We examined the transistor properties of an N,N′-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C 8 )/quaterrylene (QT) heteromolecular layer, in which the highly ordered molecular layers were stacked on the monolayer level. Ambipolar behavior was clearly observed when behaving as a fiel...
Fluorescence intensity correlation functions of single terrylene molecules in p-terphenyl crystals were measured within the temperature range 5–300K. The analysis provided the population (k 23 ) and depopulation (k 31 ) intersystem crossing (ISC) rate constants of the lowest exc...
Thermal evolution of fluorescence intensity correlation functions of single molecules of terrylene in a p-terphenyl crystal was studied and double-exponential decay at 5K was found to change to a mono-exponential decay above 17.5K. Such behavior was attributed to spin–lattice relaxation (SLR), ...
We have developed an experimental setup with a 3 He bath cryostat for picosecond photon echo (PE) measurements in a broad range of temperatures. In this Letter, a two-pulse PE investigation of the amorphous polymer polyisobutylene (PIB) doped with tetra-tert-butylterrylene (TBT) in the t...
Three helicenes based on a borylated arylisoquinoline skeleton have been prepared in their enantiopure forms and characterized with respect to their photophysical properties, including the use of chiroptical spectroscopies. The dyes show varying charge‐transfer characteristics and efficient emi...
Novel azine‐helicene hybrids (pyridine‐, pyrazine‐ and quinoxaline‐fused along the central ring [5]helicenes) have been prepared in good overall yields through a five‐step synthetic sequence. Commercially available 2,3‐dihaloazines were used as starting materials. To discern the effect of ...
An efficient and convenient synthesis of partially hydrogenated functionalized [5]helicenes and oxa[5]helicenes, such as (1,2,5,6‐tetrahydro‐3‐oxadibenzo[c,g]phenanthren‐4‐ylidene)acetonitriles 6 and (5,6‐dihydro‐3‐oxadibenzo[c,g]phenanthren‐4‐ylidene)acetonitriles 8, has been develope...
J. Crassous et al. zeigen in ihrer Zuschrift auf S. 5896 ff., wie die cis‐trans‐Isomerie von [PtIICl2(4‐Aza[6]helicen)PPh3] durch racemische und enantiomerenreine Formen des 4‐Aza[6]helicen‐Liganden gesteuert wird.
New carbo[6]helicene derivatives grafted with π‐conjugated cyano‐phenyl arms were synthesized in enantiopure forms and their π‐conjugation examined by UV–vis spectroscopy. The influence of the π‐conjugation on the circular dichroism spectra and molar rotations is discussed based on compa...
Two 1‐[6]helicenol derivatives were synthesized by Ni‐catalyzed [2+2+2] cycloaddition on a multigram scale. Both enantiomers of the 1‐[6]helicenols could be efficiently prepared by simple optical resolution. As a synthetic application of helically chiral 1‐[6]helicenols, a novel class of [6]...
Methods are proposed for the synthesis of 1,2-epoxy-4-pentene and 1,2,4,5-diepoxy-pentane on the basis of the hydroperoxide oxidation of 1,4-pentadiene. Physicochemical characteristics of 1,2-epoxy-4-pentene that have not been given in the literature are presented.
Semiempirical calculations on cyclomaltoheptaose (βCD), 1,7-dioxaspiro[5.5]undecane (1), nonanal (2), and the inclusion complexes of βCD with 1 and 2 were carried out using the AM1 method. The structure of βCD after complete geometry optimization was in very good agreement with crystallograp...
The crystal structure of the 1 : 1 inclusion complex of hexakis(2,3,6-tri-O-methyl)- α-cyclodextrin (TM αCD) with 1,7-dioxaspiro[5.5]undecane (spiroacetal) is orthorhombic, space group C2221, with a = 24.002(2), b = 14.812(1), c = 21.792(2) Å V = 7747.3(11) Å3 and Z = 8. The molecular six-fold...
Lewis acid-promoted triethylsilane reduction of 6,6-spiroketal alcohols produces cis-2,6-disubstituted tetrahydropyrans with excellent regioselectivity and stereocontrol. An appended alcohol allows bidentate coordination of the Lewis acid to selectively activate one C-O bond of the anomeric cen...
A divergent synthesis of 1- and 5-substituted 3,9-diazaspiro[5.5]undecanes and undecan-2-ones is described, in which the key step is an efficient Michael addition of a lithium enolate to a tetrasubstituted olefin acceptor. A variety of substituents (butyl, phenyl, and propoxyl) were introduced a...
The synthesis and biological activity of novel glycoprotein IIb-IIIa antagonists containing the 3,9-diazaspiro[5.5]undecane nucleus are described. The potent activity of these compounds as platelet aggregation inhibitors demonstrates the utility of the spirocyclic structures as a central templat...
Construction of 3,9-diazaspiro[5.5]undecane derivatives can be easily achieved via intramolecular spirocyclization of 4-substituted pyridines. The reaction entails in situ activation of the pyridine ring with ethyl chloroformate followed by intramolecular addition of an attached β-dicarbonyl nu...
Two novel fatty acids with cPLA 2 inhibitory activity, pinnaic acid and tauro-pinnaic acid, were isolated from the Okinawan bivalve Pinna muricata. Their structures, including the relative stereochemistry at C5, C9, C13 and C14, were elucidated by extensive 2D NMR spectroscopic analysis.
Sulfone 15, derived from d-glutamic acid, and aldehyde 23, made by diastereoselective alkylation, were linked and elaborated into enamine sulfone 33. This underwent 5-exo radical cyclization to 34, which was desulfonylated to (-)-35, a compound that represents the spirobicyclic core of halichlo...
A versatile, operationally simple and highly efficient one-pot three-component approach for the synthesis of spiro oxazolidine oxindole derivatives has been developed by the domino reaction of isatins, arylacetylenes, and N-tosyl aldimines in acetonitrile catalyzed by InBr 3 at ambient t...
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