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Industrial-scale thermal separation processes have contributed greatly to the rise in carbon dioxide emissions. Porous materials, such as metal-organic frameworks (MOFs), can potentially reduce these emissions by achieving nonthermal chemical separations through the physical adsorption of targeted species with high selectivity. Here, we report the synthesis of the channel-based MOFs

Tröger's base's chirality merges catenanes’ photosensitizing characteristics to introduce the first nitrogen-based chiral hetero[2]catenane that proceeds enantioenriching photocatalytic aerobic oxidations.

Tröger's base (TB) and its derivatives have been studied extensively due to their unique concave shape stemming from the endomethylene strap. However, the strap-clipped TB chemistry has been largely overlooked in metal-organic framework (MOF) solids, leading to a gap in our knowledge within this field. In this work, we report the in situ strap elimination of a carboxylate-carrying TB in the presence of formic acid, both in solution and in Zr(IV)-based MOFs. In the solution system, the methanodiazocine nucleus can be exclusively transformed into an

Three achiral polycyclic aromatic fluorophores─namely, 1-pyrenecarboxylic acid, 9-anthracenecarboxylic acid, and perylene-3,9-dicarboxylic acid─were chosen based on their desired properties before being incorporated into the construction of a K

The present study investigates the effects of substituents, structural rigidity, tautomerism, hydrogen bonding interaction, and spatial hindrance on the thermal stability of some azo compounds including bisazo Troger base analogs (BATBAs). The relatively large structures of BATBAs allow assessing their thermal stability before reaching the sublimation or boiling point. BATBAs carry two identical azo groups per molecule resulting in an intense and detectable sign of decomposition. Unlike most azo dyes, BATBAs are not ionic and prevent the complexity of decomposition associated with simultaneous dehydration. A few commercial azo dyes are also analyzed to evaluate the generality of the conclusion.

Bisazo Troger base analogs are claw-looking molecules that carry two identical but independent photoswitching groups. These bisazo compounds, like dual switches, can be at EE, EZ, and ZZ photoisomerization states while the ∧-shape void of Troger base scaffold may also introduce an additional possibility of stereoisomerism by holding the photoisomerizable groups in endo or exo positions. To date, the exact molecular geometries of the isomerizable analogs of Troger's base have not been elaborated. Owing to the special features and potential applications of these molecules, herein their photoisomerization is probed. The gleaned data from 15N isotope labeling and a variety of spectroscopic, spectrophotometric, crystallographic, and computational techniques have revealed the structure of the studied photoisomers and suggested their use in the design of molecular pull and push mechanisms, light driven actuators, and artificial muscles.

The enantiomer separation of a chiral Troger's base analog and its use, as an optically active building block, in the construction of molecular superstructures are presented. Various strategies are illustrated here for the attachment of azo photoswitches to the Troger's base scaffold without racemizing its stereogenic centers. The resulting optically active photoswitches introduced chirality, thermochromic, and phototunable properties to an achiral liquid crystal host. The doped mesophases reflected specific wavelengths of light owing to the formation of self-organized helical superstructures. These observations illustrate the potential use of the presented products as liquid crystal dopants.

Hünlich’s base modification has resulted in introducing a series of versatile Λ-shaped building blocks presented in this work. The methods are optimized to provide convenient approaches in the quicker production of these new building blocks in low-cost and low-risk.

Cannabis plant has long been execrated by law in different nations due to the psychoactive properties of only a few cannabinoids. Recent scientific advances coupled with growing public awareness of cannabinoids as a medical commodity drove legislation change and brought about a historic transition where the demand rose over ten-fold in less than five years. On the other hand, the technology required for cannabis processing and the extraction of the most valuable chemical compounds from the cannabis flower remains the bottleneck of processing technology. This paper sheds light on the downstream processing steps and principles involved in producing cannabinoids from Cannabis sativa L. (Hemp) biomass. By categorizing the extraction technology into seed and trichome, we examined and critiqued different pretreatment methods and technological options available for large-scale extraction in both categories. Solvent extraction methods being the main focus, the critical decision-making parameters in each stage, and the applicable current technologies in the field, were discussed. We further examined the factors affecting the cannabinoid transformation that changes the medical functionality of the final cannabinoid products. Based on the current trends, the extraction technologies are continuously being revised and enhanced, yet they still fail to keep up with market demands.

The production of azo derivatives of a di-amino analogue of Troger’s base (Hunlich base), by employing the standard procedures of diazotization, azo-coupling and Williamson etherification is described here. These versatile molecules possess a Λ-shaped core, photoswitchable groups and some carry two modifiable extremities to enable further synthesis or molecular assembly. The synthesis is straightforward and requires inexpensive starting materials, which facilitates their application to different fields of research such as light-driven molecular machine design.

Novel triazene-based polysulfone, poly 4-(4-aminophenylsulfonyl)diazobenzene, was synthesized from 4-[(4-aminobenzene)sulfonyl]aniline (Dapsone) in the presence of sodium nitrite/silica sulfuric acid system, under solvent-free conditions, and also in aqueous media to compare their polymerization process and the products. The structures of the obtained polymers under the two conditions were characterized for the first time in this investigation by several analytical and spectroscopic methods such as FT-IR, 1H-NMR, UV–vis, thermogravimetric and differential thermal analyses, gel permeation chromatography, mass spectrometry, and CHN micro-elemental analysis. The results showed that both polymerization processes had made the same product; nevertheless, the solvent-free conditions afforded silica-coated poly 4-(4-aminophenylsulfonyl)diazobenzene. In another study, the ability of the silica-coated polymer, to remove some usual applied water-soluble dyes by spectrophotometric detection, was measured in which cationic structure dyes such as Rhodamine B and Cationic blue 41 were preferably adsorbed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Trityl chloride (TrCl), efficiently catalyzes the one-pot multi-component condensation of β-naphthol with aromatic aldehydes and amides/thioamides/carbamates such as acetamide, benzamide, nicotinamide, thioacetamide, and methylcarbamate under solvent-free and neutral conditions to afford 1-amido-alkyl-2-naphthols, 1-thioamido-alkyl-2-naphthols, and 1-carbamato-alkyl-2-naphthols in high yields and very short reaction times. Mechanistically, it is interesting that trityl chloride through the in situ generation of trityl carbocation with inherent instability is efficient as a reusable homogeneous organocatalyst in neutral media.

In this work, at first, triazenes were synthesized from primary aryl amines. Afterwards, triazenes were converted into the corresponding thiophenols in one-pot using sodium sulfide in acidic media, by in situ generation of diazonium counterion beside hydrogen sulfide as anionic sulfur nucleophile at room temperature. The procedure can be a convenient shortcut for the preparation of thiophenols from primary aryl amines.

3-Methyl-1-sulfonic acid imidazolium nitrate ([Msim]NO(3)) as a new Brønsted acidic ionic liquid and nitrating agent was prepared and used for the efficient nitration of aromatic compounds (even aniline derivatives). The dramatic effect of this reagent by in situ generation of nitrogen dioxide as a radical on aromatic compounds to give nitroarenes has been studied.

A new N-bromo polysulfonamide is prepared and successfully used as catalyst for the acetylation of alcohols, phenols, thiols and amines under solvent-free conditions as well as the deacetylation of acetate esters in aqueous medium.

Sistemas de liberacao de farmacos baseados em conjugados polimero-farmaco fornecem um tratamento melhorado com menor toxidade ou efeitos colaterais e sao usados no tratamento de diferentes doencas. Conjugados de poli(estireno-alt-anidrido maleico) (PSMA) biodegradavel, com agentes terapeuticos tais como cloridrato de amantadina, amlopidina, gabapentina, zonisamida e mesalamina, foram gerados pela formacao de ligacoes de amidas dos farmacos amino que reagiram com os grupos anidridos do PSMA. As quantidades de farmacos covalentemente conjugados foram determinadas por ressonância magnetica nuclear (NMR) de 1 H, e a taxa de liberacao in vitro em solucao tampao (pH 1.3) foi estudada a temperatura do corpo (37 o C). Em estudos de cinetica, modelos de dissolucao diferentes foram examinados a fim de se obter dados de liberacao do farmaco e os dados coletados se ajustaram bem a equacao de Korsmeyer-Peppas, revelando um mecanismo de difusao Fickaniano dominante na liberacao do farmaco em condicoes in vitro. Drug delivery systems based on polymer-drug conjugates give an improved treatment with lower toxicity or side effects and be used for the treatment of different diseases. Conjugates of biodegradable poly(styrene-alt-maleic anhydride) (PSMA), with a therapeutic agents such as amantadine hydrochloride, amlodipine, gabapentin, zonisamide and mesalamine, were afforded by the formation of the amide bonds of the amino drugs that reacted with the PSMA anhydride groups. The amounts of covalently conjugated drugs were determined by a 1 H NMR spectroscopic method, and the in vitro release rate in buffer solution (pH 1.3) was studied at body temperature 37 °C. In kinetic studies, different dissolution models were examined to obtain drug release data and the collected data were well-fitted to the Korsmeyer-Peppas equation, revealing a dominant Fickian diffusion mechanism for drug release under the in vitro conditions.

A convenient method is presented for the conversion of aromatic amines to the corresponding thiols.