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Syntheses and Structures of Molecular Diphenolatonickel Compounds Containing Trimethylphosphane Ligands
Author(s) -
Klein HansFriedrich,
Dal Attila,
Jung Thomas,
Braun Siegmar,
Röhr Caroline,
Flörke Ulrich,
Haupt HansJürgen
Publication year - 1998
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/(sici)1099-0682(199805)1998:5<621::aid-ejic621>3.0.co;2-p
Subject(s) - tetracoordinate , chemistry , hexacoordinate , ligand (biochemistry) , octahedron , phenol , nuclear magnetic resonance spectroscopy , medicinal chemistry , trans effect , crystal structure , stereochemistry , phenols , crystallography , chelation , inorganic chemistry , organic chemistry , planar , biochemistry , computer graphics (images) , receptor , silicon , computer science
The reaction of substituted phenols and dioxygen with Ni(PMe 3 ) 4 yields the low‐spin tetracoordinate diphenolatonickel compounds Ni(OAr) 2 (PMe 3 ) 2 [ArOH = 2‐ tert ‐butylphenol ( 1 ), 2‐ tert ‐butyl‐4‐methylphenol ( 2 ), 2‐ tert ‐butyl‐6‐methylphenol ( 3 ), 2,4‐di( tert ‐butyl)phenol ( 4 ), 2‐ tert ‐butyl‐4‐methoxophenol ( 5 ), 2‐chloro‐4‐ tert ‐butylphenol ( 6 ), 2‐isopropylphenol ( 7 ), 3‐ tert ‐butylphenol ( 8 )]. As is revealed by variable temperature 1 H‐ and 13 C‐NMR spectroscopy the complexes constitute a mixture of two isomers, each of which can be observed separately at lower temperatures when interconversion is slower. An additional 6‐carbaldehyde function transforms the phenolate into a chelating ligand, giving rise to a high‐spin hexacoordinate compound Ni(OAr) 2 (PMe 3 ) 2 ( 9 ). X‐ray crystal‐structure determinations of 2 and 3 show a trans square‐planar structure, and that of 9 shows a trans octahedral arrangement of donor atoms P 2 O 4 . Bulky substituents in the 3‐ or 4‐position, or non‐demanding substituents in the 2‐position, are less effective in stabilizing molecular diphenolatonickel complexes.