Highly ordered mesoporous Co 3 O 4 nanostructures were prepared using LP-FDU-12 as hard templates. By changing the hydrothermal temperature or by the acid treatment of the LP-FDU-12 template, Co 3 O 4 replicas with different cell parameters and wall thicknesses have been obtained. The structure and textural characteristics of both LP-FDU-12 and Co 3 O 4 replicas were investigated by X-ray diffraction, transmission electron microscopy, and N 2 adsorption−desorption isotherm analysis. The cell parameter and wall thickness of a mesoporous Co 3 O 4 have been varied systematically within the ranges 30.4−33.9 and 24.8−18.2 nm, respectively, and the materials exhibit surface areas in the 29.6−52.9 m 2 g −1 range, while preserving a highly ordered 3D pore structure and highly crystalline walls. Most importantly, magnetic studies show that the factors which affect the magnetic behavior in the Co 3 O 4 nanosphere system are not only the sphere size but also the space-filled parameter at the nanoscale.

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Key indicators: single-crystal X-ray study; T = 298 K; mean (C-C) = 0.007 Å; R factor = 0.043; wR factor = 0.108; data-to-parameter ratio = 12.2.The mononuclear title complex, [Ce(C 7 H 5 O 3 ) 2 (NO 3 )-(C 12 H 8 N 2 ) 2 ], is isostructural to other related lanthanide structures. The Ce atom is in a pseudo-bicapped squareantiprismatic geometry formed by four N atoms from two chelating 1,10-phenanthroline (phen) ligands and by six O atoms, four from two 2,6-dihydroxybenzoate (DHB) ligands and the other two from a nitrate anion. -stacking interactions between phen and DHB ligands [centroidcentroid distances = 3.513 (3) and 3.762 (2) Å ] and phen and phen ligands [face-to-face separation = 3.423 (7) Å ] of adjacent complexes stabilize the crystal structure. Intramolecular O-HÁ Á ÁO hydrogen bonds are observed in the DHB ligands. Related literature