Cobalt (III) Complexes with (R)-1, 2-Diaminopropane and Its Derivatives

Christopher John Rudy, Western Michigan University


(R)-1,2-Diethylaminopropane (N,N'-Etlpn) was prepared by LiAlH4 reduction of (R)-1-2-diacetamidopropane (m.p. 153.5 °C). The [α]Dof N,N'-Melpn and N,N'-Etlpn was related to that of lpn and was concentration dependent. (R)-1,2-Dibenzylaminopropane was prepared. Complexes of trans,trans- and trans,cis-dinitrobis((R)- 1,2-diethylaminopropane)cobalt(III) were prepared. The hexadecadal rule was used to help assign the nitro oxygens of the complexes to sectors adjacent to the axial amine hydrogens and within the boundaries of the λ-chelate rings. The CD spectra was solvent dependent. The instability of trans-[Co(III)N4X2]+ complexes was related to the ammonia or 1,2-diamine ligand (N,N'-Bzlpn > N,N'-Etlpn > N,N'-Eten > N,N'-Melpn > N,N'-Meen > NH3 > lpn), the trans-X groups (Cl- > Br - > NO2-) and the counterion (Cl - > Br -;ClO4-; NO3-). NH4[Co(III)- (NH3)2 (1,2-diamine) (SO3)2] complexes were prepared, and trans-[Co(III)(NH3)2 (lpn)Br2]Br and trans-[CO(III) (NH3)2 - (lpn) Cl2]Cl were prepared from NH4 [Co(III)(NH3)2(lpn) - ( S03)2 using HBr or HCl.