20772-78-5Relevant academic research and scientific papers
Bis{1-[N-(2-methoxyphenyl)iminomethyl]naphthalen-2(1H)-onato-k 3O,N,O′}zinc(II) ethanol solvate
Dilovic, Ivica,Matkovic-Calogovic, Dubravka,Popovic, Zora,Roje, Vibor
, p. m351-m352 (2005)
In the crystal structure of the title compound, [Zn(C18H 14-NO2)2·C2H6O, the Zn atom displays a highly distorted octahedral coordination involving the O and N atoms of two molecules of the
Dual Catalysis of the Selective Polymerization of Biosourced Myrcene and Methyl Methacrylate Promoted by Salicylaldiminato Cobalt(II) Complexes with a Pendant Donor
Jia, Xiaoyu,Li, Wenxin,Zhao, Junyi,Yi, Feiyan,Luo, Yunjie,Gong, Dirong
, p. 278 - 288 (2019/02/01)
Cobalt complexes (Co1-Co6) bis-chelated by phenoxy (4,6-di-tert-butyl-2-phenol, naphthalen-2-ol)-imine ligands containing pendant hard oxygen (Co1 and Co4), soft sulfur (Co2 and Co5), or phosphine donors (Co3 and Co6) are reported for dual catalysis of selective polymerization for biosourced myrcene and methyl methacrylate (MMA). X-ray analysis reveals that the complexes features a distorted octahedral coordination of the cobalt center binding with phenolate oxygen, imine nitrogen, and pendant donor (P for Co3 and S for Co5). Activated by MMAO or AliBu3, all precursors are able to not only convert myrcene to cis-1,4-polymyrence but also polymerize MMA resulting in poly(methyl methacrylate) (PMMA) with moderate syndiotacticity. The introduction of pendant donor concurrently improves activity and stability particularly at 60-80 °C for polymerizations of both monomers. The enhanced activity and selectivity observed in myrcene cis-1,4 polymerization promoted by the sulfur and oxygen containing catalysts may relate to the weak Co-X (X = O, S) interaction, facilitating myrcene coordination. However, the donor effect on MMA polymerization activity is reversed, with phosphine donated catalyst demonstrating remarkably enhanced activity. This study represents the first example of cobalt catalyzed polymerization of both polar and nonpolar functions via possible mechanisms differentiated by pendant donor and also may provide valuable insights into their essential role in mediating the polymerization process.
Studies of Chelation. Part 9. Cobalt Complexes of 1--2-naphthol and 1--2-naphthol Ligands. Tautomerism and Reactivity
Connor, Joseph A.,Fine, David J.
, p. 559 - 566 (2007/10/02)
Spectroscopic characterisation (1H and 13C n.m.r., i.r., Raman, and u.v.-visible) of various 1--2-naphthols, R-Haz (R = 4'-Me, 4'-OMe, 4'-Cl, H, 2'-OMe, 2'-Me, 2'-Cl, and 2'-Br), and 1--2-naphthols, R-Hsb (R = 4'-OMe, 4'-Me, 4'-Cl, H, 4'-Br, 4'-CF3, 4'-CN, 4'-NO2, 2'-OMe, 2'-Me, 2'-CHMe2, 2'-Cl, 2'-CN, and 2'-NO2), in the solid state and in solution in both polar and non-polar solvents has shown that the hydrogen-bonded keto-tautomer is dominant in polar solvents.Reaction of cobalt(II) salts with R-Haz and with R-Hsb in ethanol produces , cis-, and fac- (L=R-az or R-sb).The tautomeric form of the ligand in these complexes is established by vibrational spetroscopy and shown to be predominantly keto (hydrazone, ketoenamine) in , in , and (X = Cl or Br) but predominantly enolimine in .The interconversion of and is established generally: the intermediate, five-co-ordinate is identified in certain cases (R = 4-OMe, 4'-Me, or H).In the chelation process, proton loss follows ring closure and is succeeded by tautomerisation where this occurs.The facility with which the chelating ligand deviates from coplanarity of the benzene and naphthalene rings is a critical feature of the chelation process.The formation of from and from in the presence of air occurs easily and is acid catalysed. is formed only under vigorously oxidising conditions.The isoelectronic ligands R-Haz and R-Hsb should not be regarded as identical in their reactivity towards cobalt(II).
A General and Practicable Synthesis of Polycyclic Heteroaromatic Compounds. Part 4. A Rationale for the Mechanism of the Synthesis
Asherson, Janet L.,Bilgic, Orhan,Young, Douglas W.
, p. 3041 - 3047 (2007/10/02)
Studies on aspects of the mechanism of our general synthesis of polycyclic heteroaromatic compounds suggest that the reaction sequence outlined in Scheme 2 is followed.Under the conditions of our synthesis, the ortho-rearrangement (8) --> (9) is preferred to the para-rearrangement which is known to occur in acid conditions.Aniline Mannich bases (29) are converted to benzacridines (30) in an intermolecular reaction.The synthesis appears to be restricted to substrates where the putative intermediate (9) is not part of an amide group.In the course of these studies effective syntheses of the tricyclic compounds (24) and (25) have been discovered.
