A chiral photochromic Schiff base: (R)-4-bromo-2-[(1-phenyl­ethyl)imino­meth­yl]phenol

The title chiral photochromic Schiff base compound, C₁₅H₁₄BrNO, was synthesized from (R)-1-phenyl­ethyl­amine and 5-bromo­salicylaldehyde. The mol­ecule is the phenol–imine tautomer, the C=N and N—C bond distances being 1.261 (7) and 1.482 (7) Å, respectively. There is an intra­molecular O—H...N hydrogen bond with an O...N distance of 2.593 (7) Å.

Key indicators

• Single-crystal X-ray study
• T = 297 K
• Mean [sigma](C-C) = 0.011 Å
• R factor = 0.046
• wR factor = 0.128
• Data-to-parameter ratio = 10.6

checkCIF/PLATON results

No syntax errors found



Alert level C
RINTA01_ALERT_3_C  The value of Rint is greater than 0.10
            Rint given   0.113
PLAT020_ALERT_3_C The value of Rint is greater than 0.10 .........       0.11
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...         11

Alert level G
REFLT03_ALERT_4_G  WARNING: Large fraction of Friedel related reflns may
                     be needed to determine absolute structure
           From the CIF: _diffrn_reflns_theta_max           27.56
           From the CIF: _reflns_number_total               1743
           Count of symmetry unique reflns         1753
           Completeness (_total/calc)             99.43%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present        yes
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C8     = .          R

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   3 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: WinAFC Diffractometer Control Software (Rigaku, 1999); cell refinement: WinAFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 2001); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: TEXSAN.

(R)-4-bromo-2-[(1-phenylethyl)iminomethyl]phenol

Crystal data

C15H14BrNO	F(000) = 616
Mr = 304.18	Dx = 1.467 Mg m^−3
Monoclinic, C2	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2y	Cell parameters from 24 reflections
a = 20.955 (8) Å	θ = 10.0–13.8°
b = 5.795 (3) Å	µ = 2.97 mm^−1
c = 14.611 (7) Å	T = 297 K
β = 129.07 (3)°	Prism, green
V = 1377.5 (13) Å^3	0.30 × 0.30 × 0.20 mm
Z = 4

Data collection

Rigaku AFC-7R diffractometer	1425 reflections with I > 2σ(I)
Radiation source: Rigaku rotating anode generator	Rint = 0.113
Graphite monochromator	θmax = 27.6°, θmin = 2.5°
ω–2θ scans	h = −10→26
Absorption correction: ψ scan (North et al., 1968)	k = 0→7
Tmin = 0.396, Tmax = 0.552	l = −18→14
1907 measured reflections	3 standard reflections every 150 reflections
1743 independent reflections	intensity decay: 1.4%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.046	H-atom parameters constrained
wR(F^2) = 0.128	w = 1/[σ^2(Fo^2) + (0.0737P)^2 + 0.6987P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max < 0.001
1743 reflections	Δρmax = 0.73 e Å^−3
164 parameters	Δρmin = −0.49 e Å^−3
1 restraint	Absolute structure: Flack (1983), no Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.01 (2)

Special details

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.

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

	x	y	z	Uiso*/Ueq
Br1	0.41682 (3)	0.53391 (18)	0.26315 (5)	0.0735 (3)
O1	0.0909 (2)	0.0538 (10)	0.0179 (4)	0.0722 (11)
H1A	0.0534	0.1339	−0.0359	0.087*
N1	0.0233 (3)	0.4037 (8)	−0.1245 (4)	0.0537 (10)
C1	0.1626 (4)	0.1602 (10)	0.0688 (5)	0.0546 (11)
C2	0.2339 (4)	0.0600 (15)	0.1653 (6)	0.0665 (15)
H2A	0.2311	−0.0820	0.1923	0.079*
C3	0.3094 (4)	0.1662 (11)	0.2228 (5)	0.0628 (13)
H3A	0.3570	0.0967	0.2879	0.076*
C4	0.3134 (3)	0.3775 (11)	0.1822 (5)	0.0545 (12)
C5	0.2436 (3)	0.4829 (9)	0.0853 (4)	0.0525 (13)
H5A	0.2473	0.6240	0.0585	0.060*
C6	0.1675 (3)	0.3757 (10)	0.0278 (4)	0.0491 (10)
C7	0.0935 (3)	0.4913 (9)	−0.0721 (4)	0.0525 (13)
H7A	0.0983	0.6325	−0.0976	0.060*
C8	−0.0494 (3)	0.5287 (15)	−0.2258 (4)	0.0565 (10)
H8A	−0.0309	0.6686	−0.2408	0.066*
C9	−0.1028 (4)	0.5971 (13)	−0.1937 (6)	0.0722 (19)
H9A	−0.0712	0.6887	−0.1232	0.088*
H9B	−0.1221	0.4608	−0.1806	0.088*
H9C	−0.1489	0.6851	−0.2569	0.088*
C10	−0.0915 (3)	0.3713 (11)	−0.3323 (5)	0.0567 (12)
C11	−0.0850 (5)	0.4105 (15)	−0.4202 (6)	0.0746 (17)
H11A	−0.0565	0.5396	−0.4150	0.092*
C12	−0.1192 (6)	0.265 (2)	−0.5129 (7)	0.100 (3)
H12A	−0.1145	0.2969	−0.5708	0.121*
C13	−0.1609 (6)	0.071 (2)	−0.5222 (6)	0.099 (3)
H13A	−0.1827	−0.0318	−0.5845	0.115*
C14	−0.1696 (4)	0.031 (2)	−0.4378 (6)	0.0879 (18)
H14A	−0.1999	−0.0952	−0.4450	0.106*
C15	−0.1339 (4)	0.1760 (13)	−0.3433 (6)	0.0720 (16)
H15A	−0.1381	0.1425	−0.2851	0.088*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0591 (3)	0.0747 (4)	0.0810 (4)	−0.0109 (4)	0.0415 (3)	−0.0138 (4)
O1	0.064 (2)	0.053 (2)	0.082 (2)	−0.005 (2)	0.0376 (19)	0.018 (3)
N1	0.060 (2)	0.044 (2)	0.056 (2)	0.000 (2)	0.036 (2)	0.002 (2)
C1	0.062 (3)	0.042 (3)	0.060 (3)	−0.001 (2)	0.038 (2)	0.004 (2)
C2	0.074 (3)	0.043 (3)	0.078 (3)	0.004 (3)	0.046 (3)	0.002 (3)
C3	0.058 (3)	0.054 (3)	0.062 (3)	0.007 (3)	0.031 (3)	0.006 (3)
C4	0.057 (3)	0.054 (3)	0.053 (3)	0.001 (2)	0.035 (2)	−0.007 (2)
C5	0.064 (3)	0.042 (3)	0.060 (3)	0.001 (2)	0.043 (2)	0.002 (2)
C6	0.059 (3)	0.042 (2)	0.053 (3)	0.000 (2)	0.038 (2)	−0.002 (2)
C7	0.063 (3)	0.047 (4)	0.054 (2)	−0.001 (2)	0.040 (2)	0.004 (2)
C8	0.063 (2)	0.045 (2)	0.057 (2)	0.000 (4)	0.036 (2)	0.008 (3)
C9	0.074 (3)	0.076 (5)	0.067 (3)	0.011 (3)	0.045 (3)	−0.001 (3)
C10	0.059 (3)	0.054 (3)	0.051 (3)	0.012 (3)	0.032 (2)	0.010 (2)
C11	0.085 (4)	0.076 (4)	0.069 (3)	0.021 (4)	0.052 (3)	0.014 (3)
C12	0.132 (7)	0.104 (7)	0.068 (4)	0.049 (6)	0.065 (5)	0.025 (5)
C13	0.103 (5)	0.092 (8)	0.056 (3)	0.035 (6)	0.029 (3)	0.001 (4)
C14	0.085 (4)	0.062 (3)	0.078 (4)	0.000 (5)	0.033 (3)	0.000 (5)
C15	0.074 (4)	0.062 (4)	0.068 (3)	−0.006 (3)	0.039 (3)	−0.004 (3)

Geometric parameters (Å, º)

Br1—C4	1.921 (6)	C8—C10	1.517 (9)
O1—C1	1.335 (7)	C8—H8A	0.9800
O1—H1A	0.8199	C9—H9A	0.9600
N1—C7	1.261 (7)	C9—H9B	0.9600
N1—C8	1.482 (7)	C9—H9C	0.9600
C1—C2	1.379 (9)	C10—C15	1.384 (10)
C1—C6	1.416 (8)	C10—C11	1.392 (9)
C2—C3	1.384 (10)	C11—C12	1.355 (13)
C2—H2A	0.9300	C11—H11A	0.9300
C3—C4	1.385 (9)	C12—C13	1.379 (16)
C3—H3A	0.9300	C12—H12A	0.9300
C4—C5	1.381 (8)	C13—C14	1.376 (14)
C5—C6	1.395 (7)	C13—H13A	0.9300
C5—H5A	0.9300	C14—C15	1.367 (12)
C6—C7	1.459 (7)	C14—H14A	0.9300
C7—H7A	0.9300	C15—H15A	0.9300
C8—C9	1.514 (9)
C1—O1—H1A	109.5	C9—C8—H8A	109.0
C7—N1—C8	118.8 (5)	C10—C8—H8A	109.0
O1—C1—C2	119.2 (5)	C8—C9—H9A	109.5
O1—C1—C6	121.9 (5)	C8—C9—H9B	109.5
C2—C1—C6	118.9 (6)	H9A—C9—H9B	109.5
C1—C2—C3	121.4 (7)	C8—C9—H9C	109.5
C1—C2—H2A	119.3	H9A—C9—H9C	109.5
C3—C2—H2A	119.3	H9B—C9—H9C	109.5
C4—C3—C2	119.1 (6)	C15—C10—C11	117.1 (6)
C4—C3—H3A	120.4	C15—C10—C8	121.8 (5)
C2—C3—H3A	120.4	C11—C10—C8	121.0 (6)
C5—C4—C3	121.3 (5)	C12—C11—C10	121.5 (8)
C5—C4—Br1	118.5 (4)	C12—C11—H11A	119.2
C3—C4—Br1	120.1 (5)	C10—C11—H11A	119.2
C4—C5—C6	119.3 (5)	C11—C12—C13	120.7 (8)
C4—C5—H5A	120.3	C11—C12—H12A	119.7
C6—C5—H5A	120.3	C13—C12—H12A	119.7
C5—C6—C1	119.9 (5)	C14—C13—C12	118.8 (9)
C5—C6—C7	119.2 (5)	C14—C13—H13A	120.6
C1—C6—C7	120.9 (5)	C12—C13—H13A	120.6
N1—C7—C6	121.3 (5)	C15—C14—C13	120.4 (10)
N1—C7—H7A	119.3	C15—C14—H14A	119.8
C6—C7—H7A	119.3	C13—C14—H14A	119.8
N1—C8—C9	108.2 (4)	C14—C15—C10	121.5 (7)
N1—C8—C10	107.4 (6)	C14—C15—H15A	119.3
C9—C8—C10	114.2 (5)	C10—C15—H15A	119.3
N1—C8—H8A	109.0
O1—C1—C2—C3	−178.4 (6)	C1—C6—C7—N1	0.3 (7)
C6—C1—C2—C3	0.4 (9)	C7—N1—C8—C9	−115.9 (6)
C1—C2—C3—C4	−0.1 (10)	C7—N1—C8—C10	120.4 (5)
C2—C3—C4—C5	−0.4 (9)	N1—C8—C10—C15	71.2 (7)
C2—C3—C4—Br1	178.0 (5)	C9—C8—C10—C15	−48.7 (8)
C3—C4—C5—C6	0.7 (7)	N1—C8—C10—C11	−105.0 (6)
Br1—C4—C5—C6	−177.8 (4)	C9—C8—C10—C11	135.1 (7)
C4—C5—C6—C1	−0.4 (7)	C15—C10—C11—C12	0.6 (10)
C4—C5—C6—C7	177.9 (5)	C8—C10—C11—C12	176.9 (7)
O1—C1—C6—C5	178.7 (5)	C10—C11—C12—C13	−0.9 (12)
C2—C1—C6—C5	−0.1 (8)	C11—C12—C13—C14	2.2 (13)
O1—C1—C6—C7	0.4 (8)	C12—C13—C14—C15	−3.3 (14)
C2—C1—C6—C7	−178.4 (6)	C13—C14—C15—C10	3.1 (13)
C8—N1—C7—C6	−179.6 (5)	C11—C10—C15—C14	−1.6 (10)
C5—C6—C7—N1	−178.0 (5)	C8—C10—C15—C14	−178.0 (7)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···N1	0.81	1.88	2.593 (7)	146