One-step covalent grafting of Fe<sub>4</sub>single-molecule magnet monolayers on gold
作者:Maria Jesus Rodriguez-Douton、Matteo Mannini、Lidia Armelao、Anne-Laure Barra、Erik Tancini、Roberta Sessoli、Andrea Cornia
DOI:10.1039/c0cc04583g
日期:——
Iron(III)-based single-molecule magnets have been covalently grafted on Au(111) in one step using 1,2-dithiolan-3-yl side groups. Reaction with the substrate quantitatively affords a monolayer of electronically intact clusters doubly linked to the surface via Au–S bonds, as demonstrated by a combination of STM, XAS/XMCD and XPS studies.
Synthesis and structure of 2-aryl-5,5-disubstituted-1,3-dioxanes and conversion into chiral (1,1,1-trishydroxymethyl) methane derivatives
作者:John M Gardiner、Paul Mather、Ramy Morjan、Robin G Pritchard、John E Warren、Malcolm L Cooper、Abd El-Rahman S Ferwanah、Omar S Abu-Tiem
DOI:10.1016/s0040-4039(02)00176-4
日期:2002.3
Pentaerythritol, (1,1,1-trishydroxymethyl)methyl methane and ( 1, 1,1-trishydroxymethyl)nitro methane are converted into 2-aryl-5.5-bis(hydroxymethyl), 2-aryl-5-hydroxymethyl-5-methyl- or 2-aryl-5-hydroxymethyl-5-nitro-1,3-dioxanes and a range of derivatives. X-Ray and NMR analysis establishes that the latter is obtained as a single diastereomer whose structure is unambiguously determined. These materials can be elaborated to chiral derivatives of the starting (1.1.1-trishydroxymethyl) methanes. (C) 2002 Elsevier Science Ltd. All rights reserved.
Rapid Library Synthesis of Amphiphiles Based On a Dioxinone Scaffold and Identification of Nonlamellar Liquid Crystals
Linear and branched amphiphiles with different lengths of lipids and different numbers of hydroxyl groups were rapidly synthesized based on a dioxinone scaffold. The liquid crystalline (LC) properties of the synthesized amphiphiles in excess water were investigated by polarizing optical microscopy and small-angle X-ray scattering (SAXS) analysis. Novel -keto ester based amphiphiles that formed non-lamellar, inverted LC phases were identified.
Self-Assembly of Molecular Dumbbells into Organized Bundles with Tunable Size
Dumbbell-shaped molecules consisting of three biphenyls connected through vinyl linkages as a conjugated rod segment and aliphatic polyether dendritic wedges with different cross-sections (i.e., dibranch (1), tetrabranch (2) and hexabranch (3)) were synthesized and characterized. The molecular dumbbells self-assemble into discrete bundles that organize into three-dimensional superlattices. Molecule 1, based on a dibranched dendritic wedge, organizes into primitive monoclinic-crystalline and body-centered, tetragonal liquid crystalline structures, while molecules 2 and 3, based on tetra- and hexabranched dendritic wedges, respectively, form only body-centered, tetragonal liquid crystalline structures. X-ray diffraction experiments and density measurements showed that the rod-bundle cross-sectional area decreases with increasing cross-section of the dendritic wedges. The influences of supramolecular structure on the bulk-state optical properties were investigated by measuring the UV/Vis absorption and steady state fluorescence spectroscopies. As the cross-section of the dendritic wedge of the molecule increases, the absorption and emission maxima shift to higher energy. This can be attributed to a quantum size effect of the three-dimensionally confined nanostructure.
PADIAS, ANNE BUYLE;HALL, H. K., JR.;TOMALIA, DONALD A.;MCCONNELL, J. R., J. ORG. CHEM., 52,(1987) N 24, 5305-5312
作者:PADIAS, ANNE BUYLE、HALL, H. K., JR.、TOMALIA, DONALD A.、MCCONNELL, J. R.