2,5-Bis(3,4-di­meth­oxy­phen­yl)-1,3,4-oxa­diazole

In the title compound, C₁₈H₁₈N₂O₅, which was synthesized by reacting N,N′-bis-(3,4-di­meth­oxy­benzo­yl)hydrazine with POCl₃, the dihedral angles between the central oxa­diazole ring and pendant 3,4-di­meth­oxy­phenyl rings are 11.37 (7) and 3.09 (7)°. In the crystal, weak C—H...O and π–π [shortest centroid–centroid separation = 3.7370 (11) Å] inter­actions are present, giving rise to a layered packing motif.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](C-C) = 0.002 Å
• H-atom completeness 91%
• R factor = 0.031
• wR factor = 0.101
• Data-to-parameter ratio = 12.4

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT919_ALERT_3_B Reflection # Likely Affected by the Beamstop ...          1 Check

Alert level C
CHEMW01_ALERT_1_C  The difference between the given and expected weight for
            compound is greater 1 mass unit. Check that all hydrogen
            atoms have been taken into account.
PLAT041_ALERT_1_C Calc. and Reported SumFormula    Strings  Differ     Please Check
PLAT934_ALERT_3_C Number of (Iobs-Icalc)/SigmaW > 10 Outliers ....          1 Check

Alert level G
FORMU01_ALERT_1_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and _chemical_formula_moiety. This is
            usually due to the moiety formula being in the wrong format.
            Atom count from _chemical_formula_sum:   C18 H20 N2 O5
            Atom count from _chemical_formula_moiety:C18 H18 N2 O5
FORMU01_ALERT_2_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and the formula from the _atom_site* data.
            Atom count from _chemical_formula_sum:C18 H20 N2 O5
            Atom count from the _atom_site data:  C18 H18 N2 O5
CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected.
CELLZ01_ALERT_1_G WARNING: H atoms missing from atom site list. Is this intentional?
           From the CIF: _cell_formula_units_Z    4
           From the CIF: _chemical_formula_sum  C18 H20 N2 O5
           TEST: Compare cell contents of formula and atom_site data

           atom    Z*formula  cif sites diff
           C         72.00     72.00    0.00
           H         80.00     72.00    8.00
           N          8.00      8.00    0.00
           O         20.00     20.00    0.00
PLAT005_ALERT_5_G No Embedded Refinement Details found in the CIF      Please Do !
PLAT909_ALERT_3_G Percentage of Observed Data at Theta(Max) Still          74 %
PLAT910_ALERT_3_G Missing # of FCF Reflection(s) Below Th(Min) ...          1 Report

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

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

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Computing details

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: APEX2 (Bruker, 2009).

2,5-Bis(3,4-dimethoxyphenyl)-1,3,4-oxadiazole

Crystal data

C18H20N2O5	F(000) = 720
Mr = 342.34	Dx = 1.410 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 22.135 (4) Å	Cell parameters from 6712 reflections
b = 8.4680 (16) Å	θ = 2.6–28.4°
c = 8.6198 (17) Å	µ = 0.10 mm^−1
β = 93.287 (2)°	T = 120 K
V = 1613.0 (5) Å^3	Needle, colorless
Z = 4	0.50 × 0.20 × 0.20 mm

Data collection

Bruker APEXII KY CCD diffractometer	2852 independent reflections
Radiation source: fine focus sealed tube	2525 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
ω scans	θmax = 25.0°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −26→26
Tmin = 0.883, Tmax = 0.979	k = −10→10
15058 measured reflections	l = −10→10

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)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.101	H-atom parameters constrained
S = 1.11	w = 1/[σ^2(Fo^2) + (0.0579P)^2 + 0.3685P] where P = (Fo^2 + 2Fc^2)/3
2852 reflections	(Δ/σ)max < 0.001
230 parameters	Δρmax = 0.22 e Å^−3
0 restraints	Δρmin = −0.20 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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	0.27372 (6)	0.16288 (15)	0.21202 (14)	0.0199 (3)
C2	0.32161 (6)	0.13524 (16)	0.10688 (14)	0.0201 (3)
C3	0.33172 (6)	−0.01921 (16)	0.05734 (15)	0.0208 (3)
H3	0.308	−0.1012	0.092	0.025*
C4	0.37645 (6)	−0.05059 (15)	−0.04213 (15)	0.0206 (3)
C5	0.41349 (6)	0.07362 (16)	−0.09198 (15)	0.0214 (3)
C6	0.40284 (6)	0.22591 (16)	−0.04297 (15)	0.0232 (3)
H6	0.4267	0.3083	−0.0764	0.028*
C7	0.35692 (6)	0.25712 (16)	0.05578 (15)	0.0223 (3)
H7	0.3499	0.3601	0.0876	0.027*
C8	0.35611 (7)	−0.32582 (17)	−0.04182 (18)	0.0304 (3)
H8A	0.3632	−0.3325	0.0689	0.046*
H8B	0.3691	−0.4219	−0.0888	0.046*
H8C	0.3137	−0.3104	−0.0668	0.046*
C9	0.50117 (6)	0.14775 (18)	−0.22004 (18)	0.0311 (3)
H9A	0.4817	0.2318	−0.2786	0.047*
H9B	0.532	0.1013	−0.2795	0.047*
H9C	0.5192	0.189	−0.1245	0.047*
C10	0.21076 (6)	0.29230 (16)	0.33921 (14)	0.0208 (3)
C11	0.17893 (6)	0.42755 (16)	0.39717 (15)	0.0214 (3)
C12	0.13070 (6)	0.39841 (16)	0.49227 (14)	0.0207 (3)
H12	0.1203	0.2951	0.5158	0.025*
C13	0.09880 (6)	0.52202 (16)	0.55061 (15)	0.0207 (3)
C14	0.11468 (6)	0.67876 (16)	0.51522 (14)	0.0207 (3)
C15	0.16219 (6)	0.70723 (16)	0.42105 (15)	0.0236 (3)
H15	0.1728	0.8104	0.3973	0.028*
C16	0.19402 (6)	0.58128 (17)	0.36215 (15)	0.0233 (3)
H16	0.2258	0.6007	0.2986	0.028*
C17	0.03218 (6)	0.34858 (16)	0.67204 (16)	0.0260 (3)
H17A	0.0216	0.2969	0.5751	0.039*
H17B	−0.0024	0.3509	0.7342	0.039*
H17C	0.0645	0.2919	0.7263	0.039*
C18	0.09139 (7)	0.95081 (16)	0.53565 (17)	0.0289 (3)
H18A	0.1322	0.9784	0.5683	0.043*
H18B	0.0638	1.0192	0.5855	0.043*
H18C	0.0858	0.9623	0.425	0.043*
N1	0.24338 (5)	0.05939 (14)	0.28535 (13)	0.0241 (3)
N2	0.20193 (5)	0.14444 (14)	0.36880 (13)	0.0248 (3)
O1	0.25592 (4)	0.31369 (11)	0.24030 (10)	0.0211 (2)
O2	0.38929 (4)	−0.19607 (11)	−0.09947 (11)	0.0259 (2)
O3	0.45738 (4)	0.03030 (11)	−0.18649 (11)	0.0280 (2)
O4	0.05134 (4)	0.50644 (11)	0.64300 (10)	0.0239 (2)
O5	0.08007 (4)	0.79125 (11)	0.57747 (11)	0.0248 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0205 (6)	0.0193 (7)	0.0198 (6)	0.0012 (5)	−0.0002 (5)	−0.0013 (5)
C2	0.0194 (6)	0.0228 (7)	0.0181 (6)	0.0007 (5)	0.0000 (5)	0.0007 (5)
C3	0.0199 (6)	0.0211 (7)	0.0213 (7)	−0.0023 (5)	0.0014 (5)	0.0019 (5)
C4	0.0212 (6)	0.0192 (7)	0.0213 (7)	0.0012 (5)	0.0004 (5)	−0.0004 (5)
C5	0.0197 (6)	0.0241 (7)	0.0206 (7)	0.0020 (5)	0.0028 (5)	0.0017 (5)
C6	0.0228 (7)	0.0217 (7)	0.0252 (7)	−0.0036 (5)	0.0035 (5)	0.0041 (5)
C7	0.0255 (7)	0.0185 (7)	0.0231 (7)	0.0020 (5)	0.0027 (5)	−0.0008 (5)
C8	0.0346 (8)	0.0199 (7)	0.0377 (8)	−0.0033 (6)	0.0109 (6)	−0.0030 (6)
C9	0.0230 (7)	0.0332 (8)	0.0380 (8)	−0.0024 (6)	0.0110 (6)	0.0047 (6)
C10	0.0180 (6)	0.0274 (7)	0.0172 (6)	−0.0010 (5)	0.0018 (5)	−0.0006 (5)
C11	0.0193 (6)	0.0257 (7)	0.0190 (6)	0.0010 (5)	−0.0004 (5)	−0.0011 (5)
C12	0.0211 (6)	0.0203 (7)	0.0205 (7)	−0.0014 (5)	0.0002 (5)	−0.0005 (5)
C13	0.0189 (6)	0.0251 (7)	0.0182 (6)	−0.0005 (5)	0.0006 (5)	−0.0007 (5)
C14	0.0202 (6)	0.0221 (7)	0.0198 (6)	0.0011 (5)	−0.0002 (5)	−0.0021 (5)
C15	0.0235 (7)	0.0217 (7)	0.0255 (7)	−0.0022 (5)	0.0017 (5)	0.0011 (5)
C16	0.0199 (6)	0.0289 (8)	0.0214 (7)	−0.0019 (6)	0.0034 (5)	0.0011 (5)
C17	0.0263 (7)	0.0227 (7)	0.0300 (7)	−0.0018 (6)	0.0088 (6)	0.0010 (6)
C18	0.0350 (8)	0.0194 (7)	0.0327 (8)	0.0017 (6)	0.0071 (6)	0.0012 (6)
N1	0.0238 (6)	0.0229 (6)	0.0261 (6)	0.0015 (5)	0.0069 (5)	−0.0007 (5)
N2	0.0233 (6)	0.0244 (6)	0.0275 (6)	0.0014 (5)	0.0076 (5)	−0.0018 (5)
O1	0.0214 (5)	0.0209 (5)	0.0215 (5)	0.0016 (4)	0.0052 (4)	−0.0004 (4)
O2	0.0291 (5)	0.0186 (5)	0.0310 (5)	−0.0006 (4)	0.0116 (4)	−0.0028 (4)
O3	0.0256 (5)	0.0254 (5)	0.0344 (6)	−0.0002 (4)	0.0140 (4)	0.0010 (4)
O4	0.0249 (5)	0.0213 (5)	0.0266 (5)	−0.0006 (4)	0.0099 (4)	−0.0003 (4)
O5	0.0274 (5)	0.0193 (5)	0.0283 (5)	0.0010 (4)	0.0073 (4)	−0.0013 (4)

Geometric parameters (Å, º)

C1—N1	1.2911 (17)	C10—O1	1.3625 (15)
C1—O1	1.3625 (16)	C10—C11	1.4485 (19)
C1—C2	1.4528 (18)	C11—C16	1.382 (2)
C2—C7	1.3818 (18)	C11—C12	1.4048 (18)
C2—C3	1.3978 (19)	C12—C13	1.3740 (19)
C3—C4	1.3723 (18)	C12—H12	0.93
C3—H3	0.93	C13—O4	1.3606 (16)
C4—O2	1.3634 (16)	C13—C14	1.4108 (19)
C4—C5	1.4156 (18)	C14—O5	1.3525 (16)
C5—O3	1.3538 (16)	C14—C15	1.3861 (19)
C5—C6	1.3815 (19)	C15—C16	1.3902 (19)
C6—C7	1.3882 (19)	C15—H15	0.93
C6—H6	0.93	C16—H16	0.93
C7—H7	0.93	C17—O4	1.4289 (16)
C8—O2	1.4266 (17)	C17—H17A	0.96
C8—H8A	0.96	C17—H17B	0.96
C8—H8B	0.96	C17—H17C	0.96
C8—H8C	0.96	C18—O5	1.4243 (16)
C9—O3	1.4298 (17)	C18—H18A	0.96
C9—H9A	0.96	C18—H18B	0.96
C9—H9B	0.96	C18—H18C	0.96
C9—H9C	0.96	N1—N2	1.3978 (15)
C10—N2	1.2949 (18)
N1—C1—O1	112.63 (11)	C16—C11—C10	122.77 (12)
N1—C1—C2	127.93 (12)	C12—C11—C10	117.60 (12)
O1—C1—C2	119.44 (11)	C13—C12—C11	120.23 (12)
C7—C2—C3	119.88 (12)	C13—C12—H12	119.9
C7—C2—C1	121.65 (12)	C11—C12—H12	119.9
C3—C2—C1	118.47 (12)	O4—C13—C12	124.79 (12)
C4—C3—C2	120.39 (12)	O4—C13—C14	115.34 (11)
C4—C3—H3	119.8	C12—C13—C14	119.86 (12)
C2—C3—H3	119.8	O5—C14—C15	125.16 (12)
O2—C4—C3	125.06 (12)	O5—C14—C13	115.02 (11)
O2—C4—C5	115.15 (11)	C15—C14—C13	119.81 (12)
C3—C4—C5	119.80 (12)	C14—C15—C16	119.86 (12)
O3—C5—C6	125.30 (12)	C14—C15—H15	120.1
O3—C5—C4	115.44 (12)	C16—C15—H15	120.1
C6—C5—C4	119.26 (12)	C11—C16—C15	120.61 (12)
C5—C6—C7	120.60 (12)	C11—C16—H16	119.7
C5—C6—H6	119.7	C15—C16—H16	119.7
C7—C6—H6	119.7	O4—C17—H17A	109.5
C2—C7—C6	120.04 (12)	O4—C17—H17B	109.5
C2—C7—H7	120.0	H17A—C17—H17B	109.5
C6—C7—H7	120.0	O4—C17—H17C	109.5
O2—C8—H8A	109.5	H17A—C17—H17C	109.5
O2—C8—H8B	109.5	H17B—C17—H17C	109.5
H8A—C8—H8B	109.5	O5—C18—H18A	109.5
O2—C8—H8C	109.5	O5—C18—H18B	109.5
H8A—C8—H8C	109.5	H18A—C18—H18B	109.5
H8B—C8—H8C	109.5	O5—C18—H18C	109.5
O3—C9—H9A	109.5	H18A—C18—H18C	109.5
O3—C9—H9B	109.5	H18B—C18—H18C	109.5
H9A—C9—H9B	109.5	C1—N1—N2	106.10 (11)
O3—C9—H9C	109.5	C10—N2—N1	106.61 (10)
H9A—C9—H9C	109.5	C1—O1—C10	102.56 (10)
H9B—C9—H9C	109.5	C4—O2—C8	116.58 (10)
N2—C10—O1	112.10 (11)	C5—O3—C9	116.83 (11)
N2—C10—C11	127.93 (12)	C13—O4—C17	116.11 (10)
O1—C10—C11	119.96 (11)	C14—O5—C18	117.12 (10)
C16—C11—C12	119.63 (12)
N1—C1—C2—C7	−169.37 (13)	C12—C13—C14—O5	179.47 (11)
O1—C1—C2—C7	11.53 (19)	O4—C13—C14—C15	−179.58 (11)
N1—C1—C2—C3	10.6 (2)	C12—C13—C14—C15	0.35 (19)
O1—C1—C2—C3	−168.55 (11)	O5—C14—C15—C16	−179.14 (12)
C7—C2—C3—C4	−0.16 (19)	C13—C14—C15—C16	−0.11 (19)
C1—C2—C3—C4	179.92 (11)	C12—C11—C16—C15	0.5 (2)
C2—C3—C4—O2	−178.77 (12)	C10—C11—C16—C15	−179.81 (12)
C2—C3—C4—C5	1.49 (19)	C14—C15—C16—C11	−0.3 (2)
O2—C4—C5—O3	−1.52 (17)	O1—C1—N1—N2	0.27 (14)
C3—C4—C5—O3	178.25 (11)	C2—C1—N1—N2	−178.88 (12)
O2—C4—C5—C6	178.38 (11)	O1—C10—N2—N1	−0.03 (14)
C3—C4—C5—C6	−1.85 (19)	C11—C10—N2—N1	179.64 (12)
O3—C5—C6—C7	−179.23 (12)	C1—N1—N2—C10	−0.14 (14)
C4—C5—C6—C7	0.9 (2)	N1—C1—O1—C10	−0.28 (14)
C3—C2—C7—C6	−0.83 (19)	C2—C1—O1—C10	178.95 (11)
C1—C2—C7—C6	179.10 (12)	N2—C10—O1—C1	0.18 (14)
C5—C6—C7—C2	0.4 (2)	C11—C10—O1—C1	−179.52 (11)
N2—C10—C11—C16	177.36 (13)	C3—C4—O2—C8	−4.66 (19)
O1—C10—C11—C16	−3.00 (19)	C5—C4—O2—C8	175.09 (12)
N2—C10—C11—C12	−2.9 (2)	C6—C5—O3—C9	9.25 (19)
O1—C10—C11—C12	176.74 (11)	C4—C5—O3—C9	−170.85 (12)
C16—C11—C12—C13	−0.21 (19)	C12—C13—O4—C17	−3.73 (18)
C10—C11—C12—C13	−179.96 (11)	C14—C13—O4—C17	176.20 (11)
C11—C12—C13—O4	179.74 (11)	C15—C14—O5—C18	3.64 (19)
C11—C12—C13—C14	−0.19 (19)	C13—C14—O5—C18	−175.43 (11)
O4—C13—C14—O5	−0.46 (17)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C17—H17B···O5^i	0.96	2.48	3.4185 (18)	165
C18—H18C···O4^ii	0.96	2.52	3.4682 (18)	170

Symmetry codes: (i) −x, y−1/2, −z+3/2; (ii) x, −y+3/2, z−1/2.