Cis- And trans-Dimolybdenum(11) Complexes with Asymmetrically 2,7-Disubstituted Naphthyridines as Bridging Ligands

Article abstract of DOI:10.1002/cber.19961290615

Treatment of [Mo(CO)₆] with Hmamnp (2-acetamido-7-methyl-1,8-naphthyridine) in diglyme at 100°C affords the mononuclear complex [Mo(CO)₄{Hmamnp)] 1, an intermediate product on the reaction pathway to tetrasubstituted species of the type [Mo₂L₄]. A disubstituted intermediate product cis-[Mo₂(mphamnp)₂(OAc)₂] 2 (Hmphamnp) (2-acetamido-5-methyl-7-phenyl-l,8-naphthyridine) may be isolated from the reaction of [Mo₂(OAc}₄] with mphamnp in THF. The relative stabilisation of such products is a result of the steric demands of the coplanar 2-acetamido substituents. 2 and the tetrasubstituted complexes trans-[Mo₂{mbznnp)₄] 3 (Hmbznnp = 2-benzylamino-7-methyl-l,8-naphthyridme), tis-[Mo₂(mphonp)₄] 4, and trans-[Mo₂(mphonp)₄] 5 (Hmphonp = 5-methyl-7-phenyl-l,8-naphthyridin-2-one) all exhibit the electronically prefered μ-N¹,X² bridging mode. Steric effects are responsible for the isolation of the unusual cis isomer 4. VCH Verlagsgesellschaft mbH, 1996.