Et3N （Mn^Ⅱ-triethylamine） complex conjugated with binuclear Mn^Ⅲ-hydroxide, Mn2（OH）3Cl and similar manganese complex with Et2NH （diethylamine） self-assembled in aqueous solutions have been investigated by simu...Et3N （Mn^Ⅱ-triethylamine） complex conjugated with binuclear Mn^Ⅲ-hydroxide, Mn2（OH）3Cl and similar manganese complex with Et2NH （diethylamine） self-assembled in aqueous solutions have been investigated by simultaneous AFM （atomic force microscopy） and SNOM （scanning near-field optical microscopy） in thin layers prepared on mica and PET （polyethylene terephthalate） The size of the particles after crystallization of the precipitated former conjugate was controlled with XRD （X-ray diffraction）. It is found that the conjugate self-assembling produces the smallest grains with the diameter of 65 ± 7.5 nm measured at contact with the support. This particle size matches the crystallite size of 44.2 nm found by XRD for the conjugate taking into account the particles deformation under the contact with the support. The self-assembly of the smallest particles in solution has produced non-transparent for light core observed on mica with the size varied between 300 to 400 nm. The latter occurs due to hydrophobic interactions since no core of the former conjugate has been found on hydrophobic PET surface. No submicroscopic core is also found in the case of similar conjugate with Mn^Ⅱ-Et2NH complex on PET film and mica both.展开更多
A two-dimensional layered manganese(II) pyrophosphate, 2[Mn3(P2O7)2(H2O)2] (1), has been synthesized hydrothermally. Its structure is determined by single-crystal X-ray diffraction analysis. Its structure is built up ...A two-dimensional layered manganese(II) pyrophosphate, 2[Mn3(P2O7)2(H2O)2] (1), has been synthesized hydrothermally. Its structure is determined by single-crystal X-ray diffraction analysis. Its structure is built up by MnO6 octahedra and P2O7 units, with ammonium NH4+ cations residing in the interlayer regions. The manganese pyrophosphate layer consists of infinite chains of cis and trans edge sharing MnO6 octahedra linked by P2O7 units. Magnetic susceptibility measurements show that this compound exhibits ferrimagnetic-like ordering below 3.2 K. Further study shows that there are two possible superexchange pathways via the oxygen anions in Mn2+ ions. Owing to the different bridging modes of O2-, the competition between ferromagnetic interactions and antiferromagnetic interactions in Mn2+ ions results in the ferrimagnetic behavior of 1.展开更多
A PSII reaction center complex consisting of three polypeptides, D_1, D_2 and Cyt. b_(559), was first purified from broad bean leaves. The complex was fairly active inDCIP photoreduction in the presence of DPC, and sh...A PSII reaction center complex consisting of three polypeptides, D_1, D_2 and Cyt. b_(559), was first purified from broad bean leaves. The complex was fairly active inDCIP photoreduction in the presence of DPC, and showed signal Ⅱs either in the dark or under illumination. The complex also contained manganese atoms. Its Mn^(2+)-EPR intensity decreased by about 40% under continuous illumination and recovered to the original level when the complex was transferred to the dark. The above results indicated that the complex reported here contains all of the PSII electron transport chain components from the secondary donor Z to the stable primary electron acceptor Q_A, and it is possible that the complex contains manganese binding sites. The alternation in dark and illumination can induce reversible valence changes of the manganese atoms in the purified complex.展开更多
文摘Et3N （Mn^Ⅱ-triethylamine） complex conjugated with binuclear Mn^Ⅲ-hydroxide, Mn2（OH）3Cl and similar manganese complex with Et2NH （diethylamine） self-assembled in aqueous solutions have been investigated by simultaneous AFM （atomic force microscopy） and SNOM （scanning near-field optical microscopy） in thin layers prepared on mica and PET （polyethylene terephthalate） The size of the particles after crystallization of the precipitated former conjugate was controlled with XRD （X-ray diffraction）. It is found that the conjugate self-assembling produces the smallest grains with the diameter of 65 ± 7.5 nm measured at contact with the support. This particle size matches the crystallite size of 44.2 nm found by XRD for the conjugate taking into account the particles deformation under the contact with the support. The self-assembly of the smallest particles in solution has produced non-transparent for light core observed on mica with the size varied between 300 to 400 nm. The latter occurs due to hydrophobic interactions since no core of the former conjugate has been found on hydrophobic PET surface. No submicroscopic core is also found in the case of similar conjugate with Mn^Ⅱ-Et2NH complex on PET film and mica both.
文摘A two-dimensional layered manganese(II) pyrophosphate, 2[Mn3(P2O7)2(H2O)2] (1), has been synthesized hydrothermally. Its structure is determined by single-crystal X-ray diffraction analysis. Its structure is built up by MnO6 octahedra and P2O7 units, with ammonium NH4+ cations residing in the interlayer regions. The manganese pyrophosphate layer consists of infinite chains of cis and trans edge sharing MnO6 octahedra linked by P2O7 units. Magnetic susceptibility measurements show that this compound exhibits ferrimagnetic-like ordering below 3.2 K. Further study shows that there are two possible superexchange pathways via the oxygen anions in Mn2+ ions. Owing to the different bridging modes of O2-, the competition between ferromagnetic interactions and antiferromagnetic interactions in Mn2+ ions results in the ferrimagnetic behavior of 1.
基金Project supported by the National Natural Science Foundation of China
文摘A PSII reaction center complex consisting of three polypeptides, D_1, D_2 and Cyt. b_(559), was first purified from broad bean leaves. The complex was fairly active inDCIP photoreduction in the presence of DPC, and showed signal Ⅱs either in the dark or under illumination. The complex also contained manganese atoms. Its Mn^(2+)-EPR intensity decreased by about 40% under continuous illumination and recovered to the original level when the complex was transferred to the dark. The above results indicated that the complex reported here contains all of the PSII electron transport chain components from the secondary donor Z to the stable primary electron acceptor Q_A, and it is possible that the complex contains manganese binding sites. The alternation in dark and illumination can induce reversible valence changes of the manganese atoms in the purified complex.
