Reaction of Ru₃(CO)₁₂ with Dibenzylideneacetone

Abstract

The thermal reaction of Ru 3 (CO) 12 with dibenzylideneacetone PhCHdCHCOCHdCHPh (1) was studied. From the solution, the trinuclear complexes Ru 3 (CO 7) were isolated, and the precipitate was found to contain the tetranuclear complex Ru 4 (CO 8). The organic ligand in complexes realizes different coordination modes forming five-membered oxaruthenacycle, η 3 -coordinated dihydropyran cycle, η 4 -coordinated diene, or oxadiene fragments. Complex 7 is unstable and undergoes chemical transformations yielding complex 8. Reversible changes occur with complex 8 upon dissolution in acetone, and binuclear complex Ru 2 (CO) 4 (η-Od CMe 9) is formed. The central Ru 2 O 2 cycle in complex 8 is cleaved and the formed vacant coordination site is occupied by an acetone molecule in complex 9. Complexes 6-9 were characterized by IR and 1 H NMR spectroscopy, and their structures were determined by single-crystal X-ray diffraction analysis. The structural and spectroscopic features and possible pathways of the complexes' transformations are discussed.

Triosmium compounds containing the oxametallacycle [Os(CO)3{C(R)CHC(O)CHC(H)C5H4FeC5H5}] moiety. Synthesis and electrochemical studies

“…In addition, one remarkable feature that supports the proposed structure for 3 comes from its IR spectrum. The pattern exhibited in the carbonyl region (2087 m, 2048 s, 2013 vs, 2004 s, 2000 m, 1978 w, 1936 w) compare well with that showed by the compound [Ru 3 (CO) 9 (l 3 -g 2 ,g 4 ,g 3 -[Me 3 SiCC(C 2 Fc)SC(Fc)CSC"CSiMe 3 ] [13] (2097m, 2071 s, 2036 vs, 2002 s, 1982 m) whose crystal structure, solved by X-ray diffraction confirmed that this ruthenium compound is formed by the Ru(CO) 3 and Ru 2 (CO) 6 fragments linked by an organic ligand.…”

“…13 (C 5 H 4 ), 70.1 (C 5 H 5 ), 42.5 and 39.6 (SCH 2 CH 2 S). IR (hexane) cm À1 m CO : 2109CO : m, 2071CO : vs, 2030CO : sh, 2028CO : s, 2005CO : s, 1985CO : m, 1975CO : w, 1962 (d,1H,J = 15.68 Hz,HC@CHCO), 7.34 (s, 1H, COCH@CS), 6.53 (d,1H,J = 15.68 Hz,HC@CHCO),4.55 and 4.52 (m,4H,C 5 H 4 ),4.16 (s,5H,C 5 H 5 ),3.48,3,32,3,12 and 2.97 (m,4H, SCH 2 CH 2 S). 13 C{ 1 H} NMR (CDCl 3 , 500 MHz, 22°C) d 218.0 COCH@CS,202.7 COCH@CS,190.6,182.5,178.9,177.8,177.0,170.5 (CO's),146.4 (HC@CHCO),127.9 (COCH@CS),120.8 (HC@CHCO),79.2,71.9,68.7 (C 5 H 4 ), 70.1 (C 5 H 5 ), 48.9, 42.9 (SCH 2 CH 2 S).…”

“…The synthesis of compounds with nuclearity higher than two is favoured by the propensity of the oxametallacycle to associate with another metal with the lone electron pair of the oxygen atom of the C@O group as well as the C@C bond i.e. [{Ru 3 (CO) 6 {l 3 -g 2 ,g 2 ,g 3 -OC(CH@CHPh)CH@CPh} 2 , {Ru 5 (CO) 11 (l 4 -O)(l 3 -H)(p-MeC 6 H 4 C(O)C(H)@CPh) 3 } and {Ru 6 (CO) 12 (l-CO) 2 (l-H) 2 (l 4 -O)(l-RCOCH@CPh) 2 }] [3]. The coordination chemistry of a,b-unsaturated ketones containing b-positioned heteroatoms, such as the ketene dithioacetals, is very interesting due to the multifunctional coordination sites they show.…”

Triruthenium complexes obtained in the thermal reaction of Ru3(CO)12 with dibenzylideneacetone

“…Introduction of new functional groups pro vides additional possibilities for the coordination to metal atoms and allows one to expect the formation of complexes with unusual coordination modes of an organic ligand. [2][3][4] Earlier, 4 we have studied the reaction of Ru 3 (CO) 12 with dibenzylideneacetone PhCH=CHCOCH=CHPh (DBA) (1), which, in contrast to oxadienes, contains two olefin groups. After long term heating of the reaction mix ture (until Ru 3 (CO) 12 disappeared and the constant IR spectrum was obtained), complexes 2-4 were isolated from the reaction mixture (Scheme 1), 4 whose structures were characterized by X ray diffraction.…”

“…4 The structure of complex 7 was established by the X ray diffraction analysis, which showed that two ligand molecules are involved in the coordination to three Table 2 and 3). The open metal chain contains two Ru-Ru bonds.…”