Bioprospecting Fluorescent Plant Growth Regulators from Arabidopsis to Vegetable Crops

The phytohormone auxin is involved in almost every process of a plant’s life, from germination to plant development. Nowadays, auxin research connects synthetic chemistry, plant biology and computational chemistry in order to develop innovative and safe compounds to be used in sustainable agricultural practice. In this framework, we developed new fluorescent compounds, ethanolammonium p-aminobenzoate (HEA-pABA) and p-nitrobenzoate (HEA-pNBA), and investigated their auxin-like behavior on two main commercial vegetables cultivated in Europe, cucumber (Cucumis sativus) and tomato (Solanumlycopersicum), in comparison to the model plant Arabidopsis (Arabidopsis thaliana). Moreover, the binding modes and affinities of two organic salts in relation to the natural auxin indole-3-acetic acid (IAA) into TIR1 auxin receptor were investigated by computational approaches (homology modeling and molecular docking). Both experimental and theoretical results highlight HEA-pABA as a fluorescent compound with auxin-like activity both in Arabidopsis and the commercial cucumber and tomato. Therefore, alkanolammonium benzoates have a great potential as promising sustainable plant growth stimulators to be efficiently used in vegetable crops

Synthesis and Crystal Structures of Luminescent Mononuclear Ni(ii) and Cd(ii) Complexes with 1,10-phenanthroline

New supramolecular systems of Ni(II) and Cd(II) with 1,10-phenanthroline constructed by non-covalent interactions have been synthesized and characterized by single-crystal X-ray diffractometry. The smaller nickel(II) ion forms a cis complex with outer-sphere perchlorates, while the cadmium(II) ion forms a trans complex involving inner-sphere perchlorates. Both compoundsrevealintraligand-basedluminescentproperties

NEW SOLVATOMORPH OF TETRAKIS(μ2-ACETATO-O,O')-BIS(ISONICOTINAMIDE-N)-DI-COPPER(II): SYNTHESIS, IR, TGA AND X-RAY STUDY

Dinucleartetracarboxylato-bridged copper(II)solvato-morph [Cu2(OAc)4(ina)2] •2dmso was prepared and studied by IR spectroscopy, TGA analysis and single crystal X-ray method. Cu(II) ions are bridged by four syn,syn-η1:η1:μ carboxylates, showing a paddle-wheel cage-type with a square-pyramidal geometry

Diaquabis(pyridine-2-carboxylato-κ2N,O)zinc dimethylformamide hemisolvate

In the title compound, [Zn(C6H4NO2)2(H2O)2]·0.5C3H7NO, the ZnII ion is coordinated in a distorted octahedral N2O4 environment by two N,O-chelating pyridine-2-carboxylate ligands and two cis water molecules. The chelating pyridine-2-carboxylate ligands create two five-membered Zn/N/C/C/O rings, which form a dihedral angle of 86.4 (2)°. In the crystal, O—H...O hydrogen bonds link the complex molecules into a two-dimensional network parallel to (100). The dimethylformamide solvent molecule is disordered about a twofold rotation axis

Tuning Structures And Emissive Properties In A Series Of Zn(Ii) And Cd(Ii) Coordination Polymers Containing Dicarboxylic Acids And Nicotinamide Pillars

New coordination polymers are reported. All polymers were prepared from a blend of four dicarboxylic acids, three neutral nicotinamide ligands, and Zn(ii) or Cd(ii) salts. The acids included: malonic (H2mal), succinic (H2suc), adipic (H2adi), and 1,4-benzenedicarboxylic (H2bdc) acids, with all of them varying in length and rigidity of the carbon skeletons. The neutral ligands included two positional isomers, isonicotinamide (iso-nia) and nicotinamide (nia), and a nia thio-analogue, thionicotinamide (S-nia). The preparation resulted in eight Cd(ii) and four Zn(ii) coordination polymers: [Cd2(suc)(sucH)2(nia)4]n (1), {[Cd(suc)(nia)3]·H2O·dmf}n (2), {[Cd(adi)(iso-nia)2]·dmf}n (3), [Cd(adi)(iso-nia)2]n, (4), {[Zn(mal)(iso-nia)(H2O)]·dmf}n (5), {[Cd(mal)(iso-nia)(H2O)]·dmf}n (6), {[Zn(mal)(nia)(H2O)]·dmf}n (7), {[Cd(mal)(nia)(H2O)]·dmf}n (8), {[Zn(mal)(S-nia)(H2O)]·dmf}n (9), {[Zn(bdc)(nia)2]·dmf}n (10), {[Cd(bdc)(nia)2]·dmf}n (11), and nicotinamide-free {[Cd(bdc)(H2O)2(dmf)]·dmf}n (12). Compounds 1-4 and 12 consist of one-dimensional arrays, while compounds 5-11 are two-dimensional coordination arrays. The coordination cores in 1, 3, 4, 10, and 11 present {M2(COO)2} (M = Zn, Cd) binuclear clusters, while the networks of 2, 5-9 and 12 are built on mononuclear metal nodes with nicotinamide ligands acting as double or single pillars. The structure-confirmed single crystal to single crystal transformation of 3 into 4 was detected and reported. While 1 and 4 are solvent-free apohosts, the remaining solids acted as hosts of water and dmf solvent which are accommodated in the crystal lattices as coordinated ligands or lattice solvents. The new solids were characterized by IR spectroscopy, thermogravimetric analysis, and single-crystal and powder X-ray diffraction methods. The luminescence properties of six as-synthesized coordination polymers and of some activated products are reported. The influence of the metal, ligand, and solvent on tuning the structures and emission properties was monitored, and the most impressive effects were interpreted with the help of TD-DFT computations

From Pink To Blue And Back To Pink Again: Changing The Co(Ii) Ligation In A Two-Dimensional Coordination Network Upon Desolvation

Heating of a pink two-dimensional Co(ii) coordination network {[Co2(μ2-OH2)(bdc)2(S-nia)2(H2O)(dmf)]·2(dmf)·(H2O)}n (1) built from 1,4-benzenedicarboxylic acid (H2bdc) residues and thionicotinamide (S-nia) ligands initiates a single-crystal-to-single-crystal transition accompanied by removal of both coordinated and co-crystallized solvents. In the dry blue form, [Co(bdc)(S-nia)]n (dry-1), the Co(ii) centers changed from an octahedral to a square pyramidal configuration

Mechanism Of Nonlinear Optical Enhancement And Supramolecular Isomerism In 1D Polymeric Zn(Ii) And Cd(Ii) Sulfates With Pyridine-4-Aldoxime Ligands

Interaction of zinc(II) and cadmium(II) sulfates with pyridine-4-aldoxime (4-pyao) and pyridine-4-amidoxime (4-pyamo) ligands resulted in four 1D metal-organic materials (MOMs) with identical composition, [M(SO 4)A2(H2O)2]n, where M = Zn(II), A = 4-pyao for 1, M = Cd(II), A = 4-pyao for 2, M = Zn(II), A = 4-pyamo for 3, M = Cd(II), A = 4-pyamo for 4, and mononuclear [Zn(SO4)(4- pyamo)2(H2O)3] 5. New coordination polymers represent the mixed-ligand supramolecular isomers different by the twisting of two pyridine-4-oxime ligands in the metal coordination environments, and crystallizing in the different space groups. Conformational preferences and nonlinear optical properties of the 4-pyao and 4-pyamo complexes were investigated using density functional theory. Spectral properties of 1-3 have been also evaluated. The solid-state emission of 1D polymers 1-3 appears to be ligand-based, as the positions of the emission maxima remain practically unchanged from free ligand to complexes. The enhancement of luminescence and two-photon absorption in polymers in comparison with the pure ligands is attributed to the chelation of the ligand to the metal center. The detailed mechanism of this enhancement upon complex formation is analyzed and can be used in future design of metal-organic nonlinear optical materials. © 2014 American Chemical Society

From Discrete Molecules To One-Dimensional Coordination Polymers Containing Mn(Ii), Zn(Ii) Or Cd(Ii) Pyridine-2-Aldoxime Building Unit

The syntheses, spectroscopic characterization and crystal structures for eight coordination compounds [Cd(HCO2)2(pya)2] (1), {[M(bdc)(pya)].1.5DMF}n (M = Mn(II), Zn(II), Cd(II) (2-4), [Zn(SO4)(pya)(H2O)3] (H2O) (5), [(ZnSO4)2(pya)4] DMF.2H2O (6), [Zn(SO4)(pya)(H2O)2]n (7), and [Cd(SO4)(pya)(H2O)]n (8) [pya = pyridine-2-aldoxime, bdc = 1,4-benzenedicarboxylate, DMF = N,N′-dimethylformamide] are reported. Compounds 1-4 and 6 contain two, while 5, 7, and 8 contain one neutral pya ligand coordinated in a chelate mode to the metal center through the N pyridyl and Noxime atoms. The dicarboxylic bdc anions provide an access to 1D polymeric arrays in 2-4. The hybrid sulfates including discrete mononuclear (5), binuclear (6), and 1D polymeric (7, 8) coordination arrays were obtained due to different binding modes of coordinated sulfate anion. While solid state fluorescence of new polymeric compounds 2-4 is similar to that of the H2bdc ligand, a rare dual emission is observed for compounds 7 and 8. According to TD-DFT calculations, emission at 400 and 650 nm originates from nπ* and ππ* states of the pya ligand respectively. © 2013 Elsevier Ltd. All rights reserved

Polymeric Luminescent Zn(Ii) And Cd(Ii) Dicarboxylates Decorated By Oxime Ligands: Tuning The Dimensionality And Adsorption Capacity

Ten Zn(II) and Cd(II) metal-organic materials were synthesized and studied by the X-ray method. Among these 10 structures, two represent binuclear clusters, and two are one-dimensional (1D) coordination polymers, while five are laminar two-dimensional (2D) solids and one is the three-dimensional (3D) framework. The investigation has been aimed at rational design of coordination polymers decorated by oxime ligands to increase the accessible adsorption area in these newly synthesized solids. The ligands used include three aliphatic dicarboxylic acids, HOOC-(CH2)n-COOH [n = 1, 2, 4 corresponding to malonic (H2mal), succinic (H2suc), and adipic (H2adi) acids], and three neutral oxime ligands [pyridine-2-aldoxime (2-pyao), pyridine-4-aldoxime (4-pyao), and 1,2-cyclohexanedionedioxime (Niox)]. These novel hybrid solids with the compositions [Zn2(suc)2(2-pyao)4] ·2H2O 1, [Cd2(suc)(2-pyao)4(H 2O)2][BF4]2 2, [Cd(suc)(2-pyao) 2]n 3, [Zn(mal)(4-pyao)(H2O)]n 4, [Cd(mal)(4-pyao)(H2O)]n 5, [Zn(suc)(4-pyao)]n 6, [Zn(adi)(4-pyao)2]n 7, {[Cd(adi)(4-pyao) 2]·dmf}n 8, [Zn(adi)(Niox)]n 9, and [Cd(adi)(Niox)]n 10 [dmf - N,N\u272-dimethylformamide] demonstrate a variable class of coordination supramolecular architectures dictated by the distinctions in the metals\u27 and oxime ligands\u27 coordination capacities and preferences, and length and flexibility of the dicarboxylic linkers. The discrete aggregates 1 and 2 differ by the components\u27 ratio and conformation of the bridging succinate anion; compounds 3 and 7 are 1D arrays, and compounds 4, 5, 6, 8, and 9 represent 2D layers of different topologies. Compound 10 is a 3D grid afforded by the concerted contribution of the longest in this series adipate anion, and the bigger atomic radius Cd(II) vs. Zn(II). The adsorptive properties of 7 and 9 are reported. For the laminar solid 9, the quantum chemical simulations of the adsorption capacity are in line with the experimental results. All new materials reveal dual green-blue wavelength emission in the solid state. © 2014 American Chemical Society