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N.R. Sreenatha, A.S. Jeevan Chakravarthy and B.N. Lakshminarayana et al. / Journal of Molecular Structure 1225 (2021) 129116
3
Table 2
Intra- and intermolecular interactions of 3 (A, ◦).
˚
D–H...A
D–H
H...A
D...A
D-H...A
Symmetry code
Intermolecular
C8–H8A...O1∗
C10–H10...O2
C6–H6A...O2
0.96
0.93
0.97
2.58
2.62
2.52
3.506(4)
3.437(1)
3.071(3)
161
147
116
x, −1 + y, z
x, 3/2 − y, −1/2 + z
Intra-molecular
∗
Weak interaction.
the bond critical points of the type (3,-1) have been computed by
the MoProViewer GUI software [30,31] using the procedures given
by Abramov expressions [32].
The other puckering parameters and their pertaining endo-cyclic
torsion angle values are given in Sup. Tables T3 and T4. The non-
hydrogen ring substituent analysis was carried out for Cg1 which
divulged that, the following bond segments C3–O1; C4–Cl1; C5–C9;
C1–C8 are oriented equatorial, while the segment C1–C7 is lying
axial to the Cremer and Pople plane of Cg1 which is mainly due
to the bulk effect of methyl groups at C1, whose supported bond
angle values are given in Sup. Table T5.
3. Results and discussions
3.1. Spectral data
The mean planes of Cg1 and Cg2 are inclined to each other with
the dihedral angle of 62.49(1)◦ which indicate that, the structure
as a whole was adopted a non planar geometry. This is also pin-
Slow evaporation techniques were employed to isolate good
quality crystals of 3 in petroleum benzine (60-74◦ C) solvent; yield:
94%. Melting Point: 63. IR (cm−1): 2951, 1685, 1604, 1487, 1456,
1300, 1249, 1142, 1115, 1022, 941, 753, 670, 597, 482.
˚
pointed by the strain in bond length of C5–C9=1.488(3)A which is
˚
1
shorter than actual value for the single bond length of C–C=1.50A
H NMR (400 MHz, CDCl3, δ/ppm): 1.15 (s, 6H), 2.55 (m, 4H),
˚
[36]. The investigation on bond lengths between C3–O1=1.215(3)A
3.82 (s, 3H), 6.95 (d, J = 8.4 Hz, 1H), 6.98 - 7.1 (m, 1H), 7.33 -7.37
˚
and C14–O2=1.365(3)A which clearly distinguishes the double and
(m, 1H).
13
single bond characters respectively, further these are not apprecia-
bly deviated from the values reported by Niranjana Devi et al. [37].
Despite, presence of –(OCH3) functional group at C14 and Cg1 moi-
ety at C9, the position of each carbon atom in a Cg2 ring is con-
sistent to an sp2 hybridization as evidenced by their endo-cyclic
C NMR (75 MHz, CDCl3, δ/ppm): 33.7, 38.2, 46.9, 51.7, 55.5,
55.6, 111.3, 120.6, 128.1, 128.2, 128.9, 130, 154.3, 155.4, 191.9. MS:
m/z Anal. Calc. for C15H17 ClO2 265, found 266. CHNS: C: 68.05, H:
6.47, found C: 68.04, H: 6.45 [19].
C–C–C valence bond angle values are averaged to
120◦. Never-
3.2. Structural description
theless, in Cg1 the valence bond angle values of C2–C3–C4 and C3–
C4–C5 atoms are affected and they are measured as 115.4(2)◦ and
123.2(2)◦ because, C3 and C4 atoms were engaged in C=O and C–Cl
The molecular configuration of 3 was considered as two parts:
cyclohexenone [Cg1: ring centroid of C1/C6] and phenyl [Cg2: ring
˚
bonds respectively. Further, the bond length of C4–Cl1=1.740(3)A
˚
centroid of C9/C14] rings are linked via a C5-C9=1.488(3)A sin-
which is not notably different from C–Cl value found in the struc-
ture reported by Sreenatha et al. [38]. The methoxy group posi-
tioned at C14 showed gauche conformation with respect to Cg1
moiety manifested by the torsional angle value of −1.3(4)◦ for
the chain of C13–C14–O2–C15 atoms. Further, the bond angle value
of [C9–C14–O2=114.7(2)◦] is shorter than [C13–C14–O2=124.8(2)◦]
which indicate the strain in bond angle due to an intra-molecular
electrostatic interaction of the type C6-H6A...O2 (Table 2). The
above bond angle strains are witnessed that the former value is
due to contraction while the latter one is due to stretching. The
similar environment were noticed in the structure reported by So-
magond et al. [39]. Furthermore, the intra-molecular interaction in-
corporated an S(6) closed ring motif to the structure as expected
and it is visualized as a cyan coloured dashed line in Fig. 2.
gle bond as depicted in the thermal ellipsoid plot drawn at 50%
of probability level (Fig. 2). In the molecular structure, the posi-
˚
tion of C1 atom was considerably deviated by 0.311(3)A from the
mean plane of Cg1 and hence, it was displayed a puckering en-
vironment by adopting a half-chair conformation of the type 1H2
˚
with the total puckering amplitude of Q=0.460(3)A [33,34]. It is
quite small compared to a similar cyclohexenone ring of our previ-
ously reported structure [35]. This ought to be due to less steric
repulsion in the compound 3 between hydrogen substituents at
C6, C2 and that of methyl groups at C1 from the Cg1 ring, this
is also evinced by lesser θ (pseudorotation angle) value of 47.1(4)◦.
3.2.1. Crystal packing
In the crystal of 3, the molecular packing was mainly organized
by virtue of intermolecular interactions of the type C10–H10...O2
and C8–H8A...O1 (Table 2). This, in turn, made the molecules to
exhibit an independent one dimensional polymeric chain that ex-
tending infinitely along crystallographic b-axis as shown in the
packing diagram illustrated in Fig. 3.
3.3. Computational calculations
3.3.1. Hirshfeld surfaces
Area and volume of the three dimensional Hirshfeld surface
was mapped on each of the property: (dnorm, molecular electro-
2
3
˚
˚
static potential, di and Curvedness) are 298.58A and 340.06A re-
spectively, which are delineated in Fig. 4(a) to (d) respectively.
The dnorm, electrostatic potential, di, Curvedness properties was gen-
erated using the following colour schemes of −0.0997, −0.0579,
Fig. 2. Thermal ellipsoidal plot of 3 drawn at 50% of probability level. The cyan
coloured dashed line indicate intra-molecular C6–H6A...O2 interaction enclosing an
S(6) ring motif (Table 2).