EPR Probes with Well-Defined, Long Distances between Two or Three Unpaired Electrons
摘要:
The synthesis of rod- and star-shaped compounds carrying two or three spin labels as end groups is described. The unpaired electrons are 2.8-5.1 nm apart from each other. The shape-persistent scaffolds were obtained through Pd-Cu-catalyzed alkynyl-aryl coupling and Pd-Cu-catalyzed alkyne dimerization in the presence of oxygen using p-phenyleneethynylene as the basic shape-persistent building block. The spin label 1-oxyl-2,2,5,5-tetramethylpyrroline-3-carboxylic acid (4) was attached through esterification of the terminal phenolic OH groups of the scaffold.
Dead-Time Free Measurement of Dipole–Dipole Interactions between Electron Spins
作者:M Pannier、S Veit、A Godt、G Jeschke、H.W Spiess
DOI:10.1006/jmre.1999.1944
日期:2000.2
improved signal-to-noise ratio. Tests on two nitroxide biradicals with known length indicate that the accessible range of distances extends from about 1.5 to 8 nm. The four-pulse DEER spectra of an ionic spin probe in an ionomer exhibit features due to probe molecules situated both on the same and on different ion clusters. The former feature provides information on the cluster size and is inaccessible with
The synthesis of rod- and star-shaped compounds carrying two or three spin labels as end groups is described. The unpaired electrons are 2.8-5.1 nm apart from each other. The shape-persistent scaffolds were obtained through Pd-Cu-catalyzed alkynyl-aryl coupling and Pd-Cu-catalyzed alkyne dimerization in the presence of oxygen using p-phenyleneethynylene as the basic shape-persistent building block. The spin label 1-oxyl-2,2,5,5-tetramethylpyrroline-3-carboxylic acid (4) was attached through esterification of the terminal phenolic OH groups of the scaffold.
Synthesis of Luminescent Rod−Coil Block Copolymers Using Atom Transfer Radical Polymerization
作者:P. K. Tsolakis、J. K. Kallitsis、A. Godt
DOI:10.1021/ma020256k
日期:2002.7.1
The synthesis of luminescent rod−coil diblock and coil−rod−coil triblock copolymers containing oligo(p-phenyleneethynylene) as the rodlike block and polystyrene as the coil was achieved via atom transfer radical polymerization using oligo(p-phenyleneethynylene)s as the initiators substituted with 2-halogenopropionyloxy or 4-(bromomethyl)benzyloxy groups.