Two ethylenediamine cobalt(II) oxalate complexes Co(ox)(en), 1 and Co(ox)(en)·2H 2 O, 2 have been hydrothermally synthesized and characterized by single crystal X-ray diffraction, IR spectrum, TG analysis, and magnetic measurements. In 1, Co atoms are coordinated by two bis-bidentate oxalate ions in transconfiguration to form Co(ox) chains, which are further bridged by ethylenediamine molecules to produce 2D grid layers, Co(ox)(en). In 2, Co atoms are coordinated by bridging oxalate ions in cis-configuration to form Co(ox) chains, and the additional chelation of ethylenediamine to Co atoms completes 1D zigzag chain, Co(en)(ox). Two lattice water molecules stabilize the chains through hydrogen bonding. Magnetic susceptibility measurements indicate that both complexes exhibit weak antiferromagnetic coupling between cobalt(II) ions with the susceptibility maxima at 23 K for 1 and 20 K for 2, respectively. In 1 and 2, the oxalate ligands afford a much shorter and more effective pathway for the magnetic interaction between cobalt ions compared to the ethylenediamine ligands, so the magnetic behaviors of both complexes could be well described with 1D infinite magnetic chain model.
Source of materialHydrothermal reactions were carried out in 23 ml Teflon-lined stainless steel vessels at 150°Cf or 2d .P iperazine (0.086 g, 1.0 mmol), telluric acid (0.690 g, 3.0 mmol), WO 3 (0.696 g, 3mmol) and H 2O(3ml) were allowed to react. The pH values of the reaction mixture before and after the reaction were~9 and~7, respectively. The solid products were recovered by vacuum filtration and washed with water. Colorless polyhedral crystals suitable for X-ray analysis were obtained. Experimental detailsHydrogen atoms associated with the piperazinium cations were placed geometrically and refined as riding. The hydrogen atoms of lattice water molecules were not located because of the large displacement parameters of oxygen atoms. DiscussionThe crystal structure of the title compound comprises discrete centrosymmetric heteronuclear [TeW 6O24] 6-anions, doubly protonated piperazinium cations and lattice water molecules. The Anderson-Evans type [TeW 6O24]6-cluster anions is formed by close packing of oxygen atoms with tellurium and tungsten atoms in octahedral sites. The Te atom occupying the inversion center is coordinated by oxygen atoms in an early regular octahedral manner with adistances of 1.916 (4) 6-anions, piperazinium cations or to each other in acomplex arrangement.
Designing metal−organic frameworks (MOFs) exhibiting fast charge and mass transport properties by utilizing their 3D network with permanent pores to facilitate electrolyte penetration into the active sites is a key challenge for the development of efficient electrocatalysts used for the oxygen evolution reaction (OER). Herein, we introduce an I 3 O 0 -type hybrid cobalt framework that functions as an efficient electrocatalyst for the OER. The structure contains a noninterpenetrated diamondoid Co−O−Co inorganic building block, which introduces unique helices and an extra-large intersecting {Co 36 } ring channel. The unique 3D cobalt oxide framework decorated by πconjugated t-cinnamate with the electron flexibility near Co centers and permanent pores with catalytic active sites results in good electrocatalytic activity toward the OER conducted in basic electrolytes. The observed overpotential of 361 mV at 10.0 mA cm −2 in 0.1 M KOH and a Tafel slop of 28 mV dec −1 are better than those of the reference materials.
The stability of porous coordination polymers during an electrochemical reaction could be improved by introducing supporter materials. An I3O0-type inorganic hybrid electrocatalyst, cobalt cinnamate, supported on reduced graphene oxide (rGO) was successfully prepared for an oxygen evolution reaction. The electrocatalytic activity and stability of cobalt cinnamate(catalyst)/rGO composite were significantly improved due to the strong interaction between catalyst and supporter, which led to enhanced anchoring stability and electrical conductivity. The catalyst/rGO composite shows ~30 mV reduction in overpotential and improvement in durability from ≥35% to ≥70% after a reaction time of 12 h, compared to the catalyst alone.
C 10 H 18 NO 4 P, orthorhombic, Aba2(no. 41), a =7.218(1) Å, b =36.600(7) Å, c =9.188(2) Å, V =2427.2 Å 3 , Z =8, R gt (F) =0.043, wR ref (F 2 ) =0.105, T =296 K. Source of materialAhydrothermalreaction was carried out in a23mlTeflon-lined stainless steel Parr hydrothermalreaction vessel at 150°C for 2d. Phosphoric acid (0.03 ml, 0.5 mmol), 4-phenyl-butylamine (0.24 ml, 1.5 mmol), and water (3.0 ml) were allowed to react. The pH value of the solution before and after the reaction was 11.3 and 7.5, respectively. Thesolid products were recovered by vacuum filtration and washedwith water. Colorless platy crystals suitable for analysis were obtained. The yield of the crystalline product was~40 %based on phosphorous. Experimental detailsHydrogen atomswere placed in calculated positions and refined as riding except those of the hydroxylg roup in H 2 PO 4 -which werelocated in differenceFouriermaps, and their positions and isotropic displacement parameters were refined. The Flack parameter was -0.03(15). DiscussionThe KH 2 PO 4 (KDP) family is one of the most important classes in non-linear optics and ferroelectrics due to its non-centrosymmetric structure [1,2]. Many KDP analogues have been reported, and the arrangement of H 2 PO 4 -can be controlled by the species of counter cations incorporated in the structure [3][4][5][6][7]. A hydrogen bond between the counter cations and dihydrogenphosphate anions is ak ey variable to construct an oncentrosymmetric array of H 2 PO 4 -with very shortO×××Odistances.The title crystal structure is built up from a4-phenylbutylammonium cation and ad ihydrogenphosphate anion. The detailed analysis of H 2 PO 4 -confirms thepositions of oxo-andhydroxyl groups by comparing the bond distances and angles, i.e., d(P-O) of 1.4942(2) Åa nd 1.5369(3) Åa re shorter than d(P-OH) of 1.5396(2) Åand 1.5647(2) Å, and ÐO-P-O =114.2(2)°is wider than ÐHO-P-OH =109.0(1)°. Each anion H 2 PO 4 -is strongly hydrogen bonded to one another forming "macroanionic" layers perpendicular to [010]
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.