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Crystallizing molecules with long flexible chains is a challenge, making it difficult to perform X‐ray crystallography. Chaperones can assist in the crystallization of compounds that do not crystallize by themselves by producing solvate crystals that contain the analyte in their three‐dimensional lattices. Among the most versatile chaperones for liquid analytes are tetraaryladamantanes (TAAs), but the size of the compounds that can be encapsulated is limited, and attempts to surpass this limit with known TAAs were unsuccessful. Here we report that 1,3,5,7‐tetrakis(2‐fluoro‐4‐methoxyphenyl)adamantane (TFM) is a crystallization chaperone for acyclic molecules up to the molecular weight of phytyl acetate (338 g/mol). Encapsulation of such a large acyclic compound was achieved when the analyte was esterified and when a two‐step temperature protocol was used for crystallization. Exploratory work indicates that a drop to −20 °C allows for encapsulation of squalene (Mr 411 g/mol), albeit with positional disorder of the analyte. Our X‐ray crystal structures of solvates with flexible analytes shed light on how crystalline order can be imposed on large acyclic analytes. The new, fluorinated TAA gives access to crystal structures that were inaccessible thus far. [ABSTRACT FROM AUTHOR]

A new crystallization chaperone called TFM has been developed, which allows for the formation of X-ray diffraction-based crystal structures of liquid molecules that would otherwise be difficult to obtain. This chaperone acts like a glove that can fit molecules of various sizes, resulting in successful crystallization. The article also introduces a new temperature jump crystallization protocol. The cover graphic of the article displays the chaperone and the crystal lattice of the squalene solvate. [Extracted from the article]

The article discusses a new crystallization chaperone called TFM, which allows for the formation of X-ray diffraction-based crystal structures that would otherwise be impossible to obtain. The chaperone acts like a glove that fits many different sizes, enabling the crystallization of liquid molecules as a solvate. The article also introduces a new temperature jump crystallization protocol. The cover graphic of the article depicts the analytes and the chaperone, along with the crystal lattice of the squalene solvate. [Extracted from the article]

Crystallizing molecules with long flexible chains is a challenge, making it difficult to perform X-ray crystallography. Chaperones can assist in the crystallization of compounds that do not crystallize by themselves by producing solvate crystals that contain the analyte in their three-dimensional lattices. Among the most versatile chaperones for liquid analytes are tetraaryladamantanes (TAAs), but the size of the compounds that can be encapsulated is limited, and attempts to surpass this limit with known TAAs were unsuccessful. Here we report that 1,3,5,7-tetrakis(2-fluoro-4-methoxyphenyl)adamantane (TFM) is a crystallization chaperone for acyclic molecules up to the molecular weight of phytyl acetate (338 g/mol). Encapsulation of such a large acyclic compound was achieved when the analyte was esterified and when a two-step temperature protocol was used for crystallization. Exploratory work indicates that a drop to -20 °C allows for encapsulation of squalene (Mr 411 g/mol), albeit with positional disorder of the analyte. Our X-ray crystal structures of solvates with flexible analytes shed light on how crystalline order can be imposed on large acyclic analytes. The new, fluorinated TAA gives access to crystal structures that were inaccessible thus far., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

A series of chiral mechanochromic copper(I) cAAC (cAAC=cyclic (alkyl)(amino)carbene) complexes with a variety of amide ligands have been studied with regard to their photophysical and chiroptical properties to elucidate structure-property relationships for the design of efficient triplet exciton emitters exhibiting circularly polarized luminescence. Depending on the environment, which determines the excited state energies, either thermally activated delayed fluorescence (TADF) from 1/3 LLCT states or phosphorescence from 3 LLCT/LC states occurs. However, neither chiral moieties at the carbene nor at the carbazolate ligands provide detectable luminescence dissymmetries g lum . An exception is [Cu(phenoxazinyl)(cAAC)], showing orange to deep red TADF with λ max =601-715 nm in solution, powders and in PMMA. In this case, the amide ligand can undergo distortions in the excited state. This design motif leads to the first linear, non-aggregated CPL-active copper(I) complex with g lum of -3.4 ⋅ 10 -3 combined with a high radiative rate constant of 6.7 ⋅ 10 5  s -1 ., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

The 2-aryl-3,4,5,6-tetraphenyl-1,2-azaborinines 1-EMe 3 and 2-EMe 3 (E=Si, Sn; aryl=Ph (1), Mes (=2,4,6-trimethylphenyl, 2)) were synthesized by ring-expansion of borole precursors with N 3 EMe 3 -derived nitrenes. Desilylative hydrolysis of 1- and 2-SiMe 3 yielded the corresponding N-protonated azaborinines, which were deprotonated with nBuLi or MN(SiMe 3 ) 2 (M=Na, K) to the corresponding group 1 salts, 1-M and 2-M. While the lithium salts crystallized as monomeric Lewis base adducts, the potassium salts formed coordination polymers or oligomers via intramolecular K⋅⋅⋅aryl π interactions. The reaction of 1-M or 2-M with CO 2 yielded N-carboxylate salts, which were derivatized by salt metathesis to methyl and silyl esters. Salt metathesis of 1-M or 2-M with methyl triflate, [Cp*BeCl] (Cp*=C 5 Me 5 ), BBr 2 Ar (Ar=Ph, Mes, 2-thienyl), ECl 3 (E=B, Al, Ga) and PX 3 (X=Cl, Br) afforded the respective group 2, 13 and 15 1,2-azaborinin-2-yl complexes. Salt metathesis of 1-K with BBr 3 resulted not only in N-borylation but also Ph-Br exchange between the endocyclic and exocyclic boron atoms. Solution 11 B NMR data suggest that the 1,2-azaborinin-2-yl ligand is similarly electron-withdrawing to a bromide. In the solid state the endocyclic bond length alternation and the twisting of the C 4 BN ring increase with the sterics of the substituents at the boron and nitrogen atoms, respectively. Regression analyses revealed that the downfield shift of the endocyclic 11 B NMR resonances is linearly correlated to both the degree of twisting of the C 4 BN ring and the tilt angle of the N-substituent. Calculations indicate that the 1,2-azaborinin-1-yl ligand has no sizeable π-donor ability and that the aromaticity of the ring can be subtly tuned by the electronics of the N-substituent., (© 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)