Theoretical Study of Hydrogen Bond Formation in Trimethylene Glycol-Water Complex

Table 6

Calculated scaled vibrational frequency (cm⁻¹), red shift (cm⁻¹), IR intensity (km-mol⁻¹) of O–H bond stretching for water molecule, and TMG molecule and TMG + n water complex (𝑛=1,2) using WB97XD/6-31++G(d,p) along with some experimental vibrational frequency (cm⁻¹).

System	O–H bond stretching for water molecule				O–H bond stretching for TMG molecule
	Scaled freq.	Red shift	IR intensity	Exp. vibrational frequency	Scaled freq.	Red shift	IR intensity
Water molecule	3802		8.2	3756 [9]
TMG molecule					3757		144.43
TMG dimer					3519	238	585.61
TMG + 1 water complex (TD)	3797	5	13.87		3663	94	717.93
TMG + 1 water complex (WD)	3736	66	95.97		3754	3	80.39
TMG + 2 water complex	3665	137	512.89		3766	—	133.90