Complexes of the bidentate ligands PPh2CH2C(But)NNR2(R = H or Me) and PPh2CH2C(But)N–NCHPh with palladium and platinum. X-Ray crystal structure of cis-[Pt{PPh2CH2C(But)NNH}2]

Abstract

tert-Butyl diphenylphosphinomethyl ketone dimethylhydrazone L¹ reacts with [PtCl₂(cod)](cod = cycloocta-1,5-diene) to give the chelate [[graphic omitted]Me₂}] with a six-membered chelate ring; the corresponding palladium complex was also prepared. The phosphino dimethylhydrazone L¹ or the phosphino hydrazone L² also react with [PtMe²(cod)] to give [[graphic omitted]R₂}], (R = Me or H); these platinum(II) complexes react with methyl iodide to give the corresponding trimethylplatinum(IV) complexes [[graphic omitted]R₂}]. Treatment of [PtCl₂(cod)] with 2 equivalents of L² gave the dication cis-[[graphic omitted]H₂}₂]²⁺ isolated as the chloride or chloride hexafluorophosphate salts. The dicationic dichloride reacted with 2 moles of sodium ethoxide to give the neutral cis-[[graphic omitted]H}₂]. Treatment of [PdCl₂(NCPh)₂] with L² gave [[graphic omitted]H₂}₂]Cl₂, which with sodium ethoxide gave the neutral trans-[[graphic omitted]H}₂]. The mixed azine monophosphine PPh₂CH₂C(Bu^t)N–NCHPh L³ with [PdCl₂(NCPh)₂] gave the chelate complex [[graphic omitted]CHPh}] and with [PtMe₂(cod)]it gave [[graphic omitted]CHPh}]. Treatment of [PtCl₂(NCMe)₂] with 2 equivalents of L³ gave trans-[PtCl₂{PPh₂CH₂C(Bu^t)N–NCHPh}₂] which on heating gave the dicationic dichloride salt cis-[[graphic omitted]–NCHPh}₂]Cl₂. Successive treatments of this salt with 1 mole of sodium methoxide gave cis-[{[graphic omitted]–NCHPh}]⁺ and cis-[{[graphic omitted]–NCHPh}₂]. Proton, ¹³C –{¹H}, ³¹P –{¹H} NMR and infrared data have been obtained. Crystals of cis-[[graphic omitted]H₂}₂] are monoclinic, space group P2₁/c, with a= 1261.5(2), b= 1794.6(3), c= 1792.0(4) pm and Z= 4; final R= 0.0451 for 4088 observed reflections.