Indi an Journal of Chemistry Vol. 40A, May 2001, pp . 538-543 Synthesis and characterization of some mono and binuclear (r{YJ 3 -C 10 H 16 ) containing ru- thenium (IV) and Ru(IV)-Ru(Il) complexes Abhaya Nand Sahay & Daya Shankar Pandey* Department of Chemistry, A P S University, Rewa 486 003, India Received 2 June 2000; revised 21 December 2000 Reac tion s of [ {Ru(r{TJ 3 -C 10 H 16 )( )l-CI )C I hl _... with I ,4- dicyanobenzene (DCB) or 1,4-piperazinedicarbonitrile (PPz) in dichloromethane in I :2 and 1: I molar ratio gives mononuclear complex [Ru("t{11 3 -C 10 H 16 )CI 2 (L)] and binuclear complex [{ Ru(11 3 : 11 3 -C 10 H 16 )C I 2 } 2 ()l-L)]. However, its reaction with I ,4- dicyanotrans-2-butene (DCBT) gives only a binuclear complex [{ Ru(11 3 : 11 3 -C 10 H 16 )CI 2 h()l-DCBT)] and with 1-piperidinecarbo- nitrile (PPd), a mon on uclear complex [Ru (11 3 : 11 3 -C 10 H 16 )C I 2 (L)]. The mononuclear complexes resulting from th e reaction of [{ Ru ( 11 3 :11 3 -CJOH1 6 )()l-CI )C I hl with DCB or PPz possesses pen- dwtt nitrile grou p. Nucleophilicity of the pendant nitrile group in th ese complexes have been employed in the synt hesi s of binuclear mixed valence-bridged complexe s, in which, the re spective metal centers are bridged by DCB or PPz ligand. The reaction products hav e been characterized by microanalyses and spectroscopic studies (IR, 1 H NMR and 13 C NMR spect ra). During recent past, much attention has been paid towards synthesis and characterization of organome- tallic compounds of ruthenium in high formal oxida- tion states and possible application of such com- pounds in homogeneous catalysis 1 . In this regard, Ru(IY) dimeric chloro bridged bis-allyl complex, [{ Ru(r{11 3 -C10H 16)(!1-Cl)Cl h) has drawn special at- tention2. It's reaction with a variety of Lewis-bases and coordinating solvents to form mononuclear com- plexes [Ru(11 3 :11 3 -C10H1 6)Clz( L)] has been taken up extensively 3 . However, there are a few reports dealing with dimeric complexes 4 . Literature survey further indicates, that reactivity of [{ Ru(11 3 : 11 3 -C 10 H1 6 )(11- Cl)Cl h) with potential bridging organonitriles having two or more donor sites, viz. 4-cyanopyridine, 1,4- dicyanobenzene, 1 ,4-piperazinedicarbonitrile, 1,4- dicyanotrans-2-butene etc. have not been reported, despite detailed reports concerning complexes of the se ligands with a number of metal ions and their complexes 5 . Because of our continuing interest in this area 6 , and in view of the potential synthetic impor- tance of [ { Ru(11 3 :11 3 -C 10H 1 6 )(11-Cl)Cl h), we have started a systematic study on the reactiVIty of [{ Ru(11 3 :11 3 -C10H 1 6)( Jl-Cl)Cl h) with organonitriles. Our prime concern in undertaking this study was to investigate relative donor capabilities of the two do- nor sites in the formation of mono/binuclear com- plexes and to investigate the possibility of formation of octadienediyl (11 3 :11 3 -C 10 H 16 ) containing homo/ hetero bridged binuclear complexes. Only recently, we have shown by elemental analyses, spectroscopic studies (IR, 1 H NMR, 13 C NMR and FAB mass spec- tra) and single crystal X-ray analyses, that reaction of [{ Ru(11 3 :11 3 -C10H 16)(Jl-Cl)Cl h) with 4-cyanopy ridi ne in 1 :2 and 1:1 molar ratio results in the formation of mononuclear complex [Ru(11 3 :11 3 -C 10 H 16 )Clz(CNPy)] and binuclear complex [{ Ru(11 3 : 11 3 -C1o H1 6) Cl2 )zCI.l- CNPy)]. Further, we have employed the mononuclear complex [Ru(11 3 :11 3 -CIOH16)Cl 2( CNPy)], in the synthe- sis of Ru(IY)-Ru(II) or Ru(IV)-Rh(III) 4- cyanopyridine bridged complexes [(11 3 :11 3 - CJOH16)ClzRu(Jl-CNPy)RuClz(11 6-are ne) ] (11 6 -arene = benzene, p-cymene or hexamethylbenzene) 7 . In this paper, we describe and discuss the spectral properties of the complexes resulting from the reactions of [{ Ru(11 3 :11 3 -C10H 1 6) (Jl-Cl)Cl h) with 1,4- dicyanobenzene (DCB), 1 ,4-piperazinedicarbonitrile, 1 ,4-dicyanotrans-2-butene (DCBT) an d 1-piperidine- carbonitrile. Experimental Analytical or chemically pure grade reagents were used throughout. All the synthetic manipulations were performed under nitrogen atmosphere. The solvents were dried and distilled by standard procedures before use. 1 ,4-dicyanobenzene, 1 ,4-piperazinedicarbonitrile, 1 ,4-dicyanotrans-2-butene, hydrated ruthenium (III) chloride, isoprene, I ,3 -cyclohexadiene, hexamethyl- benzene (all Aldrich) and a-phellandrene (Fluka) were used as received without further purification. 1- Piperidinecarbonitrile (Aldrich) was distilled prior to its use. The complexes [{Ru(11 3 :11 3 -Ci o HI 6)(Jl- CI)Cl h), [ { Ru(11 6 -C6H6)(Jl-CI)CI )2 ], [ { Ru(11 6 - C10H 14 )(!1-CI)CJ hl and [{ Ru(11 6 -C6Me6)(Jl-Cl)CI h) were prepared and purified following the literature procedures 8 · 10 .