Fukui Function Analysis and Optical, Electronic, and Vibrational Properties of Tetrahydrofuran and Its Derivatives: A Complete Quantum Chemical Study

Table 4

Vibrational assignments of 1,2-diamino tetrahydrofuran (modes having high IR intensity only) with B3LYP/6-311 G (d, p).

B3LYP (calculated) unscaled	B3LYP (calculated) scaled	IR (int.)	Vibrational assignments
257	247	77.5282	Rock NH2
424	408	30.1483	Twist NH2
753	725	46.0965	(C–C–C–C)
859	827	83.126	Rock NH2
905	872	171.3772	Rock NH2
921	887	45.5585	Rock NH2
954	919	112.828	Rock NH2
1029	991	33.4007	Twist CH2
1068	1028	80.3998	Ring deformation
1164	1121	20.3894	(C–C–H) in whole molecule
1446	1392	14.2825	(C–C–H)
1645	1584	63.057	S(NH2)
1669	1607	31.4909	S(NH2)
2974	2864	55.4405	(C–H)
3010	2899	61.7424	(C–H)
3038	2926	34.5478	(C–H)
3044	2931	53.5102	(C–H)
3074	2960	46.2551	(C–H)
3090	2976	46.8808	(C–H)
3578	3446	3.4588	(N–H)