1,4-Diiso­cyano-2,5-di­methyl­benzene

1,4-Diiso­cyano-2,5-di­methyl­benzene, p-C₆H₂(CH₃)₂(NC)₂, crystallizes in the monoclinic space group P2₁/c. One-half of the mol­ecule is crystallographically independent, with the other half being generated by an inversion centre located at the centre of the mol­ecule.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.048
• wR factor = 0.131
• Data-to-parameter ratio = 15.1

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT320_ALERT_2_C Check Hybridisation of  C1     in Main Residue .          ?

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

   0 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
   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 1997-2000); cell refinement: SAINT-Plus (Bruker 1997-1999); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXL97; software used to prepare material for publication: Please supply.

1,4-diisonitrile-2,5-dimethylbenzene

Crystal data

C10H8N2	F(000) = 164
Mr = 156.18	Dx = 1.216 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 3.9754 (9) Å	Cell parameters from 2218 reflections
b = 9.263 (2) Å	θ = 2.8–28.3°
c = 11.591 (3) Å	µ = 0.08 mm^−1
β = 91.690 (4)°	T = 100 K
V = 426.64 (17) Å^3	Block, colourless
Z = 2	0.3 × 0.2 × 0.2 mm

Data collection

Bruker AXS SMART APEX CCD diffractometer	827 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.044
Graphite monochromator	θmax = 28.3°, θmin = 2.8°
ω scans	h = −5→5
4084 measured reflections	k = −12→12
1069 independent reflections	l = −15→15

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)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.131	All H-atom parameters refined
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0698P)^2 + 0.6662P] where P = (Fo^2 + 2Fc^2)/3
1069 reflections	(Δ/σ)max < 0.001
71 parameters	Δρmax = 0.32 e Å^−3
0 restraints	Δρmin = −0.19 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
N1	0.1955 (3)	0.57034 (12)	0.70445 (9)	0.0253 (3)
C3	0.3709 (3)	0.39095 (14)	0.56848 (11)	0.0223 (3)
H3	0.271 (4)	0.3194 (16)	0.6174 (13)	0.019 (3)*
C2	0.3513 (3)	0.53568 (14)	0.60064 (10)	0.0218 (3)
C5	0.5458 (4)	0.19647 (15)	0.42952 (14)	0.0297 (4)
H5A	0.416 (5)	0.137 (2)	0.4807 (17)	0.046 (5)*
H5B	0.776 (5)	0.163 (2)	0.4300 (16)	0.050 (6)*
H5C	0.440 (5)	0.181 (2)	0.3488 (19)	0.051 (5)*
C4	0.5215 (3)	0.35178 (14)	0.46631 (11)	0.0223 (3)
C1	0.0666 (4)	0.60272 (16)	0.78962 (13)	0.0327 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0280 (6)	0.0240 (6)	0.0238 (6)	0.0020 (5)	0.0006 (5)	0.0007 (4)
C3	0.0238 (7)	0.0196 (6)	0.0236 (7)	−0.0017 (5)	0.0004 (5)	0.0035 (5)
C2	0.0213 (6)	0.0233 (7)	0.0208 (6)	0.0008 (5)	0.0008 (5)	0.0002 (5)
C5	0.0377 (9)	0.0191 (6)	0.0323 (8)	0.0008 (6)	0.0019 (6)	−0.0025 (6)
C4	0.0230 (6)	0.0192 (7)	0.0245 (7)	0.0005 (5)	−0.0021 (5)	0.0001 (5)
C1	0.0357 (8)	0.0329 (8)	0.0299 (8)	0.0059 (6)	0.0048 (6)	−0.0007 (6)

Geometric parameters (Å, º)

N1—C1	1.1648 (19)	C2—C4^i	1.4027 (18)
N1—C2	1.4066 (17)	C5—C4	1.5044 (19)
C3—C4	1.391 (2)	C5—H5A	0.97 (2)
C3—C2	1.3944 (19)	C5—H5B	0.96 (2)
C3—H3	0.965 (16)	C5—H5C	1.02 (2)
C1—N1—C2	178.26 (14)	C4—C5—H5B	111.9 (12)
C4—C3—C2	120.49 (12)	H5A—C5—H5B	109.5 (17)
C4—C3—H3	121.1 (9)	C4—C5—H5C	111.2 (11)
C2—C3—H3	118.4 (9)	H5A—C5—H5C	105.6 (16)
C3—C2—C4^i	122.88 (12)	H5B—C5—H5C	109.0 (16)
C3—C2—N1	118.53 (12)	C3—C4—C2^i	116.64 (12)
C4^i—C2—N1	118.59 (12)	C3—C4—C5	121.58 (12)
C4—C5—H5A	109.5 (12)	C2^i—C4—C5	121.79 (13)

Symmetry code: (i) −x+1, −y+1, −z+1.