7 research outputs found
Bis(4-acetyl-3-methyl-1-phenyl-1H-pyrazol-5-olato-κ2 O,O′)bis(N,N-dimethylformamide-κO)nickel(II)
The title complex, [Ni(C12H11N2O2)2(C3H7NO)2], lies on on an inversion center. The NiII ion is coordinated in a slightly distorted octahedral coordination enviroment by four O atoms from two bis-chelating 4-acety-3-methyl-1-phenyl-1H-pyrazol-5-olate ligands in the equatorial plane and two O atoms from two N,N-dimethylformamide ligands in the axial sites. In the crystal structure, weak intermolecular π–π stacking interactions with centroid–centroid distances of 3.7467 (13) Å link molecules into chains extending alongthe b axis
N′-[(5-Methyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)(thiophen-2-yl)methylidene]benzohydrazide
In the title compound, C22H18N4O2S, the seven-membered ring generated by an intramolecular N—H⋯O hydrogen bond adopts an envelope conformation in both of the two independent molecules in the asymmetric unit. In the crystal, molecules are linked into C(9) chains along [100] by N—H⋯O hydrogen bonds. The molecules are also weakly linked by C—H⋯O and C—H⋯N interactions, forming dimers with edge-connected R
2
2(9) rings. The dimers are interlinked by further weak C—H⋯N hydrogen bonds into chains along [010]
1,5-Dimethyl-4-{[1-(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-ylidene)ethyl]amino}-2-phenyl-1H-pyrazol-3(2H)-one
In the title compound, C23H23N5O2, an intramolecular N—H...O hydrogen bond generates an S(6) ring, and the dihedral angle between the pyrazole rings is 48.42 (8)°. The dihedral angles between the pyrazole rings and their attached phenyl rings are 10.06 (8) and 47.53 (8)°
Morphology and Structure Controls of Single-atom Fe-N-C Catalysts Synthesized Using FePc Powders as the Precursor
Understanding the origin of the high electrocatalytic activity of Fe–N–C electrocatalysts for oxygen reduction reaction is critical but still challenging for developing efficient sustainable nonprecious metal catalysts used in fuel cells. Although there are plenty of papers concerning the morphology on the surface Fe–N–C catalysts, there is very little work discussing how temperature and pressure control the growth of nanoparticles. In our lab, a unique organic vapor deposition technology was developed to investigate the effect of the temperature and pressure on catalysts. The results indicated that synthesized catalysts exhibited three kinds of morphology—nanorods, nanofibers, and nanogranules—corresponding to different synthesis processes. The growth of the crystal is the root cause of the difference in the surface morphology of the catalyst, which can reasonably explain the effect of the temperature and pressure. The oxygen reduction reaction current densities of the different catalysts at potential 0.88 V increased in the following order: FePc (1.04 mA/cm2) < Pt/C catalyst (1.54 mA/cm2) ≈ Fe–N–C-f catalyst (1.64 mA/cm2) < Fe–N–C-g catalyst (2.12 mA/cm2) < Fe–N–C-r catalyst (2.35 mA/cm2). By changing the morphology of the catalyst surface, this study proved that the higher performance of the catalysts can be obtaine