Solid phase peptide synthesis on an acrylate copolymer attached to porous silica beads

Epton, R.; Marr, G.; Ridley, Ruth

doi:10.1016/0032-3861(82)90321-4

Cited by 6 publications

(1 citation statement)

References 16 publications

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“…These insoluble polymer supported complexes have the advantages over their soluble counterparts of easy separation from the reaction mixture leading to operational flexibility, because of their facile regenerability and higher stability 8–10. Studies on polymer anchored complexes gained importance because of their numerous applications in water treatment11, 12 immobilization of enzymes,13 catalysts14, 15 affinity chromatography,16 and as substrate carriers 17…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of polymer supported vitamin B12 model compounds

Devi

Reddy

et al. 2000

Polym. Int.

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Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of polymer supported vitamin B12 model compounds

Devi

Reddy

et al. 2000

Polym. Int.

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Polymer‐immobilized N,N′‐bis(acetylacetone)ethylenediamine cobalt(II) Schiff base complex and its catalytic activity in comparison with that of its homogenized analogue

Gupta

AbdulKadir

Chand

2003

J of Applied Polymer Sci

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ABSTRACT:For the preparation of a heterogenized N,NЈ-bis(acetylacetone)ethylenediamine cobalt(II) Schiff base complex, first crosslinked polymer beads were prepared by the suspension copolymerization of styrene (48.97 mmol, 5.1 g), allyl chloride (48.97 mmol, 3.746 g), and divinyl benzene (DVB; 1.75 mmol, 0.228 g) in the presence of azobisisobutyronitrile (0.9 ϫ 10 Ϫ3 mmol, 0.15 g) as an initiator at 23 Ϯ 0.1°C under an inert atmosphere. The copolymerization of styrene, allyl chloride in the presence of gelatin (0.75 g), bentonite (2.0 g), and boric acid (2.5 g) produced beads of different crosslinked densities corresponding to the concentration of DVB in the reaction mixture. The amount of allyl chloride in the prepared beads varied from 5.40 to 7.40 mmol g Ϫ1 of beads with the amount of DVB varying from 2.0 to 0.8 mmol in the reaction mixture. A quadridentate Schiff base (acen) was prepared with ethylenediamine (5.0 mmol, 0.3 g) and acetylacetone (10.0 mmol, 1.0 g), and it was used to obtain a homogenized and heterogenized Co(II)(acen) 2 complex. The extent and arrangement of the Schiff base (acen) in the crosslinked beads depended on the availability of DVB in the reaction mixture. The amount of DVB in the reaction mixture influenced the extent of cobalt(II) ion loading, the degree of swelling, the porosity, and the pore size in the prepared beads. The beads (type IV) prepared with 1.75 mmol (0.228 g) of DVB in the reaction mixture showed a degree of swelling of 9.65% and efficiencies of loading and complexation for cobalt(II) ions of 49.4 and 85%, respectively, in comparison with beads obtained at other concentrations of DVB in the reaction mixture. The structure of free and polymer-supported Co(II)(acen) 2 complexes was verified with IR, UV, and magnetic measurements, which suggested a square planar geometry for the complexes under both conditions. The catalytic activities of the homogenized and heterogenized Co(II)(acen) 2 complexes were compared by the evaluation of the rate constant (k) for the decomposition of hydrogen peroxide. The heterogenized Co(II)(acen) 2 complex showed a high catalytic activity for the decomposition of hydrogen peroxide (k ϭ 2.02 ϫ 10 Ϫ4 s Ϫ1) in comparison with the homogenized Co(II)(acen) 2 complex (k ϭ 4.32 ϫ 10 Ϫ6 s Ϫ1). The energy of activation for the decomposition of hydrogen peroxide with the heterogenized Co(II)(acen) 2 complex was low (38.52 kJ mol Ϫ1 ) in comparison with that for the homogenized complex (73.44 kJ mol Ϫ1). In both cases, the rate of decomposition of hydrogen peroxide was directly proportional to the concentration of hydrogen peroxide and cobalt(II) ions. On the basis of experimental observations, a rate expression for the decomposition of hydrogen peroxide was derived.

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