Crystal structure of 2-{(R)-[1-(4-bromo-phen-yl)eth-yl]imino-meth-yl}-4-(phenyl-diazen-yl)phenol, a chiral photochromic Schiff base.

The title chiral photochromic Schiff base compound, C21H18BrN3O, was synthesized from (R)-(+)-1-(4-bromo-phen-yl)ethyl-amine and the salicyl-aldehyde of an azo-benzene derivative. The mol-ecule corresponds to the phenol-imine tautomer, the C=N and N-C bond distances being 1.285 (3) and 1.470 (3) Å, respectively. The diazenyl group adopts a trans form, with an N=N distance of 1.256 (3) Å. The hy-droxy group is involved in intra-molecular O-H⋯N hydrogen bonding. In the crystal, C-H⋯π inter-actions consolidate the crystal packing of one-dimensional chains, which exhibits short inter-molecular Br⋯C contacts of 3.400 (3) Å.

Related literature

For applications of (chiral) photochromic Schiff base compounds, see: Akitsu & Einaga (2006b ▸); Akitsu et al. (2004 ▸); Aritake et al. (2010 ▸); Miura et al. (2009 ▸). For the crystal structures of related compounds, see: Akitsu & Einaga (2005a ▸,b ▸, 2006a ▸); Akitsu (2007 ▸); Akitsu & Itoh (2010 ▸); Aslantas et al. (2007 ▸); Hadjoudis & Mavridis (2004 ▸); Khandar & Rezvani (1999 ▸).

Experimental

Crystal data

C21H18BrN3O

M = 408.29

Orthorhombic

a = 7.271 (3) Å

b = 41.901 (15) Å

c = 5.952 (2) Å

V = 1813.3 (11) Å3

Z = 4

Mo Kα radiation

μ = 2.28 mm−1

T = 113 K

0.37 × 0.23 × 0.08 mm

Data collection

Bruker APEXII CCD diffractometer

Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996 ▸) T min = 0.486, T max = 0.833

10349 measured reflections

4176 independent reflections

3723 reflections with I > 2σ(I)

R int = 0.027

Refinement

R[F 2 > 2σ(F 2)] = 0.026

wR(F 2) = 0.047

S = 1.01

4176 reflections

237 parameters

H-atom parameters constrained

Δρmax = 0.57 e Å−3

Δρmin = −0.40 e Å−3

Absolute structure: Flack x determined using 1360 quotients [(I +) − (I −)]/[(I +) + (I −)] (Parsons et al., 2013 ▸)

Absolute structure parameter: 0.005 (4)

Data collection: APEX2 (Bruker, 1998 ▸); cell refinement: SAINT (Bruker, 1998 ▸); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015 ▸); molecular graphics: SHELXTL (Sheldrick, 2008 ▸); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989015019866/cv5499sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015019866/cv5499Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S2056989015019866/cv5499Isup3.cml

Click here for additional data file.

. DOI: 10.1107/S2056989015019866/cv5499fig1.tif

Mol­ecular structure of (I) showing the atomic numbering and 50% probability displacement ellipsoids.

CCDC reference: 1432412

Additional supporting information: crystallographic information; 3D view; checkCIF report

C21H18BrN3O	Dx = 1.496 Mg m−3
Mr = 408.29	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P21212	Cell parameters from 10349 reflections
a = 7.271 (3) Å	θ = 2.8–27.7°
b = 41.901 (15) Å	µ = 2.28 mm−1
c = 5.952 (2) Å	T = 113 K
V = 1813.3 (11) Å3	Needle, orange
Z = 4	0.37 × 0.23 × 0.08 mm
F(000) = 832

Bruker APEXII CCD diffractometer	4176 independent reflections
Radiation source: fine-focus sealed tube	3723 reflections with I > 2σ(I)
Detector resolution: 8.333 pixels mm-1	Rint = 0.027
φ and ω scans	θmax = 27.7°, θmin = 2.8°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −8→9
Tmin = 0.486, Tmax = 0.833	k = −54→33
10349 measured reflections	l = −7→7

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.026	H-atom parameters constrained
wR(F2) = 0.047	w = 1/[σ2(Fo2)] where P = (Fo2 + 2Fc2)/3
S = 1.01	(Δ/σ)max = 0.002
4176 reflections	Δρmax = 0.57 e Å−3
237 parameters	Δρmin = −0.40 e Å−3
0 restraints	Absolute structure: Flack x determined using 1360 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013)
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.005 (4)

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

	x	y	z	Uiso*/Ueq
Br1	1.09221 (4)	0.26333 (2)	0.94955 (5)	0.02934 (9)
C1	0.2882 (4)	0.55533 (6)	0.2777 (4)	0.0162 (6)
H1	0.347	0.54	0.185	0.019*
C2	0.2286 (3)	0.54700 (5)	0.4928 (4)	0.0132 (6)
C3	0.2610 (4)	0.58613 (6)	0.2004 (5)	0.0191 (6)
H3	0.3033	0.5919	0.0551	0.023*
C4	0.1732 (4)	0.60841 (6)	0.3323 (5)	0.0193 (7)
H4	0.1531	0.6294	0.2766	0.023*
C5	0.1136 (4)	0.60022 (5)	0.5478 (5)	0.0189 (6)
H5	0.0549	0.6157	0.6397	0.023*
C6	0.1400 (3)	0.56948 (5)	0.6277 (4)	0.0153 (6)
H6	0.098	0.5638	0.7733	0.018*
C7	0.3225 (3)	0.45296 (5)	0.6999 (4)	0.0130 (6)
H7	0.3679	0.4579	0.5543	0.016*
C8	0.2539 (4)	0.47727 (5)	0.8343 (4)	0.0133 (6)
C9	0.1948 (3)	0.47027 (5)	1.0517 (5)	0.0147 (5)
H9	0.1538	0.487	1.1473	0.018*
C10	0.1954 (4)	0.43923 (6)	1.1290 (4)	0.0147 (6)
H10	0.1524	0.4347	1.2762	0.018*
C11	0.2586 (3)	0.41462 (5)	0.9931 (4)	0.0152 (6)
C12	0.3926 (4)	0.39625 (5)	0.6274 (4)	0.0142 (5)
H12	0.4383	0.4015	0.4826	0.017*
C13	0.3259 (4)	0.42154 (5)	0.7748 (4)	0.0120 (6)
C14	0.4556 (3)	0.34250 (5)	0.5321 (5)	0.0170 (6)
H14	0.5028	0.3533	0.394	0.02*
C15	0.2920 (4)	0.32168 (6)	0.4678 (5)	0.0273 (7)
H15A	0.2462	0.3106	0.6014	0.041*
H15B	0.3305	0.306	0.3551	0.041*
H15C	0.1941	0.3351	0.4054	0.041*
C16	0.6884 (4)	0.29788 (5)	0.5224 (5)	0.0206 (6)
H16	0.6402	0.2924	0.3791	0.025*
C17	0.6118 (4)	0.32344 (5)	0.6378 (4)	0.0148 (6)
C18	0.6859 (4)	0.33094 (6)	0.8466 (4)	0.0212 (7)
H18	0.637	0.3484	0.9289	0.025*
C19	0.8302 (4)	0.31341 (5)	0.9371 (5)	0.0220 (6)
H19	0.8799	0.3189	1.0796	0.026*
C20	0.9003 (4)	0.28803 (5)	0.8183 (4)	0.0186 (6)
C21	0.8323 (4)	0.28005 (6)	0.6082 (5)	0.0214 (7)
H21	0.8831	0.2628	0.5253	0.026*
N1	0.2355 (3)	0.50990 (4)	0.7656 (4)	0.0149 (5)
N2	0.2565 (3)	0.51440 (4)	0.5585 (4)	0.0150 (5)
N3	0.3906 (3)	0.36692 (4)	0.6905 (3)	0.0169 (5)
O1	0.2552 (3)	0.38445 (4)	1.0728 (3)	0.0200 (4)
H1A	0.2988	0.372	0.9758	0.03*

	U11	U22	U33	U12	U13	U23
Br1	0.03065 (17)	0.02551 (13)	0.03187 (16)	0.01116 (13)	−0.00603 (16)	−0.00168 (14)
C1	0.0158 (16)	0.0182 (13)	0.0147 (15)	−0.0033 (11)	−0.0014 (12)	−0.0026 (11)
C2	0.0111 (13)	0.0139 (11)	0.0148 (17)	−0.0035 (9)	−0.0047 (11)	0.0012 (10)
C3	0.0191 (16)	0.0228 (14)	0.0154 (15)	−0.0084 (12)	−0.0061 (13)	0.0028 (11)
C4	0.0186 (16)	0.0148 (13)	0.0246 (17)	−0.0040 (11)	−0.0077 (14)	0.0051 (12)
C5	0.0162 (15)	0.0147 (11)	0.0258 (14)	0.0011 (10)	−0.0031 (16)	−0.0051 (12)
C6	0.0130 (16)	0.0177 (12)	0.0151 (14)	−0.0012 (10)	−0.0021 (11)	−0.0001 (11)
C7	0.0099 (14)	0.0172 (12)	0.0118 (14)	−0.0022 (10)	−0.0003 (11)	0.0005 (11)
C8	0.0117 (15)	0.0122 (12)	0.0161 (15)	0.0003 (10)	−0.0025 (12)	0.0009 (11)
C9	0.0127 (14)	0.0186 (12)	0.0128 (13)	0.0002 (10)	−0.0016 (14)	−0.0050 (12)
C10	0.0140 (15)	0.0229 (13)	0.0071 (13)	−0.0014 (11)	−0.0001 (11)	0.0019 (11)
C11	0.0119 (14)	0.0159 (12)	0.0176 (18)	0.0004 (10)	−0.0017 (11)	0.0051 (10)
C12	0.0106 (14)	0.0176 (12)	0.0145 (13)	0.0000 (11)	−0.0009 (12)	0.0013 (10)
C13	0.0091 (14)	0.0147 (12)	0.0123 (14)	0.0014 (10)	−0.0006 (12)	0.0004 (10)
C14	0.0213 (16)	0.0132 (11)	0.0166 (14)	0.0005 (10)	0.0031 (13)	−0.0004 (11)
C15	0.0249 (17)	0.0213 (13)	0.0357 (18)	−0.0018 (11)	−0.0050 (16)	−0.0010 (14)
C16	0.0267 (16)	0.0190 (13)	0.0162 (16)	−0.0006 (11)	−0.0005 (14)	−0.0027 (11)
C17	0.0183 (15)	0.0101 (11)	0.0159 (13)	−0.0032 (11)	0.0042 (13)	0.0015 (10)
C18	0.0292 (18)	0.0126 (12)	0.0219 (16)	0.0034 (11)	−0.0003 (14)	−0.0041 (11)
C19	0.0277 (16)	0.0200 (12)	0.0182 (14)	0.0008 (11)	−0.0032 (15)	−0.0047 (13)
C20	0.0186 (15)	0.0148 (12)	0.0224 (15)	0.0015 (12)	0.0000 (15)	0.0052 (11)
C21	0.0271 (17)	0.0166 (13)	0.0206 (17)	0.0048 (11)	0.0045 (13)	−0.0051 (11)
N1	0.0144 (13)	0.0154 (11)	0.0149 (13)	−0.0001 (9)	0.0004 (10)	0.0007 (9)
N2	0.0160 (12)	0.0145 (10)	0.0146 (12)	−0.0005 (8)	0.0010 (12)	0.0021 (10)
N3	0.0157 (13)	0.0151 (10)	0.0198 (12)	0.0015 (9)	0.0020 (12)	0.0012 (9)
O1	0.0279 (12)	0.0150 (8)	0.0172 (10)	0.0034 (7)	0.0064 (10)	0.0036 (8)

Br1—C20	1.905 (3)	C11—C13	1.419 (4)
C1—C3	1.384 (3)	C12—N3	1.285 (3)
C1—C2	1.396 (3)	C12—C13	1.459 (3)
C1—H1	0.95	C12—H12	0.95
C2—C6	1.395 (3)	C14—N3	1.470 (3)
C2—N2	1.435 (3)	C14—C15	1.524 (3)
C3—C4	1.376 (4)	C14—C17	1.524 (4)
C3—H3	0.95	C14—H14	1.0
C4—C5	1.397 (4)	C15—H15A	0.98
C4—H4	0.95	C15—H15B	0.98
C5—C6	1.386 (3)	C15—H15C	0.98
C5—H5	0.95	C16—C21	1.383 (4)
C6—H6	0.95	C16—C17	1.389 (3)
C7—C8	1.388 (3)	C16—H16	0.95
C7—C13	1.390 (3)	C17—C18	1.390 (4)
C7—H7	0.95	C18—C19	1.389 (4)
C8—C9	1.395 (3)	C18—H18	0.95
C8—N1	1.433 (3)	C19—C20	1.375 (3)
C9—C10	1.380 (3)	C19—H19	0.95
C9—H9	0.95	C20—C21	1.386 (4)
C10—C11	1.389 (3)	C21—H21	0.95
C10—H10	0.95	N1—N2	1.256 (3)
C11—O1	1.350 (3)	O1—H1A	0.84
C3—C1—C2	119.6 (2)	C7—C13—C12	120.1 (2)
C3—C1—H1	120.2	C11—C13—C12	121.1 (2)
C2—C1—H1	120.2	N3—C14—C15	108.0 (2)
C6—C2—C1	120.1 (2)	N3—C14—C17	109.8 (2)
C6—C2—N2	123.5 (2)	C15—C14—C17	112.67 (19)
C1—C2—N2	116.4 (2)	N3—C14—H14	108.8
C4—C3—C1	120.6 (3)	C15—C14—H14	108.8
C4—C3—H3	119.7	C17—C14—H14	108.8
C1—C3—H3	119.7	C14—C15—H15A	109.5
C3—C4—C5	120.1 (2)	C14—C15—H15B	109.5
C3—C4—H4	120.0	H15A—C15—H15B	109.5
C5—C4—H4	120.0	C14—C15—H15C	109.5
C6—C5—C4	120.0 (3)	H15A—C15—H15C	109.5
C6—C5—H5	120.0	H15B—C15—H15C	109.5
C4—C5—H5	120.0	C21—C16—C17	122.5 (3)
C5—C6—C2	119.6 (2)	C21—C16—H16	118.7
C5—C6—H6	120.2	C17—C16—H16	118.7
C2—C6—H6	120.2	C16—C17—C18	117.4 (2)
C8—C7—C13	121.1 (2)	C16—C17—C14	119.9 (2)
C8—C7—H7	119.4	C18—C17—C14	122.6 (2)
C13—C7—H7	119.4	C19—C18—C17	121.3 (2)
C7—C8—C9	119.4 (2)	C19—C18—H18	119.3
C7—C8—N1	124.7 (2)	C17—C18—H18	119.3
C9—C8—N1	115.9 (2)	C20—C19—C18	119.3 (3)
C10—C9—C8	120.4 (2)	C20—C19—H19	120.3
C10—C9—H9	119.8	C18—C19—H19	120.3
C8—C9—H9	119.8	C19—C20—C21	121.2 (3)
C9—C10—C11	120.5 (2)	C19—C20—Br1	118.8 (2)
C9—C10—H10	119.8	C21—C20—Br1	120.02 (19)
C11—C10—H10	119.8	C16—C21—C20	118.2 (2)
O1—C11—C10	119.0 (2)	C16—C21—H21	120.9
O1—C11—C13	121.3 (2)	C20—C21—H21	120.9
C10—C11—C13	119.7 (2)	N2—N1—C8	114.3 (2)
N3—C12—C13	121.0 (2)	N1—N2—C2	113.1 (2)
N3—C12—H12	119.5	C12—N3—C14	118.3 (2)
C13—C12—H12	119.5	C11—O1—H1A	109.5
C7—C13—C11	118.8 (2)
C3—C1—C2—C6	0.8 (4)	C21—C16—C17—C18	0.3 (4)
C3—C1—C2—N2	178.1 (2)	C21—C16—C17—C14	178.9 (2)
C2—C1—C3—C4	−1.0 (4)	N3—C14—C17—C16	176.7 (2)
C1—C3—C4—C5	1.2 (4)	C15—C14—C17—C16	56.2 (3)
C3—C4—C5—C6	−1.1 (4)	N3—C14—C17—C18	−4.8 (3)
C4—C5—C6—C2	0.9 (4)	C15—C14—C17—C18	−125.3 (3)
C1—C2—C6—C5	−0.8 (4)	C16—C17—C18—C19	−0.5 (4)
N2—C2—C6—C5	−177.9 (2)	C14—C17—C18—C19	−179.0 (2)
C13—C7—C8—C9	2.8 (4)	C17—C18—C19—C20	−0.4 (4)
C13—C7—C8—N1	−176.2 (2)	C18—C19—C20—C21	1.3 (4)
C7—C8—C9—C10	−3.3 (4)	C18—C19—C20—Br1	−177.8 (2)
N1—C8—C9—C10	175.8 (2)	C17—C16—C21—C20	0.6 (4)
C8—C9—C10—C11	1.4 (4)	C19—C20—C21—C16	−1.5 (4)
C9—C10—C11—O1	−179.2 (2)	Br1—C20—C21—C16	177.69 (19)
C9—C10—C11—C13	1.1 (4)	C7—C8—N1—N2	11.8 (4)
C8—C7—C13—C11	−0.3 (4)	C9—C8—N1—N2	−167.2 (2)
C8—C7—C13—C12	177.8 (2)	C8—N1—N2—C2	177.17 (19)
O1—C11—C13—C7	178.7 (2)	C6—C2—N2—N1	−16.5 (3)
C10—C11—C13—C7	−1.6 (4)	C1—C2—N2—N1	166.3 (2)
O1—C11—C13—C12	0.5 (4)	C13—C12—N3—C14	178.6 (2)
C10—C11—C13—C12	−179.8 (2)	C15—C14—N3—C12	−113.7 (3)
N3—C12—C13—C7	−177.4 (2)	C17—C14—N3—C12	123.1 (3)
N3—C12—C13—C11	0.7 (4)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···N3	0.84	1.84	2.585 (3)	148
C12—H12···Cg1i	0.95	2.80	3.399 (3)	122
C10—H10···Cg1ii	0.95	2.74	3.415 (3)	128
C6—H6···Cg2iii	0.95	2.75	3.423 (3)	128

Table 1

Hydrogen-bond geometry (, )

Cg1 and Cg2 are centroids of C1C6 and C7C11/C13 rings, respectively.

DHA	DH	HA	D A	DHA
O1H1AN3	0.84	1.84	2.585(3)	148
C12H12Cg1i	0.95	2.80	3.399(3)	122
C10H10Cg1ii	0.95	2.74	3.415(3)	128
C6H6Cg2iii	0.95	2.75	3.423(3)	128

Symmetry codes: (i) ; (ii) ; (iii) .