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Steric influence and controlled dynamic process in a chiral square planar nickel(II) complex supported by a dipyrromethane-based NNNN tetradentate ligand.
- Source :
- New Journal of Chemistry; 9/14/2024, Vol. 48 Issue 34, p15240-15247, 8p
- Publication Year :
- 2024
-
Abstract
- The equimolar reaction between 1,9-bis(N,N-dimethylaminomethyl)-5,5′-diphenyldipyrromethane, H<subscript>2</subscript>L1 or 1,9-bis(3,5-dimethylpyrazolylmethyl)-5,5′-diethyldipyrromethane, H<subscript>2</subscript>L2 and [NiCl<subscript>2</subscript>(DME)] in the presence of KH yielded the neutral mononuclear nickel(II) complexes [Ni(L1)-κ<superscript>4</superscript>N,N,N,N], 1 and [Ni(L2)-κ<superscript>4</superscript>N,N,N,N], 2, respectively. Their X-ray structures revealed the formation of triple chelation by the ligand in both structures with quite different nickel(II)-surrounded square planar geometries owing to the steric difference between –NMe<subscript>2</subscript> and 3,5-dimethylpyrazolyl groups. While the –NMe<subscript>2</subscript> group substituted ligand L1 afforded nickel complex 1 with a plane of symmetry, 3,5-dimethylpyrazole substituted L2 rendered helical chirality in the structure of complex 2. Both the enantiomers (Δ and Λ) of complex 2 were observed in the crystal lattice. Their solution state behaviors were consistent with the solid-state structures as monitored by <superscript>1</superscript>H NMR spectroscopy. Both the enantiomers of complex 2 were present in a dynamic equilibrium in solution and studied by variable temperature <superscript>1</superscript>H NMR spectroscopy. Similar to the chiral complex, the corresponding ligand H<subscript>2</subscript>L2 also exhibited chirality as shown by its crystal structure and the two ligand enantiomers participated in a very fast dynamic interconversion, which became slower upon metalation. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 11440546
- Volume :
- 48
- Issue :
- 34
- Database :
- Complementary Index
- Journal :
- New Journal of Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 179256488
- Full Text :
- https://doi.org/10.1039/d4nj03166k