title: Highly efficient dimerization of ethylene by (imido)vanadium complexes containing (2-anilidomethyl)pyridine ligands: notable ligand effect toward activity and selectivity.
abstract: (Imido)vanadium(V) complexes containing the (2-anilidomethyl)pyridine ligand, V(NR)Cl(2)[2-ArNCH(2)(C(5)H(4)N)] (R = 1-adamantyl (Ad), cyclohexyl (Cy), phenyl), exhibit remarkably high catalytic activities (e.g. TOF = 2 730 000 h(-1) (758 s(-1)) by V(NAd)Cl(2)[2-(2,6-Me(2)C(6)H(3))NCH(2)(C(5)H(4)N)) for ethylene dimerization in the presence of MAO, affording 1-butene exclusively (selectivity 90.4 to >99%). The steric bulk of the imido ligand plays an important role in the selectivity (polymerization vs dimerization), and the electronic nature directly affects the catalytic activity (activity: R = Ad > Cy > Ph).
authors.affiliation: Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan.
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
authors.forename: Kotohiro
authors.initials: K
authors.lastname: Nomura
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D019281:Dimerization; D005030:Ethylenes / Q000138:chemical synthesis* / Q000737:chemistry; D007094:Imides / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D013237:Stereoisomerism; D014639:Vanadium / Q000737:chemistry*
chemical_list: C550581:(2-anilidomethyl)pyridine; D005030:Ethylenes; D007094:Imides; D008024:Ligands; D009942:Organometallic Compounds; D011725:Pyridines; D014639:Vanadium