Metal alkoxides as precursors for electronic and ceramic materials

Influence of Metal Fragment Mobility and Solution Dynamics on Cationic Rearrangements in Multimetallic Alkoxide Frameworks

“…[46] Small deviations in bond lengths and angles can be attributed to the different ionic radii of Zr, Hf and Ce. The bonding parameters of aluminium were also comparable to those found for other alkoxide compounds with {Al(OPr i ) 4 } À units. [47,48] Electron Impact Mass Spectrometry and multinuclear NMR Analysis…”

“…The methine proton region showed two overlapping broad multiplett signals (5.04, 4.94 ppm) with a summed up integral of 9 corresponding to the nine isopropoxo groups of the nonaisopropoxo-dicerate ligand. Two sharp overlapping septet signals displayed at 4.40 and 4.35 ppm with a summed up integral of 5 were assigned to the four isopropoxo groups of the {Al(OPr i ) 4 } À unit and the single methine proton of the coordinating solvent molecule. The two methyl proton doublets were observed in a ratio of 4 : 10.…”

“…[1][2][3][4][5][6][7][8][9] The preorganized metal À oxygen (alkoxy) bonds and the intrinsic reactivity against nucleophilic attack as well as the thermally labile nature of the organic periphery makes metal alkoxides ([M(OR) x ], [MM'(OR) x + y ]) as preferred starting materials for sol À gel and chemical vapor deposition processes. [2,[10][11][12][13][14][15][16] Metal-organic compounds in general enable low temperature processing of nanostructured oxides and their solid-solutions or composites that are challenging to obtain by traditional solid-state reactions.…”

“…[1,3,10] The extraordinary structural stability and rigidity (in solution) of the bioctahedral {M 2 (OR) 9 } À unit, also valid for other tetravalent metals (Ti, Hf, and Sn), [31,32] has played an important role in the development of polymetallic alkoxides, [13,31,[33][34][35] especially the use of heterobimetallic halo isopropoxides as building blocks for heterotrimetallic compounds. [13,31,34,35] In the context of Ce IV alkoxides, apart from the formation of [(m-OPr i )Ba{Ce 2 (OPr i ) 9 }] 2 [36] in solution, no report is available on the structural characterization of the {Ce 2 (OPr i ) 9 4 ], [37] [36] (thd = 2,2,6,6-tetramethylheptane-3,5-dione) contain appropriate assembling ligands in the metal coordination sphere. The interest for mixed-metal cerium containing ceramics [36] prompted our research work in heterobi-and trimetallic cerium-isopropoxides.…”

Polyether Adducts of d‐Block Metal Compounds as Starting Materials for New Cluster Compounds

“…clusters, and polymers or metal organic frameworks [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Indeed, since more than two decades, metal aggregates are used in the low-cost synthesis of superconductors and other oxide materials based on the sol-gel technique or as volatile precursors in the MOCVD (Metal Organic Chemical Vapor Deposition) process [3,11,13,[17][18][19][20][21]. One of the major problems of the synthesis of organo-metal(II) compounds, including the alkaline earth metal ions, is their possible tendency to form insoluble polymers [21][22][23][24], on one hand due to their low metal oxidation state M II , which only allows two anionic ligands, and on the other hand, their ionic radii, which demand a high coordination number.…”