Thermophysical Properties and Quantum Chemical Calculations of 3-Aminopropyltris(trimethylsiloxy)silane, 3-[1,3,3,3-Tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxanyl]-1-propanamine, and 1,1,1,3,5,5,5-Heptamethyl-3- <i>N</i> -2-(aminoethyl)-3-aminopro

This study systematically investigated the synthesis, thermophysical properties, and electronic characteristics of three novel trimethylsiloxy (TMS)-functionalized amino silane coupling agents: 3-aminopropyltris(trimethylsiloxy)silane (AP-trisTMS), 3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-1-disiloxanyl]-1-propanamine (AP-diTMS), and 1,1,1,3,5,5,5-heptamethyl-3-N-2-(aminoethyl)-3-aminopropyltrisiloxane (AEAP-diTMS). By precise design of the molecules through partial replacement of alkoxy groups with TMS, the hydrogen bonding ability, hydrophobicity, and thermal stability of these compounds were adjusted. Based on experimental results such as density, viscosity, and vapor pressure, combined with density functional theory calculations of electronic properties (the analysis of electrostatic potential energy of molecular surfaces, frontier molecular orbitals, simplified density gradient functional analysis, and localized orbital locator scatter plots), the molecular characteristics are comprehensively discussed. This research not only deepens our understanding of these compounds but also highlights their potential as high-performance materials.