Synthesis and Characterization of Three-Dimensional 3d−3d and 3d−4f Heterometallic Coordination Polymers with High Thermal Stability

Using 1,2-bis(4-pyridyl)ethane (bpe) and benzene-1,3-biscarboxylic acid (H2bba) as ligands, two novel heterometallic three-dimensional coordination polymers {[Zn3Mn1.5(bpe)(bba)4(Hbba)]·bpe}n (Mn−Zn) and {[Zn2Pr(bpe)(bba)3(Hbba)]·H2O}n (Pr−Zn) were isolated under hydrothermal conditions. Both complexes are constructed via 3d−3d and 3d−4f clusters as secondary building units, respectively, which represent the first template synthesis for 3D heterometallic MOFs

Synthesis and Characterization of Three-Dimensional 3d−3d and 3d−4f Heterometallic Coordination Polymers with High Thermal Stability

Using 1,2-bis(4-pyridyl)ethane (bpe) and benzene-1,3-biscarboxylic acid (H2bba) as ligands, two novel heterometallic three-dimensional coordination polymers {[Zn3Mn1.5(bpe)(bba)4(Hbba)]·bpe}n (Mn−Zn) and {[Zn2Pr(bpe)(bba)3(Hbba)]·H2O}n (Pr−Zn) were isolated under hydrothermal conditions. Both complexes are constructed via 3d−3d and 3d−4f clusters as secondary building units, respectively, which represent the first template synthesis for 3D heterometallic MOFs

Synthesis and Characterization of Three-Dimensional 3d−3d and 3d−4f Heterometallic Coordination Polymers with High Thermal Stability

Using 1,2-bis(4-pyridyl)ethane (bpe) and benzene-1,3-biscarboxylic acid (H2bba) as ligands, two novel heterometallic three-dimensional coordination polymers {[Zn3Mn1.5(bpe)(bba)4(Hbba)]·bpe}n (Mn−Zn) and {[Zn2Pr(bpe)(bba)3(Hbba)]·H2O}n (Pr−Zn) were isolated under hydrothermal conditions. Both complexes are constructed via 3d−3d and 3d−4f clusters as secondary building units, respectively, which represent the first template synthesis for 3D heterometallic MOFs

A Novel Nonlinear Optical Crystal for the IR Region: Noncentrosymmetrically Crystalline CsCdBr₃ and Its Properties

A noncentrosymmetric crystal structure of CsCdBr3 has been successfully observed with X-ray single-crystal structure analysis. It crystallizes in the hexagonal space group P6(3)mc, with a = 7.7281(14) Å, b = 7.7281(14) Å, c = 6.742(2) Å, α = 90°, β = 90°, γ = 120°, Z = 2. It was obtained by a new preparation procedure different from that reported in the literature that gave a centrosymmetric structure. The structure contains Cd−Br octahedrons, which are connected in a plane-sharing way to form one-dimensional long chains. Each octahedron is slightly distorted, as the three Cd−Br bond lengths are 2.774 Å, while the other three Cd−Br bond lengths are 2.804 Å. The distortion directions of all of the octahedrons are almost parallel and give rise to the accumulation of the microcosmic nonlinear optical (NLO) coefficient. The Kurtz powder technique shows that CsCdBr3 has a powder second harmonic generation of about 2 times as large as that of potassium dihydrogen phosphate (KDP). It shows excellent transparency in the visible and infrared regions. The thermal stability is also good. Therefore it may be utilized as a potential nonlinear optical crystal for the IR region

Mild and Phosphine-Free Iron-Catalyzed Cross-Coupling of Nonactivated Secondary Alkyl Halides with Alkynyl Grignard Reagents

A simple protocol for iron-catalyzed cross-coupling of nonactivated secondary alkyl bromides and iodides with alkynyl Grignard reagents at room temperature has been developed. A wide range of secondary alkyl halides and terminal alkynes are tolerated to afford the substituted alkynes in good yields. A slight modification of the reaction protocol also allows for cross-coupling with a variety of primary alkyl halides

Tri(1-adamantyl)phosphine: Expanding the Boundary of Electron-Releasing Character Available to Organophosphorus Compounds

We report here the remarkable properties of PAd3, a crystalline air-stable solid accessible through a scalable SN1 reaction. Spectroscopic data reveal that PAd3, benefiting from the polarizability inherent to large hydrocarbyl groups, exhibits unexpected electron releasing character that exceeds other alkylphosphines and falls within a range dominated by N-heterocyclic carbenes. Dramatic effects in catalysis are also enabled by PAd3 during Suzuki–Miyaura cross-coupling of chloro­(hetero)­arenes (40 examples) at low Pd loading, including the late-stage functionalization of commercial drugs. Exceptional space-time yields are demonstrated for the syntheses of industrial precursors to valsartan and boscalid from chloroarenes with ∼2 × 104 turnovers in 10 min

Tri(1-adamantyl)phosphine: Expanding the Boundary of Electron-Releasing Character Available to Organophosphorus Compounds

We report here the remarkable properties of PAd₃, a crystalline air-stable solid accessible through a scalable S_N1 reaction. Spectroscopic data reveal that PAd₃, benefiting from the polarizability inherent to large hydrocarbyl groups, exhibits unexpected electron releasing character that exceeds other alkylphosphines and falls within a range dominated by N-heterocyclic carbenes. Dramatic effects in catalysis are also enabled by PAd₃ during Suzuki–Miyaura cross-coupling of chloro­(hetero)­arenes (40 examples) at low Pd loading, including the late-stage functionalization of commercial drugs. Exceptional space-time yields are demonstrated for the syntheses of industrial precursors to valsartan and boscalid from chloroarenes with ∼2 × 10⁴ turnovers in 10 min

Tri(1-adamantyl)phosphine: Expanding the Boundary of Electron-Releasing Character Available to Organophosphorus Compounds

We report here the remarkable properties of PAd₃, a crystalline air-stable solid accessible through a scalable S_N1 reaction. Spectroscopic data reveal that PAd₃, benefiting from the polarizability inherent to large hydrocarbyl groups, exhibits unexpected electron releasing character that exceeds other alkylphosphines and falls within a range dominated by N-heterocyclic carbenes. Dramatic effects in catalysis are also enabled by PAd₃ during Suzuki–Miyaura cross-coupling of chloro­(hetero)­arenes (40 examples) at low Pd loading, including the late-stage functionalization of commercial drugs. Exceptional space-time yields are demonstrated for the syntheses of industrial precursors to valsartan and boscalid from chloroarenes with ∼2 × 10⁴ turnovers in 10 min

Segmenting Oil Spills from Blurry Images Based on Alternating Direction Method of Multipliers

We exploit the alternating direction method of multipliers (ADMM) for developing an oil spill segmentation method, which effectively detects oil spill regions in blurry synthetic aperture radar (SAR) images. We commence by constructing energy functionals for SAR image deblurring and oil spill segmentation separately. We then integrate the two energy functionals into one overall energy functional subject to a linear mapping constraint that correlates the deblurred image and the segmentation indicator. The overall energy functional along with the linear constraint follows the form of alternating direction method of multipliers and thus enables an effective augmented Lagrangian optimization. Furthermore, the iterative updates in the ADMM maintain information exchanges between the energy minimizations for SAR image deblurring and oil spill segmentation. Most existing blurry image segmentation strategies tend to consider deblurring and segmentation as two independent procedures with no interactions, and the operation of deblurring is thus not guided for obtaining accurate segmentation. In contrast, we integrate deblurring and segmentation into one overall energy minimization framework with information exchanges between the two procedures. Therefore, the deblurring procedure is inclined to operate in favor of more accurate oil spill segmentation. Experimental evaluations validate that our framework outperforms the separate deblurring and segmentation strategy for detecting oil spill regions in blurry SAR images

Copper-Catalyzed Alkylation of Benzoxazoles with Secondary Alkyl Halides

Copper-catalyzed direct alkylation of benzoxazoles using nonactivated secondary alkyl halides has been developed. The best catalyst is a new copper(I) complex (<b>1</b>), and the reactions are promoted by bis[2-(<i>N</i>,<i>N</i>-dimethylamino)ethyl] ether