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摘要
The reaction of naphthalene-1,8-diylbis(cyclopentadienylsodium) (1) with the nickel triple-decker compound [Ni2Cp3]BF4 affords the paramagnetic ansa-nickelocene 1,1%26apos;-(naphthalene-1?,8?-diyl)nickelocene (2). Alternatively, 2 can directly be obtained by a salt metathesis reaction of the disodium salt 1 with hexaammine nickel(II) dichloride [Ni(NH3)6]Cl2. For magnetic dilution experiments, the corresponding but diamagnetic ansa-ruthenocene 3 was synthesized by reaction of the disodium salt 1 with dichloridotetrakis(dimethyl?sulfoxide)ruthenium(II). The solid-state molecular structures of 2 and 3 were determined by single-crystal X-ray diffraction analysis and revealed bent sandwich complexes. Cyclic voltammetry studies of 2 indicate three oxidation states. The electronic structure of complex 2 has been investigated by variable-temperature 1H NMR spectroscopy, magnetic measurements, and DFT calculations. Superconducting quantum interference device (SQUID) magnetometry has been performed for the neat and diluted samples of 2. The neat crystalline material of 2 displays antiferromagnetic behavior, whereas the susceptibility of the magnetically diluted sample runs into saturation at T %26lt; 4 K. This property is in agreement with an intermolecular antiferromagnetic interaction in the bulk material of compound 2 and the triplet ground state calculated by broken-symmetry (BS)-DFT calculations.
- 出版日期2012-10
