Journal of Inclusion Phenomena and Macrocyclic Chemistry最新文献

Paul Karrer (1889–1971), a Swiss organic chemist best known for his research on vitamins, has published more than 1000 articles. In 1919, Karrer became professor of chemistry at the University of Zurich and in the same year he was appointed director of the Chemical Institute in Zurich, where he remained until his retirement in 1959. Karrer’s most famous work was on vitamins, and probably his most important contribution was his demonstration in 1931 that vitamin A was structurally related to carotenoid. Karrer also published important works on natural products, carotenoids and other plant pigments, coenzymes, alkaloids, amino acids, sugars, carbohydrates, polysaccharides, and organometallic compounds. Professor Karrer was awarded the Nobel Prize in chemistry in 1937 for his research into the constitution of carotenoids, flavins and vitamins A and B2, a prize shared with the British chemist Sir Walter Norman Haworth. However, few researchers working in the field of cyclodextrins know that Karrer was also one of the first to take an interest in these molecules. Between 1920 and 1925, he published several studies on the nomenclature, structure and chemistry of dextrin-α and dextrin-β. This historical review, on the occasion of the fiftieth anniversary of his death, aims, on the one hand, to retrace his immense scientific career highlighting selected works on vitamins and alkaloids and, on the other hand, to commemorate his contribution to (cyclo)dextrin chemistry.

Five novel chiral 2D materials with general formula λ-ZrPO₄(OH)_1-x(RCOO)_x(dmso) have been prepared by covalent anchoring of five different chiral carboxylic acids to the sheets of λ-zirconium phosphate (λ-ZrP), namely (S)-(+)-Mandelic acid (MAN), (R)-(?)-α-Methoxyphenylacetic acid (MPA), (S)-(+)-Ibuprofen (IBU), (S)-(+)-6-Methoxy-α-methyl-2-naphthaleneacetic acid (MMN) and (?)-Menthyloxyacetic acid (MEN). The synthesized materials were characterized by X-ray diffractometry, FT-IR spectrophotometry, elemental and thermogravimetric analyses and polarimetry. The X-ray diffraction patterns revealed that the interlayer separations increase from 1.02?nm (pure λ-ZrP) to 1.31–2.31?nm as a result of the incorporation of the mentioned acids within the interlayer gallery. The polarimetry measurements showed that the synthesized materials have appreciable optical activities suggesting they could have protentional applications in the field of chiral separation techniques.

Herein, we investigated the inclusion complexation of a fluorescent probe [4′,6-diamidino-2-phenylindole (DAPI)]?using various cyclodextrins (CDs) and cucurbit[7]uril (CB7). Using the?continuous variation method, DAPI was found to form a 1:1 inclusion complex with CDs and CB7. ¹H-NMR and 2D ROESY (¹H-¹H rotating frame nuclear Overhauser effect) spectroscopy indicated that the inclusion of DAPI by the CDs and CB7 occurs via the encapsulation of the phenyl group and indole moiety of DAPI. The stability of the CB7?inclusion complex was higher than?that of the CDs: the stability was attributed to the extra interaction formed between the dicationic dye (DAPI) and polar carbonyl groups at the portals of CB7. Furthermore, we determined the fluorescence quantum yield (Φ) of the inclusion complexes. The Φ values of DAPI were significantly enhanced upon its inclusion by CB7 and increased as the empirical solvent polarity parameter (E_T(30)) decreased. Based on these results, we concluded that the polarity of the microenvironment and protonation ability of the excited state of DAPI play important roles in emission efficiency.

We present a rapid and surfactant-free temperature-assisted synthesis route to prepare γ-cyclodextrin-based metal–organic framework (γ-CD-MOF). The cubic crystals of the CD-MOF with an average edge length of 10–15 μm, specific surface area of 775?m² g^?1 and total pore volume of 0.229?cm³ g^?1 were synthesized in much shorter time than conventional CD-MOFs. To show the efficiency of the synthesized CD-MOF as adsorbent of gas, the uptake of CO₂ at different temperature and pressure was investigated. It is shown that the CO₂ uptake increases with increasing pressure and decreasing temperature. Further microgravimetric investigation on gas adsorption at low pressure demonstrated superior gas uptake (ca. 147?mg g^?1) than previous reports. At the maximum equilibrium pressure, the uptake amounts of CO₂ were found to be 326 and 268?mg g^?1 at 303 and 323?K, respectively. The synthesized CD-MOF has great potential to be used in gas storage and separation applications.

The inclusion complexes of tenofovir disoproxil fumarate (TDF) with p-sulfonato-calix[4]arene (SCX4) and p-sulfanatothiacalix[4]arene (TSCX4) macrocycles are characterized through an array of experiments including ¹H NMR, NOESY, HPLC, HRMS, FT-IR and PXRD in conjunction with the density functional theory. An encapsulation of TDF within SCX4 and TSCX4 macrocycles conduce 1:1 complexes those prevail over 1:2 or 1:3 Stoichiometries which exhibis distinct structural features. A loss of crystallinity accompanying the complexation ascertains the inclusion of the guest within the macrocycle. A comparison of the measured ¹³C NMR spectra of the complexes with individual hosts ascertains the cone conformation of SCX4 in such complexes as in its free state. It has been demonstrated that the TDF guest penetrates deeply within the cavity of SCX4 facilitating the hydrogen bonding interactions between adenine protons and the hydroxyl as well as methylene protons of the macrocycle. The measured ¹H NMR spectra thus reveal large upfield signals (δ 8.35, 8.48?ppm) for adenine protons of the SCX4 complex. On the other hand, the partial encapsulation of TDF in TSCX4 reflects in the deshielding of hydroxyl protons in the measured ¹H NMR spectra. The characteristic C=N and SO stretching vibrations in the infrared spectra engender’frequency shifts’ in the opposite directions compared to the individual host or guest. A simple reverse phase high performance liquid chromatography method is presented. The adenine encapsulation further has been qualitatively correlated with MRSA activities.

In this communication, we reveal that the host compound trans-N,N′-bis(9-phenyl-9-xanthenyl)cyclohexane-1,4-diamine (1,4-DAX) possesses the ability to purify 2-methylpyridine (2MP)/pyridine (PYR) and 3-methylpyridine (3MP)/PYR binary mixtures by enclathrating PYR almost exclusively, even when such mixtures contained as little as approximately 30% PYR. For example, when these solutions were prepared with equimolar quantities of the two guests, complexes contained as much as 92.4 and 96.4% PYR, respectively. Furthermore, 1,4-DAX was capable of forming a mixed complex with as high as 87.8% PYR from an equimolar ternary mixture containing 2MP, 3MP and PYR through host?guest complexation. This work complements that of trans-N,N′-bis(9-phenyl-9-xanthenyl)cyclohexane-1,2-diamine (1,2-DAX) and trans-N,N′-bis(9-phenyl-9-thioxanthenyl)cyclohexane-1,2-diamine (1,2-DAT), disclosed in a previous submission, where 4-methylpyridine (4MP) and 2MP, correspondingly, were the preferred guest solvents. Interestingly, trans-N,N′-bis(9-phenyl-9-thioxanthenyl)cyclohexane-1,4-diamine (1,4-DAT) showed no inclusion tendencies under such conditions. Successfully-formed inclusion complexes were subjected to crystal X-ray diffraction analyses in order to understand the preference of 1,4-DAX for 4MP and PYR. Thermal analyses of these complexes were, however, less informative.

Studies on liquid-liquid extraction and bulk liquid membrane (BLM) technique-based metal ion separation by a previously published Pb²⁺-selective acridono-18-crown-6 ether selector molecule were performed. The effects of the stirring speed, the quality of apolar organic membrane, the counterions of Pb²⁺, the pH of the aqueous phase, the concentration of the source phase, the concentration of the carrier in the BLM and the temperature on the Pb²⁺-separation were investigated. Moreover, the effects of the competitive inhibition due to the presence of Ag⁺, Ca²⁺, Co²⁺, Cu²⁺, K⁺, Mg²⁺, Na⁺ and Zn²⁺ as competing ions in a multicomponent aqueous source phase of different ion-concentrations were also studied. After a proper dilution of the multicomponent aqueous source phase, excellent Pb²⁺-selectivity was achieved without a significant reduction in the efficiency compared to the liquid membrane transport of single-component systems. Based on the BLM-cell studies the applied selector molecule proved to be suitable for the development of liquid membrane-based Pb²⁺-selective separation methods, which can be greatly aided by the analysis of the effects on the separation and by the optimization of the parameters of the process discussed here.

Phototherapy is a type of medical treatment that involves exposure to ultraviolet-visible (UV–Vis) region or near-infrared (NIR) region light to treat certain medical conditions. Compared to other treatment methods such as chemotherapy and radiotherapy, it attracts a lot of attention today due to its lower cost, more effect on the tumor cell, and less side effects. Today's clinical therapy research shows that combining chemotherapeutic methods and phototherapeutic methods on a single nanostructure increases the therapeutic effect that each method alone has, and this is even more effective in destroying cancer cells. The emergence of nanomaterials recently opens up new opportunities to increase therapeutic efficacy and overcome limitations in current phototherapy techniques. Gold nanostars (GNSs) are a kind of promising photothermal agent recently in the biomedical field with its strong absorption in the NIR field, high photothermal conversion efficiency, excellent photothermal stability, and biocompatibility. In this study, the synthesis methods, optical properties of GNSs, and their current studies on cancer diagnosis and treatments are summarized.