Ligand Design for Site-Selective Metal Coordination: Synthesis of Transition-Metal Complexes with η6 -Coordination of the Central Ring of Anthracene

2017 ◽  
Vol 129 (20) ◽  
pp. 5676-5679 ◽  
Author(s):  
Eduard E. Karslyan ◽  
Alexandra O. Borissova ◽  
Dmitry S. Perekalin
2020 ◽  
Author(s):  
Euan Brechin ◽  
Constantinos J. Milios ◽  
Thomais Tziotzi ◽  
Marco Coletta ◽  
Mark Gray ◽  
...  

Ligand design remains key to the synthesis of coordination compounds possessing specific topologies, nuclearities and symmetries that direct targeted physical properties. N,O-chelates based on ethanolamine have been particularly prolific in constructing a variety of paramagnetic 3d transition metal complexes with fascinating magnetic properties. Here, we show that combining three ethanolamine moieties within the same organic framework in the form of the ligand 1,3,5-tri(2-hydroxyethyl)-1,3,5-triazacyclohexane (LH3) leads to the formation of two highly unusual Mn wheels. Reaction of Mn(NO3)2·6H2O with LH3 in basic methanolic solutions leads to the formation of [MnIII 12MnII 4(µ3-O)6(µ-OH)4(µ3-OMe)2(µOMe)2(L)4(LH)2(H2O)10](NO3)6(OH)2 (1) and [MnIII 10(µ3-O)4(µ-OH)4(µ-OMe)4(L)4(H2O)4](NO3)2 (2); the only difference in the synthesis being the ratio of metal:ligand employed. The structure of the former describes two offset [MnIII 6MnII 2] square wheels, linked through a common centre, and the latter a single [MnIII 10] wheel twisted at its centre, such that the top half is orientated perpendicular to the bottom half. In both cases the L 3- /LH2- ligands dictate the orientation of the Jahn-Teller axes of the MnIII ions which lie perpendicular to the triazacyclohexane plane. Direct current magnetic susceptibility and magnetisation data reveal the presence of competing exchange interactions in 1 and strong antiferromagnetic interactions in 2. Given the simplicity of the reactions employed and the paucity of previous work, the formation of these two compounds suggests that LH3 will prove to be a profitable ligand for the synthesis of a multitude of novel 3d transition metal complexes


2020 ◽  
Author(s):  
Euan Brechin ◽  
Constantinos J. Milios ◽  
Thomais Tziotzi ◽  
Marco Coletta ◽  
Mark Gray ◽  
...  

Ligand design remains key to the synthesis of coordination compounds possessing specific topologies, nuclearities and symmetries that direct targeted physical properties. N,O-chelates based on ethanolamine have been particularly prolific in constructing a variety of paramagnetic 3d transition metal complexes with fascinating magnetic properties. Here, we show that combining three ethanolamine moieties within the same organic framework in the form of the ligand 1,3,5-tri(2-hydroxyethyl)-1,3,5-triazacyclohexane (LH3) leads to the formation of two highly unusual Mn wheels. Reaction of Mn(NO3)2·6H2O with LH3 in basic methanolic solutions leads to the formation of [MnIII 12MnII 4(µ3-O)6(µ-OH)4(µ3-OMe)2(µOMe)2(L)4(LH)2(H2O)10](NO3)6(OH)2 (1) and [MnIII 10(µ3-O)4(µ-OH)4(µ-OMe)4(L)4(H2O)4](NO3)2 (2); the only difference in the synthesis being the ratio of metal:ligand employed. The structure of the former describes two offset [MnIII 6MnII 2] square wheels, linked through a common centre, and the latter a single [MnIII 10] wheel twisted at its centre, such that the top half is orientated perpendicular to the bottom half. In both cases the L 3- /LH2- ligands dictate the orientation of the Jahn-Teller axes of the MnIII ions which lie perpendicular to the triazacyclohexane plane. Direct current magnetic susceptibility and magnetisation data reveal the presence of competing exchange interactions in 1 and strong antiferromagnetic interactions in 2. Given the simplicity of the reactions employed and the paucity of previous work, the formation of these two compounds suggests that LH3 will prove to be a profitable ligand for the synthesis of a multitude of novel 3d transition metal complexes


2020 ◽  
Vol 73 (6) ◽  
pp. 399
Author(s):  
Claudio Pettinari ◽  
Alessia Tombesi ◽  
Fabio Marchetti ◽  
Corrado Di Nicola ◽  
Riccardo Pettinari

The outcomes of the investigations on the structures and reactivity of a massive number of main group and transition metal complexes containing different families of ligands are reviewed. All the data result from the scientific collaboration between the research groups of Claudio Pettinari and Allan White which lasted fifteen years.


2007 ◽  
Vol 63 (4) ◽  
pp. 612-620 ◽  
Author(s):  
Andrew Parkin ◽  
Gordon Barr ◽  
Anna Collins ◽  
Wei Dong ◽  
Christopher J. Gilmore ◽  
...  

Cluster analysis is shown to be an effective method to analyse and classify metal coordination geometry in a very large number of four-coordinate bis-salicylaldimato (or bis-β-iminoketonate) transition-metal complexes available in the Cambridge Structural Database. The methods described require no prior knowledge of chemistry to be input; retrieved structures are automatically clustered into groups based purely on the geometric similarity of the fragments and these groupings can then be interpreted by the structural chemist.


2021 ◽  
Vol 46 (2) ◽  
pp. 207-213
Author(s):  
Maximilian H. H. Wurzenberger ◽  
Michael S. Gruhne ◽  
Marcus Lommel ◽  
Jörg Stierstorfer

2020 ◽  
Vol 7 (3) ◽  
pp. 786-794 ◽  
Author(s):  
Jingqi Han ◽  
Kin-Man Tang ◽  
Shun-Cheung Cheng ◽  
Chi-On Ng ◽  
Yuen-Kiu Chun ◽  
...  

A new class of luminescent cyclometalated Ir(iii) complexes with readily tunable mechanochromic properties derived from the mechanically induced trans-to-cis isomerization have been developed.


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