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Disilicon Complexes with Two Hexacoordinate Si Atoms: Paddlewheel‐Shaped Isomers with (ClN 4 )SiSi(S 4 Cl) and (ClN 2 S 2 )SiSi(S 2 N 2 Cl) Skeletons
Author(s) -
Wagler Jörg,
Brendler Erica,
Heine Thomas,
Zhechkov Lyuben
Publication year - 2013
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.201300452
Subject(s) - hexacoordinate , disilane , chemistry , crystallography , denticity , silicon , sulfur , nuclear magnetic resonance spectroscopy , nmr spectra database , stereochemistry , crystal structure , spectral line , organic chemistry , physics , astronomy
The reaction of 1‐methyl‐3‐trimethylsilylimidazoline‐2‐thione with hexachlorodisilane proceeds toward substitution of four of the disilane Cl atoms during the formation of disilicon complexes with two neighboring hexacoordinate Si atoms. The N , S ‐bidentate methimazolide moieties adopt a buttressing role, thus forming paddlewheel‐shaped complexes of the type ClSi(μ‐mt) 4 SiCl (mt=methimazolyl). Most interestingly, three isomers (i.e., with (ClN 4 )SiSi(S 4 Cl), (ClN 3 S)SiSi(S 3 NCl), and (ClN 2 S 2 )SiSi(S 2 N 2 Cl) skeletons as so‐called (4,0), (3,1), and cis ‐(2,2) paddlewheels) were detected in solution by using 29 Si NMR spectroscopic analysis. Two of these isomers could be isolated as crystalline solids, thus allowing their molecular structures to be analyzed by using X‐ray diffraction studies. In accord with time‐dependent NMR spectroscopy, computational analyses proved the cis ‐(2,2) isomer with a (ClN 2 S 2 )SiSi(S 2 N 2 Cl) skeleton to be the most stable. The compounds presented herein are the first examples of crystallographically evidenced disilicon complexes with two SiSi‐bonded octahedrally coordinated Si atoms and representatives of the still scarcely explored class of Si coordination compounds with sulfur donor atoms.