Experimental and ab initio studies of the novel piperidine-containing acetylene glycols

TL;DR

This study synthesizes novel piperidine-containing diacetylene molecules, analyzes their geometries and electronic structures through experimental NMR and first-principles calculations, and suggests potential plant growth benefits under drought conditions.

Contribution

It introduces a new synthesis method for piperidine-containing diacetylenes and combines experimental and ab initio studies to characterize their structures and stability.

Findings

Calculated geometries match experimental NMR data

Triple bonds are stable and do not participate in intermolecular reactions

The molecules may enhance plant growth during drought conditions

Abstract

Synthesis routes of novel piperidine-containing diacetylene are presented. The new molecules are expected to exhibit plant growth stimulation properties. In particular, the yield in a situation of drought is expected to increase. The synthesis makes use of the Favorskii reaction between cycloketones/piperidone and triple-bond containing glycols. The geometries of the obtained molecules were determined using nuclear magnetic resonance (NMR). The electronic structure and geometries of the molecules were studied theoretically using first-principles calculations based on density functional theory. The calculated geometries agree very well with the experimentally measured ones, and also allow us to determine bond lengths, angles and charge distributions inside the molecules. The stability of the OH-radicals located close to the triple bond and the piperidine/cyclohexane rings was proven by both experimental and theoretical analyses. The HOMO/LUMO analysis was done in order to characterize the electron density of the molecule. The calculations show that triple bond does not participate in intermolecular reactions which excludes the instability of novel materials as a reason for low production rate.