359647-86-2Relevant academic research and scientific papers
Cationic π-electron systems with high quadratic hyperpolarisability
Lambert,Gaschler,N?ll,Weber,Schm?lzlin,Br?uchle,Meerholz
, p. 964 - 974 (2001)
Cationic NLO-chromophores based on tolane π-systems in which conventional electron donors are combined with ionic pyridinio or triorganoammonio and -phosphonio substituents, respectively, perform much better than conventional donor/acceptor-substituted (D/A-substituted) tolanes concerning their hyperpolarisability-transparency trade-off. This effect occurs because ionic acceptors do not enlarge the π-system in contrast to conventional acceptors. The same holds true for benzene-type chromophores. Despite their different electronic nature, the extrapolated maximal high-energy absorption of the ionic chromophore series as well as of the conventional donor/acceptor-tolanes coincide at the absorption energy of unsubstituted tolane. This proves that the maximal blue transparency of a given series of substituted chromophores is governed by the absorption maximum of the unsubstituted parent chromophore. In this way chromophores have been designed with much higher quadratic hyperpolarisability than e.g. p-nitroaniline at about the same absorption wavelength. By applying the same concept, a two- and a three-dimensional highly efficient octupolar NLO-chromophore assembly has also been synthesised.
Light-harvesting macroring accommodating a tetrapodal ligand based on complementary and cooperative coordinations
Kuramochi, Yusuke,Satake, Akiharu,Kobuke, Yoshiaki
, p. 8668 - 8669 (2004)
A porphyrin macroring, mimicking the light-harvesting complex of photosynthetic purple bacteria, was synthesized by self-assembling trisporphyrinatoZn(II) complexes with imidazolyl substituents at both molecular terminals. Very strong complementary coordination of imidazolyl to Zn(II) afforded exclusively the cyclic trimer of trisporphyrin under dilute conditions at 27 °C in CHCl3/MeOH = 9/1 (v/v). 1H NMR spectra of the macroring indicate the existence of two topological isomers, one symmetric and one asymmetric. Use of three noncoordinated porphyrinatoZn(II) sites allows a tetrapodal ligand to be incorporated into the cavity of the macroring. A Job plot and the clear bending behavior on UV-vis titration indicated the formation a 1:1 complex; the heterogeneity of two topological isomers was not observed, and both isomers similarly accommodated the tetrapodal ligand. The association constant obtained by curve fitting analysis was 8 × 108 M-1 in toluene. This large association constant reflects the cooperative nature of three coordination sites. Copyright
Metal-organic microstructures: From rectangular to stellated and interpenetrating polyhedra
Shankar, Sreejith,Balgley, Renata,Lahav, Michal,Cohen, Sidney R.,Popovitz-Biro, Ronit,Van Der Boom, Milko E.
, p. 226 - 231 (2015)
Despite the tremendous progress made in the design of supramolecular and inorganic materials, it still remains a great challenge to obtain uniform structures with tailored size and shape. Metal-organic frameworks and infinite coordination polymers are examples of rapidly emerging materials with useful properties, yet limited morphological control. In this paper, we report the solvothermal synthesis of diverse metal-organic (sub)-microstructures with a high degree of uniformity. The porous and thermally robust monodisperse crystalline solids consist of tetrahedral polypyridyl ligands and nickel or copper ions. Our bottom-up approach demonstrates the direct assembly of these materials without the addition of any surfactants or modulators. Reaction parameters in combination with molecular structure encoding are the keys to size-shape control and structural uniformity of our metal-organic materials.
Fourfold Suzuki-Miyaura and Sonogashira cross-coupling reactions on tetrahedral methane and adamantane derivatives
Schilling, Christine I.,Plietzsch, Oliver,Nieger, Martin,Muller, Thierry,Braese, Stefan
experimental part, p. 1743 - 1754 (2011/05/05)
An efficient way to generate a series of rigid tetrahedral organic building units from common methane and adamantane precursors is presented. Suzuki-Miyaura and Sonogashira cross-coupling reactions are used to effectively generate these shape-persistent m
