Structural Preferences and Vibrational Analysis of 2-Hydroxy-2-methyl-1-phenylpropan-1-one: A Computational and Infrared Spectroscopic Research

Table 1

Optimized geometry of 2-hydroxy-2-methyl-1-phenylpropan-1-one calculated at HF and B3LYP using 6-311+G** basis set.

Internal coordinates	Level of theory
	RHF/6-311+G**	DFT/6-311+G**	X-ray^a
Bond lengths (Å)
C1C2	1.395	1.405	1.39
C2C3	1.381	1.388	1.41
C3C4	1.386	1.395	1.37
C4C5	1.383	1.392	1.36
C5C6	1.385	1.392	1.42
C6C1	1.390	1.402	1.39
CH(ring)average	1.073	1.082
C1C12	1.506	1.499	1.48
C12O13	1.194	1.221	1.24
C12C14	1.547	1.554	1.55^b
C14C15	1.535	1.540	1.54^b
C15H16	1.082	1.090
C15H17	1.085	1.092
C15H18	1.084	1.092
C14C19	1.531	1.540	1.54^b
C19H20	1.084	1.092
C19H21	1.085	1.092
C19H22	1.081	1.090
C14O23	1.399	1.421	1.38^b
O23H24	0.944	0.971	0.95
Bond angles (°)
C1C2C3	120.8	120.9	120
C2C3C4	119.9	120.0	122
C3C4C5	119.7	119.7	118
C4C5C6	120.1	120.2	123
C5C6C1	120.6	120.6	118
C6C1C2	118.5	118.4	119
CCHring average	119.4	119.3
C6C1C12	125.1	124.8
C1C12O13	118.7	119.2	118
C1C12C14	124.0	123.9
C12C14C15	110.5	111.3
C14C15H16	113.6	113.4
C14C15H17	110.0	110.1
C14C15H18	108.0	107.9
C12C14C19	112.3	111.3
C14C19H20	107.9	107.9
C14C19H21	110.2	110.1
C14C19H22	113.4	113.4
C12C14O23	107.4	107.2
C14O23H24	109.0	106.2	111
Dihedral angles (°)
C1C2C3C4	0.4	0.0
C2C3C4C5	−0.1	0.0
C3C4C5C6	−0.2	0.0
C6C4C2H7	179.7	180.0
C1C2C3H8	−179.6	180.0
C2C3C4H9	179.8	180.0
C3C4C5H10	179.7	180.0
C4C5C6H11	179.9	180.0
C5C6C1C12	179.2	−179.9
C6C1C12O13	−169.4	179.9
C6C1C12C14	10.7	0.0
C1C12C14C15	−71.3	−63.2
C12C14C15H16	67.1	68.2
C12C14C15H17	−54.6	−53.7
C12C14C15H18	−172.2	−171.3
C1C12C14C19	55.4	63.2
C12C14C19H20	169.6	171.3
C12C14C19H21	52.1	53.7
C12C14C19H22	−69.9	−68.2
C1C12C14O23	171.8	−179.9
C12C14O23H24	11.2	0.0

aXRD data of closely related molecules benzoic acid and butyric acid [5, 6].
^bXRD data of 4-butyl-1-(4-hydroxyphenyl)-2-phenyl-3,5-pyrazolidinedione [7].