Symmetrical and Unsymmetrical Schiff Bases Derived from 3,4-Diaminobenzophenone: Synthesis and Thermodynamics of Five Coordinated Tertiaryphosphine Cobalt(III) Complexes
Some new cobalt(III) complexes described as [Co(Chel)(PBu<sub>3</sub>)]ClO<sub>4</sub> × H<sub>2</sub>O where (Chel) is the deprotonated form of a series of symmetric and unsymmetrical Schiff base ligands containing 3,4-diaminobenzophenone (3,4-DABP) and substitut...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Croatian Chemical Society
2016-09-01
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| Series: | Croatica Chemica Acta |
| Online Access: | http://hrcak.srce.hr/file/246129 |
| Summary: | Some new cobalt(III) complexes described as [Co(Chel)(PBu<sub>3</sub>)]ClO<sub>4</sub> × H<sub>2</sub>O where (Chel) is the deprotonated form of a series of symmetric and unsymmetrical Schiff base ligands containing 3,4-diaminobenzophenone (3,4-DABP) and substituted salicylaldehyde moieties and [Co(Chel)(PMePh<sub>2</sub>)]ClO<sub>4</sub> × H<sub>2</sub>O where (Chel) is [N’-(5-BrSalDABP)] were synthesized and characterized by 1H NMR, IR, UV–Vis spectroscopy, and elemental analysis. The formation constants and the thermodynamic parameters were determined spectrophotometrically for 1: 1 adduct formation of the new complexes as acceptor with some aliphatic amines such as benzylamine, n-butylamine, sec-butylamine and tert-butylamine as donors in DMSO solvent in constant ionic strength (I = 0.1 M NaClO4). The formation constants change according to the following trend due to the steric and the electronic factors of the cobalt(III) complexes: N’-5-OMe > N’-5-H > N’-5-Br > N’-5-Cl; N,N’-3-OMe > N,N’-4-Ome.
The trend of the formation constants of cobalt(III) Schiff base complexes toward a given donor according to the axial ligand is as follow: PBu3 > PMePh<sub>2</sub>. Also, the following binding trend of the donors toward a given cobalt(III) Schiff base complex is obtained: benzylamine >
<i>n</i>-butylamine > <i>sec</i>-butylamine > <i>tert</i>-butylamine.
<br><a rel="license" href="http://creativecommons.org/licenses/by/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by/4.0/80x15.png" /></a> This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 International License</a>. |
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| ISSN: | 0011-1643 1334-417X |