Synthesis of pyrrole-imine Schiff base ligands and their complexes with group IVB metal (Ti, Zr, Hf)

Abstract

Plastic raw materials have crucial importance to manufacture the products which are widely used in daily lives and become one of the most important key material in vary industries. Cans, bins, cloth, packaging materials, grocery bags and internal – external parts of computers can be counted in the products. With all superior properties, plastic materials have become very critical in daily lives and industries in all over the world. Around the globe, by year of 2018, it is estimated that all plastics manufacturing will have expected progress of growing at the %8 increase trend in a year and to reach 370.5 mtons. 9.46 millions tons of plastic crude products were manufacture in 2020 in Turkey. The production rate was based on the first three months of 2020 and will go on at the reasonable pace. All among the plastic materials, polyethylene is the most frequently acknowledged materials which is also utilized in our daily lives, reported that %42 of the all among the plastic consumption around the globe. The high usage rate is related to its easy to handle, lower costs of manufacture and highly designable properties. In recent days, there are common methods to produce polyethylene (PE); Phillips catalysts, Ziegler-Natta catalysts, radicalic polymerization and metallocene catalysts. Yet, restrictions has been occurred for material designers by these methods, because these routes cause limitation on analytical models and feedbacks to failures and trials. In the result, it has been long time to develop molecular architecture methods for designing the products. Innovation projects of metallocene catalysts provides a pathway for designers to handle tailoring the polymers in 1990's. Hence, monomers of olefin polymerization has been regulated by non-metallocene and metallocene catalysts which are single site and frankly active by late 2010's. Ti, Zr, Hf which are Group VI metals, metallocene and catalysts of non metallocenes were the leader materials for the product line of many kinds of polymers which have enhanced properties. For comparing, Ziegler Natta catalyst and Philip catalysts which is heterogenous and multi located, generally have well known single positing which is active and homogenous. Thus, chemistry of polymer, integration of co-monomer, control of chain transmission could be advantageous for molecular catalysts. Complexes of gropu IVB metals and producing new non-symmetric ligands is an illumination for the motivation behind our studies. Also, activation of the complexes for synthesis of polyethylene is another point to be noted for the study. As their natural behaviour, transition metals are able to incorporate olefins in general. Metal and ligands ratio which are electronically adaptable, could be managed in term of cost of catalysts of dynamic ethylene polymerization. Ligands are the most frequent objective in catalysts of polymerization in between materials of classic catalyst. Ligand-balanced catalysts, electronically flexible are needed to get high activity. Stereochemistry of non symmetric ligands and metal complexes of them are very beneficial for synthesis of ethylene polymerization, it has been seen after evaluation of olefin polymerization ligands. Dynamic ligands (FALs) were to creating ligands which can be adaptable electronically, which are able to obtain electron particles from ethylene via a metal and discharged electrons when is needed to make process of ethylene inclusion. In common sense, dynamic ligands have ability to give and pull back electrons which leads to boost up forms of olefin polymerization. This hypothesis' main focus is plan and develop another order of non symmetric ligands of pyrrole imine, which are 2-3. The ligands were used to produce new generation of group IVB metal complexes [Metals are Ti (a), Zr (b), Hf (c)], which are 2a-2c, 3a-3c. These complexes are planned to be used as catalyst for olefin polymerization. The novel non symmetric ligands (2-3) were investigated for their molecular structure via using spectroscopic methods: 1H-NMR, 13C-NMR, FT-IR. Deprotonated non symmetric ligands 1-2-3 were incorporated with the metal salts MCl4 [M = Ti (a), Zr (b), Hf (c)] of group IVB. The structure of the new complexes were investigated by using spectroscopic methods (1H-NMR, 13C-NMR, FT-IR).