scholarly journals Thermal, spectroscopic, X-ray and theoretical studies of metal complexes (sodium, manganese, copper, nickel, cobalt and zinc) with pyrimidine-5-carboxylic and pyrimidine-2-carboxylic acids

2019 ◽  
Vol 138 (4) ◽  
pp. 2813-2837 ◽  
Author(s):  
G. Świderski ◽  
R. Świsłocka ◽  
R. Łyszczek ◽  
S. Wojtulewski ◽  
M. Samsonowicz ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Nitrogen Atom ◽  
Metal Complexes ◽  
General Formula ◽  
Pyrimidine Ring ◽  
Carboxylate Ligand ◽  
Metal Centers ◽  
X Ray ◽  
Carboxylate Oxygen ◽  
3D Metal Complexes

Abstract The new 3d metal complexes of pyrimidine-2-carboxylic (2PCA) and pyrimidine-5-carboxylic (5PCA) acids were synthesized and characterized using thermal analysis (TG–DSC, TG–FTIR), X-ray, spectroscopic (IR, Raman) methods and theoretical (DFT) studies. In the complexes of pyrimidine-2-carboxylic acid of the general formula M(2PCA)2·xH2O (where 2PCA-pyrimidine-2-carboxylate; M = Mn(II), Co(II), Ni(II), Cu(II) and Zn; x = 0 for Mn and Cu; x = 2 for Co, Ni and Zn) coordination of metal ions occurs through nitrogen atom from pyrimidine ring and carboxylate oxygen atom. The complexes of pyrimidine-5-carboxylic acid of the general formula M(5PCA)2·xH2O (where 5PCA—pyrimidine-5-carboxylate; M = Mn(II), Co(II), Ni(II), Cu(II) and Zn; x = 6 for Cu and 4 for remaining complexes) were obtained as monomeric isostructural compounds. Coordination of metal centers occurs through two nitrogen atom from different pyrimidine-5-carboxylate ligand and four oxygen atoms from water molecules. The IR and Raman spectra of free acids as well as obtained metal(II) complexes were described in detail. Aromaticity (HOMA, EN, GEO and I6) of complexes was determined and discussed. The investigated compounds decompose in air in two main stages connected with dehydration and decomposition/burning of anhydrous compounds to the suitable metal oxides. Thermal decomposition in nitrogen leads to the evolution of water, carbon oxides, ammonia and pyrimidine molecules.

scholarly journals Synthesis, Crystal Structure and Magnetic Behaviour of Novel 4f-2s Heterometalic One-Dimensional Coordination Polymers on the Base of 2-Furan-Carboxylic Acid

2009 ◽  
Vol 4 (2) ◽  
pp. 60-67
Author(s):  
Silvia Melnic ◽  
Denis Prodius ◽  
Sergiu Shova ◽  
Helen Stoeckli-Evans ◽  
Yurii Simonov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Ir Spectra ◽  
Single Crystal ◽  
General Formula ◽  
Coordination Polymers ◽  
Magnetic Behaviour ◽  
One Dimensional ◽  
X Ray

Nine new complexes with the general formula {[Ln2Ba(α-Fur)8(H2O)4]}n, where Ln = Nd3+, Sm3+, Eu3+, Pr3+, Gd3+, Tb3+, Ho3+, Er3+ and La3+; α-Fur ≡ C4H3OCOO, were synthesized and characterized by IR spectra, magnetism, X-ray single crystal and powder diffractions.

(4R)-Thiazolidine-4-carboxylic acid: ligand specificity and the synthesis and X-ray structure of a cobalt(III) complex

1980 ◽  
Vol 33 (6) ◽  
pp. 1213 ◽  
Author(s):  
GJ Gainsford ◽  
WG Jackson ◽  
AM Sargeson ◽  
AD Watson
Keyword(s):  
Amino Acid ◽  
Carboxylic Acid ◽  
Carboxylate Ligand ◽  
Ligand Specificity ◽  
X Ray ◽  
Acid Ligand ◽  
Carboxylic Acid Ligand

The N,O mode of bonding of the thiazolidine-4-carboxylate ligand and the structure of the Δ-bis-(ethane-1,2-diamine)[(3R,4R)-thiazolidine-4- carboxylato-N,O]cobalt(2+) ion have been determined. The stereospecificity induced by the chiral amino acid between the A and A forms is discussed in relation to analogous proline chemistry.

Trianionic binucleating bis(trityl)/aryloxide ligands and their lithium, magnesium, and zinc complexes

2020 ◽  
Vol 98 (8) ◽  
pp. 453-459
Author(s):  
Tingshan Zhong ◽  
Jixing Zhao ◽  
Hao Lei
Keyword(s):  
Infrared Spectroscopy ◽  
Metal Complexes ◽  
Zinc Complexes ◽  
Electrochemical Methods ◽  
Redox Property ◽  
Metal Centers ◽  
X Ray ◽  
X Ray Crystallography ◽  
Lithium Complexes

A series of lithium complexes with trianionic bis(trityl)/aryloxide ligands were prepared by triple deprotonation of phenols with two ortho-diarylmethyl substituents. Transmetalation with one of the lithium complexes via salt metathesis resulted in the synthesis of corresponding Mg and Zn complexes, which showed distinct coordination stoichiometry and structures. The metal complexes were characterized by multi-nuclear NMR, UV–vis, and infrared spectroscopy. Additionally, the redox property of a trilithium compound was investigated by electrochemical methods. X-ray crystallography revealed that the new bis(trityl)/aryloxide ligands could simultaneously bind to two nearby metal centers both in chelating κ2-O,C fashion, making themselves rare examples of tridentate binucleating alkyl/aryloxo scaffolds.

The Preparation and Crystal Structure of Polymeric Anhydrous Sodium Hydrogen o-Phenylenedioxydiacetate

1992 ◽  
Vol 45 (5) ◽  
pp. 947 ◽  
Author(s):  
RC Bott ◽  
DS Sagatys ◽  
DE Lynch ◽  
G Smith ◽  
CHL Kennard
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Carboxylate Oxygen ◽  
Sodium Hydrogen ◽  
Acid Proton ◽  
Axial Bond ◽  
A Cell ◽  
Ray Methods

The crystal structure of anhydrous sodium hydrogen o-phenylenedioxydiacetate , [Na2( Hbdda )2]n, has been determined by X-ray methods and refined to a residual R 0.031 for 1234 observed reflections. Crystals are monoclinic, space group C2/c with Z 4 in a cell of dimensions a 18.415(6), b 7.4667(7), c 16.354(7) � ,β112.61(2)�. The dimeric repeating unit has two centrosymmetrically related pentagonal pyramidal Na-O6 complex centres [Na-0, 2.272-2.439(2) � ] bridged by carboxylate oxygens. The pentagonal plane comprises four oxygens from the Hbdda ligand as well as one providing the bridging link. The axial bond gives the step-polymer link while the carboxylic acid proton is hydrogen bonded to a carboxylate oxygen of the inversion-related Hbdda ligand [O…O, 2.469(2) � ].

scholarly journals Hydrogen bonded homodimetallic compounds of the formula [M(H2O)5M(dipic)2]·2H2O, M = CoII or NiII and dipic = dipicolinate anion

2017 ◽  
Vol 10 (2) ◽  
pp. 132-138 ◽  
Author(s):  
Petra Masárová ◽  
Jan Moncol
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
Metal Centers ◽  
X Ray ◽  
Carboxylate Oxygen ◽  
Polymeric Networks ◽  
Solvent Molecules ◽  
Oxygen Atoms

AbstractTwo homodimetallic dipicolinate compounds of the formulae [Co(H2O)5Co(dipic)2]·2H2O (1) and [Ni(H2O)5Ni(dipic)2]·2H2O (2) have been synthesized and their crystal structures have been determined by single-crystal X-ray diffraction analysis. The prepared isostructural compounds consist of cationic {MO5O’}2+and anionic {MN2O4}2-moieties, where CoII/CoIIor NiII/NiIImetal centers are connected together by bridging μ-carboxylate oxygen atoms from dipicolinate anions. H-bond interactions involving aqua ligands, dipicolinate oxygens and lattice solvent molecules stabilize the dimeric units by linking them into 3-D polymeric networks.

scholarly journals Molecular co-crystals of 2-aminothiazole derivatives

1999 ◽  
Vol 55 (5) ◽  
pp. 758-766 ◽  
Author(s):  
Daniel E. Lynch ◽  
Laura J. Nicholls ◽  
Graham Smith ◽  
Karl A. Byriel ◽  
Colin H. L. Kennard
Keyword(s):  
Hydrogen Bonding ◽  
Carboxylic Acid ◽  
Ir Spectroscopy ◽  
Proton Transfer ◽  
Powder Diffraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylate Oxygen ◽  
Carboxylate Groups ◽  
Graph Set

A series of molecular adducts of 2-aminothiazole derivatives – 2-aminothiazole, 2-amino-2-thiazoline and 2-aminobenzothiazole with the carboxylic-acid-substituted heterocyclics indole-2-carboxylic acid, N-methylpyrrole-2-carboxylic acid and thiophene-2-carboxylic acid – have been prepared and characterized using X-ray powder diffraction and in five cases by single-crystal X-ray diffraction methods. These five compounds are the adducts of 2-amino-2-thiazolium with indole-2-carboxylate [(C3H7N2S)+(C9H6NO2)−], and N-methylpyrrole-2-carboxylate [(C3H7N2S)+-(C6H6NO2)−], 2-aminobenzothiazolium with indole-2-carboxylate [(C7H7N2S)+(C9H6NO2)−], N-methylpyrrole-2-carboxylate [(C7H7N2S)+(C6H6NO2)−] and thiophene-2-carboxylate [(C7H7N2S)+(C5H3O2S)−]. All complexes involve proton transfer, as indicated by IR spectroscopy, while the five crystal structures display similar hydrogen-bonding patterns with the dominant interaction being an R^2_2(8) graph set dimer association between carboxylate groups and the amine/heterocyclic nitrogen sites. Futhermore, in each case a subsiduary interaction between an amino proton and a carboxylate oxygen completes a linear hydrogen-bonded chain. In addition to this, the indole-2-carboxylate molecules in the adduct structure with 2-amino-2-thiazolium form associated dimers which add to the hydrogen-bonding network.

Die Kristallstruktur des Ectoin, einer neuen osmoregulatorisch wirksamen Aminosäure / The Crystal Structure of Ectoine, a Novel Amino Acid of Potential Osmoregulatory Function

1985 ◽  
Vol 40 (11-12) ◽  
pp. 780-784 ◽  
Author(s):  
Willi Schuh ◽  
Heinrich Puff ◽  
Erwin A. Galinski ◽  
Hans G. Trüper
Keyword(s):  
Crystal Structure ◽  
Amino Acid ◽  
Carboxylic Acid ◽  
Halophilic Bacteria ◽  
Pyrimidine Ring ◽  
Structural Features ◽  
Compatible Solute ◽  
X Ray ◽  
Ectothiorhodospira Halochloris ◽  
Osmoregulatory Function

Abstract The crystal structure of ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidine carboxylic acid) isolated from the extremely halophilic phototrophic bacterium Ectothiorhodospira halochloris was determined by X-ray analysis. This novel cyclic amino acid forms zwitterionic molecules with delocalized π-bonding in the N-C-N group of the hydrated pyrimidine ring. The molecules are connected by N-H ...O hydrogen bonds. The excellent solubility of ectoine in water can be explained by its structural features which also account for its function as a compatible solute in halophilic bacteria.

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