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This work describes the synthesis and aggregation behavior of a dimeric bile acid derivative in which two steroid cores are bridged by a

Conventional materials discovery is a laborious and time-consuming process that can take decades from initial conception of the material to commercialization. Recent developments in materials acceleration platforms promise to accelerate materials discovery using automation of experiments coupled with machine learning. However, most of the automation efforts in chemistry focus on synthesis and compound identification, with integrated target property characterization receiving less attention. In this work, we introduce an automated platform for the discovery of molecules as gain mediums for organic semiconductor lasers, a problem that has been challenging for conventional approaches. Our platform encompasses automated lego-like synthesis, product identification, and optical characterization that can be executed in a fully integrated end-to-end fashion. Using this workflow to screen organic laser candidates, we have discovered 8 potential candidates for organic lasers. We test the lasing threshold of 4 molecules in thin-film devices and find 2 molecules with state-of-the-art performance. These promising results show the potential of automated synthesis and screening for accelerated materials development. This article is protected by copyright. All rights reserved.

ConspectusWe must accelerate the pace at which we make technological advancements to address climate change and disease risks worldwide. This swifter pace of discovery requires faster research and development cycles enabled by better integration between hypothesis generation, design, experimentation, and data analysis. Typical research cycles take months to years. However, data-driven automated laboratories, or self-driving laboratories, can significantly accelerate molecular and materials discovery. Recently, substantial advancements have been made in the areas of machine learning and optimization algorithms that have allowed researchers to extract valuable knowledge from multidimensional data sets. Machine learning models can be trained on large data sets from the literature or databases, but their performance can often be hampered by a lack of negative results or metadata. In contrast, data generated by self-driving laboratories can be information-rich, containing precise details of the experimental conditions and metadata. Consequently, much larger amounts of high-quality data are gathered in self-driving laboratories. When placed in open repositories, this data can be used by the research community to reproduce experiments, for more in-depth analysis, or as the basis for further investigation. Accordingly, high-quality open data sets will increase the accessibility and reproducibility of science, which is sorely needed.In this Account, we describe our efforts to build a self-driving lab for the development of a new class of materials: organic semiconductor lasers (OSLs). Since they have only recently been demonstrated, little is known about the molecular and material design rules for thin-film, electrically-pumped OSL devices as compared to other technologies such as organic light-emitting diodes or organic photovoltaics. To realize high-performing OSL materials, we are developing a flexible system for automated synthesis via iterative Suzuki-Miyaura cross-coupling reactions. This automated synthesis platform is directly coupled to the analysis and purification capabilities. Subsequently, the molecules of interest can be transferred to an optical characterization setup. We are currently limited to optical measurements of the OSL molecules in solution. However, material properties are ultimately most important in the solid state (e.g., as a thin-film device). To that end and for a different scientific goal, we are developing a self-driving lab for inorganic thin-film materials focused on the oxygen evolution reaction.While the future of self-driving laboratories is very promising, numerous challenges still need to be overcome. These challenges can be split into cognition and motor function. Generally, the cognitive challenges are related to optimization with constraints or unexpected outcomes for which general algorithmic solutions have yet to be developed. A more practical challenge that could be resolved in the near future is that of software control and integration because few instrument manufacturers design their products with self-driving laboratories in mind. Challenges in motor function are largely related to handling heterogeneous systems, such as dispensing solids or performing extractions. As a result, it is critical to understand that adapting experimental procedures that were designed for human experimenters is not as simple as transferring those same actions to an automated system, and there may be more efficient ways to achieve the same goal in an automated fashion. Accordingly, for self-driving laboratories, we need to carefully rethink the translation of manual experimental protocols.

The synthesis and characterization of a dimer in which two nuclei of 3β-acetoxy-19-hydroxyandrost-5-en-17-one are linked by the fluorescent 1,4-bis(phenylethynyl)phenylene bridge attached to the oxygenated functions at positions C-19 of each steroid fragment is described. The compound was obtained in five steps and 23 % overall yield and showed a strong blue emission with a quantum yield of 0.66.

Two diastereomeric crystalline steroid dimers were obtained by acid-catalyzed double acetalization of (20S)-5α-pregnan-3β,16β,20-triol 3-monoacetate with terephtalaldehyde. These compounds were characterized by NMR in solution, MS, single-crystal X-ray diffraction, and variable-temperature solid-state NMR by

Se realizó un estudio de pieles bovinas serranas para determinar la variación de sustancia piel (SP) producida por la cal y sulfuro de sodio con cuatro tratamientos (T) en las etapas de Pelambre y Calero; según la ASTM D 2868-17; es importante caracterizar la materia prima, seguido de los procesos de curtición hasta obtener muestras de cuero Wet Blue, análisis de SP y el tratamiento estadístico de los datos obtenidos, además se realizaron las pruebas sensoriales y físicos mecánicos en las etapas de post curtición. Obteniéndose como resultado de SP al T1 (2.0% cal-2% Na2S) y T2 (2.7% cal-2% Na2S) con los valores más altos de 79,5% y 79,3% respectivamente; en tanto que T3 (3,4% cal-2% Na2S) y T4 (4,1% cal-2% Na2S) produjeron 68,4% y 76,1%, respectivamente. Con el análisis estadístico se determinó que no existen diferencias medias significativas entre T1 y T2; los resultados de las pruebas físico mecánicas y sensoriales relacionan directamente la tendencia de SP consumida en cada tratamiento. El estudio efectuado tiene como fin conocer la relación directa entre la SP obtenida en cada tratamiento y el producto final producido por la empresa, refiriéndonos a la variabilidad del producto que se desea obtener. A study of Andean cattle skin was performed to determine the variation of skin substance (SP) produced by lime and sodium sulfide during the Liming and Calera stages using four different treatments (T). According to the ASTM D 2868-17, it is important to characterize the raw materials, followed by the tanning processes until obtaining samples of Wet Blue leather. Besides SP analysis and statistical treatment of the obtained data, sensory and physical-mechanical tests were carried out in the post-tanning stages. The results showed that SP at T1 (2.0% lime-2% Na2S) and T2 (2.7% lime-2% Na2S) produced the highest values; 79.5% and 79.3% respectively; with T3 (3.4% lime-2 % Na2S) and T4 (4.1% lime-2% Na2S) yielding 68.4% and 76.1%, respectively. The statistical analysis of the data evidenced that there is no significant differences between the means of T1 and T2. The results of the physical-mechanical and sensory tests directly relate to the trend of SP consumption in each treatment. The study carried out is aimed to recognize the direct relationship between the skin substance obtained in each treatment and the final product manufactured by the company, referred to the variability of the product to be obtained. &nbsp

In this work we report the fabrication of organic light-emitting diodes based on the carbazole derivative 1,4-bis(9H-carbazol-9-yl)phenyl)ethynyl)benzene, showing excellent CIE coordinates (0.31, 0.33). To achieve this, we developed an initial architecture where the emissive layer was sandwiched between ITO/PEDOT:PSS, that acted as anode/hole transport layer, and Ca/Ag as cathode. The electroluminescence for this initial architecture was similar to the photoluminescence of the carbazole derivative, showing blue emission with CIE coordinates (0.20, 0.22). Subsequently, when the thickness of the PEDOT:PSS layer was reduced from 60 nm to 30 nm, the electroluminescence changed from blue to greenish, with new CIE coordinates (0.26, 0.45). We attributed this effect to intermolecular interactions producing the observed emission from excitons within the emissive layer and exciplexes at the interface of the hole transport and the emissive layer. Based on these preliminary results, a second architecture using 15 nm of 4,7-diphenyl-1,10-phenanthroline as the electron transport layer (ETL) was developed. In this manner, the observed electroluminescence spectrum became wider and the devices showed white emission, with outstanding CIE coordinates (0.31, 0.33). For this architecture, new exciplexes generated at the interface between emissive and electron transport layer emitted at longer wavelengths giving the complementary emission for white light. The generation of exciplex states at the two interfaces of the emitting layer made possible the fabrication of white light organic diodes with the simplest and more commonly used OLED architecture. Interestingly, by using an ETL in the second architecture, and by changing the thickness of the hole transport layer from 60 to 30 nm, it was possible to further fine-tune the white light from cold to warm emission.

Self-driving labs, in the form of automated experimentation platforms guided by machine learning algorithms have emerged as a potential solution to the need for accelerated science. While new tools for automated analysis and characterization are being developed at a steady rate, automated synthesis remains the bottleneck in the chemical space accessible to self-driving labs. Combining automated and manual synthesis efforts immediately significantly expands the explorable chemical space. To effectively direct the different capabilities of automated (higher throughput and less labor) and manual synthesis (greater chemical versatility), we describe a protocol, the RouteScore, that quantifies the cost of combined synthetic routes. In this work, the RouteScore is used to determine the most efficient synthetic route to a well-known pharmaceutical (structure-oriented optimization), and to simulate a self-driving lab that finds the most easily synthesizable organic laser molecule with specific photophysical properties from a space of ~3500 possible molecules (property-oriented optimization). These two examples demonstrate the power and generality of our approach in mixed synthetic planning and optimization.

Amphidynamic motion in metal–organic frameworks (MOFs) is an intriguing emergent property, characterized by high rotational motion of the phenylene rings that are embedded within an open, rigid framework. Here, we show how the phenylene rings in the organic linkers of the water stable MOF PEPEP-PIZOF-2 exhibit multiple rotational rates as a result of the electronic structure of the linker, with and without the presence of highly interacting molecular guests. By selective 2H enrichment, we prepared isotopologues PIZOF-2d4 and PIZOF-2d8 and utilized solid-state 13C and 2H NMR to differentiate the dynamic behavior of specific phenylenes in the linker at room temperature. A difference of at least one order of magnitude was observed between the rates of rotation of the central and outer rings at room temperature, with the central phenylene ring, surrounded by ethynyl groups, undergoing ultrafast 180° jumps with frequencies higher than 10 MHz. Moreover, loading tetracyanoquinodimethane (TCNQ) within the pores produced significant changes in the MOF's electronic structure, but very small changes were observed in the rotational rates, providing an unprecedented insight into the effects that internal dynamics have on guest diffusion. These findings would help elucidate the in-pore guest dynamics that affect transport phenomena in these highly used MOFs., Zirconia based metal–organic framework PEPEP-PIZOF-2 exhibits the emergent property of amphidynamic motion with organic links that show multiple rotational rates related to their molecular structure and independently from presence of molecular guests.

A new rotor exhibits rich solvatomorphism behavior with eight X-ray structures obtained. A heterogeneous solid obtained by mechanical stress exhibited a dominant isotropic 2H line shape at high temperatures. The motion occurs only in the amorphous component of this solid, with an Ea of 7.4 kcal mol-1 and a low pre-exponential factor A of 6.22 × 1010 s-1, which indicates that the motion requires the distortion of the molecular axis.

The aggregation behavior and its influence on the intramolecular motion of three highly conjugated solid-state molecular rotors 2–4 with alkyl groups were investigated by a combination of fluoresce...

We report for the first time the high sorption properties of a molecular rotor with no permanent voids or channels in its crystal structure. Such crystalline phase originates from THF, DCM, or the irreversible desolvation of entrapped benzene molecules. From these, the benzene in its solvate form acts as rotation stopper, as supported by dynamic characterization using solid-state 2H NMR experiments. In the solvent-free form, the diffusion of small quantities of iodine vapors caused a significant change in the intramolecular rotation, increasing the known activation energy to rotation from 8.5 to 10.6 kcal mol–1. Notably, those results paved the way for the discovery of the high CO2 uptake (201.6 cm3 g–1 at 196 K, under 1 atm) and acetone (5 wt %), a sorption property that was attributed to both, the restriction of the molecular rotation at low temperatures and the flexibility of the molecular axle made of conjugated p-(ethynylphenylene), surrounded by carbazole.

A multicomponent diversity-oriented synthesis of new highly emissive tetracyclic isoquinolines that target specific organelles is described. The title compounds were prepared via a three-step protocol starting with an Ugi four-component reaction, followed by either an intramolecular alkyne hydroarylation and subsequent alkene isomerization or through a Pomeranz-Fritsch-type cyclization with a final intramolecular Heck reaction. Subcellular localization studies of these compounds using green channel confocal microscopy revealed remarkable and distinctive distribution patterns in live cells, showing an unprecedented high selectivity and imaging contrast. The differentiated organelle visualization-including localizers for mitochondria, lysosomes, Golgi apparatus, endoplasmic reticulum, and plasma membrane-was achieved by varying the nature of the tetracyclic system and substituent pattern, changing the original four-component set in the starting Ugi reaction.

A crystalline, porous Metal–Organic Polyhedron (MOP) 4 was readily assembled starting from 9H-carbazole-3,6-dicarboxylic acid, which was synthesised in only three steps. The single crystal X-ray diffraction analysis of the resulting supramolecule evidenced voids that were occupied by coordinated as well as uncoordinated solvent molecules from the solvothermal reaction. Careful analysis of its desolvation process, activating the sample at 150 °C and 10−5 bar (followed by FTIR), evidenced that all solvents were completely removed, leaving an empty but nevertheless crystalline MOP with coordinatively-unsaturated Cu(II) sites that was studied for gas adsorption using N2 at 77 K, and CO2 at 196 K. Notably, carbon dioxide was found to be strongly adsorbed in the activated 4 (12.1 mmol g−1, 53.2 wt%) with a molar enthalpy of adsorption of ΔH = 65.12 kJ mol−1, revealing a great selectivity over nitrogen, which in turn showed negligible uptake under the same activation conditions. In situ Raman experiments demonstrated the direct interaction of CO2 molecules and coordinatively-unsaturated Cu(II) sites within 4.

Herein we report the synthesis of the highly stable crystalline carbazole-based rotor 3 with simultaneous rapid solid state internal rotation and good fluorescence emission. Single crystal and powder X-ray diffraction studies along with microscopy revealed a phase transition from a labile benzene solvate (phase I) to highly stable crystals (phase II) that feature fast intramolecular rotation in the megahertz regime at room temperature, according to variable temperature 2H solid state NMR experiments using isotopically enriched analogues. In addition to the megahertz rotation within its crystals, this crystal phase II displays enhanced solid state fluorescence with a higher quantum yield of ϕ = 0.28, relative to the emission of this compound in THF solution (ϕ = 0.06). These two solid state properties are significantly different from shorter compounds 1 and 2 (static and nonemissive) included here for comparison purposes.

Materials Acceleration Platforms are an emerging paradigm to accelerate materials discovery as an effort to develop technology solutions that can help address or mitigate climate change concerns. These platforms combine artificial intelligence, robotic systems, and high-performance computing to achieve autonomous experimentation. Nevertheless, their development faces challenges to achieve full autonomy. In this work, we present state-of-the-art robotic platforms and machine learning approaches for autonomous experimentation, their integration, and applications, particularly in the field of materials for clean energy technologies. Later, we discuss the challenges and suggest improvements to be considered in the endeavor to accomplish autonomous experimentation.

The use of the multicomponent Ugi reaction to rapidly prepare a library of dumbbell-like molecular rotors is highlighted here. The synthetic strategy consisted of the atom-economic access to 15 bulky and structurally diverse iodinated stators, which were cross-coupled to the 1,4-diethynylphenylene rotator. From those experiments, up to six rotors 1a–c and 1l–n were obtained, with yields ranging from 35 to 69% per coupled C–C bond. In addition to the framework diversity, five of these compounds showed aggregate-enhanced emission properties thanks to their conjugated 1,4-bis(phenylethynyl)benzene cores, a property that rises by increasing the water fraction (fw) in their THF solutions. The results highlight the significance of the diversity-oriented synthesis of rapid access to new molecular fluorescent rotors.

We describe the synthesis and crystallization of two macrocyclic steroidal compounds labeled (Z)-1F2 and (E)-1F2, envisioned to work as molecular rotors with 1,4-diethynyl-2,3-difluorophenylene rotators. The introduction of the fluorine atoms rendered different crystal arrays that were fully characterized by X-ray diffraction, solid state 13C NMR, and calorimetric experiments. In both isomers, the central molecular fragments point the o-fluorine atoms toward their cavity, highlighting the preferred orientation in the solid state. By analyzing the crystal array, it can be seen that while the fluorinated Z isomer is isomorphic to its non-fluorinated analogue, the E isomer shows significant structural variations in an unanticipated crystal array with two molecules per asymmetric unit (Z′ = 2).

Thirteen steroidal derivatives were synthesized through a Sonogashira cross-coupling reaction which has been found to be an excellent synthetic strategy to introduce halo-aromatic groups into C-17-ethynyl substituted steroidal frameworks. The structural modification was performed on ethynylestradiol, mestranol, norethisterone, ethisterone and 3-ethynyl-3-epi-sarsasapogenin. The solid state study by X-ray diffraction showed that most of them belong to the orthorhombic P212121 space group and the whole family has an “L” conformation, regardless of the nature of the steroid A-ring (3-hydroxy-aromatic or 3-oxo). Due to the presence of several moieties which are susceptible to forming secondary interactions, the crystalline packing is governed by O–H⋯O, C–H⋯O, and C–H⋯π interactions, and only 17α-(4′-iodophenylethynyl)-3-methoxy-estra-1,3,5(10)-trien-17-β-ol (mestranol derivative 3) showed an iodine–iodine interaction (dI⋯I = 4.116 A). The crystalline packing for ethynylestradiol derivatives 1, 2 and 4 showed the formation of holes with diameters greater than 5.2 A suggesting their potential application in host guest chemistry or as porous materials.

We report for the first time the high sorption properties of a molecular rotor with no permanent voids or channels in its crystal structure. Such crystalline phase originates from THF, DCM, or the irreversible desolvation of entrapped benzene molecules. From these, the benzene in its solvate form acts as rotation stopper, as supported by dynamic characterization using solid-state