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

Dual Behavior of Ammonium Acetate for the Synthesis of Diverse Symmetrical/Unsymmetrical Bis[1,3]oxazines Possessing Anticancer Activity

<div><p></p><p>A simple and efficient approach was developed to synthesize symmetrical/unsymmetrical bis[1,3]oxazines using ammonium acetate with controllable substitution patterns in a one-pot fashion. In a representative crystal structure, the [1,3]oxazine ring is in a distorted semichair conformation with C2-carbon and nitrogen atoms residing above and below the naphthalene plane, leading to strain in the ring that allows ring-opening polymerization to take place. A few of the derivatives were found to possess anticancer activity. This current modest protocol affords numerous advantages such as mild reaction condition, shorter reaction time, operational simplicity, and excellent yield.</p></div

Tuning the Electronic Properties of 2‑Cyano-3-phenylacrylamide Derivatives

We are the first to report the synthesis of a new class of 2-cyanoarylacrylamide (2-CAA) derivatives and observe that the synthesized 2-CAA shows fluorescence properties due to the formation of a dimeric interaction of hydrogen bonds between carbonyl oxygens and amide hydrogens (CO···H–N–CO···H–N···); i.e., dimers are linked through dimeric N–H···O hydrogen bonds. The single-crystal X-ray structure shows molecules to be hydrogen-bonded dimers, which further form a parallel stacking arrangement, mediated by significant π–π interactions. The ¹H NMR and fluorescence spectral studies indicate the coexistence of amide and iminol tautomers in solution, which can be influenced by the nature of the solvent. Further, the excitation-wavelength-dependent fluorescence spectrum and the biexponential fluorescence decay profiles suggest the presence of more than one emitting species; i.e., amide and iminol tautomers coexists in solution. We have also shown that the equilibrium between the two tautomers can be tuned by the judicious choice of electron-donating or -withdrawing substituents