Synthesis and structure of metal complexes with organic polymers or inorganic supports

Abstract

Macromolecular ligands have been widely used in the past two decades with the objective of preparing structurally defined heterogeneous catalysts from soluble organometallic complexes. This activity has been largely reconsidered and focused on few specific systems. In this connection the present paper reviews recent data concerning the preparation of macromolecular metal complexes derived from transition metals which can produce active catalytic complexes for olefin polymerization and oligomerization and comparison is made about the suitability of both organic resins (crosslinked polystyrene) and inorganic materials (silica, alumina and zeolites).

Syntheses, magnetic and spectral studies on polystyrene supported coordination compounds of bidentate and tetradentate Schiff bases

“…26 PSCH 2 -L′Ni exhibits two bands at 20000 and 24000 cm -1 due to the 1 A 1g → 1 A 2g (ν 2 ) and 1 A 1g → 1 B 2g (ν 3 ) transitions in square planar geometry. 15 It also exhibits a weak band at 12450 cm -1 which is assigned to a spin-forbidden 1 -1 , second at 15500(sh), 16970 cm -1 and third at 19000, 25000 cm -1 respectively, corresponding to 6 A 1g → 4 T 1g (G), 6 A 1g → 4 T 2g (G), and 6 A 1g → 4 A 1g (G) transitions respectively, in octahedral symmetry. 15 PSCH 2 -L′Mn•2DMF exhibits two bands at 16950 and 24400 cm -1 due to 6 A 1g → 4 T 2g (G) and 6 A 1g → 4 A 1g (G) transitions respectively, in octahedral symmetry.…”

“…Reaction of polymer-anchored ligands with metal ions provide an easy route for the synthesis of immobilized transition metal compounds. 1 Structural studies of polymer-supported compounds appear to be useful and interesting in view of their numerous applications such as in organic synthesis, 2 immobilization of enzymes, 3 biological systems, 4 dyes, 5 analytical chemistry, 6 catalysis, 7 substrate carriers, 8 protecting groups 9 and heavy metal ions uptake 10 etc. Schiff bases are the most versatile and thoroughly studied ligands in coordination chemistry.…”

Synthesis, characterization, and catalytic activity of crosslinked poly(N‐vinyl‐2‐pyrrolidone acrylic acid) copolymer–metal complexes

“…21 The Cu(II) complex showed max at 13,037 and 25,641 cm Ϫ1 corresponding to 2 B 1g -2 B 2g and 2 B 1g -2 E g transitions in distorted octahedral/square planar geometry due to Jahn Tellar distortion. Cr(III), Fe(III), and Mn(II) showed transitions of octahedral geometry, with absorption maxima at 17,361 and 23,752 cm Ϫ1 due to 4 A 2g -4 T 2g (F) and 4 A 2g -4 T 1g (F) for Cr(III) and at 11,737 and 18,903 cm Ϫ1 due to 6 A 1g -4 T 1g (G) and 6 A 1g -4 T 2g for Fe(III), and a broad band in the region of 20,000 -25,000 cm Ϫ1 due to the combination of two transitions, 6 A 1g -4 T 2g (G) and 6 A 1g -4 E g (G), in high-spin octahedral geometry. Co(II) and Ni(II) exhibited bands at 18,656 and 34,322 cm Ϫ1 due to 4 T 1g -4 T 2g ( 1 ) and 4 T 1g (F)-4 T 1g (P) ( 3 ) and at 13,280 and 24,401 cm Ϫ1 for 3 A 2g -3 T 1g (P) and 3 A 2g -3 T 1g (F) for the Ni(II) complex, which suggested nearly octahedral geometry.…”

“…[2][3][4][5] Polymermetal complexes are widely used as immobilized catalysts with high specificity. 6 Many behave with enhanced efficiency when they are anchored to polymer systems. [7][8][9][10] The intrinsic advantages of these polymer-metal complexes in synthetic chemistry are that they may be used in excess to drive the reaction to completion without the product being contaminated and that they can be removed by simple filtration upon the completion of a reaction.…”

The influence of the preparing conditions of SiO2 supported Cp2ZrCl2 catalyst on ethylene polymerization

“…In addition, when the metallocenes are supported on magnesium dichloride, high catalytic activity is achieved,4–6 and also, in general, polymers with broad polydispersion are produced, indicating a multiplicity of active sites 7. Alumina is an inorganic oxide studied often as support for the metallocene catalysts and γ‐alumina is the type that is most frequently used 8–12. Furthermore, as silica is available in a large range of particle size and pore‐size distribution and, because of these ranges can be controlled during its synthesis, this solid material is also one of the inorganic oxides that is greatly explored in research as support for the metallocene catalysts 7–10, 12–22…”