Record number :
1375328
Title of article :
(Mesitylene)ruthenium π-complexes with benzo-15-crown-5 and dibenzo-18-crown-6
Author/Authors :
Dmitry S. Perekalin، نويسنده , , Maria V. Babak، نويسنده , , Valentin V. Novikov، نويسنده , , Konstantin A. Lyssenko، نويسنده , , Maddalena Corsini، نويسنده , , Piero Zanello*، نويسنده , , Alexander R. Kudinov، نويسنده ,
Issue Information :
دوفصلنامه با شماره پیاپی سال 2010
Pages :
5
From page :
1200
To page :
1204
Abstract :
The reactions of benzo-15-crown-5 and dibenzo-18-crown-6 with 1 equiv. of [(mes)Ru(MeNO2)3]2+ (mes = 1,3,5-C6H3Me3) give the mononuclear complexes [(mes)Ru(η6-benzo-15-crown-5)]2+ (1) and [(mes)Ru(η6-dibenzo-18-crown-6)]2+ (2) in 50% yield. Similar reaction with 2 equiv. of [(mes)Ru(MeNO2)3]2+ produces the dinuclear complex [(μ-η6:η6-dibenzo-18-crown-6)Ru2(mes)2]4+ (3) in 96% yield as a 2:3 mixture of cis- and trans-isomers. Structures of 2(OTf)2 and trans-3(OTf)4 were confirmed by X-ray diffraction. The NMR titration showed that mononuclear dications 1 and 2 bind Na+ ion less effective (Ka = 600 and 250 M–1) than free benzo-15-crown-5 and dibenzo-18-crown-6 (Ka = 2 × 105 and 5 × 106 M−1). The dinuclear tetracation 3 does not bind Na+ within measurable limits of NMR titration method. The electrochemical behaviour of complexes 1–3 was studied in propylene carbonate solution. They exhibit a partially chemically reversible Ru(II)/Ru(I) reduction, which in the case of the dinuclear complex 3 proceeds through two slightly separated steps. The redox activity of the complexes is substantially unaffected by the presence of sodium ion.
Keywords :
Crown ethers , Electrochemistry , NMR titration , Ruthenium , Sandwich complexes
Journal title :
Journal of Organometallic Chemistry
Link To Document :