Synthesis, Spectroscopic, Characterization and X-ray Structures of Lanthanide(III) Complexes Derived from 1,5-bis(phenyl(pyridin-2-yl)methylene)carbonohydrazide
Amadou Gueye,
Papa Samba Camara,
Mbossé Ndiaye-Gueye,
Sofia Zazouli,
Farba Bouyagui Tamboura,
Ousmane Diouf,
Nathalie Gruber,
Mohamed Lamine Gaye
Issue:
Volume 10, Issue 1, February 2022
Pages:
1-12
Received:
29 December 2021
Accepted:
13 January 2022
Published:
21 January 2022
Abstract: The use of 1,5-bis (phenyl (pyridin-2-yl) methylene) carbonohydrazide (H2L) in the coordination chemistry of lanthanides (III) yielded complexes in which two ligand molecules are present. The synthesis was carried out using a Ln/H2L ratio of 1/2 to lead mononuclear complexes of [Ln(H2L)2(η2-NO3)3-x](NO3)x (Ln=La (1), Sm (4), Gd (6) and Yb (7)), [Ln(H2L)2(NO3)3] (Ln=Pr(2), Eu(5) and a co-crystal {[Nd(H2L)2(η2-NO3)2(η1-NO3)], [Nd(H2L)2(η2-NO3)(h1-NO3)(H2O)]}.(NO3).2CH3OH} (3). The structures of the complexes (2) and (3)were solved by X-ray crystallography on a single crystal. In the mononuclear complex of PrIII, two neutral ligand molecules act in tridentate fashion. In the co-crystal complex, one of the NdIII atom is coordinated by two ligand molecules acting tridentately in neutral form and three nitrate anions acting in bidentate fashion while the second NdIII atom is coordinated by two ligand molecules acting tridentately in neutral form, one monodentate nitrate anion, one bidentate nitrate anion and one water molecule. The neutrality of the complex is ensured by one free nitrate anion. Two free methanol molecules are present. Complex (2) crystallizes in the triclinic space group P-1 with the following parameters: a=10.128 (2) Å, b=12.2285 (19) Å, c=20.816 (5) Å, α=85.634 (4), β=81.870 (4)°, γ=87.210 (5)°, V=2542.9 (9) Å3, Z=2, R1=0.0640, wR2=0.1377. Complex (3) crystallizes in the monoclinic space group P21/c with the following parameters: a=10.4554 (12) Å, b=44.089 (6) Å, c=23.212 (3) Å, β=90.851 (2)°, V=10699 (2) Å3, Z=4, R1=0.0630, wR2=0.1690. The coordination sphere of the twelve-coordinated PrIII atom is best described as distorted icosahedron. In the co-crystal one of the NdIII atom is eleven-coordinated while the second NdIII atom is ten-coordinated. The environments around the NdIII atoms are respectively best described as distorted pentacapped trigonal prism and a distorted bicapped square antiprism, respectively. Supramolecular structures are consolidated by numerous hydrogen bonds.
Abstract: The use of 1,5-bis (phenyl (pyridin-2-yl) methylene) carbonohydrazide (H2L) in the coordination chemistry of lanthanides (III) yielded complexes in which two ligand molecules are present. The synthesis was carried out using a Ln/H2L ratio of 1/2 to lead mononuclear complexes of [Ln(H2L)2(η2-NO3)3-x](NO3)x (Ln=La (1), Sm (4), Gd (6) and Yb (7)), [Ln...
Show More
Eating Patterns in Children, an Issue for Future Health Policy
Bianca Elena Popovici,
Maria Mitrica,
Moga Marius
Issue:
Volume 10, Issue 1, February 2022
Pages:
13-20
Received:
3 February 2021
Accepted:
23 February 2021
Published:
28 January 2022
Abstract: Background: Obesity and overweight have increased prevalence in children during the last decades all over the world. Objectives: The aim of this study was to determine the prevalence of overweight/obesity through the 12-18 year old schoolchildren in Brasov district and to describe eating patterns and the possible relationship between overweight/obesity and eating pattern. Material and Method: There were recruted 250 children for a cross-sectional study in Brasov district, Romania. Alimentary habit, snaking, meal frequencies were declared by the subjects using a retrospective questionnaire. Parents were asked to give information about family history regarding the presence of cardio-vascular risk factors. There were measured weight and height for all children and it was calculated body mass index calculated using international standard cutoff points (International Obesity Task Force values). It was also evaluated the level of phisical activityfor each children. Results: Positive family hystory for cardio-vascular risk factor, eating pattern and physical activity were associated with overweight. Healthy eating pattern including fresh fruits and vegetables loses ground in favour of fast-food as the age increases. Conclusions: The main finding was that, eating pattern in schoolchildren should worry both parents and school authorities. The family influence on children̓s eating pattern decreases as the age grow, the busy school program determine lack of phisical activities and failure of and the healthy alimentation. The prevalence of overweight was high and connected with dietary behaviour, independent associations were evident between eating patterns and overweight, indicating the need of the need for a common intervention on nutrition both from the family and from the educators.
Abstract: Background: Obesity and overweight have increased prevalence in children during the last decades all over the world. Objectives: The aim of this study was to determine the prevalence of overweight/obesity through the 12-18 year old schoolchildren in Brasov district and to describe eating patterns and the possible relationship between overweight/obe...
Show More
Hopf Fibration on Relationship Between Dihedral Angle θHnHn+1[deg] and Vicinal Angle ϕ[deg], Angles Calculated from NMR Data with 3-Shere Approach and Java Script
Carmen-Irena Mitan,
Emerich Bartha,
Constantin Draghici,
Miron-Teodor Caproiu,
Petru Filip,
Robert Michael Moriarty
Issue:
Volume 10, Issue 1, February 2022
Pages:
21-31
Received:
30 January 2022
Accepted:
19 February 2022
Published:
28 February 2022
Abstract: 3-Sphere theory, a hypersphere in four dimensions, is applied for calculation dihedral angles with the right stereochemistry and sign in D, -L ribitol series from proton and carbon chemical shift (ΔδXnXn+1[ppm], X = H, C) and vicinal coupling constant (3JHnHn+1[Hz]) with Java Script. A method in three steps, easy to calculate by hand or with Java Script program: 1. prediction of the dihedral angle only from 3JHnHn+1[Hz], 2. calculation the angle of set A with manifold equation (conic section, Villarceau circles) from chemical shift, 3. building of the seven sets unit or six sets units, from which is chose an angle almost equal with the predicted one having its stereochemistry and sign. Angles of set A and set B, relationships between vicinal angle and dihedral angle (X0-X15) are introduced instead of polar angle and azimuthal angle in spherical coordinates (eq. 1 versus eq. 3). Hopf coordinates, trigonometric equations, confirmed by algebraic equations are disclosed for all cis-ae/ea, trans-ee, trans-aa stereochemistry. Octonionic fibration S7→S15→S8 in R16, with real fibration S0 →S1 →S1 as unit, reassembles all possible stereochemistry gives by the HCCH fragment on two congruent disks, each centered on the perimeter of the other with equilateral triangles as vertices. Complex Hopf fibration in R4 ensuring the calculation of the dihedral angle from vicinal angle and vice versa, demonstrating the relationships between sets A, B, C.
Abstract: 3-Sphere theory, a hypersphere in four dimensions, is applied for calculation dihedral angles with the right stereochemistry and sign in D, -L ribitol series from proton and carbon chemical shift (ΔδXnXn+1[ppm], X = H, C) and vicinal coupling constant (3JHnHn+1[Hz]) with Java Script. A method in three steps, easy to calculate by hand or with Java S...
Show More
