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Ruthenium( II ) and Ruthenium( III ) Complexes Containing the [pyS 4 ] 2− Ligand [pyS 4 2− = 2,6‐Bis(2‐mercaptophenylthio)dimethylpyridine(2−)]
Author(s) -
Sellmann Dieter,
Hein Kinga,
Heinemann Frank W.
Publication year - 2004
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/ejic.200400066
Subject(s) - chemistry , ruthenium , ligand (biochemistry) , acetonitrile , pyrazine , stereochemistry , protonation , medicinal chemistry , crystallography , catalysis , organic chemistry , ion , receptor , biochemistry
In the search for complexes, having sulfur‐dominated coordination spheres, that potentially bind, activate, or stabilize nitrogenase‐relevant small molecules, we have synthesized several ruthenium−sulfur complexes of the type [Ru(L)(pyS 4 )] starting from the labile acetonitrile complex [Ru(NCMe)(pyS 4 )] ( 2 ). Complex 2 was obtained from the reduction of [Ru(NO)(pyS 4 )]Br ( 1 ) by N 2 H 4 ·H 2 O in the presence of MeCN. The acetonitrile ligand in 2 could be exchanged for the soft σ−π ligand CO to give [Ru(CO)(pyS 4 )] ( 3 ). Attempts to coordinate N 2 to the pyS 4 2− fragment of 2 gave [{Ru(pyS 4 )} 2 ] ( 4 ). Complex 2 reacts also with hard σ‐ligands, such as N 2 H 4 , NH 3 , pyridine, and pyrazine, to afford mononuclear [Ru(N 2 H 4 )(pyS 4 )] ( 5 ), [Ru(NH 3 )(pyS 4 )] ( 6 ), [Ru(py)(pyS 4 )] ( 7 ), and [Ru(pyr)(pyS 4 )] ( 8 ), respectively. Reaction of 2 with NEt 4 N 3 resulted in the formation of NEt 4 [Ru(N 3 )(pyS 4 )] ( 9 ). The oxidation of 2 with I 2 afforded [Ru(I)(pyS 4 )] ( 10 ). The protonated and alkylated species [Ru(NCMe)(pyS 4 ‐H)]BF 4 ( 11 ), [Ru(NCMe)(pyS 4 ‐Et)]BF 4 ( 12 ), and [{Ru(pyS 4 ‐Et)} 2 ] (BF 4 ) 2 ( 13 ) were obtained from 2 by its treatment with HBF 4 or Et 3 OBF 4 . The N 2 H 4 ligand in 5 could not be oxidized to N 2 H 2 : the oxidation of the Ru II center to Ru III takes place instead. Attempts to oxidize 5 using either [FeCp 2 ]PF 6 or I 2 gave [{Ru II/III (pyS 4 )} 2 ](PF 6 ) ( 14 ) and [Ru III (NH 3 )(pyS 4 )]X (X = PF 6 , I) ( 15 , 16 ). The oxidation of 3 and 6 by NOBF 4 gave Ru III species of [Ru III (CO)(pyS 4 )]BF 4 ( 17 ) and [Ru III (NH 3 )(pyS 4 )]BF 4 ( 18 ). The oxidation of 5 and 6 with H 2 O 2 afforded [{Ru II (pyS 4 −O 3 )} 2 ] ( 19 ), [{Ru II (pyS 4 −O 4 )} 2 ] ( 20 ) and [Ru II (NH 3 )(pyS 4 −O 4 )] ( 21 ). All complexes were characterized by spectroscopic methods and by elemental analysis. The molecular structures of 4 , 6 , 10 , 14 , 15 , 19 , and 20 were determined by X‐ray crystallographic analyses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)