Single-molecule-magnet behavior and spin changes affected by crystal packing effects.
نویسندگان
چکیده
Five Mn 3Zn 2 heterometallic complexes have been synthesized and structurally and magnetically characterized. Spin ground states up to S = 6 have been observed for these complexes and are shown to depend on the cocrystallizing cation and on the terminal ligand. Large axial zero-field interactions ( D = -1.16 K) are the result of near-parallel alignment of the Mn (III) Jahn-Teller axes. High-frequency electron paramagnetic resonance, single-crystal magnetization hysteresis, and alternating current susceptibility measurements are presented to characterize [NEt 4] 3[Mn 3Zn 2(salox) 3O(N 3) 6X 2] [X (-) = Cl (-) ( 1), Br (-) ( 2)] and [AsPh 4] 3[Mn 3Zn 2(salox) 3O(N 3) 6Cl 2] ( 3) and reveal that 1 and 2 are single-molecule magnets ( U eff = 44 K), while 3 is not.
منابع مشابه
Strong spin-phonon coupling between a single-molecule magnet and a carbon nanotube nanoelectromechanical system.
Magnetic relaxation processes were first discussed for a crystal of paramagnetic transition ions. It was suggested that mechanical vibrations of the crystal lattice (phonons) modulate the crystal electric field of the magnetic ion, thus inducing a 'direct' relaxation between two different spin states. Direct relaxation has also been predicted for single-molecule magnets with a large spin and a ...
متن کاملObservation of zero-point quantum fluctuations of a single-molecule magnet through the relaxation of its nuclear spin bath.
A single-molecule magnet placed in a magnetic field perpendicular to its anisotropy axis can be truncated to an effective two-level system, with easily tunable energy splitting. The quantum coherence of the molecular spin is largely determined by the dynamics of the surrounding nuclear spin bath. Here we report the measurement of the nuclear spin-lattice relaxation rate 1/T1n in a single crysta...
متن کاملFast tunneling Jahn–Teller isomer of the [Mn12O12(O2CC6H4-2-CH3)16(H2O)4] Æ S single-molecule magnet
The single-crystal X-ray structure of the single-molecule magnet [Mn12O12(O2CC6H4-2-CH3)16(H2O)4] Æ CH2Cl2 Æ 2H2O (complex 1) is reported. Complex 1 is a new example of a ‘‘Jahn–Teller isomer’’, since it has two Mn(III) ions with abnormally oriented Jahn–Teller elongation axes. Complex 1 has a lower activation energy (Ueff = 29 K) for magnetization reversal relative to other reported [Mn12O12] ...
متن کاملA mononuclear transition metal single-molecule magnet in a nuclear spin-free ligand environment.
The high-spin pseudotetrahedral complex [Co(C3S5)2](2-) exhibits slow magnetic relaxation in the absence of an applied dc magnetic field, one of a small number of mononuclear complexes to display this property. Fits to low-temperature magnetization data indicate that this single-molecule magnet possesses a very large and negative axial zero-field splitting and small rhombicity. The presence of ...
متن کاملMolecular Orientation of a Terbium(III)-Phthalocyaninato Double-Decker Complex for Effective Suppression of Quantum Tunneling of the Magnetization.
Single-molecule magnet (SMM) properties of crystals of a terbium(III)-phthalocyaninato double-decker complex with different molecular packings (1: TbPc₂, 2: TbPc₂·CH₂Cl₂) were studied to elucidate the relationship between the molecular packing and SMM properties. From single crystal X-ray analyses, the high symmetry of the coordination environment of 2 suggested that the SMM properties were imp...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Inorganic chemistry
دوره 47 19 شماره
صفحات -
تاریخ انتشار 2008