A Linear Ru‐Tl‐Ru Complex Obtained from Halide Abstraction: An Example of Metal‐Dative Bonding

Abstract

The simple abstraction of chloride ion from [RuCl(CO)2(η‐C5H5)] using [TlBF4] proved problematic, unexpectedly giving a new complex containing linear Ru–Tl–Ru. The complex, [{Ru(CO)2(η‐C5H5)}2(μ‐Tl)(F–BF2–F)]∞, was polymeric, as determined by a single‐crystal X‐ray diffraction experiment, in which the thallium centres are bridged by the anions. In an effort to compare the nature of the Tl–Ru bonds, an additional complex was prepared by the reaction of Tl3+ ions with [Ru(CO)2(η‐C5H5)]–. The resulting neutral complex, [{Ru(CO)2(η‐C5H5)}3(μ‐Tl)], was also structurally characterised. Quantum chemical calculations of [{Ru(CO)2(η‐C5H5)}2(μ‐Tl)][BF4] suggest that the Tl–Ru bond has ionic character with integrated atomic charges showing that the metal–metal bonding is best represented as Ru0–TlI–Ru0. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Syntheses and Structures of Ruthenium Complexes Containing a Ru‐H‐Tl Three‐Center–Two‐Electron Bond

“…In the solid‐state structure of 3 , the Ru−Tl distance (3.1571(4) Å) is over 1 Å shorter than the sum of the van der Waals radii for Ru (2.10 Å) and Tl (2.27 Å), suggesting the presence of bonding interaction between the metals. The Ru−Tl bond distance, however, is appreciably longer than the formal Ru−Tl single bonds in the complexes {CpRu(CO) 2 } 2 (μ‐Tl)(BF 4 ) (2.6298(7) and 2.6260(7) Å) or [NEt 4 ][{Ru(CO) 2 (η 5 ‐7,8‐Me 2 ‐7,8‐C 2 B 9 H 9 )} 2 (μ‐Tl)] (2.5994(4) Å) . Reported compounds closely related to 3 are bimetallic Au(μ‐H)Ru and Au(μ‐H) 2 Ru complexes.…”

“…Secondly,they are rare examples of thallium hydride (thallane) compounds characterized both spectroscopically and structurally.A lthough rich hydride chemistry has been developed for lighter Group 13 elements B, Al, Ga, and In, [39] the chemistry of thallium hydrides is underdeveloped. Reported complexes closely related to 5 include [{Ru(CO) 2 (h-C 5 H 5 )} 2 (m-Tl)(F-BF 2 -F)] [24] and [NEt 4 ][{Ru(CO) 2 (h 5 -7,8-Me 2 -7,8-C 2 B 9 H 9 )} 2 (m-Tl)]. Afew complexes with agostic Tl···HX (for example,X= B, O, and C) interaction having Tl···H contact less than 2.5 have been observed in the solid states.…”

“…In the solid-state structure of 3, the RuÀTl distance (3.1571(4) )isover 1 shorter than the sum of the van der Waals radii for Ru (2.10 )a nd Tl (2.27 ), [21] suggesting the presence of bonding interaction between the metals.T he Ru À Tl bond distance,h owever,i s appreciably longer than the formal RuÀTl single bonds in the complexes {CpRu(CO) 2 } 2 (m-Tl)(BF 4 )( 2.6298(7) and 2.6260-(7) ) [24] (4) ). In the solid-state structure of 3, the RuÀTl distance (3.1571(4) )isover 1 shorter than the sum of the van der Waals radii for Ru (2.10 )a nd Tl (2.27 ), [21] suggesting the presence of bonding interaction between the metals.T he Ru À Tl bond distance,h owever,i s appreciably longer than the formal RuÀTl single bonds in the complexes {CpRu(CO) 2 } 2 (m-Tl)(BF 4 )( 2.6298(7) and 2.6260-(7) ) [24] (4) ).…”

Syntheses and Structures of Ruthenium Complexes Containing a Ru‐H‐Tl Three‐Center–Two‐Electron Bond

“…Complexes 5 and 6 have been characterized by NMR spectroscopy and elemental analysis.T he structure of the trimetallic complex [{CpRu(dppm)} 2 (m-Tl)]PF 6 (5)h as also been confirmed by X-ray diffraction (see the Supporting Information for details). Reported complexes closely related to 5 include [{Ru(CO) 2 (h-C 5 H 5 )} 2 (m-Tl)(F-BF 2 -F)] [24] and [NEt 4 ][{Ru(CO) 2 (h 5 -7,8-Me 2 -7,8-C 2 B 9 H 9 )} 2 (m-Tl)]. [25] In summary,w eh ave successfully prepared and characterized both structurally and spectroscopically the first two complexes containing TlH, ap eriod 6m ain-group element hydride.D FT level calculations support the geometry of the bound thallane and indicate substantial fractional bond indices consistent with their formulation as s-complexes with RuÀHÀTl 3c-2e bonding.…”

“…Them ost interesting feature of the structure is that it contains aR uHTl fragment. In the solid-state structure of 3, the RuÀTl distance (3.1571(4) )isover 1 shorter than the sum of the van der Waals radii for Ru (2.10 )a nd Tl (2.27 ), [21] suggesting the presence of bonding interaction between the metals.T he Ru À Tl bond distance,h owever,i s appreciably longer than the formal RuÀTl single bonds in the complexes {CpRu(CO) 2 } 2 (m-Tl)(BF 4 )( 2.6298(7) and 2.6260-(7) ) [24] (4) ). [25] Reported compounds closely related to 3 are bimetallic Au(m-H)Ru [26] and Au(m-H) 2 Ru [27] complexes.I ti sn oted that the Ru À Tl bond distances in 3 (3.1571(4) )a re appreciably longer than the AuÀRu distances in the structurally characterized bimetallic Au(m-H)Ru and Au(m-H) 2 Ru complexes.T he longer TlÀRu distances could be partially related to the fact that the size of aTlatom is larger than that of an Au atom (the van der Waals radii of Au and Tl atoms are 2.12 and 2.27 ,respectively).…”