Growth and structural and physical properties of diiso­propyl­ammonium bromide molecular single crystals

Large single crystals of the promising molecular organic ferroelectric diiso­propyl­ammonium bromide (DIPAB) have been grown by the solution technique. A structural study was performed using single-crystal X-ray diffraction analysis. The twin element of a selected DIPAB crystal was identified by a morphological study. Intermolecular interactions present in the grown crystal were explored by Hirshfeld surface (three-dimensional) and fingerprint plot (two-dimensional) studies. In UV–vis spectroscopy, the DIPAB crystal has shown high transparency with a wide direct band gap of 5.65 eV. In the photoluminescence spectrum, sharp UV and blue emissions were observed at 370, 392, 417 and 432 nm. The electrical properties were investigated by measuring the dielectric constant ([epsilon]) and loss (tanδ) of the grown crystal. The DIPAB crystal exhibits a promising piezoelectric charge coefficient (d₃₃) value of 18 pC N⁻¹, which makes it suitable for transducer applications. A high ferroelectric Curie temperature (T_c ≃ 425 K) with high remnant polarization (20.52 µC cm⁻²) and high coercive field (12.25 kV cm⁻¹) were observed in the as-grown crystal. Vickers microhardness analysis shows that the value of Meyer's index (n = 7.27) belongs to the soft material range, which was also confirmed by void analysis along three crystallographic axes. It is shown that the DIPAB crystal has potential for optical, ferroelectric and piezoelectric applications.

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

C6H16N·Br	Dx = 1.345 Mg m^−3
Mr = 182.10	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 2791 reflections
a = 7.9986 (5) Å	θ = 3.5–23.9°
b = 8.2984 (8) Å	µ = 4.49 mm^−1
c = 13.5500 (9) Å	T = 293 K
V = 899.39 (12) Å^3	Block, colorless
Z = 4	0.5 × 0.5 × 0.5 mm
F(000) = 376

Data collection

Xcalibur, Sapphire3 diffractometer	1719 reflections with I > 2σ(I)
Radiation source: Enhance (Mo) X-ray Source	Rint = 0.091
ω scans	θmax = 29.3°, θmin = 3.0°
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.	h = −10→10
Tmin = 0.367, Tmax = 1.000	k = −11→11
13295 measured reflections	l = −18→18
2283 independent reflections

Refinement

Refinement on F^2	H-atom parameters constrained
Least-squares matrix: full	w = 1/[σ^2(Fo^2) + (0.033P)^2 + 0.118P] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.051	(Δ/σ)max = 0.022
wR(F^2) = 0.106	Δρmax = 0.72 e Å^−3
S = 1.13	Δρmin = −0.46 e Å^−3
2283 reflections	Extinction correction: SHELXL-2014/7 (Sheldrick 2014, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
78 parameters	Extinction coefficient: 0.122 (6)
0 restraints	Absolute structure: Flack x determined using 529 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
Hydrogen site location: inferred from neighbouring sites	Absolute structure parameter: −0.033 (19)

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.

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

	x	y	z	Uiso*/Ueq
Br1	−0.23258 (6)	−0.25025 (9)	−0.63435 (4)	0.0436 (3)
C3	−0.2741 (8)	−0.2559 (9)	−0.2276 (5)	0.0639 (19)
H3A	−0.3929	−0.2496	−0.2180	0.096*
H3B	−0.2196	−0.1788	−0.1857	0.096*
H3C	−0.2360	−0.3623	−0.2113	0.096*
N1	−0.3280 (6)	−0.3350 (5)	−0.4012 (4)	0.0324 (11)
H1A	−0.4366	−0.3147	−0.3942	0.039*
H1B	−0.3013	−0.3118	−0.4634	0.039*
C6	−0.4146 (9)	−0.6002 (8)	−0.4577 (5)	0.057 (2)
H6A	−0.5280	−0.5656	−0.4482	0.086*
H6B	−0.4069	−0.7141	−0.4463	0.086*
H6C	−0.3806	−0.5767	−0.5241	0.086*
C2	−0.2329 (7)	−0.2195 (7)	−0.3346 (5)	0.0428 (16)
H2	−0.1126	−0.2345	−0.3450	0.051*
C5	−0.3024 (8)	−0.5127 (7)	−0.3866 (5)	0.0375 (16)
H5	−0.3366	−0.5405	−0.3192	0.045*
C1	−0.2794 (10)	−0.0511 (8)	−0.3631 (5)	0.058 (2)
H1C	−0.3976	−0.0364	−0.3548	0.086*
H1D	−0.2500	−0.0329	−0.4309	0.086*
H1E	−0.2205	0.0239	−0.3219	0.086*
C4	−0.1194 (8)	−0.5560 (10)	−0.3990 (7)	0.076 (3)
H4A	−0.0836	−0.5281	−0.4644	0.114*
H4B	−0.1049	−0.6696	−0.3889	0.114*
H4C	−0.0539	−0.4977	−0.3516	0.114*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0375 (4)	0.0581 (5)	0.0351 (4)	−0.0035 (5)	0.0015 (2)	0.0038 (4)
C3	0.081 (5)	0.069 (5)	0.042 (4)	0.005 (8)	−0.015 (3)	−0.008 (4)
N1	0.034 (2)	0.035 (3)	0.028 (2)	−0.001 (2)	0.008 (2)	−0.002 (2)
C6	0.074 (5)	0.038 (4)	0.061 (5)	−0.008 (4)	−0.001 (4)	−0.007 (4)
C2	0.033 (3)	0.048 (5)	0.047 (3)	−0.004 (3)	0.000 (2)	−0.008 (3)
C5	0.047 (4)	0.032 (3)	0.034 (4)	−0.001 (3)	0.008 (3)	0.000 (3)
C1	0.076 (6)	0.036 (4)	0.060 (5)	−0.014 (4)	0.008 (5)	−0.007 (3)
C4	0.058 (5)	0.051 (5)	0.118 (7)	0.019 (4)	0.011 (5)	0.011 (5)

Geometric parameters (Å, º)

C3—C2	1.517 (10)	C6—C5	1.504 (8)
N1—C2	1.521 (8)	C2—C1	1.497 (9)
N1—C5	1.502 (7)	C5—C4	1.517 (9)
C5—N1—C2	118.2 (5)	N1—C5—C6	107.9 (5)
C3—C2—N1	109.4 (5)	N1—C5—C4	110.5 (5)
C1—C2—C3	112.3 (6)	C6—C5—C4	113.0 (6)
C1—C2—N1	108.1 (5)