI-MS), and NMR ( 1 H, 13 C, and 19 F). This work explores the sensing and discrimination abilities of these complexes, thus providing an innovative sensing method using a 19 F NMR chemosensory system and opening new directions in 3d/4f chemistry. Control experiments and theoretical studies shed light on the sensing mechanism, while the scope and limitations of this method are discussed and presented.

A series of 2-phenylquinoxaline ligands have been synthesised that introduce either CF 3 or OCF 3 electron-withdrawing groups at different positions of the phenyl ring. These ligands were investigated as cyclometalating reagents for platinum(II) to give neutral complexes of the form [Pt(C^N)(acac)] (in which C^N=cyclometalating ligand; acac=acetyl acetonate). X-ray crystallographic studies on three examples showed that the complexes adopt an approximate square planar geometry. All examples revealed strong Pt-Pt linear contacts of 3.2041(6), 3.2199(3) and 3.2586(2) Å. The highly coloured complexes display efficient visible absorption at 400-500 nm (ϵ ≈5000 M -1  cm -1 ) and orange red photoluminescent characteristics (λ em =603-620 nm; Φ em ≤37 %), which were subtly tuned by the ligand. Triplet emitting character was confirmed by microsecond luminescence lifetimes and the photogeneration of singlet oxygen with quantum efficiencies up to 57 %. Each complex was investigated as a photosensitiser for triplet-triplet annihilation energy upconversion using 9,10-diphenylanthracene as the annihilator species: a range of good upconversion efficiencies (Φ UC 5.9-14.1 %) were observed and shown to be strongly influenced by the ligand structure in each case., (© 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

V-Shaped porphyrin dimers, with masked p- phenylene bridges, undergo efficient oxidative coupling to form meso - meso linked cyclic porphyrin oligomers. Reductive aromatization unmasks the p -phenylenes, increasing the strain. Oxidation then fuses the porphyrin dimers, providing a nanoring with curved walls. The strain in this macrocycle bends the p -phenylene and fused porphyrin dimer units (radii of curvature of 11.4 and 19.0 Å, respectively), but it does not significantly alter the electronic structure of the fused porphyrins.

The synthesis and crystal structure (100 K) of the title compound, [(CH 3 ) 2 NH 2 ][Fe(C 10 H 11 O 2 N 3 S) 2 ], are reported. The asymmetric unit consists of an octahedral [Fe III (L) 2 ] - fragment, where L 2- is 3-ethoxysalicylaldehyde thiosemicarbazonate(2-), and a dimethylammonium cation. Each L 2- ligand binds with the thiolate S, the imine N and the phenolate O atoms as donors, resulting in an Fe III S 2 N 2 O 2 chromophore. The ligands are orientated in two perpendicular planes, with the O and S atoms in cis positions, and mutually trans N atoms. The Fe III ion is in the high-spin state at 100 K. The variable-temperature magnetic susceptibility measurements (5-320 K) are consistent with the presence of a high-spin Fe III ion with D = 0.83 (1) cm -1 and g = 2., (open access.)

Solvent-free synthesis by using a vibratory ball mill (VBM) offers the chance to access new chemical reactivity, whilst reducing solvent waste and minimising reaction times. Herein, we report the core functionalisation of N,N'-bis(2-ethylhexyl)-2,6-dibromo-1,4,5,8-naphthalenetetracarboxylic acid (Br 2 -NDI) by using Suzuki, Sonogashira and Buchwald-Hartwig coupling reactions. The products of these reactions are important building blocks in many areas of organic electronics including organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs) and organic photovoltaic cells (OPVCs). The reactions proceed in as little as 1 h, use commercially available palladium sources (frequently Pd(OAc) 2 ) and are tolerant to air and atmospheric moisture. Furthermore, the real-world potential of this green VBM protocol is demonstrated by the double Suzuki coupling of a monobromo(NDI) residue to a bis(thiophene) pinacol ester. The resulting dimeric NDI species has been demonstrated to behave as an electron acceptor in functioning OPVCs., (© 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

An [Fe III 8 ] hexagonal bipyramid displays antiferromagnetic exchange between the two capping tetrahedral ions and the six ring octahedral ions resulting in a spin ground state of S = 10.

ISOX-DUAL is a dual inhibitor of CBP/p300 (IC 50 = 0.65 μM) and BRD4 (IC 50 = 1.5 μM) bromodomains, and a useful chemical probe for epigenetic research. Aspects of the published synthetic route to this compound and its analogues are small-scale, poor-yielding or simply unamenable to scale-up without optimization. Herein we describe the development of a refined synthesis that circumvents the challenges of the original report, with notable improvements to several of the key synthetic transformations. Moreover, a general Suzuki Miyaura protocol for the late stage installation of alternative dimethyl-isoxazole acetyl-lysine (KAc) binding motifs is presented.