An insight into the synthesis, crystal structure, geometrical modelling of crystal morphology, Hirshfeld surface analysis and characterization of N-(4-methyl­benzyl)­benzamide single crystals

A versatile approach for the synthesis of N-(4-methyl­benzyl)­benzamide, C₁₅H₁₅NO, using CuI as catalyst has been reported. Single crystals of the synthesized compound were grown using the slow evaporation solution technique. The crystal structure of the N-(4-methyl­benzyl)­benzamide crystals has been determined by single-crystal X-ray diffraction. The compound crystallizes in an orthorhombic lattice, noncentrosymmetric space group Pna2₁. The crystal structure is stabilized by intermolecular N—H...O hydrogen bonds and weak C—H...π interactions to form layers parallel to the a axis. A user-friendly approach based on centre of mass propagation vector theory was used to predict the crystal morphology. The framework developed here utilizes the concept of intermolecular bond strength to discern the crystal morphology. Fourier transform IR, NMR and high-resolution mass spectrometry analytical techniques were used for the identification of functional groups and confirmation of the structure of the title compound. All of the intermolecular interactions present in the crystal structure, including the C—H...π, C—H...O and N—H...O interactions, were investigated and confirmed by molecular Hirshfeld surface analysis. From linear optical spectroscopy, the transmittance, optical band gap and UV cutoff wavelength were determined. The photoluminescence emission spectrum was recorded for a grown crystal. Dielectric measurements were performed at room temperature for various frequencies. The mechanical strength of the (001) plane of the title compound was measured using the Vickers micro-hardness technique. A piezo-coefficient of 15 pC N⁻¹ was found along the (001) plane of the title crystals. The thermal stability and melting point were also investigated. In addition, density functional theory simulations were used to calculate the optimized molecular geometry and the UV–vis spectrum, and to determine the highest occupied molecular orbital/lowest unoccupied molecular orbital energy gap. The results show that N-(4-methyl­benzyl)­benzamide is a potential candidate for multifunctional optical and piezoelectric crystals.

Computing details

Program(s) used to solve structure: SHELXS (Sheldrick, 2008); program(s) used to refine structure: SHELXL (Sheldrick, 2015); molecular graphics: Olex2 (Dolomanov et al., 2009); software used to prepare material for publication: Olex2 (Dolomanov et al., 2009).

(I)

Crystal data

C15H15NO	Dx = 1.195 Mg m^−3
Mr = 225.28	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pna21	Cell parameters from 1346 reflections
a = 9.5277 (8) Å	θ = 3.3–18.9°
b = 11.1555 (11) Å	µ = 0.08 mm^−1
c = 11.7848 (10) Å	T = 293 K
V = 1252.6 (2) Å^3	Block, colourless
Z = 4	0.5 × 0.5 × 0.5 mm
F(000) = 480

Data collection

Xcalibur, Sapphire3 diffractometer	1322 reflections with I > 2σ(I)
Radiation source: Enhance (Mo) X-ray Source	Rint = 0.108
Absorption correction: multi-scan CrysAlisPro, Agilent Technologies, Version 1.171.36.32 (release 02-08-2013 CrysAlis171 .NET) (compiled Aug 2 2013,16:46:58) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	θmax = 29.5°, θmin = 3.3°
Tmin = 0.713, Tmax = 1.000	h = −12→11
16911 measured reflections	k = −14→14
3189 independent reflections	l = −16→16

Refinement

Refinement on F^2	H-atom parameters constrained
Least-squares matrix: full	w = 1/[σ^2(Fo^2) + (0.015P)^2] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.063	(Δ/σ)max < 0.001
wR(F^2) = 0.108	Δρmax = 0.12 e Å^−3
S = 0.97	Δρmin = −0.12 e Å^−3
3189 reflections	Extinction correction: SHELXL-2016/6 (Sheldrick 2016), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
156 parameters	Extinction coefficient: 0.0122 (14)
1 restraint	Absolute structure: Flack x determined using 401 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −1.9 (10)
Hydrogen site location: inferred from neighbouring sites

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. olex2_refinement_description 1. Fixed Uiso At 1.2 times of: All C(H) groups, All C(H,H) groups, All N(H) groups At 1.5 times of: All C(H,H,H) groups 2.a Secondary CH2 refined with riding coordinates: C8(H8A,H8B) 2.b Aromatic/amide H refined with riding coordinates: C14(H14), N1(H1), C13(H13), C5(H5), C1(H1A), C10(H10), C11(H11), C3(H3), C2(H2), C4(H4) 2.c Idealised Me refined as rotating group: C15(H15A,H15B,H15C)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	−0.0275 (3)	−0.6733 (3)	−0.3283 (3)	0.0677 (10)
C6	0.1316 (5)	−0.6668 (4)	−0.1749 (4)	0.0493 (12)
C14	0.3313 (5)	−0.7751 (4)	−0.6445 (4)	0.0600 (13)
H14	0.314021	−0.856900	−0.650694	0.072*
C9	0.2651 (5)	−0.7104 (5)	−0.5608 (4)	0.0537 (12)
N1	0.1902 (4)	−0.7411 (4)	−0.3621 (3)	0.0627 (12)
H1	0.272632	−0.752847	−0.334489	0.075*
C13	0.4235 (5)	−0.7207 (5)	−0.7201 (4)	0.0645 (15)
H13	0.466828	−0.766568	−0.775959	0.077*
C7	0.0919 (5)	−0.6947 (4)	−0.2950 (4)	0.0544 (13)
C5	0.2463 (5)	−0.7184 (4)	−0.1217 (4)	0.0679 (15)
H5	0.303957	−0.770560	−0.161953	0.081*
C1	0.0506 (5)	−0.5895 (4)	−0.1140 (5)	0.0654 (14)
H1A	−0.026841	−0.554057	−0.148366	0.079*
C8	0.1647 (5)	−0.7730 (5)	−0.4807 (4)	0.0661 (15)
H8A	0.069162	−0.751564	−0.500657	0.079*
H8B	0.174434	−0.859003	−0.489598	0.079*
C10	0.2939 (5)	−0.5903 (5)	−0.5534 (5)	0.0679 (14)
H10	0.251583	−0.544295	−0.497188	0.082*
C12	0.4511 (5)	−0.6005 (6)	−0.7134 (4)	0.0666 (15)
C11	0.3858 (6)	−0.5373 (5)	−0.6292 (5)	0.0767 (17)
H11	0.403762	−0.455626	−0.622637	0.092*
C3	0.1947 (6)	−0.6146 (5)	0.0502 (5)	0.0813 (18)
H3	0.216023	−0.596478	0.125256	0.098*
C2	0.0811 (6)	−0.5627 (5)	−0.0019 (5)	0.0768 (17)
H2	0.024611	−0.509477	0.038140	0.092*
C15	0.5490 (6)	−0.5395 (6)	−0.7953 (5)	0.102 (2)
H15A	0.591896	−0.598406	−0.843504	0.152*
H15B	0.620461	−0.497520	−0.753825	0.152*
H15C	0.497103	−0.483577	−0.840860	0.152*
C4	0.2758 (6)	−0.6931 (5)	−0.0095 (5)	0.0846 (19)
H4	0.351754	−0.729915	0.025656	0.102*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0413 (19)	0.097 (3)	0.065 (2)	0.0048 (19)	−0.0082 (18)	0.012 (2)
C6	0.040 (3)	0.056 (3)	0.052 (3)	−0.004 (2)	−0.003 (2)	0.007 (2)
C14	0.066 (3)	0.067 (3)	0.047 (3)	−0.005 (3)	−0.012 (3)	−0.003 (3)
C9	0.045 (3)	0.073 (3)	0.043 (3)	0.002 (2)	−0.008 (2)	−0.003 (3)
N1	0.038 (2)	0.100 (3)	0.051 (3)	−0.005 (2)	−0.008 (2)	−0.002 (2)
C13	0.067 (4)	0.084 (4)	0.043 (3)	0.005 (3)	0.000 (3)	0.003 (3)
C7	0.043 (3)	0.069 (4)	0.052 (3)	−0.009 (3)	−0.002 (3)	0.010 (3)
C5	0.063 (4)	0.092 (4)	0.049 (3)	0.010 (3)	−0.004 (3)	−0.001 (3)
C1	0.062 (4)	0.067 (4)	0.068 (4)	0.001 (3)	−0.007 (3)	−0.003 (3)
C8	0.058 (4)	0.096 (4)	0.044 (3)	−0.007 (3)	0.000 (3)	−0.008 (3)
C10	0.067 (4)	0.071 (4)	0.065 (3)	0.012 (3)	−0.006 (3)	−0.014 (3)
C12	0.053 (4)	0.088 (4)	0.059 (4)	0.001 (3)	−0.009 (3)	0.018 (3)
C11	0.076 (4)	0.069 (4)	0.085 (4)	−0.005 (3)	0.003 (4)	0.013 (4)
C3	0.076 (4)	0.104 (5)	0.065 (4)	−0.006 (4)	−0.015 (4)	−0.010 (3)
C2	0.073 (4)	0.085 (4)	0.072 (4)	−0.001 (3)	0.008 (3)	−0.025 (3)
C15	0.080 (5)	0.134 (5)	0.090 (5)	−0.015 (4)	−0.007 (4)	0.039 (4)
C4	0.075 (4)	0.119 (6)	0.059 (4)	0.026 (4)	−0.015 (3)	−0.002 (4)

Geometric parameters (Å, º)

O1—C7	1.227 (5)	N1—C8	1.462 (5)
C6—C7	1.498 (6)	C13—C12	1.369 (6)
C6—C5	1.385 (6)	C5—C4	1.381 (6)
C6—C1	1.361 (6)	C1—C2	1.386 (6)
C14—C9	1.376 (6)	C10—C11	1.383 (6)
C14—C13	1.390 (6)	C12—C11	1.367 (6)
C9—C8	1.515 (6)	C12—C15	1.506 (6)
C9—C10	1.370 (6)	C3—C2	1.371 (6)
N1—C7	1.331 (5)	C3—C4	1.364 (6)
C5—C6—C7	122.7 (5)	C4—C5—C6	120.6 (5)
C1—C6—C7	119.1 (5)	C6—C1—C2	121.3 (5)
C1—C6—C5	118.2 (5)	N1—C8—C9	112.2 (4)
C9—C14—C13	121.3 (5)	C9—C10—C11	120.3 (5)
C14—C9—C8	119.6 (5)	C13—C12—C15	121.7 (5)
C10—C9—C14	117.8 (5)	C11—C12—C13	117.4 (5)
C10—C9—C8	122.5 (5)	C11—C12—C15	120.9 (6)
C7—N1—C8	123.1 (4)	C12—C11—C10	122.4 (5)
C12—C13—C14	120.8 (5)	C4—C3—C2	119.2 (5)
O1—C7—C6	119.7 (5)	C3—C2—C1	120.1 (5)
O1—C7—N1	122.6 (5)	C3—C4—C5	120.7 (5)
N1—C7—C6	117.7 (4)