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Le diméthyl‐ et le diéthyl‐tétracarbonylosmium Synthèse et réactivité
Author(s) -
L'Eplattenier F.,
Pélichet Mlle C.
Publication year - 1970
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19700530524
Subject(s) - chemistry , osmium , bromine , medicinal chemistry , octahedron , sodium iodide , ethyl iodide , catalysis , alkyl , iodide , stereochemistry , crystal structure , crystallography , organic chemistry , ruthenium
The sodium salt Na 2 [Os(CO) 4 ] has been obtained in high yields by the reduction of either OsH 2 (CO) 4 or Os 3 (CO) 12 with sodium sand in the presence of catalytic amounts of 2, 2′‐bipyridyle. The reaction of Na 2 [Os(CO) 4 ] with alkylating agents such as methyl and ethyl iodide produces OsR 2 (CO) 4 (R = CH 3 , C 2 H 5 ). NMR. and IR. spectra indicate a cis ‐octahedral structure of symmetry C 2 v for these new alkyl compounds. Bromine breaks one osmium‐carbon bond in cis ‐Os(CH 3 ) 2 (CO) 4 to give cis ‐OsCH 3 Br(CO) 4 , whereas in cis ‐Os(C 2 H 5 ) 2 (CO) 4 both ethyl groups are easily displaced by bromine to give cis ‐OsBr 2 (CO) 4 . Under CO pressure and at elevated temperature cis ‐Os(CH 3 ) 2 (CO) 4 is converted to Os(CO) 5 and ethane. With cis ‐Os(C 2 H 5 ) 2 (CO) 4 two CO are inserted in osmium‐carbon bonds to give . NMR. and IR. data suggest a cis ‐configuration for this derivative and the possibility of the presence of rotational isomers.