Neodymium Alkoxides: Synthesis, Characterization and Their Combinations with Dialkylmagnesiums as Unique Systems for Polymerization and Block Copolymerization of Ethylene and Methyl Methacrylate

Gromada, Jérôme; Mortreux, André; Chenal, Thomas; Ziller, Joseph W.; Leising, Frédéric; Carpentier, Jean‐François

doi:10.1002/1521-3765(20020816)8:16<3773::aid-chem3773>3.0.co;2-s

Cited by 92 publications

(56 citation statements)

References 20 publications

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“…Two additional μ 3 -bridging alkoxy ligands (O1 and O2) are present below and above the triangular plane, resulting in a 6-fold oxygen coordination around each of the Pr centers as generally favored by this class of lanthanide compounds. 12,23 The obtained molecular structure is similar to those reported for yttrium, lanthanum, terbium, and gadolinium tert-butoxides. 6a,b,11,13 Herein, the Pr−O bond lengths (Table 4) fit well with the trend of the Ln−O bond 24 ).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Templating Influence of Molecular Precursors on Pr(OH)₃ Nanostructures

et al. 2015

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Four new praseodymium alkoxo and amido compounds ([Pr3(μ3-OtBu)2(μ2-OtBu)3(OtBu)4(HOtBu)2] (1), [Pr{OC(tBu)3}3(THF)] (2), [PrCl{N(SiMe3)2}2(THF)]2 (3), and [PrCl{OC(tBu)3}2(THF)]2 (4)) were synthesized and structurally characterized by single-crystal X-ray diffraction analysis. Application of these compounds in solvothermal synthesis of praseodymium oxide/hydroxide nanostructures showed their templating influence on the morphology and phase composition of the resulting solid-state materials. Differential reactivity of the chosen alkoxide ligands toward water and the different arrangements of metal-oxygen units in the studied precursor compounds strongly influenced the kinetics of hydrolysis and cross-condensation reactions as manifested in the morphological changes and phase composition of the final products. Thermal decomposition studies of 1-4 confirmed their conversion into the corresponding oxide phases. Activation of compounds 1, 2, and 4 by either a base or a stoichiometric amount of water showed the distinct influence of their chemical configuration on the obtained nanopowders: whereas 1 solely produced nanorods of Pr(OH)3, 2 predominantly formed a mixture of rod-shaped and spherical particles. The solvothermal decomposition of 4 resulted in Pr(OH)2Cl or PrOCl due to the presence of Cl ligands in the molecular precursor. The resultant materials were thoroughly characterized to demonstrate the relationship between precursor chemistry and the processing parameters that are clearly manifested in the morphology and phase of the final ceramics.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Templating Influence of Molecular Precursors on Pr(OH)₃ Nanostructures

et al. 2015

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“…A full listing of individual compounds would be prohibitively long, and as many of the products are not organometallic species, they are often discussed in other places, such as CCC (2004). 206 Dialkylmagnesium Figure 25). It has been used to produce magnesium thiolates, 176-178 amides 179-184 (sometimes with heteroleptic alkyl/amide species), 180,185 carboxylato or carbamato complexes, 186 furfurylamides, 187 isothiocyanate and carbodiimide insertion products, 149 phosphides, 185,188-190 hydrazides, 191,192 phosphanediides, 193,194 arsandiides, 195 arsinoanilides, 196 aryloxides, [197][198][199] siloxides, 199 molecular hydrides, 200 4 .…”

Section: Reactionsmentioning

confidence: 99%

Alkaline Earth Organometallics

Hanusa

2014

Reference Module in Chemistry, Molecular Sciences and Chemical Engineering

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“…In 2000, a neodymium t-butoxide complex, [Nd 3 (l 3 -OBu t ) 2 (l 2 -OBu t ) 3 (OBu t ) 4 (THF) 2 ] (56), was reported to show moderate activity for ethylene polymerization in the presence of one equivalent of dialkylmagnesium in toluene at 0°C [45,46]. Progressive deactivation of the catalyst system was observed above 20°C.…”

Section: Cp-free Complexesmentioning

confidence: 99%

“…During the course of the polymerization, polymer-like precipitate appears in the reaction mixture. The precipitate is assumed to be a Nd-polyethylenyl compound, which still has activity for further ethylene polymerization and enables block copolymerization of ethylene with MMA [46]. Calixarene complexes of rare earth metals exhibit moderate activity in the presence of AlBu i 3 , although their structures are not clear [48].…”

Section: Cp-free Complexesmentioning

confidence: 99%