Functional (Supra)Molecular Nanostructures - ruben-group

Recommendations

Info

Habilitation Dr. Mario Ruben ULP Strasbourg curves show a pronounced step-like hysteresis up to a blocking temperature of TB = 4 K. The observed steps can be explained by Quantum Tunneling of the magnetization (QTM) involving multiple anti-level crossings at close distance. [42] The observed features of the broad steps in the hysteresis at finite fields can be explained by a complex interplay of intermolecular exchange, dipolar and hyperfine interactions. a) b) c) Figure 23. a) The Hamiltonian used in the analysis of the b) direction-dependent magnetization data rendering the second order field parameters D = -5.0 K and E = 0.7 K. c) Single crystal hysteresis loop measurements for different temperatures along the easy axis ([100]) at different temperatures. In conclusion, the Dysprosium bis-phthalocyanine compound, which consists of only one single metal ion, is the first member of the new class of Single-Ion Molecular Magnets (SIMMs). The value of the zero-field splitting parameter D = -5.0 K has been determined by anisotropy SQUID measurements on single crystals. The effective barrier height for the reversal of the magnetization Ueff = 70 K and the blocking temperature of TB = 4 K are larger than for any other known SMM. Preliminary experiments on the Terbium analogues have shown even larger blocking temperatures. [43] 35 M/ M 0. - 1 0 -
7. Molecular Electronics Habilitation Dr. Mario Ruben ULP Strasbourg 7.1. Multilevel Molecular Species (in collaboration with Dr. J.-P. Giesselbrecht, University of Strasbourg) The drive to shrink electronic devices to the nano-level, has, in recent years, led to the design and investigation of molecular-scale components endowed with sensing, switching, logic, and information storage functions. [44] Although the implementation of information processing with such devices faces hurdles in the development of logic architecture and intermolecular hook up schemes, molecular data storage and processing are subjects to active interest. Species suitable for molecular data storage (i) must possess two or more physico- chemically distinct states that can be conveniently switched by application of external triggers (e.g. thermodynamic parameters or electro-magnetic fields) and (ii) should be addressable and switchable within the nanometer regime. In this respect, interest for [2x2] grid-like molecular architectures might arise from an alternative encoding concept called “quantum cellular automata”, in which molecules do not act as current switches but as structured charge containers. [45] Envisioned first for quantum dots, binary information is encoded in the charge configuration of a cell composed of a small number of differently charged redox centres, which are electronically communicating within the entity but are not completely delocalised (Figure 24). Each cell has two degenerate ground states, which can be interconverted by an internal electron density redistribution (e.g. by the transfer of two or more electrons within the cell). The electrostatic interaction of two neighbouring cells (arranged in two- or three- dimensions) lifts the given degeneracy and results in “1” or “0” states. Remarkably, the intercellular information exchange is purely based on Coulomb interactions and involves no current flow. If such interaction can be realized, this approach may enable a general purpose computation, the “universal computer. [46] Fro m the standpoint of nanochemistry, the cells can equally consist of molecular or supramolecular entities with an electronic delocalisation of the Robin-Day type II character between internal redox centres. Provided it is possible to achieve a fine-tuning of the intra- as well as intermolecular electronic and Coulomb interactions, tetranuclear metal ion coordination arrays arranged on surfaces (as shown in chapter 4.2.A) could represent particularly interesting candidates for “Molecular Cellular Automata”, especially due to their 36
Page 1 and 2: Habilitation Dr. Mario Ruben ULP St
Page 27 and 28: 6. Molecular Magnetism Habilitation
Page 35: Habilitation Dr. Mario Ruben ULP St
Page 47 and 48: 9. Conclusion Habilitation Dr. Mari
Page 55: Habilitation Dr. Mario Ruben ULP St
Page 58 and 59: Highlights previously described gri
Page 60 and 61: Metallosupramolecular Chemistry Rec
Page 62 and 63: Metallosupramolecular Chemistry Fig
Page 64 and 65: Metallosupramolecular Chemistry Tho
Page 66 and 67: Metallosupramolecular Chemistry two
Page 70 and 71: Metallosupramolecular Chemistry (Fi
Page 72 and 73: Metallosupramolecular Chemistry The
Page 76 and 77: Metallosupramolecular Chemistry [3]
Page 78 and 79: DOI: 10.1039/b303922f Synthesis of
Page 82 and 83: enable a highly efficient informati
Page 84 and 85: implies a multistep SC process, whi
Page 86 and 87:
e716 Scheme 1. Fig. 1. 1 H-NMR spec
Page 88:
FULL PAPER Supramolecular Spintroni
Page 91 and 92:
Supramolecular Spintronic Devices 4
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
merge, since the molecular surround
Page 99 and 100:
Supramolecular Spintronic Modules F
Page 101 and 102:
Supramolecular Spintronic Modules r
Page 103 and 104:
APS/123-QED Quantum Tunneling of th
Page 105 and 106:
certain fields, which are shifted t
Page 107 and 108:
[3] Transition metal catalyzed form
Page 109 and 110:
transfer of four electrons at ‡1.
Page 111 and 112:
Functional Supramolecular Devices:
Page 113 and 114:
Functional Supramolecular Devices 2
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
��¨
Page 123 and 124:
��
Page 125 and 126:
ΔE 0.06 0.05 0.04 0.03 0.02 0.01 0
Page 127 and 128:
�¦��
Page 129 and 130:
Figure 1. The masters on the roof o
Page 131 and 132:
to have approached him in late 1926
show all

Functional (Supra)Molecular Nanostructures - ruben-group

Create successful ePaper yourself

Delete template?

Save as template?