Synthetic studies and structural aspects of novel metallacyclic compoundsof titanium(IV) incorporating nitrogen, oxygen and sulphur: 1. Reactions of cis-dialkoxy-bis(acetylacetonato)titanium(IV) with alkoxyalkanols and the crystal structure of a new modification: di-μ-oxo-bis[diacetylacetonatotitanium(IV)]

Reactions of cis-dialkoxy-bis(acetylacetonato)titanium(IV), [(acac)2Ti(OR)2] (R = Et, Pr i ) with alkoxyalkanols (ROCH2CH2OH) (R = Me, Et, n-Bu) in 1:1 and 1:2 molar ratios in refluxing benzene under anhydrous conditions yield [(acac)2Ti(OR)2-n (OCH2CH2OR) n ] (n = 1 or 2) complexes, which were purified by distillation under reduced pressure. On the basis of i.r. and n.m.r. (1H- and 13C-) spectral studies, a cis-octahedral environment around TiIV is proposed. On keeping the distilled dark brown-red viscous liquid [(acac)2Ti(OEt)(OCH2CH2OBu)] for 2 weeks, orange yellow crystals of [(acac)2TiO]2 were obtained. A single crystal X-ray diffraction study suggests the product is a new modification of [(acac)2TiO]2

Fluorescent aluminum chelate complexes as modified precursors for nano-structured alumina

<p>A series of new mononuclear heteroleptic derivatives of aluminum(III), {[(CH₃COCHCOCH₃)AlL] (<b>1</b> and <b>4</b>)}, {[(C₆H₅COCHCOC₆H₅)AlL] (<b>2</b>, <b>5</b>, and <b>7</b>)}, and {[(C₉H₆NO)AlL] (<b>3</b> and <b>6</b>)}, have been synthesized by reacting Al(OPr^<i>i</i>)₃ with tridentate Schiff base H₂L^x (H₂L¹ = C₁₃H₁₀BrNO₂; H₂L² = C₁₄H₁₃NO₃; H₂L³ = C₁₇H₁₃NO₂) and β-diketone/8-hydroxyquinoline (β-diketone = acetylacetone/dibenzoylmethane) in 1 : 1 : 1 stoichiometry using anhydrous benzene and ethanol. All the complexes were characterized by elemental analysis, FTIR, and NMR (¹H and ¹³C) spectral studies. Molecular structures obtained from single-crystal XRD of aqua <b>1</b> (<b>1a</b>) and DMSO coordinated <b>2</b> (<b>2a</b>) authenticate their existence. Further, nanostructured α-alumina was synthesized from <b>1</b> by well-established sol–gel method and was characterized by powder XRD, TEM, and EDX analyses.</p

Synthesis, structural, and ε-caprolactone polymerization studies of heteroleptic derivatives of aluminum(III)

<div><p>A series of metallo-organic complexes of Al(III), [(CH₃COCHCOCH₃)₂Al(OR)]₂ [where R = <i>o</i>-MeC₆H₄ (<b>1</b>), <i>m</i>-MeC₆H₄ (<b>2</b>), <i>p</i>-MeC₆H₄ (<b>3</b>), C₆H₅CH₂ (<b>4</b>), <i>o</i>-ClC₆H₄CH₂ (<b>5</b>), <i>m</i>-ClC₆H₄CH₂ (<b>6</b>), and <i>p</i>-ClC₆H₄CH₂ (<b>7</b>), were synthesized quantitatively by treating Al(OPrⁱ)₃ with CH₃COCH₂COCH₃ and the phenols (<i>o</i>-MeC₆H₄OH, <i>m</i>-MeC₆H₄OH, and <i>p</i>-MeC₆H₄OH) concerned as well as phenylmethanols (C₆H₅CH₂OH, <i>o</i>-ClC₆H₄CH₂OH, <i>m</i>-ClC₆H₄CH₂OH, and <i>p</i>-ClC₆H₄CH₂OH) in suitable stoichiometry using benzene as solvent. All these complexes were soluble in common organic solvents, having sharp melting points, and they were characterized by elemental analysis, IR, and NMR (¹H and ¹³C) spectral studies. Single-crystal XRD followed by ORTEP diagram of solvated complex (<b>1a</b>) revealed its dimeric nature and the existence of six-coordinate aluminum. The complexes were studied in ring-opening polymerization of ε-caprolactone. The molecular weight and polydispersity index values of polycaprolactone were obtained by gel permeation chromatography analysis.</p></div