The present invention provides a novel transition metal complex where a monocy-clopentadienyl ligand to which an amido group is introduced is coordinated, a method for synthesizing the complex, and olefin polymerization using the same. The method for preparing a transition metal complex according to the present invention comprises a step of blocking a by-reaction of a nitrogen atom using a compound containing a protecting group, and thus it is possible to prepare a transition metal complex in a simpler manner in a high yield. Further, the transition metal complex according to the present invention has a pentagon ring structure having an amido group connected by a phenylene bridge in which a stable bond is formed in the vicinity of a metal site, and thus, sterically monomers can easily approach the transition metal complex.

Method for preparing transition metal complexes, transition metal complexes prepared using the method, catalyst composition containing the complexes

New ferrocenoylacetonate complexes of several rare earth elements, [Ln(fca)3(bpy)]·MeC6H5 (Ln = Pr (1), Eu (2), Gd (3), Tb (4), Dy (5), Ho (6), Y (7); bpy – 2,2′-bipyridine; Hfca – FcCOCH2COMe) as well as scandium ferrocenoylacetonate [Sc(fca)3]·0.5MeC6H5 (8), were synthesized and characterized by single crystal X-ray diffraction analysis. In the crystal lattice of the isostructural complexes 1–7, two [Ln(fca)3(bpy)] molecules form a pair due to stacking interactions between the bpy ligands. The Ln3+ ions are coordinated in a square antiprism geometry with a coordination number of 8. The Sc3+ ions in complex 8 are coordinated in an octahedral geometry. Thermolysis of complexes 1–7 was studied under air and argon atmospheres; in the first case, it affords perovskites LnFeO3 as one of the products. Complexes 4–6 display single-molecule magnet properties, and the effective relaxation barrier for the Dy complex 5, was found to be Δeff/kB = 241 K, which is one of the highest values obtained for a mononuclear β-diketonate lanthanide complex.

Synthesis, structure, and physical properties of new rare earth ferrocenoylacetonates

Synthesis of 2-ferrocenylidene-4-cyclopentene-1,3-diones

Information concerning the structures of compounds of rare earth elements with carboxylic acids and a β-diketone containing stable organometallic moieties that we obtained previously is presented. Additional results for 15 complexes with the [Gd2O2] core allowed confirming and improving the correlation between JGd–Gd′ and the Gd…Gd distance for complexes of this type that we found earlier. For the first time, dc and ac magnetic measurements were carried out for the formerly-described complex [Dy2(O2CCym)4(NO3)2(DMSO)4] (2), Cym = (η5-C5H4)Mn(CO)3), and two new binuclear complexes, namely [Dy2(O2CFc)4(NO3)2(DMSO)4] (3), and [Dy2(O2CFc)6(DMSO)2(H2O)2] (4), Fc = (η5-C5H4)Fe(η5-C5H5)). For binuclear [Dy2(O2CCym)6(DMSO)4] (1), as well as for a 1D-polymer [Dy(O2CCym)(acac)2(H2O)]n (6), ac magnetic measurements were carried out more precisely. The characteristics of a single-molecule magnet and of a single-chain magnet were determined for Complexes 2 and 6, respectively.

https://www.mdpi.com/2312-7481/2/4/38/pdf

Magnetic Behavior of Carboxylate and β-Diketonate Lanthanide Complexes Containing Stable Organometallic Moieties in the Core-Forming Ligand

Using ferrocenecarboxylic acid (FcCO2H) and triethanolamine (H3tea) as ligands, the isostructural heterotrimetallic complexes [LnIII2CrIII2(OH)2(FcCO2)4(NO3)2(Htea)2]·2MePh·2THF (Ln = Tb (1), Dy (2), Ho (3), Er (4), and Y (5); Fc = (η5-C5H4)(η5-C5H5)Fe; H3tea = N(CH2CH2OH)3) were obtained. In all of the complexes which possess a defective dicubane structure, two doubly deprotonated triethanolamine ligands chelate the chromium ions. However, during the synthesis of 1, an isomeric complex 1a in which Tb3+ is chelated by triethanolamine as a tetradentate ligand, was also isolated as a few single crystals. Magnetic susceptibility measurements revealed dominant antiferromagnetic interactions in the {LnIII2CrIII2} cores of 1–4 leading to the formation of complexes with an uncompensated magnetic moment, while weak Cr–Cr ferromagnetic interactions were detected in the Y analogue. Complexes 1, 2, and 3 exhibit single-molecule magnet properties dominated by an Orbach-type relaxation mechanism with magnetization reversal barriers (Δ/kB) estimated around 54, 75, and 47 K, respectively. The Dy complex exhibits a magnetization hysteresis in an applied magnetic field at temperatures below 4 K. Thermolysis of the complexes was studied by TGA and DSC techniques; the final products obtained under an air atmosphere contain mixed oxide Cr0.75Fe1.25O3 and heterotrimetallic oxide LnCr1−xFexO3 (with x ≈ 0.75) phases.

Tetranuclear Cr-Ln ferrocenecarboxylate complexes with a defect-dicubane structure: synthesis, magnetism, and thermolysis.

1.

The dissociation constants of p-, m-, and o-ferrocenylbenzoic acids, ferrocenecarboxylic acid, and p-ferrocenylphenol were determined, along with the basicity constants of p-, m-, and o-ferrocenylanilines and ferrocenylamine.




2.

The values of the σ constants for ferrocenyl as a substituent in the phenyl ring were calculated.




3.

The nature of certain electronic effects of ferrocenyl as a substituent was studied. Ferrocenyl exhibits a strong positive inductive effect and a weak positive conjugation effect.

K. I. Grendberg

Papers

Electronic influence of ferrocenyl as a substituent