Mononuclear and Tetranuclear Copper(II) Complexes Bearing Amino Acid Schiff Base Ligands: Structural Characterization and Catalytic Applications
Abstract
:1. Introduction
2. Results and Discussion
2.1. Synthesis of Schiff Bases Ligands and Copper (II) Complexes
2.2. Single Crystal X-ray Diffraction (SCXRD)
2.3. FTIR Spectra Analysis of Schiff Bases Ligands and Copper (II) Complexes
2.4. Thermal Analysis of the Copper (II) Complexes
2.5. UV-Vis Spectroscopy of Schiff Bases Ligands and Copper (II) Complexes
2.6. Electron Paramagnetic Resonance of Copper (II) Complexes
2.7. Catalytic Activity of Copper (II) Complexes in Olefin Cyclopropanation
3. Materials and Methods
3.1. General Procedure
3.2. Synthesis of the Copper (II) Complexes
3.3. X-ray Crystallography
3.4. Catalytic Assay
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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3 | 4 | ||
---|---|---|---|
Cu (1)-O (1) | 1.851 (4) | Cu (1)-O (3) # 1 | 1.8560 (17) |
Cu (1)-N (1) | 1.929 (3) | Cu (1)-N (1) # 1 | 1.9288 (18) |
Cu (1)-O (2) | 1.902 (2) | Cu (1)-O (1) # 1 | 1.9467 (17) |
Cu (1)-O (6) | 1.927 (2) | Cu (1)-O (2) | 1.9572 (15) |
O (1)-Cu (1)-N (1) | 95.28 (11) | O (3) # 1-Cu (1)-N (1) # 1 | 95.19 (7) |
O (1)-Cu (1)-O (2) | 176.10 (12) | O (3) # 1-Cu (1)-O (1) # 1 | 178.97 (7) |
N (1)-Cu (1)-O (2) | 86.30 (11) | N (1) # 1-Cu (1)-O (1) # 1 | 85.82 (7) |
O (1)-Cu (1)-O (6) | 89.40 (10) | O (3) # 1-Cu (1)-O (2) | 91.42 (7) |
N (1)-Cu (1)-O (6) | 169.41 (12) | N (1) # 1-Cu (1)-O (2) | 173.12 (7) |
O (2)-Cu (1)-O (6) | 89.64 (11) | O (1) # 1-Cu (1)-O (2) | 87.56 (7) |
Compound | 1 | 3 | 2 | 4 |
---|---|---|---|---|
V (OH) | 3400 | 3065 | 3239 | - |
v (C=O) | 1616 | 1601 | 1618 | 1605 |
v (C=N) | 1616 | 1601 | 1618 | 1605 |
vasym (COO−) | 1398 | 1433 | 1406 | 1452 |
vsym (COO−) | 1342 | 1382 | 1350 | 1305 |
v (N-O) | 1348 | 1484, 1324 | - | - |
Complex | Molecular Formula | Stages | Temperature of TGA (°C) | Temperature of DTG (°C) | Mass Loss (%) | Assignment | |
---|---|---|---|---|---|---|---|
found | Calc. | ||||||
3 | C10H12CuN2O7 | I II III | 79–192 192–320 320–484 | 138 243 392 | 12 30 37 | 11 | 2 H2O |
4 | C44H44Cu4N4O12 | I II III | 193–267 267–363 363–453 | 233 291 403 | 39 32 9 | - | - |
Compound | π–π * | n–π * | d–d |
---|---|---|---|
1 | 241 | 382 | |
3 | 249 | 364 | 652 |
2 | 254 | 338 | |
4 | 267 | 377 | 638 |
Compound | Polycrystalline State (298K) | Methanol Solution (77 K) | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
giso | g|| | g┴ | G | g|| | g┴ | gav | A|| a | A┴ a | Aav a | |
3 | - | 2.203 | 2.047 | 4.4899 | 2.271 | 2.065 | 2.1336 | 164 | 14 | 64 |
4 | - | 2.231 | 2.086 | 2.7323 | 2.266 | 2.053 | 2.1240 | 166 | 13 | 64 |
Complex | Conversion (%) b | Yield (%) c | trans/cisc |
---|---|---|---|
3 | >99.9 | 96 | 98/2 |
4 | >99.9 | 90 | >99.9/<0.1 |
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López-Gastélum, K.-A.; Velázquez-Contreras, E.F.; García, J.J.; Flores-Alamo, M.; Aguirre, G.; Chávez-Velasco, D.; Narayanan, J.; Rocha-Alonzo, F. Mononuclear and Tetranuclear Copper(II) Complexes Bearing Amino Acid Schiff Base Ligands: Structural Characterization and Catalytic Applications. Molecules 2021, 26, 7301. https://doi.org/10.3390/molecules26237301
López-Gastélum K-A, Velázquez-Contreras EF, García JJ, Flores-Alamo M, Aguirre G, Chávez-Velasco D, Narayanan J, Rocha-Alonzo F. Mononuclear and Tetranuclear Copper(II) Complexes Bearing Amino Acid Schiff Base Ligands: Structural Characterization and Catalytic Applications. Molecules. 2021; 26(23):7301. https://doi.org/10.3390/molecules26237301
Chicago/Turabian StyleLópez-Gastélum, Karla-Alejandra, Enrique F. Velázquez-Contreras, Juventino J. García, Marcos Flores-Alamo, Gerardo Aguirre, Daniel Chávez-Velasco, Jayanthi Narayanan, and Fernando Rocha-Alonzo. 2021. "Mononuclear and Tetranuclear Copper(II) Complexes Bearing Amino Acid Schiff Base Ligands: Structural Characterization and Catalytic Applications" Molecules 26, no. 23: 7301. https://doi.org/10.3390/molecules26237301