Guest Chemistry (guest + chemistry)

Distribution by Scientific Domains


Selected Abstracts


Dual Stimuli-Responsive Supramolecular Polypeptide-Based Hydrogel and Reverse Micellar Hydrogel Mediated by Host,Guest Chemistry

ADVANCED FUNCTIONAL MATERIALS, Issue 4 2010
Yi Chen
Abstract Versatile strategies are currently being discovered for the fabrication of synthetic polypeptide-based hybrid hydrogels, which have potential applications in polymer therapeutics and regenerative medicine. Herein, a new concept,the reverse micellar hydrogel,is introduced, and a versatile strategy is provided for fabricating supramolecular polypeptide-based normal micellar hydrogel and reverse micellar hydrogels from the same polypeptide-based copolymer via the cooperation of host,guest chemistry and hydrogen-bonding interactions. The supramolecular hydrogels are thoroughly characterized, and a mechanism for their self-assembly is proposed. These hydrogels can respond to dual stimuli,temperature and pH,and their mechanical and controlled drug-release properties can be tuned by the copolymer topology and the polypeptide composition. The reverse micellar hydrogel can load 10% of the anticancer drug doxorubicin hydrochloride (DOX) and sustain DOX release for 45 days, indicating that it could be useful as an injectable drug delivery system. [source]


Calix[6]pyrrole and Hybrid Calix[n]furan[m]pyrroles (n + m = 6): Syntheses and Host,Guest Chemistry.

CHEMINFORM, Issue 44 2002
Grazia Cafeo
No abstract is available for this article. [source]


Self-Assembly and Host,Guest Chemistry of a 3.5-nm Coordination Nanotube

CHEMISTRY - AN ASIAN JOURNAL, Issue 4 2007
Takumi Yamaguchi
Abstract Upon complexation with PdII ions, precisely designed strandlike ligands with two tris(3,5-pyridine) units at both terminals were assembled, with the aid of a linear template molecule, into a discrete tubular complex with a length of 3.5,nm. The high stability and the well-defined structure of the coordination nanotube were revealed by NMR spectroscopy, cold-spray ionization MS, and single-crystal X-ray analysis. Guest lengths were discriminated by the tube: When the association of strandlike guest molecules, in which two biphenylene units are linked with an (OCH2CH2)n linker, were compared, the tube selectively recognized an appropriate guest whose length was comparable to that of the tube. Tetrathiafulvalene (TTF)-terminated linear guests were directly oxidized to TTF2+ in the tube, but reduced stepwise via TTF+, outside the tube. [source]


Dual Stimuli-Responsive Supramolecular Polypeptide-Based Hydrogel and Reverse Micellar Hydrogel Mediated by Host,Guest Chemistry

ADVANCED FUNCTIONAL MATERIALS, Issue 4 2010
Yi Chen
Abstract Versatile strategies are currently being discovered for the fabrication of synthetic polypeptide-based hybrid hydrogels, which have potential applications in polymer therapeutics and regenerative medicine. Herein, a new concept,the reverse micellar hydrogel,is introduced, and a versatile strategy is provided for fabricating supramolecular polypeptide-based normal micellar hydrogel and reverse micellar hydrogels from the same polypeptide-based copolymer via the cooperation of host,guest chemistry and hydrogen-bonding interactions. The supramolecular hydrogels are thoroughly characterized, and a mechanism for their self-assembly is proposed. These hydrogels can respond to dual stimuli,temperature and pH,and their mechanical and controlled drug-release properties can be tuned by the copolymer topology and the polypeptide composition. The reverse micellar hydrogel can load 10% of the anticancer drug doxorubicin hydrochloride (DOX) and sustain DOX release for 45 days, indicating that it could be useful as an injectable drug delivery system. [source]


Organic,inorganic hybrid mesoporous silicas: functionalization, pore size, and morphology control

THE CHEMICAL RECORD, Issue 1 2006
Sung Soo Park
Abstract Topological design of mesoporous silica materials, pore architecture, pore size, and morphology are currently major issues in areas such as catalytic conversion of bulky molecules, adsorption, host,guest chemistry, etc. In this sense, we discuss the pore size-controlled mesostructure, framework functionalization, and morphology control of organic,inorganic hybrid mesoporous silicas by which we can improve the applicability of mesoporous materials. First, we explain that the sizes of hexagonal- and cubic-type pores in organic,inorganic hybrid mesoporous silicas are well controlled from 24.3 to 98.0, by the direct micelle-control method using an organosilica precursor and surfactants with different alkyl chain lengths or triblock copolymers as templates and swelling agents incorporated in the formed micelles. Second, we describe that organic,inorganic hybrid mesoporous materials with various functional groups form various external morphologies such as rod, cauliflower, film, rope, spheroid, monolith, and fiber shapes. Third, we discuss that transition metals (Ti and Ru) and rare-earth ions (Eu3+ and Tb3+) are used to modify organic,inorganic hybrid mesoporous silica materials. Such hybrid mesoporous silica materials are expected to be applied as excellent catalysts for organic reactions, photocatalysis, optical devices, etc. 2006 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 32,42; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20070 [source]


A two-dimensional network formed by self-associating silver(I) perchlorate with 3-[4-(2-thienyl)-2H -cyclopenta[d]pyridazin-1-yl]benzonitrile

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2009
Xiao-Yan Li
In the organometallic silver(I) supramolecular complex poly[[silver(I)-,3 -3-[4-(2-thienyl)-2H -cyclopenta[d]pyridazin-1-yl]benzonitrile] perchlorate methanol solvate], {[Ag(C18H11N3S)](ClO4)CH3OH}n, there is only one type of AgI center, which lies in an {AgN2S,} coordination environment. Two unsymmetric multidentate 3-[4-(2-thienyl)-2H -cyclopenta[d]pyridazin-1-yl]benzonitrile (L) ligands link two AgI atoms through ,,AgI interactions into an organometallic box-like unit, from which two 3-cyanobenzoyl arms stretch out in opposite directions and bind two AgI atoms from neighboring box-like building blocks. This results in a novel two-dimensional network extending in the crystallographic bc plane. These two-dimensional sheets stack together along the crystallographic a axis to generate parallelogram-like channels. The methanol solvent molecules and the perchlorate counter-ions are located in the channels, where they are fixed by intermolecular hydrogen-bonding interactions. This architecture may provide opportunities for host,guest chemistry, such as guest molecule loss and absorption or ion exchange. The new fulvene-type multidentate ligand L is a good candidate for the preparation of Cp,AgI -containing (Cp is cyclopentadienyl) organometallic coordination polymers or supramolecular complexes. [source]