6-Meth­oxy-2-(2-pyridylmethyl­imino­meth­yl)phenol

A new tetra­dentate unsymmetrical Schiff base, C₁₄H₁₄N₂O₂, has been synthesized and structurally characterized. There exists a strong O...H—N intra­molecular hydrogen bond in the structure.

Key indicators

• Single-crystal X-ray study
• T = 273 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.043
• wR factor = 0.134
• Data-to-parameter ratio = 17.5

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT230_ALERT_2_B Hirshfeld Test Diff for    C7     -   C8      ..       8.67 su
PLAT230_ALERT_2_B Hirshfeld Test Diff for    C9     -   C10     ..       7.08 su

Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C5
PLAT707_ALERT_1_C D...A   Calc  2.5707(17), Rep    2.573(3), Dev..       1.35 Sigma
              O1   -N2      1.555   1.555
PLAT728_ALERT_1_C D-H..A  Calc      148.00, Rep      146.00 Dev...       2.00 Deg.
              O1   -H1   -N2      1.555   1.555   1.555

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

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

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S1. Comment

Recently, Schiff base ligands, especially the relative flexible unsymmetrical tridentate Schiff base ligands and their hydrogenerated derivatives have been employed to assembly alkoxo- or phenoxo-bridged clusters and polymers with beautiful molecular structures and interesting magnetic properties in the field of coordination chemistry. (Koizumi et al., 2005; Boskovic et al., 2003; Oshiob et al., 2005).

Herein, we report the synthesis and crystal structure of a new unsymmetrical Schiff base 6-Methoxy-2-(2-pyridylmethyliminomethyl)phenol, (I), which possesses a O₂N₂ donor set affording a potentially tetradentate ligand.

The structure of (I) is shown in Fig. 1. The imide bond length of 1.278 (3) Å for N2—C7 is slightly longer than that of 4-Bromo-2-(2-pyridylmethyliminomethyl)phenol (1.269 (4) Å) (Zhang et al., 2003). The C—N bond distances of 1.338 (2) Å for C1—N1 and 1.330 (2) Å for C5—N1 are slightly shorter than those of C—C bond lengths in the same pyridine ring. It is noteworthy that there exists a relative strong intramolecular bond in the title compound with hydrogen bond length 2.573 (3) Å for N2—O1 and bond angle 145.75 (3)° for N2—H1—O1, which is similar to those of its derivative 4-Bromo-2-(2-pyridylmethyliminomethyl)phenol (Zhang et al., 2003).

The molecules in (I) are connected through relatively weak π-π interactions between the two adjacent pyridine rings and beween benzene rings and imine groups yielding a one-dimensional supramolecular structure along the b axis (Fig. 2).

Related literature

For related literature, see: Boskovic et al. (2003); Kannappan et al. (2005); Koizumi et al. (2005); Oshiob et al. (2005); Zhang et al. (2003).

S2. Experimental

6-Methoxy-2-(2-pyridylmethyliminomethyl)phenol was prepared according to the method reported in the literature (Kannappan et al., 2005). 2-(2-aminomethyl)-pyridine (2.16 g, 0.02 mol) was added to a stirred ethanol solution of O-vanillin (3.04 g, 0.02 mol (10 ml). The reaction mixture was stirred about 3 h and then the mixture was stand at room temperature for about two days. to yield yellow crystals suitable for X-ray diffraction analysis. Yield: 60%.

S3. Refinement

H atoms bound to C and O atoms were visible in difference maps and were placed using the HFIX commands in SHELXL97. All H atoms were allowed for as riding atoms (C—H 0.97 Å, O—H 0.86 Å) with the constraint U_iso(H) = 1.5U_eq(methyl carrier), 1.5U_eq(O) and 1.2U_eq(carrier) for all other H atoms.

Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Sheldrick, 1998); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. A view of (I) with the unique atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. The one-dimensional supramolecular structure in (I).

6-Methoxy-2-(2-pyridylmethyliminomethyl)phenol

Crystal data

C14H14N2O2	F(000) = 512
Mr = 242.27	Dx = 1.291 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2859 reflections
a = 9.0899 (2) Å	θ = 2.2–27.5°
b = 5.6626 (1) Å	µ = 0.09 mm^−1
c = 24.2440 (5) Å	T = 273 K
β = 92.626 (2)°	Strip, yellow
V = 1246.59 (4) Å^3	0.2 × 0.1 × 0.08 mm
Z = 4

Data collection

Bruker APEX II CCD area-detector diffractometer	2859 independent reflections
Radiation source: fine-focus sealed tube	1920 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
φ and ω scans	θmax = 27.5°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −10→11
Tmin = 0.989, Tmax = 0.993	k = −7→7
9173 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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.134	H-atom parameters constrained
S = 0.99	w = 1/[σ^2(Fo^2) + (0.0707P)^2 + 0.1506P] where P = (Fo^2 + 2Fc^2)/3
2859 reflections	(Δ/σ)max < 0.001
163 parameters	Δρmax = 0.13 e Å^−3
0 restraints	Δρmin = −0.20 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
O1	0.17097 (10)	0.9235 (2)	0.15683 (4)	0.0665 (3)
H1	0.1843	0.8212	0.1337	0.100*
C13	0.29151 (14)	1.0610 (3)	0.16245 (5)	0.0549 (4)
O2	0.16576 (11)	1.2706 (2)	0.22814 (4)	0.0723 (3)
C8	0.41579 (15)	1.0222 (3)	0.13125 (6)	0.0602 (4)
N2	0.30337 (15)	0.7011 (3)	0.08109 (5)	0.0684 (4)
C12	0.29218 (14)	1.2481 (3)	0.20015 (6)	0.0589 (4)
C7	0.41632 (17)	0.8307 (3)	0.09163 (6)	0.0688 (4)
H7	0.5019	0.8009	0.0732	0.083*
C9	0.53800 (16)	1.1743 (4)	0.13884 (7)	0.0735 (5)
H9	0.6205	1.1511	0.1182	0.088*
C11	0.41353 (16)	1.3924 (3)	0.20683 (6)	0.0679 (4)
H11	0.4132	1.5160	0.2321	0.081*
C5	0.22332 (15)	0.5451 (3)	−0.01100 (6)	0.0586 (4)
N1	0.22922 (16)	0.3658 (2)	−0.04625 (6)	0.0763 (4)
C6	0.3129 (2)	0.5075 (3)	0.04198 (6)	0.0771 (5)
H6A	0.2799	0.3637	0.0593	0.093*
H6B	0.4152	0.4857	0.0334	0.093*
C14	0.1541 (2)	1.4681 (4)	0.26385 (7)	0.0784 (5)
H14A	0.0610	1.4632	0.2810	0.118*
H14B	0.1608	1.6112	0.2429	0.118*
H14C	0.2324	1.4634	0.2918	0.118*
C4	0.14319 (18)	0.7454 (3)	−0.02253 (7)	0.0697 (4)
H4	0.1425	0.8690	0.0027	0.084*
C2	0.06709 (19)	0.5785 (4)	−0.10834 (7)	0.0825 (5)
H2	0.0134	0.5838	−0.1419	0.099*
C10	0.53675 (17)	1.3544 (4)	0.17593 (7)	0.0761 (5)
H10	0.6184	1.4525	0.1807	0.091*
C3	0.0637 (2)	0.7607 (4)	−0.07208 (8)	0.0817 (5)
H3	0.0081	0.8948	−0.0806	0.098*
C1	0.1515 (2)	0.3875 (4)	−0.09402 (8)	0.0862 (5)
H1A	0.1553	0.2641	−0.1192	0.103*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0514 (5)	0.0836 (7)	0.0651 (6)	−0.0019 (5)	0.0084 (4)	−0.0028 (5)
C13	0.0409 (6)	0.0741 (9)	0.0495 (7)	0.0037 (6)	0.0002 (5)	0.0160 (6)
O2	0.0535 (6)	0.0903 (8)	0.0740 (7)	−0.0043 (5)	0.0140 (5)	−0.0109 (6)
C8	0.0467 (7)	0.0854 (10)	0.0486 (7)	0.0129 (7)	0.0027 (5)	0.0182 (7)
N2	0.0651 (8)	0.0878 (9)	0.0523 (7)	0.0203 (7)	0.0023 (5)	0.0062 (6)
C12	0.0470 (7)	0.0755 (10)	0.0542 (7)	0.0035 (7)	0.0031 (6)	0.0125 (7)
C7	0.0535 (8)	0.1018 (12)	0.0516 (7)	0.0252 (9)	0.0070 (6)	0.0189 (8)
C9	0.0438 (7)	0.1100 (14)	0.0671 (9)	0.0060 (8)	0.0085 (6)	0.0268 (10)
C11	0.0566 (8)	0.0792 (11)	0.0676 (9)	−0.0033 (7)	−0.0010 (6)	0.0125 (8)
C5	0.0590 (8)	0.0606 (9)	0.0571 (8)	0.0078 (7)	0.0124 (6)	0.0051 (6)
N1	0.0852 (9)	0.0679 (9)	0.0763 (9)	0.0097 (7)	0.0103 (7)	−0.0070 (7)
C6	0.0834 (11)	0.0843 (11)	0.0636 (9)	0.0316 (9)	0.0042 (8)	0.0065 (8)
C14	0.0738 (10)	0.0926 (13)	0.0695 (10)	0.0045 (9)	0.0108 (8)	−0.0056 (9)
C4	0.0752 (10)	0.0659 (10)	0.0676 (9)	0.0148 (8)	−0.0018 (7)	−0.0001 (8)
C2	0.0691 (10)	0.1114 (15)	0.0660 (10)	−0.0136 (10)	−0.0057 (8)	0.0048 (10)
C10	0.0532 (8)	0.0937 (13)	0.0812 (11)	−0.0099 (8)	0.0015 (7)	0.0178 (10)
C3	0.0782 (11)	0.0851 (12)	0.0803 (11)	0.0114 (9)	−0.0125 (9)	0.0118 (10)
C1	0.0923 (13)	0.0908 (13)	0.0759 (11)	−0.0093 (11)	0.0079 (10)	−0.0207 (10)

Geometric parameters (Å, º)

O1—C13	1.3459 (17)	C5—C4	1.370 (2)
O1—H1	0.8200	C5—C6	1.504 (2)
C13—C12	1.399 (2)	N1—C1	1.334 (2)
C13—C8	1.4052 (19)	C6—H6A	0.9700
O2—C12	1.3669 (16)	C6—H6B	0.9700
O2—C14	1.421 (2)	C14—H14A	0.9600
C8—C9	1.411 (2)	C14—H14B	0.9600
C8—C7	1.449 (2)	C14—H14C	0.9600
N2—C7	1.278 (2)	C4—C3	1.376 (2)
N2—C6	1.454 (2)	C4—H4	0.9300
C12—C11	1.376 (2)	C2—C1	1.362 (3)
C7—H7	0.9300	C2—C3	1.357 (3)
C9—C10	1.360 (3)	C2—H2	0.9300
C9—H9	0.9300	C10—H10	0.9300
C11—C10	1.392 (2)	C3—H3	0.9300
C11—H11	0.9300	C1—H1A	0.9300
C5—N1	1.3300 (19)
C13—O1—H1	109.5	N2—C6—H6A	108.8
O1—C13—C12	118.90 (11)	C5—C6—H6A	108.8
O1—C13—C8	121.74 (14)	N2—C6—H6B	108.8
C12—C13—C8	119.36 (13)	C5—C6—H6B	108.8
C12—O2—C14	117.61 (13)	H6A—C6—H6B	107.7
C13—C8—C9	118.82 (15)	O2—C14—H14A	109.5
C13—C8—C7	120.05 (14)	O2—C14—H14B	109.5
C9—C8—C7	121.13 (14)	H14A—C14—H14B	109.5
C7—N2—C6	119.44 (14)	O2—C14—H14C	109.5
O2—C12—C11	125.02 (14)	H14A—C14—H14C	109.5
O2—C12—C13	114.59 (12)	H14B—C14—H14C	109.5
C11—C12—C13	120.39 (13)	C5—C4—C3	118.90 (16)
N2—C7—C8	122.36 (13)	C5—C4—H4	120.6
N2—C7—H7	118.8	C3—C4—H4	120.6
C8—C7—H7	118.8	C1—C2—C3	117.91 (17)
C10—C9—C8	120.90 (14)	C1—C2—H2	121.0
C10—C9—H9	119.5	C3—C2—H2	121.0
C8—C9—H9	119.5	C9—C10—C11	120.19 (16)
C12—C11—C10	120.33 (16)	C9—C10—H10	119.9
C12—C11—H11	119.8	C11—C10—H10	119.9
C10—C11—H11	119.8	C2—C3—C4	119.42 (17)
N1—C5—C4	122.53 (14)	C2—C3—H3	120.3
N1—C5—C6	113.86 (13)	C4—C3—H3	120.3
C4—C5—C6	123.60 (14)	N1—C1—C2	124.35 (17)
C5—N1—C1	116.88 (15)	N1—C1—H1A	117.8
N2—C6—C5	113.82 (13)	C2—C1—H1A	117.8

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	D···A	D—H···A
O1—H1···N2	0.82	2.573 (3)	146