@phdthesis{Kurth2002, author = {Kurth, Dirk G.}, title = {Self-assembly of hierachically structured architectures of metallo-supramolecular modules}, pages = {179 S.}, year = {2002}, language = {en} } @article{BodenthinGrenzerLauteretal.2002, author = {Bodenthin, Yves and Grenzer, J{\"o}rg and Lauter, Robert and Pietsch, Ullrich and Lehmann, Pit and Kurth, Dirk G. and M{\"o}hwald, Helmuth}, title = {Temperature and time resolved x-ray scattering at thin organic films}, year = {2002}, language = {en} } @article{PietschBodenthinGrenzeretal.2005, author = {Pietsch, Ullrich and Bodenthin, Yves and Grenzer, J{\"o}rg and Geue, Thomas and M{\"o}hwald, Helmuth and Kurth, Dirk G.}, title = {Structure and temperature behavior of metallo-supramolecular assemblies}, year = {2005}, abstract = {A detailed structural analysis of a Langmuir-Blodgett (LB) multilayer composed of a polyelectrolyte-amphiphile complex (PAC) is presented. The PAC is self-assembled from metal ions, ditopic bis-terpyridines, and amphiphiles. The vertical structure of the LB multilayer is investigated by X-ray reflectometry. The multilayer has a periodicity of 57 A, which corresponds to an architecture of flat lying metallo-supramolecular coordination polyelectrolyte (MEPE) rods and upright-standing amphiphiles (dihexadecyl phosphate, DHP). In-plane diffraction reveals hexagonal packing of the DHP molecules. Using extended X-ray absorption fine structure (EXAFS) experiments, we prove that the central metal ion is coordinated to the terpyridine moieties in a pseudo-octahedral coordination environment. The Fe-N bond distances are 1.82 and 2.0 angstrom, respectively. Temperature resolved measurements indicate a reversible phase transition in a temperature range up to 55 degrees C. EXAFS measurements indicate a lengthening of the average Fe-N bond distance from 1.91 to 1.95 angstrom. The widening of the coordination cage upon heating is expected to lower the ligand field stabilization, thus giving rise to spin transitions in these composite materials}, language = {en} } @article{PietschBodenthinMoehwaldetal.2005, author = {Pietsch, Ullrich and Bodenthin, Yves and M{\"o}hwald, Helmuth and Kurth, Dirk G.}, title = {Inducing spin crossover in metallo-supramolecular polyelectrolytes through an amphiphilic phase transition}, year = {2005}, abstract = {A phase transition in an amphiphilic mesophase is explored to deliberately induce mechanical strain in an assembly of tightly coupled metal ion coordination centers. Melting of the alkyl chains in the amphiphilic mesophase causes distortion of the coordination geometry around the central transition metal ion. As a result, the crystal field splitting of the d-orbital subsets decreases resulting in a spin transition from a low-spin to a high-spin state. The diamagnetic-paramagnetic transition is reversible. This concept is demonstrated in a metallo-supramolecular coordination polyelectrolyte-amphiphile complex self-assembled from ditopic bis-terpyridines, Fe(II) as central transition metal, and dialkyl phosphates as amphiphiles. The magnetic properties are studied in a Langmuir-Blodgett multilayer. The modularity of this concept provides extensive control of structure and function from molecular to macroscopic length scales and gives access to a wide range of new molecular magnetic architectures such as nanostructures, thin films, and liquid crystals}, language = {en} }