Metal complexes as ligands' for the synthesis of coordination polymers: a MnIII monomer as a building block for the preparation of an unprecedented 1-D {MnIIMnIII}n linear chain
| Autor: | Georgios Karotsis, Albert Escuer, Konstantinos N. Pantelis, Theocharis C. Stamatatos, Christos Lampropoulos, Luís Cunha-Silva |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Coordination polymer
Supramolecular chemistry 010402 general chemistry Ligands 01 natural sciences lcsh:Technology supramolecular chemistry Química supramolecular Coordination complex chemistry.chemical_compound Deprotonation Polímers inorgànics Metal complexes General Materials Science Carboxylate single-crystal x-ray crystallography lcsh:Microscopy lcsh:QC120-168.85 chemistry.chemical_classification Schiff base lcsh:QH201-278.5 010405 organic chemistry Ligand lcsh:T schiff bases Complexos metàl·lics 0104 chemical sciences Crystallography coordination polymers Monomer Lligands chemistry lcsh:TA1-2040 Inorganic polymers manganese metalloligands lcsh:Descriptive and experimental mechanics Coordination compounds magnetic properties lcsh:Electrical engineering. Electronics. Nuclear engineering Compostos de coordinació lcsh:Engineering (General). Civil engineering (General) lcsh:TK1-9971 |
| Zdroj: | Dipòsit Digital de la UB Universidad de Barcelona Materials, Vol 13, Iss 6, p 1352 (2020) Materials Volume 13 Issue 6 |
| Popis: | A relatively unexplored synthetic route in redox-active Mn(II/III) coordination chemistry has been employed toward the preparation of a new mixed-valence MnII/III 1-D linear chain from the reaction of [MnIII(sacb)2]&minus precursor with a MnII source, where sacbH2 is the Schiff base ligand N-salicylidene-2-amino-5-chlorobenzoic acid. The mononuclear (Pr2NH2)[MnIII(sacb)2] (1) compound was obtained in excellent yields (> 85%) from the 1:2:3 reaction of Mn(O2CMe)2∙4H2O, sacbH2 and Pr2NH, respectively. In 1, the two doubly deprotonated sacb2&minus ligands act as Ocarboxylate,Nimine,Ophenoxide-tridentate chelates, while the second carboxylate O atom of sacb2&minus is dangling and H-bonded to the Pr2NH2+ countercation. Complex 1 was subsequently used as a &lsquo ligand&rsquo to react stoichiometrically with the &lsquo metal&rsquo Mn(NO3)2∙4H2O, thus leading to the 1-D coordination polymer {[MnIIMnIII(sacb)2(H2O)2(MeOH)2](NO3)}n (2) in good yields (~50%). The removal of Pr2NH2+ from the vicinity of the [MnIII(sacb)2]&minus metalloligand has rendered possible (vide infra) the coordination of the second Ocarboxylate of sacb2&minus to neighboring {MnII(H2O)2(MeOH)2}2+ units, and consequently the formation of the 1-D polymer 2. Direct-current (dc) magnetic susceptibility studies revealed the presence of very weak antiferromagnetic exchange interactions between alternating MnIII and MnII atoms with a coupling constant of J = &minus 0.08 cm&minus 1 for g = 2.00. The combined results demonstrate the potential of the &lsquo metal complexes as ligands&rsquo approach to yield new mixed-valence Mn(II/III) coordination polymers with interesting structural motifs and physicochemical properties. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|