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Spectroscopic, Structural and Theoretical Investigation of Alkenyl Ruthenium Complexes Supported by Sulfur–Nitrogen Mixed‐Donor Ligands
Author(s) -
WiltonEly James D. E. T.,
Wang Ming,
Benoit David M.,
Tocher Derek A.
Publication year - 2006
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.200600241
Subject(s) - chemistry , deprotonation , sulfur , ligand (biochemistry) , chelation , ruthenium , nitrogen , stereochemistry , medicinal chemistry , lone pair , molecule , inorganic chemistry , organic chemistry , catalysis , ion , biochemistry , receptor
Abstract A series of molecules bearing both sulfur and nitrogen donors has been investigated as ligands for σ‐alkenyl ruthenium complexes. On deprotonation, the ligands, 4‐amino‐2‐mercaptopyrimidine (HL 1 ), 2‐amino‐5‐mercapto‐1,3,4‐thiadiazole (HL 2 ), 2‐mercaptothiazoline (HL 3 ), 4‐hydroxy‐2‐mercaptopyrimidine (HL 4 ) and 2‐mercaptoquinoline (HL 5 ) all react with alkenyl complexes of the form [RuRCl(CO)(BTD)(PPh 3 ) 2 ] [R = CH=CHC 6 H 5 , CH=CHC 6 H 4 Me‐4, C(C≡CPh)=CHPh; BTD = 2,1,3‐benzothiadiazole] through loss of chloride and BTD ligands to yield [RuR(L)(CO)(PPh 3 ) 2 ]. Four of these ligands have alternative potential coordination modes and donor groups. In all cases complexation occurs to form four‐membered nitrogen–sulfur chelates with the pendant amino or hydroxy functionality playing no role in coordination. In the case of the 4‐aminopyrimidine‐2‐thiolate (L 1 ) ligand, this was confirmed by a single‐crystal X‐ray study. 2‐Mercaptothiazoline (L 3 ) has the ability to coordinate through two sulfur donors, however, chelation to nitrogen and sulfur donors is preferred as demonstrated by a structural study. This observation is supported by theoretical calculations, which show that a complex displaying the nitrogen–sulfur chelate is of significantly lower energy than one bonded to the ligand through two sulfur donors, despite lone pairs being available in both cases. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)