Use of Titanium Complexes Bearing Diphenolate or Calix[n]arene Ligands in α-Olefin Polymerization and the ROP of Cyclic Esters

Abstract

In this review, we discuss the use of titanium complexes bearing either bridged diphenolate or calix[n]arene (n = 4, 6, 8) ligation, in the formation of plastics from α-olefins or via the ring opening polymerization (ROP) of cyclic esters. The syntheses, molecular structures and catalytic behaviour of these systems are discussed, as well as where possible, the properties of the resultant polymers.

INSIGHTS into the structures adopted by titanocalix[6 and 8]arenes and their use in the ring opening polymerization of cyclic esters

“…173.17 16, O 14-Ti 6-N(4A) 169.60 16, Cl 9-Ti(7)-Cl 10167.29 6, O 15-Ti(7)-N(5A) 173.91 15, O 16-Ti 7-O(19) 164.48 (15). (6•6MeCN).…”

“…We have recently reviewed the use of titanium diphenolates and titanocalix [4]arenes for both α-olefin polymerization and the ROP of cyclic esters. 15…”

Olefin polymerization behavior of titanium(IV) alkoxo complexes with fluorinated diolate ligands: The impact of the chelate ring size and the nature of organoaluminum compounds

“…Catalytic systems containing titanium complexes have been applied both for ethylene homopolymerization and its copolymerization with other olefins. [3][4][5] Titanium(IV) complexes can even catalyze the copolymerization of ethylene with olefins functionalized with polar groups, which is a challenging task for early transition metals. [6,7] Recently it was shown that Ti(IV) alkoxide complexes with 1,2-and 1,4-diolate ligands activated by binary activator {Bu 2 Mg + Et 2 AlCl} catalyze the polymerization of ethylene with the formation of ultra-high molecular weight polyethylene (UHMWPE).…”

Synthesis of Biodegradable Polymers: A Review on the Use of Schiff-Base Metal Complexes as Catalysts for the Ring Opening Polymerization (ROP) of Cyclic Esters

“…On the other hand, undesired transesterification reactions are promoted by tin octoate, resulting in broad molecular weight distributions. Hence, alternative systems based on different metal/ligand combinations, capable of better control over the polymerization process, have been explored [11][12][13][14][15][16]. Complexes derived from Schiff-base ligands emerged as efficient catalysts for the polymerization of α-olefins [17][18][19][20][21], and their use in the production of biodegradable polymers has been receiving growing interest.…”