Table 7.

B97D frequencies and IR intensities for CH₃COOCH₃ and CH₃CSSCH₃ ^a.

	Gas		CHCl3		CH3CN		Exp b
	ω	Int	ω	Int	ω	Int
CH3COOCH3, cis
C-H stretching
acetyl methyl	3088	8.3	3080	9.2	3077	5.2	2844–3026
	3041	6.5	3034	3.2	3031	1.9
	2967	5.8	2960(c)	5.0	2956(c)	13.3
ester methyl	3080	15.3	3079	10.2	3079	12.3
	3045	23.1	3046	20.8	3046	20.1
	2961	33.0	2957	26.5	2955(c)	15.5
torsional
O=C-O-CH3	177	6.0	196	8.4	197	9.5
CH3COOCH3, trans
C-H stretching
acetyl methyl	3092	6.0	3085	4.3	3082	3.4
	3031(c)	14.7	3026	0.9	3022	0.3
	2961	7.7	2955	3.0	2952(c)	4.4
ester methyl	3067	18.5	3073	13.5	3074	11.6
	3020(c)	24.8	3036	22.5	3041	15.9
	2941	35.6	2948	27.9	2949	21.0
CH3CSSCH3, cis
C-H stretching
acetyl methyl	3042	5.1	3032	7.4	3027	10.7
	3025	9.4	3022	8.5	3021	5.3
	2945	9.4	2939	3.4	2936	1.9
ester methyl	3070	4.0	3064	1.9	3061	1.0
	3063	3.0	3058	1.4	3056	0.8
	2969	11.7	2953	5.0	2950	2.8
torsional
S=C-S-CH3	220	4.3	191	7.3	188	8.3
CH3CSSCH3, trans
C-H stretching
acetyl methyl	3069	3.7	3063(c)	2.8	3061(c)	2.8
	3003	7.8	2999	2.7	2995	0.8
	2938	10.5	2933	2.6	2929	0.3
ester methyl	3064	5.6	3062(c)	2.7	3061	0.6
	3061	6.9	3062(c)	2.5	3060(c)	1.8
	2960	2960	2955	5.2	2952	1.9

^a Frequencies (ω) in cm⁻¹. Letter “c” in parentheses refers to non-negligible coupling with displacements in the other methyl group. ^b Ref. [48], data recorded in dilute CCl₄ solution.