Molecules Designed to Contain Two Weakly Coupled Spins with a Photoswitchable Spacer
Controlling the charges and spins of molecules lies at the heart of spintronics. A photoswitchable molecule consisting of two independent spins separated by a photo- switchable moiety was designed in the form of new ligand H4L, which features a dithienylethene photochromic unit and two lateral coord...
| Autores: | , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2017 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/118837 |
| Acceso en línea: | https://hdl.handle.net/2445/118837 |
| Access Level: | acceso abierto |
| Palabra clave: | Compostos de coordinació Fotoquímica orgànica Propietats magnètiques Coordination compounds Organic photochemistry Magnetic properties |
| Sumario: | Controlling the charges and spins of molecules lies at the heart of spintronics. A photoswitchable molecule consisting of two independent spins separated by a photo- switchable moiety was designed in the form of new ligand H4L, which features a dithienylethene photochromic unit and two lateral coordinating moieties, and yields molecules with [MM···MM] topology. Compounds [M4L2(py)6] (M = Cu, 1; Co, 2; Ni, 3; Zn, 4) were prepared and studied by single-crys- tal X-ray diffraction (SCXRD). Different metal centers can be selectively distributed among the two chemically distinct sites of the ligand, and this enables the preparation of many double-spin systems. Heterometallic [MM'···M'M] analogues with formulas [Cu2Ni2L2(py)6] (5), [Co2Ni2L2(py)6] (6), [Co2Cu2L2(py)6] (7), [Cu2Zn2L2(py)6] (8), and [Ni2Zn2L2(py)6] (9) were prepared and analyzed by SCXRD. Their composition was established unambiguously. All complexes exhibit two weakly interacting [MM'] moieties, some of which embody two-level quantum systems. Compounds 5 and 8 each ex- hibit a pair of weakly coupled S = 1=2 spins that show quan- tum coherence in pulsed Q-band EPR spectroscopy, as re- quired for quantum computing, with good phase memory times (TM = 3.59 and 6.03 ms at 7 K). Reversible photoswitch- ing of all the molecules was confirmed in solution. DFT cal- culations on 5 indicate that the interaction between the two spins of the molecule can be switched on and off on photo- cyclization. |
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