Ultrasonic velocity (U), Density (ρ), and Viscosity (η) have been measured for unsaturated aromatic aldehyde with o-phenyldiamine in n-hexane at 303 K, 308 K and 313 K. Acoustical parameters such as the adiabatic compressibility (β), acoustic impedance (Z), free length (Lf), free volume (Vf), internal pressure (πi), cohesive energy (CE), Lenard Jones potential(LJP), formation constant (K), free energy of formation (ΔG), free energy activation (ΔG) and viscous relaxation time (ґ) are also calculated. The variation of parameter with different temperature is also discussed in terms of unsaturated and mechanism of reaction. The thermodynamic parameter is also conformed strong charge transfer complex. Excess thermo acoustic parameters conclude the existence of hydrogen bonded complexes between cinnamaldehyde and amine.