Supramolecular networks and Hirshfeld surfaces of oxydiacetic acid and iminodiacetic acid salts

2019 ◽  
Vol 75 (3) ◽  
pp. 449-458
Author(s):  
V. Gomathi ◽  
C. Theivarasu
Keyword(s):  
Iminodiacetic Acid ◽  
Intramolecular Proton Transfer ◽  
Zigzag Chain ◽  
One Dimensional ◽  
Molecular Salts ◽  
Hirshfeld Analysis ◽  
Supramolecular Networks ◽  
Oxydiacetic Acid ◽  
Supramolecular Chains

Oxydiacetic acid (Oda) and iminodiacetic acid (Ida) have been combined with two diamines, namely ethylenediamine (en) and o-phenylenediamine (o-phen), to give three molecular crystals of compositions [(Oda2−)(en2+)]·H2O (Odaen), [(Ida−)(0.5en+)] (Idaen) and [(Oda−)(o-phen+)] (Odaophen). Single crystal X-ray structure determination of the three molecular salts revealed that the hydrogen bonding interactions form distinct supramolecular chains. In Odaen, water molecules and Oda2− anions generate one-dimensional supramolecular chains where two chains overlap each other in zigzag form. In Odaophen, Oda− anions generate a one-dimensional linear supramolecular chain. In Idaen, both intermolecular and intramolecular proton transfer occurs. Ida− anions generate a one-dimensional zigzag chain. These one-dimensional supramolecular chains extend to form different two-dimensional supramolecular chains by the interaction of diaminium and monoaminium cations. Intermolecular close contacts are also examined using Hirshfeld analysis to reveal similarities and differences in the crystal structures.

Hydrogen-bonded assemblies in the molecular crystals of 2,2′-thiodiacetic acid with ethylenediamine ando-phenylenediamine

2017 ◽  
Vol 73 (2) ◽  
pp. 97-103 ◽  
Author(s):  
V. Gomathi ◽  
C. Theivarasu
Keyword(s):  
Crystal Engineering ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Molecular Crystals ◽  
Charge Transfer Complexes ◽  
Supramolecular Network ◽  
One Dimensional ◽  
Supramolecular Networks ◽  
Supramolecular Chains ◽  
Hydrogen Bonded

Carboxylate molecular crystals have been of interest due to the presence of hydrogen bonding, which plays a significant role in chemical and crystal engineering, as well as in supramolecular chemistry. Acid–base adducts possess hydrogen bonds which increase the thermal and mechanical stability of the crystal. 2,2′-Thiodiacetic acid (Tda) is a versatile ligand that has been widely explored, employing its multidendate and chelating coordination abilities with many metals; however, charge-transfer complexes of thiodiacetic acid have not been reported. Two salts, namely ethylenediaminium 2,2′-thiodiacetate, C2H10N22+·C4H4O4S22−, denoted Tdaen, and 2-aminoanilinium 2-(carboxymethylsulfanyl)acetate, C6H9N2+·C4H5O4S−, denoted Tdaophen, were synthesized and characterized by IR,1H and13C NMR spectroscopies, and single-crystal X-ray diffraction. In these salts, Tda reacts with the aliphatic (ethylenediamine) and aromatic (o-phenylenediamine) diamines, and deprotonates them to form anions with different valencies and different supramolecular networks. In Tdaen, the divalent Tda2−anions form one-dimensional linear supramolecular chains and these are extended into a three-dimensional sandwich-type supramolecular network by interaction with the ethylenediaminium cations. However, in Tdaophen, the monovalent Tda−anions form one-dimensional zigzag supramolecular chains, which are extended into a three-dimensional supramolecular network by interaction with the 2-aminoanilinium cations. Thus, both three-dimensional structures display different ring motifs. The structures of these diamines, which are influenced by hydrogen-bonded assemblies in the molecular crystals, are discussed in detail.

Improved thin-layer chromatographic determination of phospholipids in gastric aspirate from newborns, for assessment of lung maturity.

1988 ◽  
Vol 34 (4) ◽  
pp. 736-738 ◽  
Author(s):  
D Serrano de la Cruz ◽  
E Santillana ◽  
A Mingo ◽  
G Fuenmayor ◽  
A Pantoja ◽  
...  
Keyword(s):  
Thin Layer ◽  
Fetal Lung ◽  
Chromatographic Determination ◽  
Solvent Mixture ◽  
Gastric Aspirate ◽  
One Dimensional ◽  
Acetic Acid Water ◽  
Chromatographic Resolution ◽  
Lung Maturity

Abstract This one-dimensional thin-layer chromatographic method is used for assay of phospholipids in the gastric aspirate of newborns. The solvent mixture (chloroform/hexane/methanol/glacial acetic acid/water, 12/7/4/3/0.3 by vol) completely resolves lecithin, sphingomyelin, phosphatidylinositol, phosphatidylserine, phosphatidylethanolamine, and phosphatidylglycerol. The method is simple, precise, inexpensive, and rapid (chromatographic development takes less than 25 min) and gives high chromatographic resolution. We used this method to determine the lecithin/sphingomyelin densitometric ratio (L/S ratio) and the phosphatidylglycerol percentage in 200 samples of gastric aspirate and found an L/S ratio of 2.5 to be a satisfactory cutoff value for distinguishing fetal lung maturity and immaturity. We confirmed that the presence of phosphatidylglycerol excluded the possibility of respiratory distress.

Formalism for the determination of intermediate stress gradients using X-ray diffraction

2009 ◽  
Vol 42 (2) ◽  
pp. 192-197 ◽  
Author(s):  
Thomas Gnäupel-Herold
Keyword(s):  
Lattice Strain ◽  
Narrow Line ◽  
X Ray Diffraction ◽  
Beam Spot ◽  
Strain Measurements ◽  
One Dimensional ◽  
X Ray ◽  
Stress Gradients ◽  
Shaped Beam

A method is outlined that allows the determination of one-dimensional stress gradients at length scales greater than 0.2 mm. By using standard four-circle X-ray diffractometer equipment and simple aperture components, length resolutions down to 0.05 mm in one direction can be achieved through constant orientation of a narrow, line-shaped beam spot. Angle calculations are given for the adjustment of goniometer angles, and for the effective azimuth and tilt of the scattering vector for general angle settings in a four-circle goniometer. The latter is necessary for the computation of stresses from lattice strain measurements.

Experimental determination of spectral densities in quasi-one-dimensional electron systems

1998 ◽  
Vol 249-251 ◽  
pp. 175-179
Author(s):  
B. Kardynal ◽  
C.H.W. Barnes ◽  
E.H. Linfield ◽  
D.A. Ritchie ◽  
J.T. Nicholls ◽  
...  
Keyword(s):  
Experimental Determination ◽  
Electron Systems ◽  
Dimensional Electron ◽  
Spectral Densities ◽  
One Dimensional

Determination of soil water hydraulic parameters from infiltration data

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yan Gao ◽  
Kai Chang ◽  
Xuguang Xing ◽  
Jiaping Liang ◽  
Nian He ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Test Method ◽  
Water Retention Curve ◽  
Absorption Method ◽  
Retention Curve ◽  
Content Type ◽  
One Dimensional ◽  
Water Diffusivity

PurposeTraditional laboratory measurements of soil water diffusivity (D) and soil water retention curve (SWRC) are always time-consuming and labor-intensive. Therefore, this paper aims to present a simple and robust test method for determining D and SWRC without reducing accuracy.Design/methodology/approachIn this study, a D model of unsaturated soil was established based on Gardner–Russo model and then a combination of Gardner–Russo model with one-dimensional horizontal absorption method to obtain n and a parameters of Gardner–Russo model. One-dimensional horizontal absorption experiments on loam, silt loam and sandy clay loam were conducted to obtain the relationships between measured infiltration rate and cumulative infiltration with wetting front distance. Based on the obtained relationships, the measured infiltration data from the one-dimensional horizontal absorption tests were used to calculate n and a parameters and further constructing D and SWRC.FindingsBoth the calculated D and SWRC inversed from the infiltration data were in good agreement with the measured ones that obtained from the traditional horizontal absorption method and the centrifuge method, respectively. Error analysis indicated that only the infiltration data are enough to reliably synchronously determine D and SWRC.Originality/valueA simple and robust method is proposed for synchronous determination of soil water diffusivity and water retention curve.

scholarly journals Understanding Uncertainty and Risk in Management

2020 ◽  
Vol 12 (1) ◽  
pp. 12-35
Author(s):  
Piotr Jedynak ◽  
Sylwia Bąk
Keyword(s):  
Value Added ◽  
Research Process ◽  
Main Method ◽  
Proper Understanding ◽  
Organization Management ◽  
One Dimensional ◽  
Modern Management ◽  
Research Findings ◽  
Selection Of

AbstractObjective: The purpose of this text is to identify approaches to defining and subsequently reviewing the definitions of uncertainty and risk as interdisciplinary terms which are of key importance in modern management.Methodology: The work is theoretical. The main method used in the research process was the analysis of scientific literature. A one-dimensional logical classification method was also used, in order to categorize approaches to defining uncertainty and risk, satisfying the exhaustive and mutually exclusive criteria in the selection of categories of approaches.Findings: The main results of the work are: 1) identification of approaches to defining uncertainty and risk, 2) interdisciplinary review of definitions of uncertainty and risk indicating the criteria to distinguish between the two, and 3) determination of the meaning of the terms uncertainty and risk in modern management.Value Added: Considering the approaches to defining uncertainty and risk taken from many fields and disciplines of science, this text is a compendium of theoretical knowledge for the proper understanding and meaning of these concepts in management.Recommendations: The research findings can have implications for both management theory as well as the practice of organization management.

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