Showing papers by "Daniel Maspoch published in 2011"

Nanoscale metal–organic materials

Abstract: Metal–organic materials are found to be a fascinating novel class of functional nanomaterials. The limitless combinations between inorganic and organic building blocks enable researchers to synthesize 0- and 1-D metal–organic discrete nanostructures with varied compositions, morphologies and sizes, fabricate 2-D metal–organic thin films and membranes, and even structure them on surfaces at the nanometre length scale. In this tutorial review, the synthetic methodologies for preparing these miniaturized materials as well as their potential properties and future applications are discussed. This review wants to offer a panoramic view of this embryonic class of nanoscale materials that will be of interest to a cross-section of researchers working in chemistry, physics, medicine, nanotechnology, materials chemistry, etc., in the next years.

Coordination Polymer Nanofibers Generated by Microfluidic Synthesis

Abstract: One-dimensional coordination polymer nanostructures are an emerging class of nanoscale materials with many potential applications. Here, we report the first case of coordination polymer nanofibers assembled using microfluidic technologies. Unlike common synthetic procedures, this approach enables parallel synthesis with an unprecedented level of control over the coordination pathway and facilitates the formation of 1D coordination polymer assemblies at the nanometer length scale. Finally, these nanostructures, which are not easily constructed with traditional methods, can be used for various applications, for example as templates to grow and organize functional inorganic nanoparticles.

Single-Crystal Metal−Organic Framework Arrays

Abstract: A novel, versatile pen-type lithography-based methodology was developed to control the growth of HKUST-1 crystals on surfaces by direct delivery of femtoliter droplets containing both inorganic and organic building block precursors. This approach shows that through the use of surfaces with low wettability it is possible to control the crystallization of a single submicrometer metal−organic framework crystal at a desired location on a surface.

Three-Dimensional Open-Frameworks Based on LnIII Ions and Open-/Closed-Shell PTM Ligands: Synthesis, Structure, Luminescence, and Magnetic Properties

Abstract: A series of isostructural open-framework coordination polymers formulated as [Ln(dmf)3(ptmtc)] (Ln=Sm (1), Eu (2), Gd (3), Tb (4), Dy (5); PTMTC=polychlorotriphenylmethyl tricarboxylate) and [Ln(dmf)2H2O(αH-ptmtc)] (Ln=Sm (1′), Eu (2′), Gd (3′), Tb (4′), Dy (5′)) have been obtained by treating LnIII ions with PTMTC ligands with a radical (PTMTC3−) or a closed-shell character (αH-PTMTC3−). X-ray diffraction analyses reveal that these coordination polymers possess 3D architectures that combine large channels and fairly rare lattice complex T connectivity. In addition, these compounds show selective framework dynamic sorption properties. For both classes of ligands, the ability to act as an antenna in Ln sensitization processes has been investigated. No luminescence was observed for compounds 1–5, and 3′ because of the PTMTC3− ligand and/or GdIII ion characteristics. Conversely, photoluminescence measurements show that 1′, 2′, 4′, and 5′ emit dark orange, red, green, and dark cyan metal-centered luminescence. The magnetic properties of all of these compounds have been investigated. The nature of the {Ln–radical} exchange interaction in these compounds has been assessed by comparing the behavior of the radical-based coordination polymers 1–5 with those of the compounds with the diamagnetic ligand set. While antiferromagnetic {Sm–radical} interactions are found in 1, ferromagnetic {Ln–radical} interactions propagate in the 3D architectures of 3, 4, and 5 (Ln=Gd, Tb, and Dy, respectively). This procedure also provided access to information on the {LnLn} exchange existing in these magnetic systems.

Controlling the length and location of in situ formed nanowires by means of microfluidic tools.

Abstract: Progress in microelectronics, sensors and optics is strongly dependent on the miniaturization of components, and the integration of nanoscale structures into applicable systems. In this regard, conventional top-down technologies such as lithography have limits concerning the dimensions and the choice of material. Therefore, several bottom-up approaches have been investigated to satisfy the need for structures with large aspect ratios in the nanometre regime. For further implementation, however, it is crucial to find methods to define position, orientation and length of the nanowires. In this study, we present a microchip to trap in situ formed bundles of nanowires in microsized cages and clamps, thereby enabling immobilisation, positioning and cutting-out of desired lengths. The microchip consists of two layers, one of which enables the formation of metal–organic nanowires at the interface of two co-flowing laminar streams. The other layer, separated by a thin and deflectable PDMS membrane, serves as the pneumatic control layer to impress microsized features (“donuts”) onto the nanowires. In this way, a piece of the nanowire bundle with a prescribed length is immobilised inside the donut. Furthermore, partly open ring-shaped structures enabled trapping of hybrid wires and subsequent functionalisation with fluorescent beads. We believe that the method is a versatile approach to form and modify nanoscale structures via microscale tools, thereby enabling the construction of fully functional nanowire-based systems.

Guided assembly of nanowires and their integration in microfluidic devices

Abstract: In this contribution, we present an effective strategy for assembling and integrating functional, in situ formed micro- and nanosized structures. Microfluidic platforms are employed to form anisotropic hybrid structures and coordination polymers at the interface of two precursor streams. Microstamps, embedded in the microfluidic device and actuated by pressure, provide a facile and reliable technology for structure trapping, localization and integration.

Nanoscale Metal—Organic Materials

Abstract: Metal–organic materials are found to be a fascinating novel class of functional nanomaterials. The limitless combinations between inorganic and organic building blocks enable researchers to synthesize 0- and 1-D metal–organic discrete nanostructures with varied compositions, morphologies and sizes, fabricate 2-D metal–organic thin films and membranes, and even structure them on surfaces at the nanometre length scale. In this tutorial review, the synthetic methodologies for preparing these miniaturized materials as well as their potential properties and future applications are discussed. This review wants to offer a panoramic view of this embryonic class of nanoscale materials that will be of interest to a cross-section of researchers working in chemistry, physics, medicine, nanotechnology, materials chemistry, etc., in the next years.

Metal—Biomolecule Frameworks (MBioFs)

Abstract: Biomolecules are the building blocks of life. Nature has evolved countless biomolecules that show promise for bridging metal ions. These molecules have emerged as an excellent source of biocompatible building blocks that can be used to design Metal–Biomolecule Frameworks (MBioFs). This feature article highlights the advances in the synthesis of this class of MOFs. Special emphasis is provided on the crystal structures of these materials, their miniaturization to the submicron length scale, and their new potential storage, catalytic, and biomedical applications.