11 research outputs found
Synthesis, structure and magnetic properties of heterometallic complexes towards single-molecule magnets using flexible aminopolyol ligands
No abstract available
Surface Charge Control of Quantum Dot Blinking
A characteristic property of colloidal semiconductor nanocrystal quantum dots (QDs) is their emission intermittency. Although a unifying theory of QD photoprocesses remains elusive, the importance of charged states is clear. We now report a new approach to directly study the role of surface charge on QD emission by adding metal ions to individual, core-only QDs immobilized in aqueous solution in an agarose gel. The CdTe QDs show very stable emission in the absence of metal ions but a dramatic and reversible increase in blinking due to the presence of trivalent metal ions. Our results support a charge-separation model, in which the major blinking pathway is the surface trapping of electrons; transiently bound metal ions close to the QD surface enhance this process
CCDC 1031792: Experimental Crystal Structure Determination
An entry from the Cambridge Structural Database, the worldâs repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures
CCDC 1031793: Experimental Crystal Structure Determination
An entry from the Cambridge Structural Database, the worldâs repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures
CCDC 1031794: Experimental Crystal Structure Determination
An entry from the Cambridge Structural Database, the worldâs repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures
CCDC 1031791: Experimental Crystal Structure Determination
An entry from the Cambridge Structural Database, the worldâs repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures
Rational serendipity: âundirectedâ synthesis of a large {MnIII10CuII5} complex from pre-formed Mn II
Il trattamento sanitario su minore o incapace: il miglior interesse del paziente vulnerabile fra (piĂč) volontĂ e scienza.
New
{TbCu<sub>3</sub>} and {DyCu<sub>3</sub>} single-molecule magnets
(SMMs) containing a low-symmetry Ln<sup>III</sup> center (shape measurements
relative to a trigonal dodecahedron and biaugmented trigonal prism
are 2.2â2.3) surrounded by three Cu<sup>II</sup> metalloligands
are reported. SMM behavior is confirmed by frequency-dependent out-of-phase
ac susceptibility signals and single-crystal temperature and sweep
rate dependent hysteresis loops. The ferromagnetic exchange interactions
between the central Ln<sup>III</sup> ion and the three Cu<sup>II</sup> ions could be accurately measured by inelastic neutron scattering
(INS) spectroscopy and modeled effectively. The excitations observed
by INS correspond to flipping of Cu<sup>II</sup> spins and appear
at energies similar to the thermodynamic barrier for relaxation of
the magnetization, âŒ15â20 K, and are thus at the origin
of the SMM behavior. The magnetic quantum number <i>M</i><sub>tot</sub> of the cluster ground state of {DyCu<sub>3</sub>}
is an integer, whereas it is a half-integer for {TbCu<sub>3</sub>},
which explains their vastly different quantum tunneling of the magnetization
behavior despite similar energy barriers