Synthesis and Characterization of a Series of Lanthanide Complexes Constructed from Orotic Acid

Understanding the Self-Assembling Behavior of Biological Building Block Molecules: A Spectroscopic and Microscopic Approach

"Mother nature" utilizes molecular self-assembly as an efficient tool to design several fascinating supramolecular architectures from simple building blocks like amino acids, peptides, and nucleobases. The self-assembling behavior of various biologically important molecules, morphological outcomes, molecular mechanism of association, and finally their applications in the real world draw broad interest from chemical and biological point of views. In this present Feature Article, the amyloid hypothesis is extended to include nonproteinaceous single metabolites that invoke a new paradigm for the pathology of inborn metabolic disorders. In this scenario, we dedicate this paper to understanding the morphological consequences and mechanistic insight of the self-assembly of some important amino acids (e.g., l-phenylalanine, l-tyrosine, glycine, etc.) and nucleobases (adenine and eight uracil moiety derivatives). Using proper spectroscopic and microscopic tools, distinct assembling mechanisms of different amino acids and nucleobases have been established. Again, lanthanides, polyphenolic compounds such as crown ethers, and a worldwide drink, beer, are elegantly employed as inhibitors of the resulting fibrillar aggregated structures. As a consequence, this study will cover literally a vast region in the self-assembling outcomes of single biologically important molecules, and therefore, we expect that a detailed understanding of such morphological outcomes using spectroscopic and microscopic approaches may open a new paradigm in this burgeoning field.

Two novel 3d–4f heterometallic coordination polymers with infinite [Ln4(OH)4]n8n+ chains involving in situ decarboxylation

Two novel heterometallic coordination polymers with infinite Ln₄(OH)₄]_n⁸ⁿ⁺ chains [Ln₄Co(QDA)₂(QA)₆(OH)₄(H₂O)₄] (Ln = Tb1, Dy2; H₂QDA = 2,3-quinolinedicarboxylic acid, HQA = 3-quinolinecarboxylic acid) have been achieved.

Solid state simulation of tetramer form of 5-aminoorotic acid: the vibrational spectra and molecular structure study by using MP2 and DFT calculations

The Raman and IR spectra of the biomolecule 5-aminoorotic acid in the solid state were simulated by a dimer and tetramer forms, with the special interest in the interactions that involve the NH and NH(2) groups. The unit cell expected in the crystal was simulated as a tetramer form by density functional calculations. They were performed to clarify wavenumber assignments of the experimentally observed bands in the spectra. Correlations with the molecule of uracil were made, and accurate scaling procedures deduced by us were employed in the calculated wavenumbers of 5-aminoorotic acid. Good reproduction of the experimental wavenumbers is obtained and the % error is very small in the majority of cases. This fact confirms our simplified solid state model. The scaling leads to a reassignment of the IR and Raman experimental bands. The NBO atomic charges and several thermodynamic parameters were also calculated.

Poly[aqua-(μ(5)-2-oxido-4-sulfonato-benzoato)lanthanum(III)]

The title compound, [La(C(7)H(3)O(6)S)(H(2)O)](n), forms a three-dimensional framework in which the asymmetric unit contains one La(III) atom, one 5-sulfosalicylate (2-oxido-4-sulfonatobenzoate) ligand and one coordinated water mol-ecule. The La(III) atom is coordinated by nine O atoms from three carboxyl-ate, three sulfonate and two hydroxyl groups, and one water mol-ecule, forming a distorted trigonal-prismatic square-face tricapped geometry.

New Coordination Polymers of Lanthanide(III) with Tetrazole-1-acetic Acid: Synthesis, Crystal Structures, and Magnetic Properties

New coordination polymers {[Ln(tza)3(H2O)2]·mH2O}n (Ln = LaIII 1 and PrIII 2, m = 2; Ln = NdIII 3, m = 1.5) and {[Sm2(tza)6(H2O)5]·H2O}n 4 (Htza = tetrazole-1-acetic acid) have been synthesized and characterized by IR spectroscopy, elemental analysis, X-ray crystallography, and magnetic measurements. The Htza ligand coordinates to the lanthanide cations through the carboxylate group in a monodentate, bridging bidentate coordination mode or bridging tridentate to two metal centres. Complexes 1 and 2 are isostructural. Complex 3 has a similar structure to 1 and 2, but the arrangement of ligands has changed. Complex 4 consists of two types of metallic molecules. Magnetic measurements show weak antiferromagnetic coupling between the metal centres in complexes 2 and 3.

Syntheses, Structures, and Luminescent and Magnetic Properties of Novel Three-Dimensional Lanthanide Complexes with 1,3,5-Benzenetriacetate

Five novel lanthanide complexes with the formulas [Nd(bta)(H2O)2.4.35H2O]n(1), [Sm(bta)(H2O)2.4.5H2O]n (2), [Eu(bta)(H2O).1.48H2O]n (3), [Tb(bta)(H2O).1.31H2O]n (4), and [Yb(bta)(H2O).H2O]n (5) (H3bta = 1,3,5-benzenetriacetic acid) have been prepared by using the corresponding lanthanide salt and H3bta. The results of an X-ray crystallographic analysis revealed that all the complexes have three-dimensional channel-like structures, in which the bta3- ligands adopt different coordination modes: monodentate and mu2-eta2:eta1-bridging coordination modes in 1, 2, and 5 and mu2-eta1:eta1-bridging and mu2-eta2:eta1-bridging coordination modes in 3 and 4, respectively. Complexes 1 and 2, as well as 3 and 4, are isostructural, respectively, in which all the Ln(III) (Ln = Nd, Sm, Eu, and Tb) atoms are nine-coordinated, while the Yb(III) atoms in complex 5 are eight-coordinated. Both complexes 3 and 4 showed strong luminescence upon excitation, and their luminescence decay curves fit well with single exponential decays of which the lifetime is 0.45 ms for 3 and 1.0 ms for 4. The magnetic properties of the complexes were investigated in the temperature range of 1.8-300 K.