Novel in situ manganese-promoted double-aldol addition
| Autor: | Cyril Cook, Ilia Korobkov, Muralee Murugesu, Fatemah Habib |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
chemistry.chemical_classification
Base (chemistry) Inorganic chemistry chemistry.chemical_element Manganese Inorganic Chemistry chemistry.chemical_compound Crystallography chemistry Transition metal Aldol reaction Cubane Materials Chemistry Antiferromagnetism Molecule Physical and Theoretical Chemistry Single crystal |
| Zdroj: | Inorganica Chimica Acta. 380:378-385 |
| ISSN: | 0020-1693 |
| Popis: | A novel in situ Mn n + -promoted double-aldol reaction is reported. Single crystal X-ray measurements confirm the addition of acetone to two o -vanillin molecules in an original in situ α , α double aldol reaction promoted by Mn ions in the presence of base. The newly formed ligands coordinate to four Mn III ions forming a defect-dicubane core structure ( 1 ) bridged exclusively by oxygen-based ligands. Other 3 d metals were employed under the same reaction conditions, however no aldol addition occurred and tetranuclear cubane-like structures formed using Co II ( 2 ) and Ni II ( 3 ) ions. Magnetic measurements were carried out on all complexes using SQUID magnetometry. Dominant ferromagnetic interactions were observed for complexes 1 and 3 with J = 1.8 cm −1 , J ′ = −2.5 cm −1 , g = 1.95 for 1 and J = 3.1 cm −1 , g = 2.17 for 3 while complex 2 exhibited antiferromagnetic exchange interactions. Notably, complex 1 was shown to exhibit spin frustration rarely seen in {Mn III } 4 systems resulting in an intermediate spin ground state of S T = 6. |
| Databáze: | OpenAIRE |
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