Role of metal(ii) hexacyanocobaltate(iii) surface chemistry for prebiotic peptides synthesis

Abstract

Double metal cyanide (DMC), a heterogeneous catalyst, provides a surface for the polymerization of amino acids. Based on the hypothesis, the present study is designed to evaluate favorable environmental conditions for the chemical evolution and origin of life, such as the effects of temperature and time on the oligomerization of glycine and alanine on metal(II) hexacyanocobaltate(III), MHCCo. A series of MHCCo complexes were synthesized and characterized by XRD and FT-IR techniques. The effect of outer metal ions present in the MHCCo complexes on the condensation of glycine and alanine was studied. Our results revealed that Zn²⁺ ions in the outer sphere showed high catalytic activity compared to other metal ions in the outer sphere. Manganese(II) hexacyanocobaltate(III) (MnHCCo), iron(II) hexacyanocobaltate(III) (FeHCCo), nickel(II) hexacyanocobaltate(III) (NiHCCo) complexes condense the glycine up to trimer and the alanine up to dimer. At the same time, ZnHCCo showed the most valuable catalytic properties that change glycine into a tetramer and alanine into a dimer with a high yield at 90 °C after four weeks. ZnHCCo showed high catalytic activity because of its high surface area compared to other MHCCo complexes. High-Performance Liquid Chromatography (HPLC) and Electron Spray Ionization-Mass Spectroscopy (ESI-MS) techniques were used to confirm the oligomer products of glycine and alanine formed on MHCCo complexes. The results also exposed the catalytic role of MHCCo for the oligomerization of biomolecules, thus supporting chemical evolution.