rac-1-(2-Amino­carbonyl-2-bromo­eth­yl)pyridinium bromide

In the crystal structure of the title compound, C8H10BrN2O+·Br−, inter­molecular N—H⋯Br hydrogen bonds link the mol­ecules into infinite chains along [001]. The inclined angle between the pyridine ring plane and the plane defined by the acid amide group is 63.97 (4)°

Methyl 3,5,5,6,8,8-hexa­methyl-5,6,7,8-tetra­hydro­naphthalene-2-carboxyl­ate (AHTN–COOMe)

Crystals of the title compound, C18H26O2, were grown from ethyl acetate. Due to the racemic precursor, the title compound is also obtained as a racemate. Disorder was observed during structure refinement, originating from two possible half-chair conformations of the non-aromatic ring. The disorder was refined by introducing split positions in the cyclo-hexane ring regarding the two possible R and S-enantiomers at the chiral CH group [ratio 0.744 (3):0.256 (3)]. The crystal structure features pairs of inversion-related molecules connected by pairs of non-classical C—H⋯O hydrogen bonds

(3S,11Z)-14,16-Dihy­droxy-3-methyl-3,4,5,6,9,10-hexa­hydro-1H-2-benz­oxacyclo­tetra­decine-1,7(8H)-dione (cis-zearalenone): a redetermination

The title compound, also known as cis-zearalenone (cis-ZEN), C18H22O5, has already been reported elsewhere [Griffin et al. (1981 ▶). ACA Ser. 29, 35], but no atomic coordinates are publicly available. The mol­ecule is of inter­est with respect to its toxicity. In the crystal, intra­molecular O—H⋯O hydrogen bonds stabilize the mol­ecular conformation, while inter­molecular O—H⋯O hydrogen bonds link the mol­ecules to form infinite chains along the [110] and [1-10] directions. The absolute configuration has been assigned by reference to an unchanging chiral centre in the synthetic procedure

Ergotaminine

The title compound {systematic name: (6aR,9S)-N-[(2R,5S,10aS,10bS)-5-benzyl-10b-hy­droxy-2-methyl-3,6-dioxoocta­hydro-8H-oxazolo[3,2-a]pyrrolo­[2,1-c]pyrazin-2-yl]-7-methyl-4,6,6a,7,8,9-hexa­hydro­indolo[4,3-fg]quinoline-9-carboxamide}, C33H35N5O5, was formed by an epimerization reaction of ergotamine. The non-aromatic ring (ring C of the ergoline skeleton) directly fused to the aromatic rings is nearly planar [maximum deviation = 0.317 (4) Å] and shows an envelope conformation, whereas ring D, involved in an intra­molecular N—H⋯N hydrogen bond exhibits a slightly distorted chair conformation. The structure displays chains running approximately parallel to the diagonal of bc plane that are formed through N—H⋯O hydrogen bonds

Ergometrinine

The absolute configuration of ergometrinine, C19H23N3O2 {systematic name: (6aR,9S)-N-[(S)-1-hy­droxy­propan-2-yl]-7-methyl-4,6,6a,7,8,9-hexa­hydro­indolo[4,3-fg]quinoline-9-carb­ox­amide}, was established based on epimerization reaction of ergometrine, which was followed by preparative HPLC. The non-aromatic ring (ring C of the ergoline skeleton) directly fused to the aromatic rings is nearly planar [maximum deviation = 0.271 (3) Å] and shows an envelope conformation, whereas ring D, involved in an intra­molecular N—H⋯N hydrogen bond, exibits a slightly distorted chair conformation. The structure displays undulating layers in the ac plane formed by O—H⋯O and N—H⋯O hydrogen bonds

Structure and properties of fluorinated and non‐fluorinated Ba‐coordination polymers – the position of fluorine makes the difference

As the most electronegative element, fluorine has a strong influence on material properties such as absorption behaviour or chemical and thermal stability. Fluorine can be easily integrated into coordination polymers (CPs) via a fluorinated acetate, here trifluoroacetate in Ba(CF3COO)2, or directly via a metal fluorine bond (BaF(CH3COO)). In the present study both possibilities of fluorine integration were tested and their effect on structure and properties of barium coordination polymers was investigated in comparison with the non-fluorinated barium acetate (Ba(CH3COO)2). In addition to the study of their thermal behaviour and their decomposition temperature, the CPs structures were tested for their application as possible anode materials in lithium ion batteries and for their sorption of water and ammonia. The properties of the CPs can be traced back to the individual structural motifs and could thus trigger new design ideas for CPs in LIBs and/or catalysis.HU BerlinBAMPeer Reviewe

Liquid reagents are not enough for liquid assisted grinding in the synthesis of [(AgBr)(n-pica)]n

This study investigates the mechanochemical reactions between AgBr 3-picolylamine and 4-picolylamine. The use of different stoichiometry ratios of the reagents allows [(AgBr)(n-pica)](n) and [(AgBr)(2)(n-pica)](n) to be obtained, and we report the new structures of [(AgBr)(2)(3-pica)](n) and [(AgBr)(2)(4-pica)](n) which are characterized by the presence of the following: (a) infinite inorganic chains, (b) silver atom coordinated only by bromide atoms and (c) argentophilic interactions. Furthermore, we studied the interconversion of [(AgBr)(n-pica)](n)/[(AgBr)(2)(n-pica)](n) by mechanochemical and thermal properties. The in situ experiments suggest that [(AgBr)(3-pica)](n) is kinetically favoured while [(AgBr)(2)(3-pica)](n) is converted into [(AgBr)(3-pica)](n) only with a high excess of the ligand. Finally, the liquid nature of the ligands is not sufficient to assist the grinding process, and the complete reaction is observed with the addition of a small quantity of acetonitrile

An amorphous Lewis-acidic zirconium chlorofluoride as HF shuttle: C–F bond activation and formation

An exceptional HF transfer reaction by C–F bond activation of fluoropentane and a subsequent hydrofluorination of alkynes at room temperature is reported. An amorphous Lewis-acidic Zr chlorofluoride serves as heterogeneous catalyst, which is characterised by an eightfold coordination environment at Zr including chlorine atoms. The studies are seminal in establishing sustainable fluorine chemistry.Peer Reviewe

Kinetics of the mechanically induced ibuprofen-nicotinamide co-crystal formation by in-situ X-ray diffraction

Mechanochemistry is drawing the attention of the pharmaceutical industry given its potential for sustainable material synthesis and manufacture. Scaling mechanochemical processes to the industry level remains a challenge due to the incomplete understanding of their underlying mechanisms. We show how time-resolved in situ powder X-ray diffraction data, coupled with analytical kinetic modelling, is crucial for gaining deeper insight into mechanochemical reactions. By using the ibuprofen-nicotinamide co-crystal mechanosynthesis as a benchmark system, we investigate the behaviour of the solids involved and identify the factors promoting the reaction. With this chemistry becoming increasingly clear, we believe that mechanochemistry may soon represent a breakthrough in the industrial preparation of pharmaceuticals