Crystal structure of dichloro(N,N-dimethylpyridin-4-amine)- (η6-p-cymene)ruthenium(II), RuCl2(C7H10N2)(C10H14)

Abstract

Source of material [RuCl 2 (h 6 -p-cymene)] 2 (0.245 mg,0 .4 mmol) dissolved in dichloromethane (20 mL)was treated with N,N-dimethylpyridin-4-amine (DMAP, 0.098 mg, 0.8 mmol). The orange-red solution was heated under reflux for 1h,cooled to room temperature, filtered and evaporated to 2mLunder reduced pressure. Then it was layered with petroleum ether and filtered to give orange-red residue. The solid residue was washedseveral timeswith petroleum ether. It is soluble in dichloromethane, acetone, and methanol. Orange-red crystals were obtained by crystallization from dichloromethane/petroleum ether (yield 0.21 mg;61.2 %). Experimental detailsAll Hatomswere positioned geometrically and allowed to ride on theirparentatoms at distances of d(Csp.96 Åwith U iso =1.5 U eq (parent atom). DiscussionOrganometallic compounds are generally considered to be toxic and unstable, undergoing decomposition when exposed to air and water [1]. Arene ruthenium compounds as anticanceragents had first been introduced by Tocher et al. in 1992 [2], who had observed acytotoxicity enhancement by coordinating the anticancer agent metronidazole (1-b-hydroxyethyl-2-methyl-5-nitroimidazole) to ab enzene ruthenium dichloro fragment, stimulating the search for organometallic anticancer drugs [3][4][5].The accelerating pace of reported applications for DMAP (N,Ndimethylpyridin-4-amine) and the availability of DMAP in commercial quantities at modest prices hasc ontinued to stimulate great interest in its useasacatalyst in the fields of organic, polymer, analytical and biochemistry [6]. It has ar elatively high toxicity andisparticularlydangerous becauseofits abilitytobe absorbedthrough theskin [7].Inorder to developnew synergistic anticancer drugs, we trytocoordinateDMAPtothe arene-ruthenium half-sandwich "piano-stool"u nitw hich is an excellent scaffold forthe coupling of organicsegments for targeted chemotherapy [8].The title complex adopts at ypical "three-legged piano-stool" configuration with the tetrahedral arrangement of the p-cymene andthe otherthree ligands(DMAP boundvia nitrogen atom,and twochloridoligands)about them etal center ruthenium.The pcymene ring is planar with mean deviation of 0.005(4) Å, the pyridylring is also planar with mean deviation of 0.003 (4)