A rare syn-anti catemer in 4-nitro­phenyl­propiolic acid

The crystal structure of 4-nitro­phenyl­propiolic acid, C₉H₅NO₄, is described. The carboxyl­ic acid functional group adopts the rare syn-anti conformation and the mol­ecules are arranged in a catemeric chain.

Key indicators

• Single-crystal X-ray study
• T = 223 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.058
• wR factor = 0.163
• Data-to-parameter ratio = 15.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         N1
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.27
PLAT371_ALERT_2_C Long   C(sp2)-C(sp1) Bond  C1     -   C2     ...       1.44 Ang.
PLAT371_ALERT_2_C Long   C(sp2)-C(sp1) Bond  C3     -   C4     ...       1.43 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H9     ..  O2      ..       2.70 Ang.

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

   1 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
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2000) and X-SEED (Barbour, 2001); software used to prepare material for publication: SHELXTL.

4-nitrophenylpropynoic acid

Crystal data

C9H5NO4	F(000) = 392
Mr = 191.14	Dx = 1.514 Mg m^−3
Monoclinic, P21/n	Melting point: 474(2) K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 3.726 (2) Å	Cell parameters from 2334 reflections
b = 7.511 (5) Å	θ = 3.0–26.9°
c = 29.983 (18) Å	µ = 0.12 mm^−1
β = 91.937 (12)°	T = 223 K
V = 838.6 (9) Å^3	Rod, yellow
Z = 4	0.32 × 0.21 × 0.12 mm

Data collection

Siemens SMART CCD area-detector diffractometer	2065 independent reflections
Radiation source: fine-focus sealed tube	1200 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.055
φ and ω scans	θmax = 28.4°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Blessing, 1995)	h = −4→4
Tmin = 0.962, Tmax = 0.986	k = −10→9
5168 measured reflections	l = −21→40

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: difference Fourier map
wR(F^2) = 0.163	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0814P)^2] where P = (Fo^2 + 2Fc^2)/3
2065 reflections	(Δ/σ)max < 0.001
134 parameters	Δρmax = 0.29 e Å^−3
0 restraints	Δρmin = −0.31 e Å^−3

Special details

Experimental. Crystals were grown by slow evaporation from a mixture of acetonitrile and carbon tetrachloride

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	Occ. (<1)
O1	−0.5047 (5)	−0.1751 (2)	−0.00247 (5)	0.0446 (5)
O2	−0.3341 (5)	−0.4175 (2)	0.03411 (6)	0.0546 (6)
H2	−0.44 (2)	−0.448 (8)	0.007 (2)	0.082*	0.50
O3	0.6415 (6)	0.4808 (3)	0.23541 (6)	0.0739 (7)
O4	0.5499 (8)	0.6644 (3)	0.18114 (9)	0.0998 (9)
N1	0.5272 (6)	0.5168 (3)	0.19849 (8)	0.0517 (6)
C1	−0.3514 (6)	−0.2494 (3)	0.03076 (7)	0.0369 (5)
C2	−0.1875 (6)	−0.1423 (3)	0.06561 (7)	0.0371 (6)
C3	−0.0659 (6)	−0.0336 (3)	0.09100 (7)	0.0354 (5)
C4	0.0778 (6)	0.1043 (3)	0.11950 (7)	0.0309 (5)
C5	0.2032 (6)	0.0697 (3)	0.16287 (7)	0.0383 (6)
H5	0.1903	−0.0464	0.1744	0.046*
C6	0.3459 (6)	0.2046 (3)	0.18887 (7)	0.0385 (6)
H6	0.4319	0.1825	0.2182	0.046*
C7	0.3599 (6)	0.3739 (3)	0.17082 (7)	0.0343 (5)
C8	0.2321 (6)	0.4123 (3)	0.12852 (8)	0.0406 (6)
H8	0.2415	0.5292	0.1175	0.049*
C9	0.0900 (6)	0.2776 (3)	0.10251 (7)	0.0372 (6)
H9	0.0013	0.3016	0.0734	0.045*
H1	−0.475 (16)	−0.077 (7)	−0.0023 (19)	0.055 (19)*	0.50

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0652 (12)	0.0218 (9)	0.0459 (9)	−0.0034 (8)	−0.0117 (8)	−0.0048 (7)
O2	0.0782 (14)	0.0204 (9)	0.0634 (12)	−0.0010 (8)	−0.0221 (10)	−0.0036 (7)
O3	0.0859 (17)	0.0737 (14)	0.0604 (12)	−0.0076 (12)	−0.0239 (11)	−0.0282 (11)
O4	0.138 (2)	0.0320 (12)	0.1263 (19)	−0.0161 (13)	−0.0419 (17)	−0.0135 (12)
N1	0.0470 (14)	0.0419 (13)	0.0657 (14)	0.0017 (10)	−0.0056 (11)	−0.0232 (11)
C1	0.0387 (14)	0.0249 (11)	0.0471 (13)	−0.0050 (10)	0.0005 (11)	−0.0077 (9)
C2	0.0401 (14)	0.0242 (11)	0.0464 (13)	0.0014 (9)	−0.0045 (10)	−0.0037 (9)
C3	0.0303 (12)	0.0308 (11)	0.0452 (12)	0.0033 (10)	0.0005 (10)	−0.0047 (10)
C4	0.0272 (12)	0.0277 (10)	0.0377 (11)	0.0024 (9)	−0.0001 (9)	−0.0067 (9)
C5	0.0418 (14)	0.0277 (11)	0.0453 (13)	0.0022 (9)	−0.0001 (11)	0.0009 (9)
C6	0.0391 (13)	0.0383 (13)	0.0376 (11)	0.0056 (10)	−0.0070 (10)	−0.0021 (9)
C7	0.0285 (12)	0.0282 (11)	0.0459 (12)	0.0025 (9)	−0.0016 (10)	−0.0122 (9)
C8	0.0468 (15)	0.0244 (11)	0.0504 (13)	0.0017 (10)	−0.0002 (11)	−0.0012 (9)
C9	0.0416 (14)	0.0330 (12)	0.0365 (11)	0.0031 (10)	−0.0046 (10)	−0.0002 (9)

Geometric parameters (Å, º)

O1—C1	1.262 (3)	C4—C5	1.391 (3)
O1—H1	0.75 (5)	C4—C9	1.399 (3)
O2—C1	1.268 (3)	C5—C6	1.375 (3)
O2—H2	0.92 (6)	C5—H5	0.9400
O3—N1	1.203 (3)	C6—C7	1.383 (3)
O4—N1	1.229 (3)	C6—H6	0.9400
N1—C7	1.481 (3)	C7—C8	1.370 (3)
C1—C2	1.438 (3)	C8—C9	1.373 (3)
C2—C3	1.195 (3)	C8—H8	0.9400
C3—C4	1.435 (3)	C9—H9	0.9400
C1—O1—H1	112 (5)	C6—C5—H5	119.9
C1—O2—H2	99 (4)	C4—C5—H5	119.9
O3—N1—O4	124.4 (2)	C5—C6—C7	118.3 (2)
O3—N1—C7	118.8 (2)	C5—C6—H6	120.8
O4—N1—C7	116.8 (2)	C7—C6—H6	120.8
O1—C1—O2	121.5 (2)	C8—C7—C6	122.6 (2)
O1—C1—C2	119.8 (2)	C8—C7—N1	119.5 (2)
O2—C1—C2	118.7 (2)	C6—C7—N1	117.9 (2)
C3—C2—C1	170.9 (2)	C7—C8—C9	119.1 (2)
C2—C3—C4	176.7 (2)	C7—C8—H8	120.5
C5—C4—C9	120.0 (2)	C9—C8—H8	120.5
C5—C4—C3	121.9 (2)	C8—C9—C4	119.7 (2)
C9—C4—C3	118.1 (2)	C8—C9—H9	120.2
C6—C5—C4	120.2 (2)	C4—C9—H9	120.1

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O1^i	0.75 (5)	1.90 (5)	2.635 (3)	168 (6)
O2—H2···O2^ii	0.92 (6)	1.78 (6)	2.660 (3)	158 (6)
C5—H5···O4^iii	0.94	2.56	3.345 (4)	142
C6—H6···O3^iv	0.94	2.57	3.367 (4)	143
C9—H9···O2^v	0.94	2.70	3.425 (3)	134

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