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Synthesis of [RuX(CO){η 2 ‐ C , N ‐C 6 H 4 C(H)=NC 6 H 4 ‐4‐NO 2 }(PPh 3 ) 2 ] (X = F, Cl, Br, I): Evidence of Non‐Conventional Ru−X Hydrogen Bonds Leading to Octahedral Coordination at the Halide Atom
Author(s) -
Flower Kevin R.,
Pritchard Robin G.,
Warren John E.
Publication year - 2003
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.200200527
Subject(s) - chemistry , halogen , ligand (biochemistry) , cationic polymerization , crystallography , crystal structure , ruthenium , stereochemistry , x ray crystallography , medicinal chemistry , catalysis , alkyl , diffraction , biochemistry , optics , receptor , physics , organic chemistry
Abstract Treatment of [RuCl(CO){η 2 ‐ C , N ‐C 6 H 4 C(H)=NC 6 H 4 ‐4‐NO 2 }(PPh 3 ) 2 ] ( 4‐Cl ) with Ag[BF 4 ] in acetone/CH 2 Cl 2 gives the cationic complex [Ru{O=C(CH 3 ) 2 }(CO){η 2 ‐ C , N ‐C 6 H 4 C(H)=NC 6 H 4 ‐4‐NO 2 }(PPh 3 ) 2 ][BF 4 ] (not isolated), which then reacts with NaX (X = F, Br, I) to afford the new compounds [RuX(CO){η 2 ‐ C , N ‐C 6 H 4 C(H)=NC 6 H 4 ‐4‐NO 2 }(PPh 3 ) 2 ] (X = F, Br, I) ( 4‐F , 4‐Br , and 4‐I ). All of the new compounds have been characterised by elemental analysis (C, H, and N), 1 H, 13 C{ 1 H}, 31 P{ 1 H} NMR spectroscopy and IR spectroscopy. The IR data support the hypothesis that the fluoride ligand is the strongest halogen π‐donor to the metal centre. In addition, the compounds 4‐Br· 1.5CHCl 3 , 4‐Cl· 1.5CHCl 3 , 4‐F· 2CDCl 3 , and 4‐I· 1.5CHCl 3 have been characterised by single‐crystal X‐ray diffraction studies; all show Ru−X ··· HCCl 3 interactions with the Ru−F interaction being the strongest. In addition, there is evidence for the presence of competing RuX ··· ClCHCl 2 (X = Cl, Br) interactions in compounds 4‐Br and 4‐Cl ; these appear to be charge transfer in nature. The generality of these interactions has been probed using searches of the Cambridge Crystallographic Database and the data obtained suggests that these interactions have some, but limited, precedence. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)