Probing the interaction of Ti clusters with isopropanol for ether production: an experimental and computational study

Ti clusters were successfully synthesized in isopropanol using laser ablation in liquid. According to the isotope pattern and the corresponding m/z ratio, the dominant peak is assigned to Ti-5(C3H8O)(13). Density functional theory (DFT) calculations, are applied to illustrate the interaction of isopropanol with Ti. Among the Tin(2-7) clusters, Ti-5 has the highest electrophilicity and chemical potential, justifying the reasonable stability of Ti-5 in forming the experimentally observed Ti-5-C3H8O complex. Natural bond orbital analysis shows that the various interactions emanating from & sigma;& RARR; & sigma;* and LP & RARR;LP orbitals within the complex contribute to the high stability of the Ti cluster. Moreso, that the Ti-O bond is more of covalent than electrostatic since the Laplacian of electron density for the bond critical point is negative. Finally, the Ti clusters are found to catalyze the coupling of isopropanol to diisopropylether as evidenced from the calculated reaction pathways and high-resolution mass spectrometry analysis. The energy profiles in the reaction coordinates show that the triplet state pathway is the most thermodynamically preferred path. The energy barrier for the Ti-5 pathway are also lower compared to Ti-3 and Ti-7 pathways, showing that the reaction is favorable for Ti-5.

Automated summary

Ti clusters were synthesized using laser ablation in liquid in isopropanol. The dominant peak is assigned to Ti-5(C3H8O)(13) based on isotope pattern and m/z ratio. DFT calculations show that Ti-5 cluster has the highest electrophilicity and chemical potential, explaining its stability in forming Ti-5-C3H8O complex. Natural bond orbital analysis reveals the various interactions within the complex contribute to its high stability, with the Ti-O bond being more covalent than electrostatic. Furthermore, Ti clusters catalyze the coupling of isopropanol to diisopropylether, with the Ti-5 pathway being thermodynamically favorable based on energy profiles.