Journal of Inclusion Phenomena and Macrocyclic Chemistry最新文献

The effective binding of Rhodamine B (RhB), a xanthene dye, in solutions of amphiphilic sulfobetaine tetrapentylcalix[4]resorcinarene (C₅-SB) at millimolar concentrations has been found. Using the FT-PGSE NMR technique, it was determined that the binding fraction (P_b) of RhB in the solution with a С(RhB)/С(С₅-SB) ratio of 3.75 mM/5 mM was 0.57, whereas in a solution with an order of magnitude lower concentration, the P_b was only 0.12. This significant difference in interaction is also supported by 2D NOESY and ¹H NMR spectra. Based on fluorimetry data, it appears that the influence of C₅-SB on the spectral properties of RhB increases as the C₅-SB/RhB molar ratio increases, but decreases as the concentration of C₅-SB and RhB decreases. By comparing the spectral properties of RhB in the presence of C₅-SB and tetrapentylcalix[4]resorcinarene with carboxylic (C₅-COO⁻) and trimethylammonium (C5-N⁺Me₃) peripheral groups, an assumption about the driving forces behind RhB, which led to an enhancement of the emission properties of the dye, was made. The study demonstrates the possibility of controlling the emissive properties of a xanthene dye by binding it to a supramolecular associate with amphiphilic calix [4] resorcinarene.

Physical manipulation can be carried out on molecules and cells through the utilization of nanomachines which are machines with nano dimensions. There are different types of nanomachines. Among them, rotaxanes stand out as the most well-known. The term of rotaxane originates from the combination of the Latin words wheel and axis. The application of nanomachines is identifying and measuring the concentration of toxic substances in the environment, targeted drug delivery and cancer diagnosis. The objective of this study is to synthesize and identify several new nanomachines in the form of rotaxanes (internally locked molecules) with nanopharmaceutical properties from the corresponding crown compounds. In the first step, 2,2-dimethylphenol was converted into bisphenol compound (1) in reaction with thionyl chloride. Bisphenol compound (1) was converted into methyl diester compound (2) in reaction with methyl chloroacetate. The methyl diester compound (2) reacts with the appropriate diamine to form the diamide macrocycle compound (3). Rod (4) is prepared from the reaction of diethylene glycol ditosylate, 4,4-bipyridine and a bulk phenol such as 4-tert-butylphenol in DMF. Each of the rings in the presence of the prepared rod leads to the corresponding rotaxane compound (5). Chemical structure of the obtained compounds were established by ¹HNMR, ¹³CNMR, FT-IR and SEM spectroscopic methods.

The reaction of a square-planar platinum(II) complex containing two bis(2-diphenylphosphinoethyl)phenylphosphine (triphos), [Pt(triphos)₂](NO₃)₂, with [Au(tu)₂]Cl (tu = thiourea) gave a new trinuclear Au^I₂Pt^II complex, [Pt(triphos)₂{Au(tu)}₂]Cl₂(NO₃)₂, through Au-P coordination. While the [Pt(triphos)₂]²⁺ unit in [Pt(triphos)₂](NO₃)₂ adopted the trans-meso configuration, only the cis-racemic isomer was observed for [Pt(triphos)₂{Au(tu)}₂]Cl₂(NO₃)₂. ³¹P NMR spectroscopy indicated rapid equilibrium among the possible isomers of [Pt(triphos)₂]²⁺, which facilitated the trans-to-cis transformation at the Pt^II center in this system. Additionally, we observed that this structural transformation led to an increase in the emission intensity.

To improve the efficiency of cyclodextrins as carotenoid carriers, the kinetics and thermodynamics of the inclusion complex formation between modified β-cyclodextrin (βCD-NH₂) and β-carotene (βCT) were studied using surface plasmon resonance (SPR) at pH 7.4 and theoretical calculations. The observed dissociation rate of the [βCD-NH₂/βCT]° inclusion complex is small ((2.59times 1{0}^{-1} {text{s}}^{-1})), indicating that βCD-NH₂ only interacted with the βCT ionone group to form inclusion complex. The βCD-NH₂/βCT binding constant is (2.80times 1{0}^{4} text{L} {text{m}text{o}text{l}}^{-1}) (at 298.15 K), and its temperature dependence indicates that the [βCD-NH₂/βCT]° formation is driven by hydrophobic interactions (({Delta }H^circ = 28.83 text{k}text{J} text{m}text{o}{text{l}}^{-1}) and (T{Delta }S^circ = 54.21 text{k}text{J} text{m}text{o}{text{l}}^{-1})) caused mainly by the βCT end group desolvation. In contrast, the formation of the [βCD-NH₂/βCT]^‡ activated complex via association between free molecules and dissociation of [βCD-NH₂/βCT]° occurred with the overcoming of an energy barrier ((E_{a}^{ddag } = 40.77~{text{kJ mol}}^{{ - 1}} ~) and ({E}_{d}^{ddag}=11.94 text{k}text{J} text{m}text{o}{text{l}}^{-1})) and decrease in entropy ((T{varDelta S}_{a}^{ddag}=-11.70 text{k}text{J} text{m}text{o}{text{l}}^{-1}) and (T{varDelta S}_{d}^{ddag}=- 65.92 text{k}text{J} text{m}text{o}{text{l}}^{-1})).

Bone adhesives are known as a promising fracture treatment material because they can quickly heal broken bones. However, the existing bone adhesives have the disadvantages of weak binding ability to bone tissue, non-absorption, or difficulty in curing under wet conditions, which limits their wide application in the field of bone tissue engineering. In this study, the raw material of magnesium phosphate bone adhesive was modified, and the composite material of magnesium phosphate bone repair was prepared by the method of solid–liquid blending crosslinking. Mineral-organic composite, a new type of bone adhesive was prepared using calcined dolomite and montmorillonite as mineral components, phytic acid and gelatin as organic components. The compressive strength, porosity and bonding strength of the magnesium phosphate-based bone adhesive were analyzed by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. When the dosage of dolomite is 8 wt% and the concentration of gelatin is 9 wt%, the adhesion strength of the bone adhesive is 2.04 MPa after 168 h placement. And the compressive strength of the bone adhesive was 6.66 MPa after 168 h placement. After the prepared bone adhesives were immersed in SBF solution for 14 and 21 days, EDS analysis showed that the accumulated material was bone-like hydroxyapatite, indicating that the prepared bone adhesives had good osteogenic activity. In addition, it was also found that the bone adhesive had fluid absorption ability and no cytotoxicity. So, conclusively it can be stated that such newly synthesized bone adhesive has significant medical potential.

In the present work, host compounds trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylate (H1), trans-α,α,α’,α’-tetraphenyl-9,10-dihydro-9,10-ethanoanthracene-11,12-dimethanol (H2) and trans-α,α,α’,α’-tetra(p-chlorophenyl)-9,10-dihydro-9,10-ethanoanthracene-11,12-dimethanol (H3) were assessed for their host ability for anisole (ANI) and 2-, 3- and 4-bromoanisole (2-, 3- and 4-BA). It was demonstrated that H3 formed complexes with each of these guest species, while H1 and H2 only possessed the ability to enclathrate ANI. When H3 was crystallized from equimolar binary guest solutions, a significantly enhanced host affinity was observed for ANI and 3-BA. As examples, equimolar binary ANI/2-BA and 2-BA/3-BA solutions afforded complexes that demonstrated a near-complete H3 selectivity towards ANI (97.5%) and 3-BA (94.5%), respectively. Furthermore, from H3 crystallization experiments in binary ANI/2-BA, ANI/4-BA, 3-BA/2-BA and 3-BA/4-BA mixtures, where the molar guest amounts were varied sequentially, were calculated significant selectivity coefficients (K values), so much so that H3 may be used to separate very many of the guest anisole mixtures prepared in this work, through supramolecular chemistry strategies, which serves as a greener separation protocol compared with tedious and energy intensive fractional distillations. Thermal analyses were also used to investigate the relative stabilities of each of the single solvent complexes.

Functional dyes can interconvert energies, such as light, heat, and electricity, and they have broad applications in various fields. This review highlights our endeavors in the creation of novel photofunctional materials in solution and solid states via molecular assemblies, linkage, and distortion and the integration of supramolecular complex formation and host–guest chemistry. One approach involves the synthesis of solid-state luminescent materials with the use of cocrystals comprising host molecules with dye backbones and guest molecules derived from aromatic compounds. Cocrystal formation is tuned via intermolecular interactions, such as hydrogen bonding, charge-transfer interactions, π-π stacking, and inclusion phenomena of the crystal engineering approach. This state leads to the emergence of properties such as fluorescence, room-temperature phosphorescence, and the potential for applications in optical sensors. In the second approach, functional dyes comprising multidentate ligands with various elements, which results in photofunctional properties in solution and solid states. This method delves into structural characteristics affected by the distortion and torsional angles of multinuclear complexes and their resulting photophysical properties. Multinuclear complexes encompass helical and axial chirality. Here, we discuss the isolation of enantiomers through optical resolution and their subsequent circular dichroism and circularly polarized luminescence characteristics. The position and nature of substituents considerably affected the ground and excited states of the complexes, which led to the formation of unique photofunctional materials. These methodologies offer insightful and effective avenues for the further improvement of the functionality and device applicability of functional dyes.

The interaction between ciprofol and human serum albumin (HSA) was studied using spectroscopy-based approaches at different temperatures under simulated physiological conditions in vitro. Quenching of intrinsic Trp fluorescence of HSA with increasing ciprofol concentration is the actuating tool in the analysis. Experimental results proved that ciprofol quenched the intrinsic fluorescence of HSA through a static quenching mechanism. The thermodynamic parameters (ΔG = -2.35 × 10⁴ J·mol⁻¹, ΔS = -131 J·mol⁻¹·K⁻¹, and ΔH = -6.39 × 10⁴ J·mol⁻¹ at 310 K), binding sites (n = 0.83), and binding constant (K_A = 9.12 × 10³ M⁻¹) indicated that hydrogen bond and van der Waals forces played a major role in the HSA-ciprofol association with weak binding force. Furthermore, the circular dichroism, synchronous, and three-dimensional fluorescence spectral results indicated adaptive structural changes of HSA in the presence of ciprofol. In addition, the effect of some common metal ions on the binding between ciprofol and HSA was examined, and Fe³⁺ and Hg²⁺ were proven to help prolong the storage time and improve the drug efficacy. The study provides accurate and full basic data for clarifying the binding mechanisms of ciprofol with HSA and helps understand its effect on protein function during the blood transportation process and activity in vivo.

Trialkyl-monoacetic acid derivatives of p–t-octylcalix[4]arene and calix[4]arene were prepared to investigate the effect of the alkyl branches attached to the phenoxy oxygen atoms and the p-position on the selective extraction of Li⁺ over Na⁺. Alkyl branches on the phenoxy oxygen atoms remarkably affected the Li⁺ selectivity, whereas those at the p-position had less effect. The former can contribute to excluding Na⁺ extraction while enabling Li⁺ extraction. Optimal selection of the alkyl branch improves the Li⁺ selectivity of calix[4]arene. However, sterically-hindered p–t-octylcalix[4]arene with three 2-ethylbutyl branches exhibited opposite selectivity.