Abstract <p>Resonance-assisted hydrogen bonding (RAHB), a special type of intramolecular hydrogen bond (IMHB), plays a crucial role in biological systems and exhibits significant potential in material design, biomolecular chemistryand catalytic chemistry. Due to its importance, RAHB has been extensively studied. Accurate estimation of RAHB energy is essential for understanding molecular interactions and conformational behavior. In this study, we synthesized thirty-three <i>N</i>-(phenylethylene)anilines (2-OH-R¹PEAR²) with varying substituents and measured their ¹H NMR chemical shift δ_H(OH) of the OH and the ¹³C NMR chemical shift δ_C(CMe=N) of the CMe=N. Using these model compounds, we calculated the hydrogen bond energy <i>E</i>_HB, bond lengths <i>d</i>_O<i>–</i>H and <i>d</i>_N···H, and the aromaticity of the phenyl rings (PDI). We investigated the relationship between the <i>E</i>_HB and the bond lengths (<i>d</i>_O–H, <i>d</i>_N···H) in 2-OH-R¹PEAR², the correlation between NMR chemical shifts δ_H(OH), δ_C(CMe=N), <i>E</i>_HB and the aromaticity of the hydrogen-bonded ring (PDI_Q). A comparative analysis was performed with structurally similar ortho-hydroxy diaryl Schiff bases (2-OH-R¹BAR²). In 2-OH-R¹PEAR², the calculated <i>d</i>_O–H and <i>d</i>_N···H values show a strong correlation. The <i>E</i>_HB also correlates well with <i>d</i>_O–H, suggesting that <i>d</i>_O–H can serve a reliable indicator of hydrogen bond strength. In compound 2-OH-R¹PEAR², <i>E</i>_HB has good correlations with δ_H(OH), δ_C(CMe=N) and PDI_Q. The introduction of α-CH₃ on the bridge bond causes the two benzene rings in 2-OH-R¹PEAR² to deviate from the coplanar more severely than in 2-OH-R¹BAR², rendering the aromaticity of ring B negligible in influencing δ_H(OH) and δ_C(CMe=N).</p>