Self-Assembly of Metallo-Supramolecules with Dissymmetrical Ligands and Characterization by Scanning Tunneling Microscopy
Asymmetrical and dissymmetrical structures are widespread and play a critical role in nature and life systems. In the field of metallo-supramolecular assemblies, it is still in its infancy for constructing artificial architectures using dissymmetrical bui
Phenothiazine-bridged cyclic porphyrin dimers as high-affinity hosts for fullerenes and linear array of C60 in self-assembled porphyrin nanotube
Free-bases and a nickel(II) complex of phenothiazine-bridged cyclic porphyrin dimers bearing self-assembling 4-pyridyl groups (M2-Ptz- CPDPy(OCn); M = H2 or Ni, OCn = OC6 or OC3) at opposite meso-positions have been prepared as host molecules for fullerenes. The free-base dimer (H4-Ptz- CPDPy(OC6)) includes fullerenes with remarkably high association constants such as 3.9 ± 0.7 × 106 M -1 for C60 and 7.4 ± 0.8 × 107 M-1 for C70 in toluene. This C60 affinity is the highest value ever among reported receptors composed of free-base porphyrins. The nickel dimer (Ni2-Ptz-CPDPy(OC 6)) also shows high affinities for C60 (1.3 ± 0.2 × 106 M-1) and C70 (over 107 M-1). In the crystal structure of the inclusion complex of C 60 within H4-Ptz-CPDpy(OC3), the C60 molecule is located just above the centers of the porphyrins. The two porphyrin planes are almost parallel to each other and the center-to-center distance (12.454 A?) is close to the optimal separation (~12.5 A?) for C60 inclusion. The cyclic porphyrin dimer forms a nanotube through its self-assembly induced by C-H?N hydrogen bonds between porphyrin β-CH groups and pyridyl nitrogens as well as π-π interactions of the pyridyl groups. The C60 molecules are linearly arranged in the inner channel of this nanotube.
Synthesis of shape-persistent macrocycles by a one-pot suzuki-miyaura cross-coupling reaction
Ring creation: Shape-persistent macrocyclic structures were prepared by a one-pot catalyst-transfer Suzuki-Miyaura cross-coupling (CTSMCC) reaction (see figure). The reaction of 3,6-dibromo-substituted carbazoles and diboronic ester monomers afforded shap
Self-association and electron transfer in donor-acceptor dyads connected by meta-substituted oligomers
The synthesis of a new series of electron donor-acceptor conjugates (5, 10, 13, and 16) in which the electron acceptor - C60 - and the electron donor - π-extended tetrathiafulvalene (exTTF) - are bridged by means of m-phenyleneethynylene spacer
Shape-persistant macrocycles with terpyridine units: Synthesis, characterization, and structure in the crystal
The synthesis of a variety of shape-persistent macrocycles with either one (1a-d, 2) or two (opposing) terpyridine units (3, 4, 5a-c) and inner diameters of up to 2 nm is described. The sequences are mainly based on transition metal cross-coupling reactio
Grave, Christian,Lentz, Dieter,Schaefer, Andreas,Samori, Paolo,Rabe, Juergen P.,Franke, Peter,Schlueter, A. Dieter
p. 6907 - 6918
(2007/10/03)
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