4-Hy­droxy-3-meth­oxy­benzaldehyde–nicotinamide (1/1)

In the title compound, C₆H₆N₂O·C₈H₈O₃, an equimolar co-crystal of nicotinamide and vanillin, the aromatic ring and the amide fragment of the nicotinamide mol­ecule make a dihedral angle of 32.6 (2)°. The vanillin mol­ecule is almost planar, with an r.m.s. deviation for all non-H atoms of 0.0094 Å. The vaniline and nicotinamide aromatic rings are nearly coplanar, the dihedral angle between them being 3.20 (9)°. In the crystal, the two components are linked through N—H...O and O—H...N hydrogen bonds into chains along the a axis. The chains are connected via C—H...O inter­actions, forming a three-dimensional polymeric structure.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.045
• wR factor = 0.112
• Data-to-parameter ratio = 11.7

checkCIF/PLATON results

No syntax errors found



Datablock: I


Alert level C
DIFMX01_ALERT_2_C  The maximum difference density is > 0.1*ZMAX*0.75
            _refine_diff_density_max given =      0.664
            Test value =      0.600
DIFMX02_ALERT_1_C  The maximum difference density is > 0.1*ZMAX*0.75
            The relevant atom site should be identified.
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......      0.974
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.39
PLAT097_ALERT_2_C Large Reported Max.  (Positive) Residual Density       0.66 eA-3
PLAT230_ALERT_2_C Hirshfeld Test Diff for    O1     --  C1      ..        5.2 su
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600         59

Alert level G
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite          5
PLAT003_ALERT_2_G Number of Uiso or Uij Restrained Atom Sites ....          2
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          4
PLAT909_ALERT_3_G Percentage of Observed Data at Theta(Max) still          72 Perc.

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   8 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   4 ALERT level G = General information/check it is not something unexpected

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   6 ALERT type 2 Indicator that the structure model may be wrong or deficient
   5 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

---

S1. Comment

The crystal structures of nicotinamide (Miwa et al.,1999; Li et al., 2011) and 4-hydroxy-3-methoxybenzaldehyde, vanillin, (Velavan et al.,1995) have been previously reported. The title compound is an equimolar cocrystal of nicotinamide and vanillin (Fig. 1). The nicotinamide aromatic ring and the plane of the amide fragment, N1—C9—O4, are twisted with respect to each other, making a dihedral angle of 32.6 (2)°. The vanillin molecule is essentially planar, the highest deviation from the best plane passing through all non-H atoms being 0.0156 (13) Å for O3 atom. In the crystal, the molecules of nicotinamide and vanillin are linked through N—H···O and O—H···N hydrogen bonds into infinite chains along the a axis (Fig. 2). The chains are connected via C—H···O interactions (Table 1 and Fig. 2) to form a three-dimensional polymeric structure.

Related literature

For the crystal structure of nicotinamide, see: Miwa et al. (1999); Li et al. (2011). For the structure of vanillin, see: Velavan et al. (1995).

S2. Experimental

A mixture of vanillin (1.52 g, 0.1 mol) and nicotinamide (1.22 g, 0.1 mol) in ethanol (30 ml) was heated for 1 hr. The solvent was then evaporated partially and the solution was left at room temperature. The colorless crystals of the title compound were obtained in a day.

S3. Refinement

The C-bound H atoms were placed at calculated positions and were treated as riding on their parent C atoms with C—H distances of 0.95 (aryl) and 0.98 (methyl) Å. The N– and O-bound H atoms were located in a difference Fourier map, and refined with distance restraints of O—H = 0.84 (2) Å and N—H = 0.88 (2) Å. For all H atoms, U_iso(H) was set to 1.2–1.5_eq(carrier atom). An additional rigid-bond type restraint (DELU in SHELXL97) was placed on the displacement parameters of C1 and C2.

Computing details

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010).

Figures

	Fig. 1. Molecular structure of the title compound with displacement ellipsoids drawn at 50% probability level. Hydrogen atoms are drawn as spheres of arbitrary radii.
	Fig. 2. A chain along the a axis formed by N—H···O and O—H···N hydrogen bonds.

4-Hydroxy-3-methoxybenzaldehyde–nicotinamide (1/1)

Crystal data

C6H6N2O·C8H8O3	Z = 2
Mr = 274.27	F(000) = 288
Triclinic, P1	Dx = 1.429 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.8979 (1) Å	Cell parameters from 1226 reflections
b = 8.5440 (2) Å	θ = 2.6–29.7°
c = 15.4713 (4) Å	µ = 0.11 mm^−1
α = 98.108 (1)°	T = 100 K
β = 92.810 (2)°	Lath, colorless
γ = 94.784 (2)°	0.22 × 0.14 × 0.04 mm
V = 637.52 (3) Å^3

Data collection

Bruker APEXII CCD diffractometer	2243 independent reflections
Radiation source: fine-focus sealed tube	1862 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.019
φ and ω scans	θmax = 25.3°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −5→5
Tmin = 0.977, Tmax = 0.996	k = −10→10
3432 measured reflections	l = −18→18

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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.112	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0439P)^2 + 0.4685P] where P = (Fo^2 + 2Fc^2)/3
2243 reflections	(Δ/σ)max < 0.001
191 parameters	Δρmax = 0.66 e Å^−3
4 restraints	Δρmin = −0.28 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	0.3651 (3)	0.83011 (19)	0.61085 (10)	0.0359 (4)
O2	0.8107 (3)	0.63328 (16)	0.23075 (9)	0.0195 (3)
H2	0.949 (4)	0.698 (2)	0.2250 (15)	0.029*
O3	0.4028 (3)	0.44026 (16)	0.25734 (9)	0.0218 (3)
C1	0.3070 (5)	0.7306 (3)	0.54863 (14)	0.0286 (5)
H1	0.1529	0.6570	0.5522	0.034*
C2	0.4516 (4)	0.7113 (2)	0.46701 (13)	0.0210 (4)
C3	0.6726 (4)	0.8148 (2)	0.45164 (13)	0.0221 (5)
H3	0.7380	0.9016	0.4951	0.026*
C4	0.7972 (4)	0.7912 (2)	0.37307 (13)	0.0204 (4)
H4	0.9482	0.8620	0.3629	0.024*
C5	0.7035 (4)	0.6648 (2)	0.30888 (12)	0.0166 (4)
C6	0.4793 (4)	0.5600 (2)	0.32443 (12)	0.0176 (4)
C7	0.3561 (4)	0.5847 (2)	0.40255 (13)	0.0208 (5)
H7	0.2040	0.5146	0.4128	0.025*
C8	0.1709 (4)	0.3323 (2)	0.26827 (14)	0.0217 (5)
H8A	0.2110	0.2765	0.3179	0.033*
H8B	0.1328	0.2551	0.2150	0.033*
H8C	0.0103	0.3917	0.2793	0.033*
O4	0.8254 (3)	0.71964 (19)	−0.04761 (9)	0.0299 (4)
N1	0.3766 (4)	0.6341 (2)	−0.07875 (11)	0.0205 (4)
H1A	0.207 (3)	0.645 (3)	−0.0672 (14)	0.025*
H1B	0.415 (4)	0.586 (2)	−0.1293 (11)	0.025*
N2	0.2385 (3)	0.80224 (19)	0.18395 (10)	0.0170 (4)
C9	0.5840 (4)	0.7129 (2)	−0.02755 (13)	0.0197 (4)
C10	0.5123 (4)	0.7959 (2)	0.05932 (12)	0.0169 (4)
C11	0.6653 (4)	0.9350 (2)	0.09779 (13)	0.0201 (4)
H11	0.8121	0.9801	0.0687	0.024*
C12	0.5998 (4)	1.0066 (2)	0.17913 (13)	0.0220 (5)
H12	0.6997	1.1023	0.2066	0.026*
C13	0.3864 (4)	0.9363 (2)	0.21971 (13)	0.0192 (4)
H13	0.3429	0.9856	0.2757	0.023*
C14	0.3015 (4)	0.7346 (2)	0.10499 (12)	0.0162 (4)
H14	0.1966	0.6397	0.0788	0.019*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0440 (10)	0.0363 (9)	0.0266 (9)	0.0056 (8)	0.0038 (7)	0.0006 (7)
O2	0.0182 (8)	0.0217 (7)	0.0174 (7)	−0.0031 (6)	0.0053 (6)	0.0004 (6)
O3	0.0223 (8)	0.0214 (7)	0.0198 (7)	−0.0045 (6)	0.0064 (6)	−0.0016 (6)
C1	0.0356 (13)	0.0308 (12)	0.0189 (10)	0.0104 (10)	−0.0028 (9)	−0.0012 (9)
C2	0.0226 (11)	0.0246 (11)	0.0170 (10)	0.0074 (8)	0.0004 (8)	0.0045 (8)
C3	0.0270 (11)	0.0214 (10)	0.0165 (10)	0.0060 (9)	−0.0036 (8)	−0.0020 (8)
C4	0.0187 (10)	0.0193 (10)	0.0218 (11)	−0.0018 (8)	−0.0001 (8)	0.0014 (8)
C5	0.0157 (10)	0.0209 (10)	0.0145 (9)	0.0054 (8)	0.0026 (8)	0.0043 (8)
C6	0.0193 (10)	0.0176 (10)	0.0157 (10)	0.0033 (8)	0.0002 (8)	0.0007 (8)
C7	0.0193 (11)	0.0242 (11)	0.0199 (10)	0.0020 (8)	0.0046 (8)	0.0055 (8)
C8	0.0185 (11)	0.0198 (10)	0.0259 (11)	−0.0031 (8)	0.0035 (8)	0.0021 (8)
O4	0.0144 (8)	0.0516 (10)	0.0228 (8)	0.0064 (7)	0.0038 (6)	−0.0003 (7)
N1	0.0172 (9)	0.0279 (9)	0.0153 (9)	0.0046 (7)	0.0035 (7)	−0.0030 (7)
N2	0.0171 (9)	0.0194 (8)	0.0148 (8)	0.0031 (7)	0.0012 (6)	0.0027 (6)
C9	0.0178 (11)	0.0255 (11)	0.0168 (10)	0.0055 (8)	0.0018 (8)	0.0042 (8)
C10	0.0144 (10)	0.0210 (10)	0.0156 (10)	0.0038 (8)	−0.0008 (7)	0.0030 (8)
C11	0.0149 (10)	0.0240 (10)	0.0221 (10)	0.0003 (8)	0.0020 (8)	0.0058 (8)
C12	0.0227 (11)	0.0180 (10)	0.0234 (11)	−0.0030 (8)	−0.0011 (8)	−0.0002 (8)
C13	0.0217 (11)	0.0192 (10)	0.0160 (10)	0.0031 (8)	0.0002 (8)	0.0001 (8)
C14	0.0157 (10)	0.0162 (9)	0.0161 (10)	0.0009 (7)	−0.0013 (8)	0.0012 (7)

Geometric parameters (Å, º)

O1—C1	1.197 (3)	C8—H8B	0.9800
O2—C5	1.343 (2)	C8—H8C	0.9800
O2—H2	0.854 (16)	O4—C9	1.236 (2)
O3—C6	1.365 (2)	N1—C9	1.330 (3)
O3—C8	1.435 (2)	N1—H1A	0.868 (16)
C1—C2	1.474 (3)	N1—H1B	0.869 (16)
C1—H1	0.9500	N2—C13	1.336 (2)
C2—C3	1.391 (3)	N2—C14	1.338 (2)
C2—C7	1.396 (3)	C9—C10	1.500 (3)
C3—C4	1.384 (3)	C10—C14	1.388 (3)
C3—H3	0.9500	C10—C11	1.392 (3)
C4—C5	1.391 (3)	C11—C12	1.384 (3)
C4—H4	0.9500	C11—H11	0.9500
C5—C6	1.410 (3)	C12—C13	1.384 (3)
C6—C7	1.375 (3)	C12—H12	0.9500
C7—H7	0.9500	C13—H13	0.9500
C8—H8A	0.9800	C14—H14	0.9500
C5—O2—H2	112.6 (16)	O3—C8—H8C	109.5
C6—O3—C8	117.44 (15)	H8A—C8—H8C	109.5
O1—C1—C2	126.2 (2)	H8B—C8—H8C	109.5
O1—C1—H1	116.9	C9—N1—H1A	121.6 (15)
C2—C1—H1	116.9	C9—N1—H1B	117.5 (15)
C3—C2—C7	119.56 (18)	H1A—N1—H1B	120 (2)
C3—C2—C1	122.83 (19)	C13—N2—C14	117.72 (17)
C7—C2—C1	117.59 (19)	O4—C9—N1	123.82 (19)
C4—C3—C2	119.93 (19)	O4—C9—C10	119.84 (18)
C4—C3—H3	120.0	N1—C9—C10	116.34 (17)
C2—C3—H3	120.0	C14—C10—C11	118.15 (18)
C3—C4—C5	120.68 (18)	C14—C10—C9	121.73 (18)
C3—C4—H4	119.7	C11—C10—C9	120.07 (18)
C5—C4—H4	119.7	C12—C11—C10	118.88 (18)
O2—C5—C4	124.72 (18)	C12—C11—H11	120.6
O2—C5—C6	115.90 (17)	C10—C11—H11	120.6
C4—C5—C6	119.38 (18)	C13—C12—C11	118.77 (19)
O3—C6—C7	125.62 (18)	C13—C12—H12	120.6
O3—C6—C5	114.82 (17)	C11—C12—H12	120.6
C7—C6—C5	119.56 (18)	N2—C13—C12	123.12 (18)
C6—C7—C2	120.88 (19)	N2—C13—H13	118.4
C6—C7—H7	119.6	C12—C13—H13	118.4
C2—C7—H7	119.6	N2—C14—C10	123.34 (18)
O3—C8—H8A	109.5	N2—C14—H14	118.3
O3—C8—H8B	109.5	C10—C14—H14	118.3
H8A—C8—H8B	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O4^i	0.87 (2)	2.05 (2)	2.900 (2)	167 (2)
N1—H1B···O2^ii	0.87 (2)	2.42 (2)	3.085 (2)	134 (2)
N1—H1B···O3^ii	0.87 (2)	2.20 (2)	3.019 (2)	156 (2)
O2—H2···N2^iii	0.85 (2)	1.80 (2)	2.634 (2)	164 (2)
C8—H8A···O1^iv	0.98	2.59	3.381 (3)	137
C8—H8C···O2^i	0.98	2.55	3.337 (2)	138
C13—H13···O1^v	0.95	2.49	3.185 (3)	130

Symmetry codes: (i) x−1, y, z; (ii) −x+1, −y+1, −z; (iii) x+1, y, z; (iv) −x+1, −y+1, −z+1; (v) −x+1, −y+2, −z+1.