Results and discussion
Molecular geometry
The most optimized structural parameters of 2BBF were calculated
by DFT/B3LYP level with 6-31G(d,p) basis set are presented in
Table 1. The atom numbering scheme of the compound is given in
Fig. 1. The calculated molecular structure for this compound is
found to be non-planar and is as shown in Fig. 1. In order to reveal
all possible conformations of 2BBF, a detailed potential energy surface
(PES) scan for C15–C14–C8–C7 dihedral angle was performed.
The scan was carried out by minimizing the potential energy in all
geometrical parameters by changing the torsion angle 10 in steps
for 360 rotation around the bond using 6-31G(d,p) basis set. The
shape of the potential energy as a function of the dihedral angle
is illustrated in Fig. 2. The total minimum energy obtained by the
DFT for the 2BBF was found to be 3107.4276734 Hartrees. The
calculated optimized geometrical parameters are compared with
the available experimental data of 2-(2-methoxyphenyl)-1-benzofuran,
3-(2-bromoacetyl)-6-fluoro-2Hchromen-2-one and 1-(1-
benzofuran-2-yl)-2-(phenylsulfonyl)-ethanone [41–43] as crystal
data of 2BBF is not available.
From the Table 1, it can be seen that there are some deviations
in the computed geometric parameters from the experimental
value. These differences are due to the fact that the crystalline state
involves the intermolecular hydrogen bonding, whereas the results
of the calculations are applicable to the gas phase. Further, it is
noticed that the maximum deviation between calculated and