Organometallic Derivatives of Cyclotriphosphazene as Precursors of Nanostructured Metallic Materials: A New Solid State Method

Solid-state synthesis of embedded single-crystal metal oxide and phosphate nanoparticles and in situ crystallization

“…The broad and relatively low intensity peaks in the double-angle 2θ range 10-28° can be assigned to P 4 O 7 [21] and has been previously observed in the pyrolysis of organometallic derivatives of polyphosphazenes [22] and cyclotriphosphazenes. [23,27] In addition, some relatively weak reflections are observed at 2θ = 5.9° and 6.4° suggest the formation of quantities of hexagonally ordered mesoporous SiO 2 . [28] The SEM images exhibit a tridimensional porous network, as is shown in Fig.…”

“…[22] The formation in air of the nanostructures from the organometallic cyclic phosphazenes can be summarized by the loss or decomposition of some ligands of the organometallic fragment to produce vacant sites, producing a cyclomatrix network. [23] Scheme 2 represents the initial thermal decomposition, where it has been shown [34] that the organometallic fragments Mo(CO) 5 and Mo(CO) 4 py linked to the phosphazene precursors, respectively, lose carbon monoxide through decarbonylation upon heating to 300 °C. Extensive cross-linking leads to W centers that migrate toward the vacancies generated in the cyclomatrix.…”

“…Organometallic derivatives, both cyclic and polymeric phosphazenes, are emerging as useful precursors of metallic nanostructured materials. [21][22][23] Precursors containing two different organometallic fragments coordinated to the phosphorus ring of a cyclotriphosphazene have not yet been successfully realized as nanomaterial precursors. [24] This method is so versatile it allows us to form many transition metals to form as oxide, phosphate and also pyrophosphates which offer high lithium-ion mobilities for fast charging lithium-ion phosphate-based cathode materials.…”

Layered Graphitic Carbon Host Formation during Liquid-free Solid State Growth of Metal Pyrophosphates

“…As previously shown 24 , this step is essential in preventing the volatilization of the sample on heating. The second step involves carbonization of the organic matter.…”

“…By comparison, relatively few solid-state strategies for pure metallic nanostructured materials have been reported [18][19][20][21][22] . In recent work [23][24][25][26][27][28][29] , we reported a new solid-state method allowing the formation of metallic (M), oxidic (M x O y ) and (pyro)phosphate-based (M x P y O z ) nanostructured materials without necessitating liquids or solutions. Detailed investigations have shown that the resulting structures and their shapes strongly depend on the metal used, which can be a noble, transition or valve metal, and also on the molecular precursors to which the metal centers are coordinated.…”