Retracted: 2-(Benzyl­imino­meth­yl)-6-methoxy­phenol

In the title Schiff base compound, C₁₅H₁₅NO₂, the C=N and C—N bond lengths are 1.277 (4) and 1.453 (5) Å, respectively, while the C—O bond length of the hydroxyl group is 1.334 (3) Å. The mol­ecule exhibits an intra­molecular O—H...N hydrogen bond with an O...N distance of 2.548 (3) Å.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.058
• wR factor = 0.202
• Data-to-parameter ratio = 17.9

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT230_ALERT_2_B Hirshfeld Test Diff for    C2     -   C3      ..       7.65 su
PLAT331_ALERT_2_B Small Average Phenyl C-C Dist.   C1     -C6            1.36 Ang.
PLAT411_ALERT_2_B Short Inter H...H Contact  H7     ..  H11     ..       2.09 Ang.

Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT143_ALERT_4_C su on c - Axis Small or Missing (x 100000) .....         20 Ang.
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C1     -   C2      ..       5.19 su
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          5

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

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

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 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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S1. Comment

Schiff bases have been utilized as ligands for a long time due to their straightforward synthesis and versatility in metal complexes. They therefore play an important role in the development of coordination chemistry as well as inorganic biochemistry, catalysis, optical materials and so on (Garnovskii et al., 1993; Huang et al., 2002). Considerable attention has been focused on the syntheses and structures of copper(II) and nickel(II) complexes. The nickel complexes with multidentate Schiff-base ligands have aroused particular interest because this metal can exhibit several oxidation states and may provide the basis for models of active sites of biological systems. The main attention with optically active Schiff-base complexes is concentrated on their catalytic abilities in stereo-selective synthesis (Bhadbhade & Srinivas, 1993; Bunce et al., 1998). As part of our research aiming to understand the molecular properties of chiral Schiff-base complexes, we describe here the synthesis and crystal structure of the title Schiff-base ligand (Figure 1).

Related literature

For related literature, see: Bhadbhade & Srinivas (1993); Bunce et al. (1998); Garnovskii et al. (1993); Huang et al. (2002).

S2. Experimental

A mixture of benzylamine (5.00 mmol) and o-vanillin (5.00 mmol) in methanol (40 ml) was refluxed with stirring for one hour to give an orange precipitate which was filtered and washed with methanol to give the title compound in 86% yield. Elemental analysis calculated: C 74.69, H 6.22, N 5.81%; found: C 74.66, H 6.12, N 5.79%.

S3. Refinement

H atoms were positioned geometrically with O—H = 0.82 Å and C—H = 0.93 or 0.96 Å, then constrained to ride on their parent atoms with U_iso(H) = xU_eq(C), where x = 1.5 for methyl H, and 1.2 for all other H atoms.

Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL (Bruker, 2001).

Figures

Fig. 1. The molecular structure of the title compound showing 30% probability displacement ellipsoids for non-H atoms.

2-(Benzyliminomethyl)-6-methoxyphenol

Crystal data

C15H15NO2	F(000) = 512
Mr = 241.28	Dx = 1.309 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2958 reflections
a = 8.9236 (2) Å	θ = 2.3–28.1°
b = 5.7681 (1) Å	µ = 0.09 mm^−1
c = 23.8006 (2) Å	T = 293 K
β = 92.432 (2)°	Block, colourless
V = 1223.97 (4) Å^3	0.26 × 0.24 × 0.12 mm
Z = 4

Data collection

Bruker APEXII CCD diffractometer	2958 independent reflections
Radiation source: fine-focus sealed tube	1876 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
φ and ω scans	θmax = 28.1°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −10→11
Tmin = 0.978, Tmax = 0.990	k = −7→7
8962 measured reflections	l = −31→31

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.058	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.202	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.1284P)^2 + 0.1359P] where P = (Fo^2 + 2Fc^2)/3
2958 reflections	(Δ/σ)max = 0.003
165 parameters	Δρmax = 0.45 e Å^−3
0 restraints	Δρmin = −0.39 e Å^−3

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.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
C1	0.2240 (3)	0.5473 (5)	−0.01082 (11)	0.0597 (7)
C2	0.2308 (3)	0.3654 (5)	−0.04596 (12)	0.0640 (7)
H11	0.2868	0.2332	−0.0373	0.077*
C3	0.1488 (4)	0.3901 (8)	−0.09541 (16)	0.0889 (11)
H18	0.1501	0.2699	−0.1214	0.107*
C4	0.0667 (4)	0.5786 (8)	−0.10837 (15)	0.0832 (10)
H15	0.0116	0.5850	−0.1424	0.100*
C5	0.0631 (4)	0.7614 (7)	−0.07204 (15)	0.0821 (10)
H17	0.0074	0.8934	−0.0811	0.098*
C6	0.1428 (4)	0.7460 (6)	−0.02230 (13)	0.0705 (8)
H14	0.1425	0.8672	0.0035	0.085*
C7	0.3131 (4)	0.5078 (7)	0.04205 (13)	0.0771 (9)
H12A	0.2776	0.3682	0.0599	0.093*
H12B	0.4172	0.4837	0.0334	0.093*
C8	0.4167 (3)	0.8313 (7)	0.09167 (11)	0.0698 (9)
H7	0.5043	0.8025	0.0730	0.084*
C9	0.4159 (3)	1.0214 (6)	0.13121 (11)	0.0627 (8)
C10	0.2909 (3)	1.0611 (5)	0.16243 (10)	0.0561 (7)
C11	0.2914 (3)	1.2476 (5)	0.20011 (11)	0.0597 (7)
C12	0.1536 (4)	1.4678 (7)	0.26392 (15)	0.0782 (9)
H13A	0.2306	1.4617	0.2933	0.117*
H13B	0.0570	1.4676	0.2802	0.117*
H13C	0.1648	1.6068	0.2423	0.117*
C13	0.4141 (3)	1.3927 (6)	0.20707 (13)	0.0690 (8)
H9	0.4130	1.5144	0.2327	0.083*
C14	0.5364 (3)	1.3557 (7)	0.17609 (15)	0.0773 (9)
H16	0.6190	1.4535	0.1801	0.093*
C15	0.5382 (3)	1.1745 (7)	0.13892 (13)	0.0753 (10)
H8	0.6228	1.1517	0.1181	0.090*
N1	0.3035 (3)	0.7008 (5)	0.08094 (9)	0.0697 (7)
O1	0.1661 (2)	1.2709 (4)	0.22824 (9)	0.0730 (7)
O2	0.1710 (2)	0.9237 (4)	0.15680 (8)	0.0670 (6)
H2	0.1852	0.8256	0.1327	0.101*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0579 (15)	0.0649 (17)	0.0569 (14)	0.0073 (12)	0.0109 (11)	0.0053 (12)
C2	0.0709 (17)	0.0586 (16)	0.0630 (15)	0.0114 (13)	0.0089 (13)	−0.0047 (13)
C3	0.088 (2)	0.101 (3)	0.078 (2)	−0.012 (2)	0.0095 (18)	−0.023 (2)
C4	0.067 (2)	0.116 (3)	0.0658 (18)	−0.012 (2)	−0.0051 (14)	0.0036 (19)
C5	0.074 (2)	0.093 (3)	0.078 (2)	0.0119 (17)	−0.0122 (16)	0.0131 (18)
C6	0.0740 (18)	0.0723 (19)	0.0648 (16)	0.0136 (15)	−0.0014 (14)	0.0005 (15)
C7	0.082 (2)	0.088 (2)	0.0613 (17)	0.0314 (18)	0.0042 (14)	0.0068 (16)
C8	0.0531 (15)	0.106 (2)	0.0503 (13)	0.0250 (16)	0.0068 (11)	0.0195 (15)
C9	0.0455 (13)	0.095 (2)	0.0476 (13)	0.0132 (13)	0.0032 (10)	0.0198 (13)
C10	0.0406 (12)	0.0800 (18)	0.0477 (12)	0.0038 (11)	0.0003 (9)	0.0160 (12)
C11	0.0477 (13)	0.0786 (19)	0.0530 (13)	0.0035 (12)	0.0028 (10)	0.0137 (13)
C12	0.0698 (18)	0.100 (3)	0.0659 (17)	0.0036 (17)	0.0089 (14)	−0.0046 (17)
C13	0.0538 (15)	0.085 (2)	0.0675 (16)	−0.0037 (14)	−0.0020 (12)	0.0145 (15)
C14	0.0515 (15)	0.102 (3)	0.0781 (19)	−0.0111 (16)	0.0025 (13)	0.0179 (19)
C15	0.0411 (13)	0.119 (3)	0.0662 (17)	0.0057 (15)	0.0086 (11)	0.0276 (19)
N1	0.0616 (14)	0.0969 (19)	0.0508 (12)	0.0196 (13)	0.0033 (10)	0.0071 (12)
O1	0.0525 (11)	0.0963 (17)	0.0711 (12)	−0.0048 (10)	0.0131 (9)	−0.0105 (11)
O2	0.0489 (10)	0.0910 (16)	0.0617 (11)	−0.0020 (9)	0.0083 (8)	−0.0016 (10)

Geometric parameters (Å, º)

C1—C2	1.345 (4)	C8—H7	0.930
C1—C6	1.378 (4)	C9—C10	1.386 (4)
C1—C7	1.477 (4)	C9—C15	1.409 (5)
C2—C3	1.367 (5)	C10—O2	1.334 (3)
C2—H11	0.930	C10—C11	1.401 (4)
C3—C4	1.340 (6)	C11—O1	1.334 (3)
C3—H18	0.930	C11—C13	1.383 (4)
C4—C5	1.365 (5)	C12—O1	1.425 (4)
C4—H15	0.930	C12—H13A	0.960
C5—C6	1.357 (5)	C12—H13B	0.960
C5—H17	0.930	C12—H13C	0.960
C6—H14	0.930	C13—C14	1.360 (4)
C7—N1	1.453 (5)	C13—H9	0.930
C7—H12A	0.970	C14—C15	1.370 (5)
C7—H12B	0.970	C14—H16	0.930
C8—N1	1.277 (4)	C15—H8	0.930
C8—C9	1.445 (5)	O2—H2	0.820
C2—C1—C6	124.3 (3)	C10—C9—C15	117.6 (3)
C2—C1—C7	111.9 (3)	C10—C9—C8	120.0 (3)
C6—C1—C7	123.8 (3)	C15—C9—C8	122.4 (3)
C1—C2—C3	114.7 (3)	O2—C10—C9	120.6 (3)
C1—C2—H11	122.7	O2—C10—C11	120.1 (2)
C3—C2—H11	122.7	C9—C10—C11	119.3 (3)
C4—C3—C2	123.4 (3)	O1—C11—C13	123.8 (3)
C4—C3—H18	118.3	O1—C11—C10	114.7 (2)
C2—C3—H18	118.3	C13—C11—C10	121.5 (2)
C3—C4—C5	120.5 (3)	O1—C12—H13A	109.5
C3—C4—H15	119.7	O1—C12—H13B	109.5
C5—C4—H15	119.7	H13A—C12—H13B	109.5
C6—C5—C4	118.5 (3)	O1—C12—H13C	109.5
C6—C5—H17	120.8	H13A—C12—H13C	109.5
C4—C5—H17	120.8	H13B—C12—H13C	109.5
C5—C6—C1	118.6 (3)	C14—C13—C11	119.3 (3)
C5—C6—H14	120.7	C14—C13—H9	120.3
C1—C6—H14	120.7	C11—C13—H9	120.3
N1—C7—C1	112.4 (3)	C13—C14—C15	120.1 (3)
N1—C7—H12A	109.1	C13—C14—H16	120.0
C1—C7—H12A	109.1	C15—C14—H16	120.0
N1—C7—H12B	109.1	C14—C15—C9	122.2 (3)
C1—C7—H12B	109.1	C14—C15—H8	118.9
H12A—C7—H12B	107.9	C9—C15—H8	118.9
N1—C8—C9	123.5 (3)	C8—N1—C7	120.8 (3)
N1—C8—H7	118.2	C11—O1—C12	117.9 (2)
C9—C8—H7	118.2	C10—O2—H2	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···N1	0.82	1.81	2.548 (3)	150