Journal of Inclusion Phenomena and Macrocyclic Chemistry最新文献

In the present work, a plausible host candidate is provided for the separation of 3-methylpyridine (3MP) from 4-methylpyridine (4MP), isomers that are extremely difficult to separate by conventional means. Host compound N,N′-bis(9-phenyl-9-xanthenyl)ethylenediamine (H2), when recrystallized from an equimolar mixture of 3MP and 4MP, contained 91.6% 3MP, a significantly improved outcome compared with the alternate host compound N,N′-bis(9-phenyl-9-thioxanthenyl)ethylenediamine (H1) which only enclathrated 70% of this isomer in the same experimental conditions. Single crystal diffraction and thermoanalytical experiments were conducted in order to investigate this preference for 3MP by considering both host⋯guest interactions and relative complex stabilities. Many of the guest components in 3(H2)·5(3MP)·0.268(O) experienced at least one other short contact measuring less than the sum of the van der Waals radii of the involved atoms, an observation that may explain the selectivity of H2 for this guest since this was not the case in complexes containing PYR and 4MP. Results from the thermal analyses were less informative.

A micromachined thin film thermocouple (TFTC), that is, a contact-type temperature sensor, was fabricated to diagnose the physiological state. The TFTC involved two metal films (copper and constantan) with considerably different Seebeck coefficients. Six types of TFTCs with different film thickness values were fabricated and experimentally characterized to determine the thickness-dependent temperature coefficient attesting to a high sensitivity of the sensors. The performance of each TFTC was evaluated by measuring the induced thermal electric motive force and temperature in the temporal and spatial domains by using a data acquisition board and an infrared camera, respectively. Moreover, an in vivo experiment of the proposed TFTC with the highest temperature coefficient (38.9 µV/°C) was conducted by measuring the body temperature difference of an anesthetized porcine model during its euthanasia process to evaluate the device performance.

In recent years, functional materials using cyclodextrin (CD)-based polyrotaxanes have attracted considerable attention, and derivatization reactions are often performed to develop them because of the insolubility of the parent polyrotaxane in water. Recently, we prepared CD-based radial polycatenanes in one-pot through polypseudorotaxane formation between β-CD and thiolated pluronic and subsequent cyclization via disulfide bonds. However, no reports are available on syntheses of CD polycatenane derivatives. The disulfide bonds are not stable enough to synthesize CD polycatenane derivatives; therefore, we herein prepared a chemically stable β-CD polycatenane via amide bond through cyclization of β-CD/aminated pluronic polypseudorotaxane with terephthaloyl chloride. This allowed the derivatization of the polycatenane owing to its stable chemical structure, and resulted in the syntheses of three different water soluble polycatenane derivatives: aminated, succinylated, and hydroxypropylated polycatenanes. These findings may provide useful information for the fabrication of polycatenane-based materials such as slide-ring materials, drug carriers, and biomaterials.

Two compounds, 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), were assessed for their host ability in the presence of four heterocyclic guest species, namely pyridine (PYR), piperidine (PIP), morpholine (MOR) and dioxane (DIO). Each of these guests formed single solvent complexes with both host compounds. When 1,2-DAX and 1,2-DAT were recrystallized from various guest mixtures, it was shown that their selectivity orders were identical, DIO (46.6%) > MOR (23.0%) > PYR (18.9%) > PIP (11.5%) and DIO (85.9%) > MOR (23.7%) > PYR (8.9%) > PIP (8.5%), respectively, but that the thio host derivative possessed a significantly enhanced preference for DIO compared with its oxygen analogue. Additional experiments in order to investigate the various parameters at play in these complexation experiments involved single crystal diffraction experiments and thermal analyses.

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) were recrystallized independently from each of the xylene isomers (o-Xy, m-Xy and p-Xy) and ethylbenzene (EB) to ascertain their host ability for these guest solvents. It was thus shown that both compounds were capable of forming complexes with each guest species. The hosts were then recrystallized from various mixtures of these solvents in order to establish if they possessed any preference for a particular guest species from the series, with the view to possibly offering an alternative separation strategy for such mixtures using host‒guest chemistry principles and 1,2-DAX and/or 1,2-DAT. In so doing, each host compound was revealed to have comparable selectivities, favouring o-Xy and discriminating against p-Xy. This contrasted markedly with earlier findings reported for related host compounds 1,4-DAX and 1,4-DAT, which both preferred p-Xy whilst displaying a bias against o-Xy. We subsequently calculated the void volumes that remained after removal of each of the guest species from the packing calculation and found that the preferred guests always occupied the smallest volumes compared with guests that were less favoured (for complexes of 1,2-DAX, 1,2-DAT, 1,4-DAX and 1,4-DAT). This finding implied that the favoured guest species, here, experienced a tighter packing than any of the other solvents from the series. Additional to this information, data from single crystal diffraction and thermal analyses for each complex are also provided here.

Two coordination polymers, [(bpba)Zn(CH₃COO)₂]_n (1) and [(bpba)₃Cd₂(NO₃)₄]_n·nMeOH·4nH₂O (2) (bpba = bis(4-pyridyl)benzylamine), were obtained using Zn(CH₃COO)₂·2H₂O/Cd(NO₃)₂·4H₂O and bpba in a mixture of solvents, and were further characterized. The zinc(II) ion of 1 showed a tetrahedral geometry with two oxygen atoms of the acetate ligands and two pyridine groups of the bpba ligands, and it is linked to the neighboring zinc(II) ions through the bpba ligands, giving rise to an interesting one-dimensional helical structure. Contrastingly, the cadmium(II) ion of polymer 2 was bonded by three pyridine groups of three different bpba ligands and four oxygen atoms of two nitrate ligands, exhibiting a T-shaped geometry. Thus, polymer 2 forms a two-dimensional wave-like structure by the coordination of cadmium(II) ion and bpba ligand to each other. Polymers 1 and 2 showed strong UV emissions depending on the metal ions and are red-shifted, compared to the bpba ligand.

A demand for a cost-effect and portable methane gas sensor has been increasing since new world-wide greenhouse gas regulations have been aggressively targeting methane emissions. Here, we present a methane sensing device which is made of Cu-BDC on a quartz crystal microbalance (QCM). The Cu-BDC film is simply and rapidly fabricated using a facile intense pulsed light technique for in-situ growth of the film on the QCM. The fabricated sensor is characterized in terms of sensitivity, selectivity, and reproducibility under room temperature and atmospheric pressure. The experimental results show that resonant frequency change is linearly proportional to the methane concentration from 100 to 500 ppm. The fabricated sensor also exhibits higher selectivity for the methane gas compared to volatile organic compounds and water. Five gas sensors were fabricated with the same procedure at the same time and demonstrated good reproducibility.

The present study aims to evaluate the effectiveness of the Transperineal Pelvic Floor Electrical Stimulation (TPFES) system as a treatment option for females with stress urinary incontinence (SUI). A total of 8 females who were diagnosed with SUI were included in the study. All the patients received TPFES and were educated to use it daily for 12 weeks. The patients completed ‘International Consultation on Incontinence Questionnaire-Urinary Incontinence (ICIQ-UI)’ and ‘Overactive Bladder Symptom Score Questionnaire’ before and after applying NPFES at every visit. Age, body mass index (BMI), maximum flow rate, and postvoid residual of each patient were obtained before the study. Repeated-measures ANOVA was performed using the estimates of variables at each visit to evaluate the effectiveness of TPFES in SUI. Also, a linear mixed model was derived to verify the variables that affect the effectiveness of TPFES treatment. The mean age and BMI of the patients were 61.88 ± 16.49 years and 24.62 ± 2.87 kg/m², respectively. Among the investigated variables, the mean ICIQ-UI total score showed significant change depending on the duration of TPFES treatment (p < 0.001); the mean ICIQ-UI total score tended to decrease as the duration of TPFES treatment increases. The post-hoc test revealed a significant decrease of mean ICIQ-UI total score at 8 weeks and 12 weeks compared to the baseline (p = 0.012 and p = 0.005, respectively). Also, the mean ICIQ-UI total score was significantly affected by the treatment duration of TPFES (p = 0.001). Thus, consistent and long-term use of the TPFES system can be a non-surgical treatment option that effectively improves SUI.