Syntheses of Titanium(IV) Complexes with Mono-Cp and Schiff Base Ligands and Their Catalytic Activities for Ethylene Polymerization and Ethylene/1-Hexene Copolymerization

Abstract

The syntheses of two kinds of titanium(IV) complexes with mono-Cp and Schiff base as the mixed ligands are reported. These complexes are synthesized by the reaction of CpTiCl3 with the Schiff base lithium salt, and they are characterized by 1 H NMR, EA, IR, and MS. When activated by excess methylaluminoxane (MAO), all complexes are active for ethylene polymerization and ethylene/1-hexene copolymerization. 1/MAO shows 3 times as active as complex 7 (Cp2TiCl2) to the ethylene/1-hexene copolymerization, and the molecular weight of the copolymer obtained by 1/MAO is almost 2 times that of complex 3 and 5 times that of complex 7. Complex 1 combines the advantages of non-metallocene (complex 3) and metallocene (complex 7) to the ethylene polymerization and ethylene/1-hexene copolymerization.

Synthesis of novel zirconium complexes bearing mono‐Cp and tridentate Schiff base [ONO] ligands and their catalytic activities for olefin polymerization

“…Complex 6 exhibits the high catalytic activity (2.56 × 10 5 g/mol Zr h) and low 1-hexene incorporation ability (1.10%). 1-Hexene incorporation level were significantly lower than our cyclopentadienyl bis(phenoxy-imine) titanium complex 31 and much lower than Nomura's cyclopentadienyl phenoxide titanium complexes. 40 Obviously the introduction of tridentate ligand to zirconium complex has reduced the coordination space around the metal center, which is less open for 1-hexene coordination.…”

Titanium(IV) complexes containing mono-cyclopentadienyl and bulky trityloxy mixed ligands: synthesis and polymerization activity

“…13,14 We have reported a series of titanium(IV) complexes with monoCp and Schiff-base mixed ligands that show the advantages of Cp and non-Cp complexes in ethylene polymerization and ethylene-1-hexene copolymerization. 15 Recently, the Cp TiCl 2 (OAr) or Cp TiCl 2 [NAr(R)] complexes reported by Nomura and co-workers 16 -18 have shown high catalytic activity in ethylene polymerization 16,17 and in ethylene-α-olefin copolymerization 17,18 . These complexes, with a bulky ancillary ligand (OAr) or NAr(R) on the titanium center, were favorable for increasing the activity of α-olefin polymerization.…”

The effect of fullerene and some electron donating/withdrawing substituents on the molecular orbitals, strength and the nature of CN bond in a number of RCHNR′ imines: A theoretical study

“…The DFT studies have been performed by means of B3LYP and the newly developed M06 [57][58][59] functional. The geometries of the E/Z isomers of RACH@NAR 0 (R, R 0 = Me, Ph, t-Bu and CF 3 ) compounds have been optimized at the B3LYP and M06 levels with 6-311++G ⁄⁄ , def2-TZVP and aug-cc-pVDZ basis sets. The single point calculations and NBO analysis were performed at the same level of theory.…”

“…During the past decade, the imine compounds and their metal complexes have been the subject of numerous investigations, both experimentally and theoretically. A few examples of most important features of Schiff bases and/or their metal complexes are their catalytic [2][3][4][5][6][7][8][9][10] and biological activities [11][12][13][14][15][16][17], their application as sensors for the metal ions [18][19][20][21][22][23][24][25][26][27], as molecular switches [28][29][30][31], and also as anticancer agents [32][33][34][35][36][37].…”

“…Indeed, the purpose of the present work is to study the effects of fullerene (C 60 ) and electron donating/withdrawing substituents on the nature and strength of C@N double bond in RACH@NAR 0 compounds. To achieve this, we considered the R and/or R 0 groups as Me, t-Bu, Ph, CF 3 and also two derivatives of fullerene molecule including C 60 H and C 60 CH. To gain more insight into substituent effects on the strength of C@N bond, the interaction energy between two RACH and NAR 0 fragments in RACH@NAR 0 compounds has been calculated.…”