K. Veera Reddy

SOME COMPLEXES OF RUTHENIUM(II) AND (III) WITH MONOTERTIARY PHOSPHINES AND ARSINES

The complexes RuCl/sub 2/(PPh/sub 3/)/sub 3/ and RuCl/sub 3/(AsPh/sub 3/)/sub 2/(MeOH) were employed as convenient starting materials. Methods were developed to prepare cis- or trans-isomers of the type RuCl/sub 2/L/sub 4/ (L = AsMePh/sub 2/, AsMe/sub 2/Ph) starting from RuCl/sub 2/(PPh/sub 3/)/sub 3/. Meridonial complexes of the type RuCl/sub 3/L/sub 3/ (L = PPh/sub 3/, PMePh/sub 2/, PMe/sub 2/Ph, PEtPh/sub 2/) were obtained by the reaction of Wilkinsons green complex, RuCl/sub 3/(AsPh/sub 3/)/sub 2/(MeOH) with an excess of L in benzene. In the presence of a large excess of methyldiphenylphosphine in benzene, a five coordinate complex RuCl/sub 2/(PMePh/sub 2/)/sub 3/ was obtained. The temperature of the reaction and solvent decide the nature of the reaction product. Thus a polymeric complex of the composition (RuCl/sub 2/(AsPh/sub 3/)/sub 2/)/sub n/ was obtained from RuCl/sub 3/(AsPh/sub 3/)/sub 2/(MeOH) with triphenylarsine in boiling propanol. The reaction of RuCl/sub 3/.3H/sub 2/O with PPh/sub 3/ and then AsPh/sub 3/ in propanol gave mixed ligand polymers of the type (RuCl/sub 2/(PPh/sub 3/)(AsPh/sub 3/))/sub n/.

Platinum metal complexes with some new bifunctional ligands—I. Pyrazole amide complexes with PdII and PtII

Abstract The pyrazolyl group has been used in conjuction with the amido group for the design and synthesis of a new series of bifunctional ligands, PzCH2C(O)NHR, where Pz = 1-pyrazolyl/3,5-dimethyl-1-pyrazolyl; R = H(APz/ADMPz), Me(MAPz/MADMPz), Ph(PAPz/PADMPz). These ligands have been characterized based on their mass, IR, 1H and 13C{H} NMR spectra and their complexes with PdII and PtII reported. Simple mixing of aqueous solutions of K2[MCl4] (M = Pd, Pt) and the pyrazole amide in a 1:2 ratio gave neutral complexes of the type cis-MCl2L2. Alternatively, an aqueous solution of K2[MCl4] added to an aqueous solution of ligand at pH ∼ 8.0 afforded neutral bis-chelates of the type ML2. A neutral monodentate coordination (LH) has been assigned for the ligand in the former complexes, whereas uninegative bidentate coordination through deprotonated amide nitrogen has been assigned in the latter complexes.

Ruthenium(II) complexes with 2-methyl-3-substituted (3H)-quinazolin-4-ones

Abstract A number of ruthenium(II) complexes of some polydentate ON, OO and ONO donors in the form of 2-methyl-3-substituted (3 H )-quinazolin-4-ones have been synthesized and studied. The reaction between RuCl 2 (DMSO) 4 and the uninegative bidentate ligands yielded complexes of the type Ru(DMSO) 2 (OO) 2 (OO = MHQ, PHQ, MHEQ, MHPQ or MCMQ), displacing only two DMSO groups along with chlorides, whereas the neutral bidentate ligands gave RuCl 2 (ON) 2 (ON = MAQ, PAQ, MANQ, PANQ, MAAQ, MAPQ, MPQ or PPQ), displacing all the DMSO groups. A uninegative terdentate ligand (MHAQ) with ONO donors, however, yielded a bis chelate of ruthenium(II).

Trichlorobis(tri-p-tolylarsine)(methanol)ruthenium(III) and some of its reactions with nitrogen donor ligands

Abstract The interaction of tri-p-tolylarsine with ruthenium trichloride trihydrate in acidified methanol under reflux gave a complex, RuCl 3 (AsTol P 3 ) 2 (MeOH) ( 1 ). Complex 1 has been employed as a useful starting material for the preparation of other ruthenium(II) and (III) complexes. On treating complex 1 with excess of nitriles, complexes of the type RuCl 3 (AsTol P 3 ) 2 (RCN) (R = CH 3 , C 6 H 5 , C 6 H 5 CH 2 ) were obtained. Complex 1 gave RuCl 3 (AsTol P 3 (Py) 2 and RuCl 2 (Py) 4 respectively, on reaction with excess of pyridine in n-hexane and dichloromethane. The reactions of 2,2′-bipyridine and 1,10-phenanthroline (NN) with complex 1 in dichloromethane resulted in the formation of RuCl 3 (AsTol P 3 )(NN). A five coordinate complex RuCl 3 (AsTol P 3 ) 2 was isolated from dichloromethane, chloroform or benzene solutions of complex 1 . The dissolution of complex 1 in acetone gave a stable adduct RuCl 3 (AsTol P 3 ) 2 (Me 2 CO).

A Binuclear Ruthenium(III)-Dioxygen Complex

Abstract A binuclear μ-peroxo ruthenium(III) complex of the composition [Cl2(AsPh3)3RuO2Ru(AsPh3)3Cl2]Cl2 is reported.

Some benzimidazole amide complexes of ruthenium(II)

The synthesis and characterisation of ruthenium(II) complexes with 2-amidobenzimidazoles are reported. The complexes RuCl2(DMSO)4 and RuCl2(PPh3) react with 2-(acetamido)benzimidazole (AB) and 2-(benzamido)benzimidazole (BB) it acetone to give products of the type [Ru(L)2(N−O)2]Cl2 [L=DMSO, PPh3, N−O=AB, BB). The displacement reactions are faster in the case of methyl (AB) than phenyl (BB) substituted ligands. The ligands are bifunctional chelating agents coordinating through the tertiary nitrogen of benzimidazole ring and amide oxygen. The complexes are characterised based on their elemental analysis, conductivity data, infrared,1H and31P nmr spectra. Acis-geometry is proposed for all the complexes reported.

A ruthenium(II) complex ofbis(1-pyrazolyl) borate

A new neutral ruthenium(II) complex of dihydro-bis(1-pyrazolyl) borate is synthesised by the reaction of RuCl2(PPh3)3 with the ligand in methanol and is characterised on the basis ofir and31P{1H}nmr spectra.

Cationic complexes of ruthenium-(II) and -(III) with uni- and poly-dentate ligands

The reaction of ruthenium(III) perchlorate with some polytertiary phosphines or arsines has been investigated. With bidentate ligands in ethanol cationic complexes of the type [Ru(L–L)3(ClO4)]ClO4(L–L = Ph2PCH2PPh2, Ph2PCH2CH2PPh2, Ph2AsCH2CH2AsPh2, or Ph2AsCH2CH2PPh2) are obtained. With terdentate ligands the complexes obtained are of the type [RuL2(ClO4)][ClO4]2[L = NH(CH2CH2PPh2)2 or NH(CH2CH2AsPh2)2]. The reaction of the complex [RuCl3(AsPh3)2(MeOH)] with AsPh3 and PPh3 in the presence of an excess of NaClO4 in methanol gave [Ru(AsPh3)4(ClO4)2]ClO4 and [Ru(AsPh3)(PPh3)3(ClO4)2]ClO4 respectively. With terdentate ligands [RuCl3(AsPh3)2(MeOH)] afforded mixed-ligand cationic complexes of the type [Ru(AsPh3)2L(ClO4)][ClO4]2[L = NH(CH2CH2PPh2)2 or NH(CH2C2AsPh2)2]. Perchlorate co-ordination is discussed in terms of the i.r. spectra of complexes, and structures are proposed based on the 1H, 31P, and 14N n.m.r. spectra.

A high-spin iodo-arsine ruthenium(III) complex

A metathetical reaction conducted between RuCl3(AsPh3)2(MeOH) and a large excess of NH4I afforded a high-spin pentacoordinate complex, RuI3(AsPh3)2 (high-spin /paramagnetic/triphenylarsine/iodide/ruthenium(III) complex).