Showing papers by "Daniel Maspoch published in 2007"
TL;DR: This critical review provides an up-to-date survey to this new generation of multifunctional open-framework solids, classified into five different sections: magnetic, chiral, conducting, optical, and labile open-frameworks for sensing applications.
Abstract: The literature on open-framework materials has shown numerous examples of porous solids with additional structural, chemical, or physical properties. These materials show promise for applications ranging from sensing, catalysis and separation to multifunctional materials. This critical review provides an up-to-date survey to this new generation of multifunctional open-framework solids. For this, a detailed revision of the different examples so far reported will be presented, classified into five different sections: magnetic, chiral, conducting, optical, and labile open-frameworks for sensing applications. (413 references.)
989 citations
50 citations
TL;DR: Rings of single-walled carbon nanotubes (SWNTs) were assembled by dip-pen nanolithography (DPN) generated molecular templates consisting of COOH-terminated monolayers in circular patterns surrounded by passivating CH3-terminate SAMs.
Abstract: Rings of single-walled carbon nanotubes (SWNTs) were assembled by dip-pen nanolithography (DPN) generated molecular templates consisting of COOH-terminated monolayers in circular patterns surrounded by passivating CH3-terminated SAMs. Experimental data and atomic-level Monte Carlo simulations show that SWNTs assemble into rings with radii as small as 100 nm at the edge of the COOH templates. This directed assembly is strongly length-dependent; only when the length of a SWNT is longer than half of the circumference of the circle does the SWNT bend to precisely follow the interface of the COOH-terminated monolayer. The theoretical modeling shows that the strain energy of each SWNT is balanced by the energy difference between the van der Waals interactions of the tube with COOH and CH3 templates to produce the resulting ring structure.
48 citations
TL;DR: Interestingly, both structural and magnetic changes are reversible after removal of guest solvent molecules, and predominant antiferromagnetic interactions are observed for the inclusion adducts.
Abstract: Solvent inclusion/evacuation caused variations in the structural and magnetic characteristics of the purely organic porous magnet based on the tricarboxylic-substituted PTMTC radical. Whereas no inclusion is observed for nonpolar solvents, the exposure of crystals of the alpha-phase of PTMTC to vapors of polar organic solvents with hydrogen acceptor and/or donor functionalities, such as, ethanol, benzoic alcohol, n-decanol, THF, and DMSO results in the inclusion of these solvents in the highly polar tubular channels of the alpha-phase. The resulting inclusion compounds of formula PTMTC.x(guest) show several structural rearrangements, as confirmed by IR and XRPD (X-ray powder diffraction) measurements. The crystal transformations have been studied for a specific case: the PTMTC.EtOH adduct. The crystal structure reveals that included guest solvent molecules participate in the formation of new hydrogen bonds with the carboxylic groups of PTMTC radicals, inducing the disruption of several direct hydrogen bonds among these radicals. As expected, the interruption of direct hydrogen bonds between PTMTC radicals induces large transformations in the magnetic properties. From the ferromagnetic behavior of the alpha-phase, predominant antiferromagnetic interactions are observed for the inclusion adducts. Interestingly, both structural and magnetic changes are reversible after removal of guest solvent molecules.
40 citations
34 citations
TL;DR: The synthesis, crystal structures, and magnetic properties of a series of mononuclear, metal-radical complexes with first-row transition-metal ions using a new class of radical-based ligands, the polychlorinated triphenylmethyl (PTM) radicals are reported.
Abstract: We report the synthesis, crystal structures, and magnetic properties of a series of mononuclear, metal−radical complexes with first-row transition-metal ions using a new class of radical-based ligands, the polychlorinated triphenylmethyl (PTM) radicals. Crystal structures of three new PTM-based complexes of general formula M(PTMMC)2(py)4-x(H2O)x [PTMMC = PTM radical functionalized at the para position with one carboxylic group; M = Zn(II), x = 2 (1); M = Ni(II), x = 1 (2); M = Co(II), x = 1 (3)] show similar molecular structures in which mononuclear complexes are formed by an octahedral metal ion coordinated by two monodentated PTMMC units. From a magnetic point of view, these similar configurations describe a quasilinear, trimeric magnetic model (PTMMC−M(II)−PTMMC), in which the metal [Ni(II) or Co(II)]−radical magnetic-exchange coupling constants have been determined for the first time. In all of these complexes, the temperature dependence of the magnetic susceptibility reveals moderate antiferromagneti...
31 citations
TL;DR: An overview of the work that have been developed over the last six years in our group on the use of polychlorotriphenylmetyl radicals (PTM) functionalized by carboxylic groups to access to purely organic/molecular magnetic materials is reported in this paper.
17 citations
TL;DR: Two europium (III) complexes (3 and 4) have been obtained by as discussed by the authors, which react with two polychlorotriphenylmethyl radicals properly functionalized with one (PTMMC−, 1) and six carboxylate groups.
9 citations
TL;DR: The literature on open-framework materials has shown numerous examples of porous solids with additional structural, chemical, or physical properties as discussed by the authors, and these materials show promise for applications ranging from sensing, catalysis and separation to multifunctional materials.
Abstract: The literature on open-framework materials has shown numerous examples of porous solids with additional structural, chemical, or physical properties. These materials show promise for applications ranging from sensing, catalysis and separation to multifunctional materials. This critical review provides an up-to-date survey to this new generation of multifunctional open-framework solids. For this, a detailed revision of the different examples so far reported will be presented, classified into five different sections: magnetic, chiral, conducting, optical, and labile open-frameworks for sensing applications. (413 references.)
5 citations
TL;DR: An overview of the work that have been developed over the last six years in our group on the use of polychlorotriphenylmetyl radicals (PTM) functionalized by carboxylic groups to access to purely organic/molecular magnetic materials is reported in this article.
Abstract: An overview of the work that have been developed over the last six years in our group on the use of polychlorotriphenylmetyl radicals (PTM) functionalized by carboxylic groups to access to purely organic/molecular magnetic materials is reported. From the seminal work on the monocarboxylic PTM (Section 2), of great importance to determine both the ability of these molecules to form intermolecular H-bonds and the nature of the intermolecular interactions mediated through the resulting supramolecular motifs, we will move to the self-assembly of PTM radicals functionalized with two and three carboxylic groups (Section 3). In those cases, the self-assembly of the paramagnetic units yield robust and porous magnetic structures, associating in some cases magnetic ordering to the latest remarkable characteristics. The last part of the review will present the latest results obtained with the idea to increase both the structural and magnetic dimensionality in purely organic PTM-based materials using a PTM radical functionalized by six carboxylic groups (Section 4). New trends and challenges for this research line, concerning the design and synthesis of new PTM radicals, as well as the obtaining of PTM based sensors or multifunctional materials will be presented in the concluding section (Section 5).