Multi-yolk–shell Bi@C nanostructures were prepared via a facile one-pot template-free hydrothermal approach. The prepared Bi@C nanostructures can act as a solid catalyst in the thermal decomposition of cyclotrimethylenetrinitramine (RDX) and display excellent catalytic activity, which highlights their application in the field of energetic materials.

•Two first-row transition metal complexes are reported.•1 and 2 consist of tetranuclear manganese and binuclear cobalt.•Dominant antiferromagnetic interactions between manganese ions were observed for 1.•Static magnetic measurement for 2 confirms its mixed valence CoΙΙ/CoΙΙΙ nature.The reactions of 2-(((2-hydroxy-3-methoxyphenyl)methylene)amino)-2-(hydroxymethyl)-1,3-propanediol (H4L) and Mn(ClO4)2·6H2O or Co(SCN)2·3H2O in the presence of triethylamine in methanol led to the formation of two new complexes [MnΙΙΙ4(HL)2(H2L)2(CH3OH)4]·4CH3OH·(ClO4)2 (1) and [CoΙΙCoΙΙΙ(H2L)2(CH3OH)(SCN)]·1.5CH3OH·1.5H2O (2), respectively. According to structural data and magnetic properties tetranuclear complex 1 contains four homo-valence manganese (ΙΙΙ) atoms, while in the binuclear complex 2 composed of hetero-valence bi- and trivalent cobalt (ΙΙ, ΙΙΙ) atoms. Weak antiferromagnetic exchange interactions between neighboring manganese ions in 1 have place. χMT for 2 was fitted using a model of isolated cobalt (ΙΙ) ion with zero-field splitting parameters and the study confirms its mixed valence CoΙΙ/CoΙΙΙ nature. No slow magnetic relaxation effects were observed for both complexes in the absence of an applied dc magnetic field.Homo-valence tetranuclear manganese and hetero-valence binuclear cobalt complexes with the formula [MnΙΙΙ4(HL)2(H2L)2(CH3OH)4]·4CH3OH·(ClO4)2 (1) and [CoΙΙCoΙΙΙ(H2L)2(CH3OH)(SCN)]·1.5CH3OH·1.5H2O (2) have been structurally and magnetically characterized.

This work is directed towards the synthesis of multifunctional nanoparticles composed of Fe3O4–Au nanocomposite cores and a porous silica shell (Fe3O4–Au/pSiO2), aimed at ensuring the stability, magnetic, and optical properties of magnetic-gold nanocomposite simultaneously. The prepared Fe3O4–Au/pSiO2 core/shell nanoparticles are characterized by means of TEM, N2 adsorption-desorption isotherms, FTIR, XRD, UV-vis, and VSM. Meanwhile, as an example of the applications, catalytic activity of the porous silica shell-encapsulated Fe3O4–Au nanoparticles is investigated by choosing a model reaction, reduction of o-nitroaniline to benzenediamine by NaBH4. Due to the existence of porous silica shells, the reaction with Fe3O4–Au/pSiO2 core/shell nanoparticles as a catalyst follows second-order kinetics with the rate constant (k) of about 0.0165 l mol−1 s−1, remarkably different from the first-order kinetics with the k of about 0.002 s−1 for the reduction reaction with the core Fe3O4–Au nanoparticles as a catalyst.

Multi-yolk–shell Bi@C nanostructures were prepared via a facile one-pot template-free hydrothermal approach. The prepared Bi@C nanostructures can act as a solid catalyst in the thermal decomposition of cyclotrimethylenetrinitramine (RDX) and display excellent catalytic activity, which highlights their application in the field of energetic materials.

This work is directed towards the synthesis of multifunctional nanoparticles composed of Fe3O4–Au nanocomposite cores and a porous silica shell (Fe3O4–Au/pSiO2), aimed at ensuring the stability, magnetic, and optical properties of magnetic-gold nanocomposite simultaneously. The prepared Fe3O4–Au/pSiO2 core/shell nanoparticles are characterized by means of TEM, N2 adsorption-desorption isotherms, FTIR, XRD, UV-vis, and VSM. Meanwhile, as an example of the applications, catalytic activity of the porous silica shell-encapsulated Fe3O4–Au nanoparticles is investigated by choosing a model reaction, reduction of o-nitroaniline to benzenediamine by NaBH4. Due to the existence of porous silica shells, the reaction with Fe3O4–Au/pSiO2 core/shell nanoparticles as a catalyst follows second-order kinetics with the rate constant (k) of about 0.0165 l mol−1 s−1, remarkably different from the first-order kinetics with the k of about 0.002 s−1 for the reduction reaction with the core Fe3O4–Au nanoparticles as a catalyst.