An Investigation into the Role of Capping on Second Harmonic Generation from Nonlinear Organic Polymer and Guest-Host Thin Films by In-Situ Poling

In attempts to fabricate thermally stable second-order nonlinear polymer thin films, we have investigated the second harmonic generation (SHG) from both nonlinear polymer and guest-host thin films. We have also investigated the role of capping on the SHG, temporal stability and relaxation of dipole alignment. Corona poling techniques were employed to orient the dopants into the noncentrosymmetric structure required to obtain the SHG. The effect of capping with a polymeric encapsulant below the glass transition temperature of the polymers on the unpoled and corona poled thin films was studied. Capping of the nonlinear polymer and guest host thin films have resulted in high SHG with good temporal stability. SHG signal falls drastically during the first 8 days after poling while no further significant decay in SHG signal was observed after about 33 days. Our investigations have identified the characteristics required for a good encapsulant on a non-con-ductive surface.

Formation and Properties of Organic Long Persistent Luminescence Crystals Containing Benzidine Derivatives by Melt Crystallization

Organic molecules that exhibit long persistent luminescence (LPL) are rapidly gaining attention for a variety of applications. In this study, organic molecules with simple structures were selected and organic long persistent luminescence (OLPL) crystals were prepared. The crystal structure of the prepared OLPL crystal was elucidated and the guideline for the design of OLPL crystal was clarified. LPL was observed in OLPL crystals prepared with TMB as the guest molecule and 1,2-bis(diphenylphosphino)ethane as the host molecule. XRD measurements of the OLPL crystals suggest that the guest molecule is a solid solution substituted in the stable crystal structure of the host molecule in a lattice-shrinking direction.

Preparation, Characterization and Optical Properties of Host-guest Nanocomposite Material Mordenite-silver Iodide

Silver iodide nanoclusters were successfully prepared in the channels of mordenite by a heat diffusion method. Powder X ray diffraction, adsorption technique and infrared spectroscopy were used to characterize the prepared materials, which showed that the guest silver iodide had been encapsulated in the channels of mordenite. The optical properties of the solid phase diffuse reflectance absorption of nanocomposite material NaM AgI were studied, showing that the absorption bands of the diffuse reflectance absorption of the prepared material moved to the region of high energy. The absorption peak of the material prepared shifted to the region of high energy. Namely, blue shift was caused. This has demonstrated the incorporation of silver iodide into the channels of the zeolite. We observed the luminescence and surface photovoltage spectra of NaM AgI sample, proposing the mechanisms of the photoluminescence and photovoltaic responses.

Lattice dynamics study of low energy guest-host coupling in clathrate hydrate

Our lattice dynamics simulation of Xe-hydrate with four-site TIP4P oxygen-shell model can accurately reproduce each peak position in the inelastic incoherent neutron scattering spectrum at the acoustic band （below 15 meV） and yield correct relative intensity. Based on the results, the uncertain profile at ～6 meV is assigned to anharmonic guest modes coupled strongly to small cages. Blue shift is proposed in phonon dispersion sheet in the case of anticrossing and found to be an evident signal for guest-host coupling that explains the anomalous thermal conductivity of clathrate hydrate.

Highly Luminescent Host-Guest Systems Based on Zeolite L and Lanthanide Complexes

Supramolecular incorporation of lanthanide complex has been obtained by loading of organic ligand into Eu3+-exchanged zeolite L. This was achieved by a two-step procedure: (1) zeolite L was ion-exchanged with Eu(Ⅲ) ions; (2) organic ligand was then loaded into the channels of the Eu3+-exchanged zeolite by gas diffusion procedure. Loading of ligand into the channels of zeolite L was confirmed by element analysis. Luminescence spectroscopy has confirmed that lanthanide complex are formed in the nanochannels of zeolite L crystals. In addition to the sharp emissions of lanthanide ions, broad band ranged from 350～500 nm can also be observed. This study provides alternative method for fabricating full-color display materials.

Host-guest interaction of β-cyclodextrin with isomeric ursolic acid and oleanolic acid:physicochemical characterization and molecular modeling study

Ursolic acid(UA) and oleanolic acid(OA) are insoluble drugs. The objective of this study was to encapsulate them into β-cyclodextrin(β-CD) and compare the solubility and intermolecular force of β-CD with the two isomeric triterpenic acids. The host-guest interaction was explored in liquid and solid state by ultraviolet-visible absorption,1H NMR, phase solubility analysis, and differential scanning calorimetry, X-ray powder diffractometry, and molecular modeling studies. Both experimental and theoretical studies revealed that β-CD formed 1: 1 water soluble inclusion complexes and the complexation process was naturally favorable. In addition, the overall results suggested that ring E with a carboxyl group of the drug was encapsulated into the hydrophobic CD nanocavity. Therefore, a clear different inclusion behavior was observed, and UA exhibited better affinity to β-CD compared with OA in various media due to little steric interference, which was beneficial to form stable inclusion complex with β-CD and increase its water solubility effectively.

Interaction between Hosts and Guests of Rural Tourism in Northeast China Based on Symbolic Interaction Theory

With constant economic development and continuous improvement of living standards in Northeast China,rural tourism,as a new type of tourism,is increasingly favored. From the perspective of symbolic interaction theory,taking the current situation of rural tourism in Northeast China as an example,this paper explained the semiotic significance between hosts and guests in rural tourism. It established the evaluation indicators for authentic symbolic perception of rural tourism. Also,combined with the theories of sociology and anthropology,it studied the interaction between hosts and tourists of rural tourism in Northeast China.

A Spectrophotometric Study on the Host-Guest Complexation of β-Cyclodextrin with 3-Indolyl Acetate in Dilute Aqueous Solution by Determining Solubility of Guest Substance

3-Indolyl acetate can be soluhilized in dilute aqueous solution of beta cy clodextrin. dueto the formation of host-guest complex through hydrophobic interaction between the indolyl groupand the inside cave of the cyclodextrin molecule. The thermodynamic pararneters of thecomplexing process can be estimated utilizing the spectrophotometric data.

Characteristic Studies of Arylated β-Cyclodextrins in Host-Guest Complexation with Small Molecules

The aryl moiety which was bonded as a functional group on the primary alcohol side ofβ-CD or the secondary alcohol side of β-CD or the secondary alcohol side of β-CD with anethylenediamino chain could show remarkable different molecular recognition abilities in thecomplexation with small molecular guests such as alkanes, cycloketones etc.

Synthesis and Characterization of the Host-Guest NanocompositeMaterial Zeolite Y-Iron Bipyridine

This paper reports the synthesis of host-guest nanocomposite material [Fe(bpy)(3)]Y2+ (where bpy=2,2'-bipyridine) using the flexible ligand method. X-ray diffraction analysis. adsorption technique, and cyclic voltammetry were used to characterize the material. The results show that [Fe(bpy)(3)](2+) has been entrapped in the supercage of zeolite, its electron transfer is realized by electron hopping of [Fe(bpy)(3)](2+) within the supercage of zeolite.

In-situ-selective-UV crosslinking fabrication of solid liquid host guest electrolyte: A facile one-step method realizing highly flexible electrochromic device

Flexible electrochromic devices (FECDs) are promising candidates for the next generation of wearable electronics due to their low operating voltage and energy consumption. For the flexible electrochromic devices, the electrolyte is an important component. Typically, the electrolyte needs to be formulated according to the device structure and usage scenario. A high-performance electrolyte involves consideration of many factors, including choosing the right polymer, solvent, curing agent, and ion type to satisfy particular device specifications. In this work, a ultraviolet-curable solid–liquid host–guest (UV-SLHG) electrolyte is developed. Several aspects of performance are improved by introducing the solid–liquid coexisting microstructure without changing the electrolyte formulation, including excellent adhesion, a 30% increase in tensile characteristics, and a seven-fold increase in ionic conductivity when compared to a fully cured solid-state electrolyte. More importantly, the unique advantage of SLHG electrolytes lies that the thickness will not change significantly during bending. The FECD made by using the UV-SLHG-based electrolyte sustained 10,000 bending cycles at the bending radius of 2.5 mm while maintaining outstanding optical modulation. A wearable ring-type ECD and a battery-free FECD wine label were made as demonstrators. The UV-SLHG strategy is not only suitable for the FECDs but also universally applicable to other electrolyte-based of flexible electronics such as flexible capacitors and batteries.

Chalcogenoviologen Enhanced Host–Guest Recognition

In the field of supramolecular chemistry,cyclophanes with novel properties are highly sought after since they can be tailored to fulfill specific tasks.In this article,we incorporate chalcogenoviologen-based units into tetracationic cyclophanes,resulting in enhanced host–guest recognition.The cyclophanes can be tuned through the addition of chalcogen bridging atoms—S,Se,and Te—which enhance their rigidity,regulate bond rotation and introduce additional steric bulk.Three cyclophanes containing chalcogen bridging atoms were synthesized and characterized in both the solution and solid states.The energy barriers for their interconversion between syn-and anti-conformations in solution were found to be correlated with chalcogen atom size.The photophysical properties of the cyclophanes are strongly dependent on the chalcogen atomic number,with intersystem crossing rates increasing from S to Se to Te.UV–vis-NIR spectroscopic and fluorometric titrations revealed that the chalcogenoviologenbased cyclophanes exhibit significantly stronger binding with electron-rich guests compared to the well-known,unsubstituted cyclobis(paraquat-pphenylene).This enhancement in binding can be attributed to restricted rotation within the chalcogenoviologen units.This research provides insight into the rational design and tailored synthesis of cationic cyclophanes.

Theoretical Study on the Conformational Conversion of 1,3-Dioxane Inside a Capsular Host

The mechanism for the conformational conversion of 1,3-dioxane guest encapsulated inside a capsular host was theoretically investigated using semiempirical PM3 method and DFT methods. The free-state process of the conformational conversion of 1,3-dioxane was also investigated to make a comparison between the two different states using the same theory. The influences of the inner phase of the capsule on the conformational conversion of guest molecule were discussed via analyzing the comparative results. It was found that the capsular host could accommodate 1,3-dioxane within its cavity by the weak attractive interactions between host and guest, and it responds to the conformational conversion of guest by the deformation of hydrogen-bonding seam at the middle of the capsule. When entrapped in the capsule, the guest molecule undergoes the conformational conversion from chair form to twist-boat form slower than that under the free condition. The deformation of the capsule is favorable to maximize the attractive interactions between host and guest.

Synthesis and Enhanced Guest-Binding Affinities of Dendrimer-Based Cyclophane Tetramer and Octamer

Dendritic cyclophane tetramer and octamer were prepared by aminolysis of succinimidyl ester derivative of tetraaza [6.1.6.1] paracyclophane with the corresponding poly(amidoamine) dendrimers as a scaffold, followed by removal of the protecting groups. The present cyclophane tetramer and octamer showed enhanced guest-binding affinities toward fluorescent guests such as 6-p-toluidinonaphthalene-2-sulfonate and 6-anilinonaphthalene-2-sulfonate, in comparison with those of monocyclic cyclophane, reflecting multivalency effects in macrocycles.

Synthesis of Branch-Type Cyclophane Tetramers Having a Multivalently Enhanced Guest-Binding Ability

A cationic branch-type cyclophane tetramer (1a) was synthesized by introducing three Boc-protected cyclophane derivatives into a N-acetylated tetraaza[6.1.6.1]paracy-clophane derivative as a core skeleton through DCC condensation, followed by removal of the external Boc-protecting groups. Cationic cyclophane tetramer 1a exhibited a high affinity toward an anionic and hydrophobic fluorescent guest, TNS, with binding constant of 4.8 × 105 M-1. This value of 1a was about 80-fold larger than that of the corresponding monomeric cyclophane for the identical guest, reflecting multivalent effect on the guest binding. As for electrostatic recognition, the obtained binding constant of 1a was one order of magnitude larger than that of an analogous anionic cyclophane tetramer (1b) for the identical guest. These enhanced guest-binding abilities of 1a were easily evaluated by fluorescence titration experiments.

Synthesis of a Rhodamine-Appended Cyclophane as a Fluorescence Host in Water

A cationic water-soluble cyclophane (1a) having a rhodamine moiety as a red-fluorescence fluorophore was prepared by reaction of a monoamine derivative of tetraaza[6.1.6.1]paracyclophane having three N-t-butoxycarbonyl-β-alanine residues with rhodamine B isothiocyanate, followed by removal of the protecting groups. The guest-binding behavior of 1a toward anionic guests such as dabsyl derivative and 4-(1-pyrene)butanoate was investigated by fluorescence spectroscopy. The results suggested the formation of host-guest complexes with a stoichiometric ratio of 1:1 and the binding constants (K) of the host-guest complexes were evaluated.

Synthesis and Guest-Binding Behavior of Water-Soluble Cyclophanes Bearing PEG Residues

A water-soluble cyclophane (1) having poly(ethylene glycol) (PEG) moieties has been prepared from a tetraazide-functionalized cyclophane derivative and four poly(ethylene glycol) methyl ether acetylenes by Cu(I)-catalyzed 1,3 dipolar cycloadditions (click chemistry). An analogous derivative having a pyrene moiety (2) was also prepared in a similar manner. The guest-binding behavior of 1 and 2 toward anionic guests such as 6-p-toluidinonaphthalene-2-sulfonate was investigated by fluorescence spectroscopy. The binding constants (K) of the host-guest complexes were evaluated.

大孔Mo-Ni/Al_2O_3催化剂的催化裂化柴油加氢性能研究

采用三次纳米自组装合成法,制备了一种以二次纳米自组装Al2O3为主体的大孔主客体催化剂FA-40,具有0.78 cm3· g-1的孔容、114 m2·g-1的比表面积、27 nm的平均孔径、6.0 nm和40 nm的双峰孔结构、孔分布在10～100 nm高度集中、低堆积密度为0.56 g·cm-3、活性金属含量高达35.70％.XRD和TEM分析结果显示,活性金属以直径小于2 nm的微晶态纳米粒子形式均匀分散于主体表面.采用劣质催化裂化柴油进行20 h加氢实验评价,反应趋于稳定时,FA-40的脱硫、脱氮及芳烃饱和率分别达到94.4％、95.5％和67.9％,与F-5相比分别提高了20％、80％和140％.300 h的长周期加氢实验表明,FA-40具有良好的加氢性能.

钴(Ⅲ)-胺配合物模板导向合成新型草酸盐化合物[Co(dien)_2][NaCo_2(C_2O_4)_4]·H_2O

以Co(dien)2.Cl3为模板剂,在水热条件下导向合成出新型草酸盐化合物[Co(dien)2].[NaCo2(C2O4)4].H2O,并通过X射线单晶结构分析、元素分析、ICP以及X射线粉末衍射分析对该化合物的结构进行了表征.结果表明,该化合物结构属于单斜晶系,C2/c空间群,晶胞参数a=1.3805(3)nm,b=1.3017(3)nm,c=1.5913(3)nm,β=104.41(3)°,V=2.7695(10)nm3,Z=4.在该化合物的结构中,Co2+先与草酸基团相互交替连接形成一个常见的链状结构基元[Co(C2O4)2]2nn-,这些链状结构基元进一步被分布于链间的Na+连接成三维开放骨架结构[NaCo2(C2O4)4]3nn-.金属配合物离子Co(dien)23+存在于孔道中起模板剂的作用.

光致发光主客体配合物[Au_2(μ-PNP)_3](ClO_4)_2的谱学研究

光致发光配合物[Au_2(μ-PNP)_3](ClO_4)_2(PNP=2,6-双二苯基膦吡啶)具有一个空腔,作为一个主体配合物,当客体分子尺寸和性质特点匹配时,主客体分子相互作用,主体配合物光致发光性能和谱学性质发生变化.利用电子吸收光谱、^(31)P核磁共振波谱、发射光谱等方法,对不同客体分子存在下,配合物光物理性质改变情况作了深入的讨论.