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Neutral Pentacoordinate Halogeno‐ and Pseudohalogenosilicon(IV) Complexes with an SiSONCX Skeleton (X=F, Cl, Br, I, N, C): Synthesis and Structural Characterization in the Solid State and in Solution
Author(s) -
Metz Stefan,
Theis Bastian,
Burschka Christian,
Tacke Reinhold
Publication year - 2010
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201000152
Subject(s) - tetracoordinate , chemistry , ligand (biochemistry) , denticity , trifluoromethyl , crystallography , stereochemistry , silicon , nuclear magnetic resonance spectroscopy , crystal structure , medicinal chemistry , organic chemistry , biochemistry , alkyl , receptor , computer graphics (images) , computer science , planar
A series of neutral pentacoordinate silicon(IV) complexes with an SiSONCX skeleton (X=F, Cl, Br, I, N, or C) was synthesized and structurally characterized by multinuclear solution‐state and solid‐state NMR spectroscopy and single‐crystal X‐ray diffraction. These compounds contain an identical tridentate dianionic S , N , O ligand, a monodentate (pseudo)halogeno ligand (F, Cl, Br, I, NCS, N 3 , or CN), and a monodentate organyl ligand (methyl, phenyl, 4‐(trifluoromethyl)phenyl, or pentafluorophenyl). For most of these compounds, a dynamic equilibrium between the pentacoordinate silicon(IV) complex and two isomeric tetracoordinate silicon species in solution was observed. Most surprisingly, comparison of two series of analogous compounds containing fluoro, chloro, bromo, or iodo ligands demonstrated that pentacoordination in these series of silicon(IV) complexes is favored in the rank order I≈Br>Cl>F; i.e., increasing the softness of the halogeno ligand favors pentacoordination.