1-(4-Chloro­phen­yl)-2-(imidazolidin-2-yl­idene)ethanone

At 294 K, the C=C(H)—C=O grouping and the imidazoline ring of the title compound, C₁₁H₁₁ClN₂O, are coplanar as a result of an intra­molecular N—H...O hydrogen bond and the conjugation, while the 4-chloro­phenyl ring is twisted from the plane by 23.5 (2)°. Inter­molecular N—H...O hydrogen bonding helps to establish the crystal packing.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.036
• wR factor = 0.095
• Data-to-parameter ratio = 13.7

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT111_ALERT_2_B ADDSYM Detects (Pseudo) Centre of Symmetry .....         80 PerFit

Alert level C
STRVA01_ALERT_4_C           Flack test results are ambiguous.
           From the CIF: _refine_ls_abs_structure_Flack    0.350
           From the CIF: _refine_ls_abs_structure_Flack_su    0.090
PLAT033_ALERT_2_C Flack Parameter Value Deviates from Zero .......       0.35
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT241_ALERT_2_C Check High      Ueq as Compared to Neighbors for         N2
PLAT352_ALERT_3_C Short   N-H Bond (0.87A)   N1     -   H1     ...       0.74 Ang.

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           26.54
           From the CIF: _reflns_number_total               1996
           Count of symmetry unique reflns         1192
           Completeness (_total/calc)            167.45%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       804
           Fraction of Friedel pairs measured     0.674
           Are heavy atom types Z>Si present        yes

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

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

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Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); 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, 2002); software used to prepare material for publication: SHELXTL.

1-(4-Chlorophenyl)-2-(imidazolidin-2-ylidene)ethanone

Crystal data

C11H11ClN2O	Dx = 1.397 Mg m^−3
Mr = 222.67	Melting point: 511 K
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
a = 6.5657 (17) Å	Cell parameters from 1409 reflections
b = 6.976 (2) Å	θ = 3.1–26.2°
c = 11.602 (3) Å	µ = 0.33 mm^−1
β = 94.981 (4)°	T = 294 K
V = 529.4 (2) Å^3	Prism, colorless
Z = 2	0.24 × 0.18 × 0.16 mm
F(000) = 232

Data collection

Bruker SMART CCD diffractometer	1996 independent reflections
Radiation source: fine-focus sealed tube	1676 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
ω scans	θmax = 26.5°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2002)	h = −8→8
Tmin = 0.924, Tmax = 0.949	k = −7→8
3013 measured reflections	l = −14→8

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.036	w = 1/[σ^2(Fo^2) + (0.0486P)^2 + 0.064P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.095	(Δ/σ)max = 0.001
S = 1.05	Δρmax = 0.18 e Å^−3
1996 reflections	Δρmin = −0.20 e Å^−3
146 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.040 (6)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 804 Friedel pairs
Secondary atom site location: difference Fourier map	Absolute structure parameter: 0.35 (9)

Special details

Experimental. IR (KBr, ν cm^-1): 3340, 3160, 1605, 1540; ¹H NMR (CDCl₃): δ 9.20 (br, 1H), 7.45 (m, 5H), 7.40 (br, 1H), 5.22 (s, 1H), 3.75 (s, 4H); ¹³C NMR (CDCl₃): δ 180.1, 165.0, 139.9, 133.4,127.4, 127.2, 72.8, 42.3.

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
Cl1	0.88618 (11)	0.72632 (13)	−0.23600 (5)	0.0698 (3)
N1	0.4995 (3)	0.7641 (4)	0.48199 (15)	0.0451 (5)
N2	0.1841 (3)	0.7930 (5)	0.41534 (18)	0.0632 (9)
O1	0.7841 (2)	0.7512 (4)	0.32938 (12)	0.0565 (5)
C1	0.3939 (4)	0.7716 (4)	0.58667 (18)	0.0459 (6)
H1A	0.4286	0.8868	0.6308	0.055*
H1B	0.4248	0.6602	0.6351	0.055*
C2	0.1707 (3)	0.7729 (5)	0.53831 (18)	0.0505 (7)
H2A	0.1030	0.6542	0.5560	0.061*
H2B	0.0975	0.8796	0.5689	0.061*
C3	0.3755 (3)	0.7778 (4)	0.38634 (17)	0.0359 (5)
C4	0.4355 (3)	0.7787 (4)	0.27344 (16)	0.0370 (6)
H4	0.3358	0.7884	0.2117	0.044*
C5	0.6390 (3)	0.7654 (4)	0.25089 (16)	0.0350 (5)
C6	0.6934 (3)	0.7590 (4)	0.12747 (17)	0.0333 (5)
C7	0.5692 (4)	0.8305 (4)	0.0349 (2)	0.0400 (6)
H7	0.4447	0.8862	0.0482	0.048*
C8	0.6264 (4)	0.8209 (4)	−0.0773 (2)	0.0463 (6)
H8	0.5415	0.8698	−0.1387	0.056*
C9	0.8112 (3)	0.7377 (5)	−0.09638 (17)	0.0438 (6)
C10	0.9370 (4)	0.6655 (4)	−0.0065 (2)	0.0483 (7)
H10	1.0611	0.6095	−0.0204	0.058*
C11	0.8788 (4)	0.6762 (4)	0.1048 (2)	0.0430 (6)
H11	0.9649	0.6274	0.1657	0.052*
H1	0.611 (4)	0.760 (6)	0.476 (2)	0.060 (9)*
H2	0.089 (4)	0.791 (4)	0.371 (2)	0.053 (9)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0832 (5)	0.0871 (6)	0.0437 (3)	−0.0124 (5)	0.0323 (3)	−0.0115 (4)
N1	0.0342 (10)	0.0697 (16)	0.0312 (9)	0.0019 (13)	0.0021 (8)	−0.0005 (10)
N2	0.0276 (10)	0.132 (3)	0.0309 (10)	0.0048 (14)	0.0070 (8)	0.0062 (13)
O1	0.0263 (7)	0.1049 (17)	0.0381 (8)	0.0026 (12)	0.0017 (6)	0.0061 (11)
C1	0.0586 (14)	0.0491 (17)	0.0304 (10)	0.0020 (14)	0.0073 (9)	0.0037 (11)
C2	0.0457 (13)	0.072 (2)	0.0363 (11)	−0.0018 (15)	0.0145 (10)	−0.0013 (13)
C3	0.0303 (10)	0.0442 (16)	0.0334 (10)	−0.0003 (11)	0.0029 (8)	−0.0001 (10)
C4	0.0271 (10)	0.0566 (17)	0.0270 (10)	−0.0012 (12)	0.0016 (7)	−0.0001 (10)
C5	0.0343 (11)	0.0369 (14)	0.0343 (10)	−0.0005 (12)	0.0060 (8)	0.0003 (10)
C6	0.0312 (10)	0.0350 (13)	0.0346 (10)	−0.0009 (11)	0.0088 (7)	0.0011 (10)
C7	0.0376 (12)	0.0429 (15)	0.0406 (12)	0.0062 (10)	0.0099 (10)	0.0014 (10)
C8	0.0538 (14)	0.0493 (17)	0.0366 (12)	0.0002 (12)	0.0087 (11)	0.0055 (10)
C9	0.0558 (14)	0.0430 (15)	0.0355 (11)	−0.0065 (16)	0.0207 (10)	−0.0044 (13)
C10	0.0408 (13)	0.0530 (18)	0.0542 (15)	0.0044 (12)	0.0215 (11)	−0.0022 (12)
C11	0.0378 (12)	0.0471 (17)	0.0453 (13)	0.0066 (11)	0.0106 (10)	0.0056 (11)

Geometric parameters (Å, º)

C3—C4	1.400 (3)	C2—H2B	0.9700
C4—C5	1.387 (3)	C4—H4	0.9300
C3—N1	1.322 (3)	C5—C6	1.506 (3)
C3—N2	1.333 (3)	C6—C7	1.384 (3)
C5—O1	1.263 (2)	C6—C11	1.393 (3)
Cl1—C9	1.7354 (19)	C7—C8	1.387 (3)
N1—C1	1.451 (3)	C7—H7	0.9300
N1—H1	0.74 (3)	C8—C9	1.380 (4)
N2—C2	1.444 (3)	C8—H8	0.9300
N2—H2	0.78 (3)	C9—C10	1.368 (4)
C1—C2	1.523 (3)	C10—C11	1.380 (3)
C1—H1A	0.9700	C10—H10	0.9300
C1—H1B	0.9700	C11—H11	0.9300
C2—H2A	0.9700
C3—N1—C1	113.33 (19)	C3—C4—H4	119.0
C3—N1—H1	117 (2)	O1—C5—C4	123.23 (17)
C1—N1—H1	129 (2)	O1—C5—C6	117.16 (16)
C3—N2—C2	112.43 (19)	C4—C5—C6	119.56 (16)
C3—N2—H2	123.6 (19)	C7—C6—C11	117.9 (2)
C2—N2—H2	122.7 (19)	C7—C6—C5	123.69 (18)
N1—C1—C2	101.90 (16)	C11—C6—C5	118.36 (18)
N1—C1—H1A	111.4	C6—C7—C8	121.5 (2)
C2—C1—H1A	111.4	C6—C7—H7	119.3
N1—C1—H1B	111.4	C8—C7—H7	119.3
C2—C1—H1B	111.4	C9—C8—C7	118.9 (2)
H1A—C1—H1B	109.3	C9—C8—H8	120.5
N2—C2—C1	103.01 (17)	C7—C8—H8	120.5
N2—C2—H2A	111.2	C10—C9—C8	120.90 (19)
C1—C2—H2A	111.2	C10—C9—Cl1	119.53 (18)
N2—C2—H2B	111.2	C8—C9—Cl1	119.56 (19)
C1—C2—H2B	111.2	C9—C10—C11	119.7 (2)
H2A—C2—H2B	109.1	C9—C10—H10	120.2
N1—C3—N2	108.61 (19)	C11—C10—H10	120.2
N1—C3—C4	125.66 (19)	C10—C11—C6	121.1 (2)
N2—C3—C4	125.72 (18)	C10—C11—H11	119.5
C5—C4—C3	122.02 (17)	C6—C11—H11	119.5
C5—C4—H4	119.0
C3—N1—C1—C2	5.5 (3)	O1—C5—C6—C11	21.1 (3)
C3—N2—C2—C1	8.3 (4)	C4—C5—C6—C11	−156.3 (3)
N1—C1—C2—N2	−7.7 (3)	C11—C6—C7—C8	−0.1 (4)
C1—N1—C3—N2	−0.6 (3)	C5—C6—C7—C8	−179.9 (2)
C1—N1—C3—C4	178.6 (2)	C6—C7—C8—C9	0.1 (4)
C2—N2—C3—N1	−5.1 (4)	C7—C8—C9—C10	−0.1 (4)
C2—N2—C3—C4	175.6 (3)	C7—C8—C9—Cl1	−179.4 (2)
N1—C3—C4—C5	−0.3 (4)	C8—C9—C10—C11	−0.1 (4)
N2—C3—C4—C5	178.9 (3)	Cl1—C9—C10—C11	179.3 (2)
C3—C4—C5—O1	0.2 (4)	C9—C10—C11—C6	0.2 (4)
C3—C4—C5—C6	177.5 (2)	C7—C6—C11—C10	−0.1 (4)
O1—C5—C6—C7	−159.0 (3)	C5—C6—C11—C10	179.8 (2)
C4—C5—C6—C7	23.5 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1	0.74 (3)	2.12 (3)	2.685 (3)	133 (3)
N2—H2···O1^i	0.78 (3)	2.04 (3)	2.743 (3)	152 (3)

Symmetry code: (i) x−1, y, z.