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This paper presents an online image-based visual servoing (IBVS) controller for a 6-degrees-of-freedom (DOF) robotic system based on the robust model predictive control (RMPC) method. The controller is designed considering the robotic visual servoing system’s input and output constraints, such as robot physical limitations and visibility constraints. The proposed IBVS controller avoids the inverse of the image Jacobian matrix and hence can solve the intractable problems for the classical IBVS controller, such as large displacements between the initial and the desired positions of the camera. To verify the effectiveness of the proposed algorithm, real-time experimental results on a 6-DOF robot manipulator with eye-in-hand configuration are presented and discussed. [ABSTRACT FROM AUTHOR]

Two purely inorganic three-dimensional (3D) frameworks [Mn4(H2O)11VIV18O42(PO4)]7− (1) and [Mn2(H2O)7VIV18O42(PO4)]11− (2) were synthesized under hydrothermal conditions and fully characterized by single-crystal X-ray structural analysis, IR spectroscopy, thermogravimetric analysis and PXRD. Structural analysis revealed that these two compounds contained a similar all reduced polyoxoanion [VIV18O42(PO4)]15− linked by different amounts of manganese centers to form 3D framework materials. The V centers in these two compounds were all reduced to the +IV oxidation state, resulting in an all reduced polyoxoanion, which was firstly used as the building block for constructing 3D framework materials. The all reduced typical polyoxoanion [VIV18O42(PO4)]15− with 15 negative charges supplied enough charge amount to accept TM cations. In these two structures, the anions were surrounded by 12 and 5 Mn2+ ions, respectively, adjusted by varying the feeding amount of MnCl2·4H2O. An electrocatalytic study revealed that compound 1 exhibits electrocatalytic activity for reduction of H2O2. [ABSTRACT FROM AUTHOR]

Three new chain compounds in which the Mn2(salen)2 dimers are bridged by O–P–O units are reported, namely, [Mn2(salen)2(C6H9PO3H)](ClO4) (1), [Mn2(salen)2(C6H5PO3H)](ClO4) (2) and [Mn2(salen)2(C6H5PHO2)](ClO4) (3). The phosphonate or phosphinate ligands adopt a syn–anti bidentate bridging mode in 1, while a syn–syn bidentate bridging mode in 2 and 3, thus leading to a difference in the Mn–O…O–Mn torsion angle over the O–P–O bridge. Compound 1 shows a paramagnetic behavior with dominant antiferromagnetic interactions. In compounds 2 and 3, the antiferromagnetic interactions through the O–P–O bridges are considerably stronger than those in 1. They display coexistence of single chain magnet (SCM) behaviour with a spin canted structure and metamagnetism at low temperature. The results demonstrate that the magnetic dynamics of the O–P–O bridged Mn2(salen)2 chains may be modulated by selecting suitable phosphonate or phosphinate ligands. [ABSTRACT FROM AUTHOR]

This paper reports two metal phosphonate clusters containing MnIII-Schiff base units, namely, [Mn2(5-Brsalen)2(C10H7PO3H)2] ·2CH3OH ( 1) and [Mn6(5-Brsalen)6(C10H7PO3)2(H2O)2](ClO4)2 ·7.6H2O ( 2) [5-Brsalen = N, N′-ethylenebis(5-bromosalicylideneiminate) dianion]. Compound 1 shows a discrete dinuclear structure in which dimers of Mn2(5-Brsalen)2 are terminated by the naphthylphosphonate ligand. In 2, each naphthylphosphonate ligand connects three Mn atoms, forming triangular units of {Mn3PO3}, which are further cross-linked through phenoxide oxygen atoms into a hexanuclear cluster. Magnetic studies reveal that the exchange couplings mediated through the phenoxide bridges within the dimer are ferromagnetic in compounds 1 and 2. Further, slow magnetization relaxation, characteristic of single-molecule magnets (SMMs), is observed in both 1 and 2, in contrast to the non-SMM behavior in the precursor of [Mn(5-Brsalen)(H2O)]2(ClO4)2. [ABSTRACT FROM AUTHOR]

Sit back and relax: The title compound [Mn6(salen)6(H2O)V4O12](ClO4)2⋅7 H2O is the first example of a 3D coordination polymer with embedded out ‐ of ‐ plane MnIII Schiff base dimers, where the Mn2(salen)22+ dimers are connected by the cyclic V4O124− clusters through covalent bonds. Slow magnetization relaxation is observed at low temperature. [ABSTRACT FROM AUTHOR]