Bis(3-cyano-pentane-2,4-dionato) (CNacac) metal complex, [M(CNacac)(2)], which acts as both a metal-ion-like and a ligand-like building unit, forms supramolecular structures by self-assembly. Co-grinding of the metal acetates of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with CNacacH formed a CNacac complex in all cases: mononuclear complex was formed in the cases of Mn(II), Cu(II) and Zn(II), whereas polymeric ones were formed in the cases of Fe(II), Co(II) and Ni(II). Subsequent annealing converted the mononuclear complexes of Mn(II), Cu(II) and Zn(II) to their corresponding polymers as a result of dehydration of the mononuclear complexes. The resultant Mn(II), Fe(II), Co(II), Ni(II) and Zn(II) polymeric complexes had a common 3 D structure with high thermal stability. In the case of Cu(II), a 1 D polymer was obtained. The Mn(II), Cu(II) and Zn(II) polymeric complexes returned to their original mononuclear complexes on exposure to water vapour but they reverted to the polymeric complexes by re-annealing. Co-grinding of metal chlorides with CNacacH and annealing of the mononuclear CNacac complexes prepared from solution reactions were also examined for comparison. [Mn(CNacac)(2)(H(2)O)(2)], [M(CNacac)(2)(H(2)O)] (M=Cu(II) and Zn(II)) and [M(CNacac)(2)](infinity) (M=Mn(II), Fe(II) and Zn(II)) are new compounds, which clearly indicated the power of the combined mechanochemical/annealing method for the synthesis of varied metal coordination complexes. 相似文献
This article describes novel optical functionalities such as photomagnetic effects and magnetization-induced second harmonic
generation (MSHG) in several cyano-bridged metal assemblies. Single crystal- and film-types of a cyano-bridged Cu–Mo bimetallic
assembly, , were electrochemically prepared. When this compound was irradiated with light, spontaneous magnetization with a Curie temperature
(TC) of 23 K was observed. Electrochemically prepared FeII[CrIII(CN)6]2/3·5H2O thin film, which was a ferromagnet with TC=21 K, showed photoreduced magnetization. This photomagnetism is due to the change of ferromagnetic coupling between FeII and CrIII. MSHG was observed in CsICoII[CrIII(CN)6]·0.5H2O. This -type Prussian blue analog-based magnet is proven to be a piezoelectric ferromagnet, i.e., condensed matter with both piezoelectric
and ferromagnetism. This MSHG is due to the coupling between a piezoelectric structure of and ferromagnetism with a TC of 46 K.
To explore the anion recognition ability of silanol derivatives, ESI-MS and 1H NMR titrations of a 1,3-disiloxanediol 1 with anions were studied in CDCl3 and MeCN-d3. The results indicate that 1 showed strong binding to anions such as AcO− and halides. 相似文献
Aldehydes were found to be oxidized with molecular oxygen to the corresponding carboxylic acid in the presence of catalytic hydrobromic acid or bromine under photo-irradiation. 相似文献
Self-diffusion coefficients of Li+DLi+, PF6−DPF6− and solvent propylene carbonate (PC) DPC in LiPF6−PC solutions were determined at 298 K by the pulse gradient spin echo (PGSE) NMR technique over the salt concentration range of 0.1–3.0 M (M = mol dm– 3). The order of the diffusion coefficients was found to be DLi+ < DPF6− < DPC over the concentration range examined, and they were monotonically decreased with increasing the salt concentration. Haven ratio Λ/ΛNMR, where Λ and ΛNMR represent the ionic conductivity measured electrochemically and that estimated via the Nernst-Einstein equation using the diffusion coefficient, respectively, was evaluated as the measure of the ion–ion interaction in the LiPF6–PC solutions. Though Λ/ΛNMR values for LiPF6-solutions decrease with increasing the salt concentration, they were greater than those for LiBF4–PC solutions over the whole concentration range examined, which indicates that the ion pair formation ability of PF6– ion is weaker than that of the BF4– ion. The smaller value of the ionic conductivity for the highly concentrated LiPF6–PC solution (above 2.0 M) than that of the LiBF4-solutions can be attributed to the more rapidly increased viscosity relative to the LiBF4-solution. Classic molecular dynamics (MD) simulations for the respective LiPF6 and LiBF4-solution of 0.5 and 1.0 M were also carried out based on the effective pair potentials. Diffusion coefficients, ionic conductivity and Haven ratio for these solutions were calculated from MD trajectories, and they qualitatively agree with those evaluated by experiments. Pair correlation functions gLiO(r) (for Li+–O (PC) pair) and gLiPF6(r) (for Li+–PF6– pair) or gLiBF4(r) (for Li+–BF4– pair) revealed that the lithium ion weakly forms the contact ion pairs with PF6–, whilst strongly with BF4–, which supports the present experimental results. Moreover, the simulation results show that both anions in the contact ion pairs predominantly take the monodentate form, which is in contrast to the multidentate coordination predicted by ab initio calculation in gas phase. 相似文献
Carbon tetrabromide enables us to carry out oxidative cleavage of the C-C double bonds of styrenes under aerobic photo-irradiation conditions. Oxidative cleavage of the various β-substituted styrenes produced benzoic acid in good yields. Since this reaction is found to be applicable to the α- or β-substituted styrenes, which showed very low reactivity under our previous cleavage reaction condition with FSM-16 and I2, this reaction can be used complementarily. 相似文献
Anion recognition by 1,3-disiloxane-1,1,3,3-tetraols has been elucidated by 1H NMR titrations and ESI-MS in organic solvents. The association constants of the receptors for halide anions are larger than those of silanediol and 1,3-disiloxane-1,3-diol due to the cooperative hydrogen bonds by four silanol hydroxy groups of 1,3-disiloxane-1,1,3,3-tetraols. 相似文献
Reversible and non‐bonding interaction between SWNTs and ODCB is observed from the analyses of visible near‐infrared absorption data and Raman spectroscopies (see spectra). The solvent effect on SWNTs effectively controls the electronic structure of SWNTs under homogeneous conditions.
We introduce a stochastic generalization of Lipschitz retracts, and apply it to the extension problems of Lipschitz, Hölder, large-scale Lipschitz and large-scale Hölder maps into barycentric metric spaces. Our discussion gives an appropriate interpretation of a work of Lee and Naor. 相似文献