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Modification of aluminium alkoxides with dialkylmalonates.

Lichtenberger R, Baumann SO, Bendova M, Puchberger M, Schubert U - Monatsh. Chem. (2010)

Bottom Line: Al(malonate)3 (malonate = dimethyl, diethyl, di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)4(malonate)2 (malonate = di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)2(di-iso-propylmalonate)4 and Al3(OH)(OEt)3(diethylmalonate)5.An Al2(OiPr)2(dialkylmalonate)4 derivative was only obtained by disproportionation of Al2(OiPr)4(di-iso-propylmalonate)2, but not by reaction of Al(OiPr)3 with dialkylmalonates in the corresponding molar ratio.Reactions of Al(OtBu)3 only resulted in Al(malonate)3 derivatives, but no transesterification was observed, contrary to the reaction of Al(OiPr)3 with dimethyl or diethyl malonate.

View Article: PubMed Central - PubMed

Affiliation: Institute of Materials Chemistry, Vienna University of Technology, Vienna, Austria.

ABSTRACT

Abstract: Depending on the reaction conditions, different aluminium dialkylmalonate derivatives were obtained by reaction of aluminium alkoxides Al(OR)3 (R = Et, iPr, tBu) with dialkylmalonates, viz. Al(malonate)3 (malonate = dimethyl, diethyl, di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)4(malonate)2 (malonate = di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)2(di-iso-propylmalonate)4 and Al3(OH)(OEt)3(diethylmalonate)5. All compounds were characterized by NMR spectroscopy, and single crystal structure analyses are reported for each type of compound. An Al2(OiPr)2(dialkylmalonate)4 derivative was only obtained by disproportionation of Al2(OiPr)4(di-iso-propylmalonate)2, but not by reaction of Al(OiPr)3 with dialkylmalonates in the corresponding molar ratio. Reactions of Al(OtBu)3 only resulted in Al(malonate)3 derivatives, but no transesterification was observed, contrary to the reaction of Al(OiPr)3 with dimethyl or diethyl malonate.

No MeSH data available.


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Molecular structure of 1d (hydrogen atoms omitted for clarity)
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Fig2: Molecular structure of 1d (hydrogen atoms omitted for clarity)

Mentions: Single crystal X-ray diffraction (XRD) of 1a and 1d (Fig. 2) revealed nearly ideal octahedral coordination around the central aluminium atom, with negligible differences in Al–O bond distances (186.9(1)–189.3(1) pm) and bite angles of the malonates very close to 90° (90.39(4)–91.36(4)°). Interestingly, the bond distances are distinctly shorter than those observed for Al–Oester bonds in Al(tert-butyl acetoacetate)3 [26] (193.0(2)–195.1(2) pm) and are more in the range of the Al–Oketo distances (185.7(2)–186.8(2) pm) in the same complex [27] or in Al(acac)3 (acac = acetylacetonate) (188.0(2) pm) [27].Fig. 2


Modification of aluminium alkoxides with dialkylmalonates.

Lichtenberger R, Baumann SO, Bendova M, Puchberger M, Schubert U - Monatsh. Chem. (2010)

Molecular structure of 1d (hydrogen atoms omitted for clarity)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4494765&req=5

Fig2: Molecular structure of 1d (hydrogen atoms omitted for clarity)
Mentions: Single crystal X-ray diffraction (XRD) of 1a and 1d (Fig. 2) revealed nearly ideal octahedral coordination around the central aluminium atom, with negligible differences in Al–O bond distances (186.9(1)–189.3(1) pm) and bite angles of the malonates very close to 90° (90.39(4)–91.36(4)°). Interestingly, the bond distances are distinctly shorter than those observed for Al–Oester bonds in Al(tert-butyl acetoacetate)3 [26] (193.0(2)–195.1(2) pm) and are more in the range of the Al–Oketo distances (185.7(2)–186.8(2) pm) in the same complex [27] or in Al(acac)3 (acac = acetylacetonate) (188.0(2) pm) [27].Fig. 2

Bottom Line: Al(malonate)3 (malonate = dimethyl, diethyl, di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)4(malonate)2 (malonate = di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)2(di-iso-propylmalonate)4 and Al3(OH)(OEt)3(diethylmalonate)5.An Al2(OiPr)2(dialkylmalonate)4 derivative was only obtained by disproportionation of Al2(OiPr)4(di-iso-propylmalonate)2, but not by reaction of Al(OiPr)3 with dialkylmalonates in the corresponding molar ratio.Reactions of Al(OtBu)3 only resulted in Al(malonate)3 derivatives, but no transesterification was observed, contrary to the reaction of Al(OiPr)3 with dimethyl or diethyl malonate.

View Article: PubMed Central - PubMed

Affiliation: Institute of Materials Chemistry, Vienna University of Technology, Vienna, Austria.

ABSTRACT

Abstract: Depending on the reaction conditions, different aluminium dialkylmalonate derivatives were obtained by reaction of aluminium alkoxides Al(OR)3 (R = Et, iPr, tBu) with dialkylmalonates, viz. Al(malonate)3 (malonate = dimethyl, diethyl, di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)4(malonate)2 (malonate = di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)2(di-iso-propylmalonate)4 and Al3(OH)(OEt)3(diethylmalonate)5. All compounds were characterized by NMR spectroscopy, and single crystal structure analyses are reported for each type of compound. An Al2(OiPr)2(dialkylmalonate)4 derivative was only obtained by disproportionation of Al2(OiPr)4(di-iso-propylmalonate)2, but not by reaction of Al(OiPr)3 with dialkylmalonates in the corresponding molar ratio. Reactions of Al(OtBu)3 only resulted in Al(malonate)3 derivatives, but no transesterification was observed, contrary to the reaction of Al(OiPr)3 with dimethyl or diethyl malonate.

No MeSH data available.


Related in: MedlinePlus