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The title compound, C19H20N4, is found to crystallize in both the orthorhombic and the monoclinic crystal systems. In the monoclinic polymorph, the dihedral angle between the two phenyl rings is 53.5 (2)°. Centrosymmetrically related mol­ecules in the crystal are linked by N—H...N hydrogen bonds to form cyclic dimers. The structure of the monoclinic polymorph differs from that of the orthorhombic form reported earlier [Subbiah Pandi et al., (2000). Cryst. Res. Technol. 35, 1373–1381] with regard to the conformation of the bi­phenyl ring system and the molecular packing.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536802001745/ci6096sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536802001745/ci6096Isup2.hkl
Contains datablock I

CCDC reference: 182596

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.005 Å
  • R factor = 0.068
  • wR factor = 0.185
  • Data-to-parameter ratio = 16.7

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


Yellow Alert Alert Level C:
RINTA_01 Alert C The value of Rint is greater than 0.10 Rint given 0.124 PLAT_371 Alert C Long C(sp2)-C(sp1) Bond C(2) - C(7) = 1.43 Ang. PLAT_371 Alert C Long C(sp2)-C(sp1) Bond C(4) - C(8) = 1.44 Ang. PLAT_420 Alert C D-H Without Acceptor N(1) - H(1B) ?
0 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
4 Alert Level C = Please check

Comment top

Biphenyl derivatives exhibit a wide spectrum of photophysical, biological and laser activities (Shukla et al., 1985; Nieger et al., 1998). We recently reported the structure of 3-Amino-4'-(N,N-diethylamino)-5-methylbiphenyl-2,4-dicarbonitrile, (I), in the orthorhombic system (Subbiah Pandi et al., 2000). Here we report the structural details of the monoclinic polymorph of (I).

The bond lengths and bond angles observed in the present study agree well with the corresponding values reported for the orthorhombic form. However, the structures of the two polymorphs differ in the conformations of the biphenyl ring system and the diethyl substituent. The dihedral angle between the two phenyl rings is 53.5 (2)° in the monoclinic form, whereas it is 41.4 (1)° in the orthorhombic form. In the monoclinic polymorph, one of the ethyl groups is twisted 9° more about the C4'—N4 bond compared to the orthorhombic form. Even though in both polymorphs the packing of the molecules is stabilized by intermolecular N—H···N hydrogen bonds, the pattern of hydrogen bonding is different. In the monoclinic form, the molecules are linked by N1—H1A···N3i hydrogen bonds into cyclic centrosymmetric dimers denoted by the R22(12) (Bernstein et al., 1995) ring system [H1A···N3 2.22, N1···N3 3.038 (5) Å and N1—H1A···N3 159°; symmetry code (i): 3 - x, -y, -z]. In the orthorhombic form, the molecules are linked by N—H···N hydrogen bonds to form zigzag chains.

Experimental top

The title compound was synthesized according to the reaction described by Raghukumar et al., (2001). The crystals of the monoclinic form were grown at room temperature by slow evaporation of a ethyl acetate and hexane (1:1) solution of the compound. In our earlier work, the crystals of the orthorhombic form were grown from a mixture of ethyl acetate and methanol.

Refinement top

Owing to the poor quality of the crystal, the higher angle relections were very weak and only 32% of the reflections were found to be observed with I>2σ(I). This resulted in a high Rint value. The 2θ maximum was limited to 53° because of the large fraction of weak data at higher angles. All H atoms were fixed geometrically and allowed to ride on the corresponding non-H atoms.

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ZORTEP (Zsolnai, 1997); software used to prepare material for publication: SHELXL97 and WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. The structure of (I) showing 50% probability displacement ellipsoids and the atom-numbering scheme.
3-Amino-4'-(N,N-diethylamino)-5-methylbiphenyl-2,4-dicarbonitrile top
Crystal data top
C19H20N4F(000) = 648
Mr = 304.39Dx = 1.197 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 9.2925 (4) ÅCell parameters from 3225 reflections
b = 10.8655 (3) Åθ = 2.2–28.3°
c = 16.7229 (5) ŵ = 0.07 mm1
β = 90.367 (2)°T = 293 K
V = 1688.44 (10) Å3Slab, yellow
Z = 40.26 × 0.14 × 0.10 mm
Data collection top
Siemens SMART CCD area detector
diffractometer
3496 independent reflections
Radiation source: fine-focus sealed tube1313 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.124
Detector resolution: 8.33 pixels mm-1θmax = 26.5°, θmin = 2.2°
ω scansh = 1111
Absorption correction: empirical (using intensity measurements)
(SADABS; Sheldrick, 1996)
k = 1213
Tmin = 0.978, Tmax = 0.990l = 2020
10442 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.068Riding
wR(F2) = 0.185 w = 1/[σ2(Fo2) + (0.0674P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.92(Δ/σ)max < 0.001
3496 reflectionsΔρmax = 0.19 e Å3
209 parametersΔρmin = 0.18 e Å3
0 restraintsExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.010 (2)
Crystal data top
C19H20N4V = 1688.44 (10) Å3
Mr = 304.39Z = 4
Monoclinic, P21/cMo Kα radiation
a = 9.2925 (4) ŵ = 0.07 mm1
b = 10.8655 (3) ÅT = 293 K
c = 16.7229 (5) Å0.26 × 0.14 × 0.10 mm
β = 90.367 (2)°
Data collection top
Siemens SMART CCD area detector
diffractometer
3496 independent reflections
Absorption correction: empirical (using intensity measurements)
(SADABS; Sheldrick, 1996)
1313 reflections with I > 2σ(I)
Tmin = 0.978, Tmax = 0.990Rint = 0.124
10442 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0680 restraints
wR(F2) = 0.185Riding
S = 0.92Δρmax = 0.19 e Å3
3496 reflectionsΔρmin = 0.18 e Å3
209 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
N11.2550 (3)0.1435 (2)0.04938 (17)0.0627 (10)
H1A1.33550.10440.04920.075*
H1B1.23230.18950.08940.075*
N20.9802 (4)0.3249 (3)0.1129 (2)0.0769 (11)
N31.4420 (4)0.0533 (3)0.0832 (2)0.0753 (11)
N40.4297 (3)0.4792 (3)0.10641 (17)0.0527 (8)
C1'0.8075 (3)0.2666 (3)0.08398 (19)0.0429 (9)
C2'0.8091 (4)0.3932 (3)0.07514 (19)0.0491 (9)
H2'0.89530.43200.06290.059*
C3'0.6867 (4)0.4634 (3)0.08397 (19)0.0493 (10)
H3'0.69270.54850.07880.059*
C4'0.5531 (3)0.4092 (3)0.10059 (19)0.0432 (9)
C5'0.5515 (3)0.2820 (3)0.1093 (2)0.0485 (9)
H5'0.46520.24230.12030.058*
C6'0.6752 (3)0.2137 (3)0.10183 (19)0.0487 (9)
H6'0.67020.12890.10900.058*
C10.9396 (3)0.1910 (3)0.0799 (2)0.0422 (9)
C21.0330 (3)0.1983 (3)0.0147 (2)0.0417 (9)
C31.1640 (4)0.1325 (3)0.0133 (2)0.0441 (9)
C41.1961 (3)0.0586 (3)0.0799 (2)0.0460 (9)
C51.1036 (4)0.0476 (3)0.1446 (2)0.0482 (9)
C60.9761 (4)0.1141 (3)0.1434 (2)0.0527 (10)
H60.91320.10700.18620.063*
C70.9996 (3)0.2700 (3)0.0548 (2)0.0519 (10)
C81.3319 (4)0.0049 (3)0.0824 (2)0.0535 (10)
C91.1408 (4)0.0327 (3)0.2149 (2)0.0688 (12)
H9A1.06460.02910.25340.103*
H9B1.22870.00420.23910.103*
H9C1.15290.11610.19720.103*
C100.2906 (4)0.4206 (3)0.1182 (3)0.0723 (12)
H10A0.28780.34550.08690.087*
H10B0.21640.47480.09730.087*
C110.2543 (5)0.3893 (5)0.2031 (3)0.1119 (18)
H11A0.32520.33350.22420.168*
H11B0.16120.35120.20480.168*
H11C0.25350.46310.23470.168*
C120.4342 (4)0.6127 (3)0.1089 (2)0.0602 (11)
H12A0.33960.64430.09520.072*
H12B0.50080.64160.06870.072*
C130.4785 (6)0.6639 (4)0.1883 (2)0.1050 (18)
H13A0.41180.63760.22840.157*
H13B0.47910.75220.18570.157*
H13C0.57320.63490.20180.157*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0456 (19)0.072 (2)0.070 (2)0.0191 (16)0.0188 (17)0.0173 (16)
N20.075 (3)0.082 (3)0.074 (3)0.022 (2)0.003 (2)0.018 (2)
N30.051 (2)0.077 (3)0.099 (3)0.0224 (19)0.013 (2)0.0235 (19)
N40.0386 (18)0.0498 (19)0.070 (2)0.0088 (16)0.0001 (15)0.0035 (15)
C1'0.035 (2)0.047 (2)0.047 (2)0.0033 (18)0.0029 (16)0.0006 (17)
C2'0.040 (2)0.056 (2)0.052 (2)0.0020 (19)0.0009 (18)0.0031 (18)
C3'0.046 (2)0.045 (2)0.057 (2)0.0056 (19)0.0013 (19)0.0023 (17)
C4'0.036 (2)0.052 (2)0.042 (2)0.0089 (18)0.0029 (16)0.0037 (17)
C5'0.032 (2)0.052 (2)0.061 (2)0.0042 (18)0.0053 (17)0.0035 (18)
C6'0.044 (2)0.042 (2)0.060 (2)0.0067 (19)0.0037 (19)0.0017 (17)
C10.0278 (18)0.048 (2)0.051 (2)0.0044 (17)0.0021 (17)0.0053 (17)
C20.0330 (19)0.041 (2)0.051 (2)0.0076 (16)0.0019 (17)0.0019 (17)
C30.040 (2)0.042 (2)0.051 (2)0.0004 (17)0.0045 (18)0.0036 (18)
C40.0307 (19)0.045 (2)0.063 (2)0.0093 (17)0.0026 (18)0.0036 (18)
C50.036 (2)0.053 (2)0.056 (2)0.0053 (18)0.0013 (18)0.0008 (19)
C60.038 (2)0.064 (2)0.055 (2)0.0067 (19)0.0065 (18)0.008 (2)
C70.033 (2)0.057 (2)0.066 (3)0.0119 (19)0.011 (2)0.001 (2)
C80.048 (2)0.049 (2)0.063 (3)0.002 (2)0.008 (2)0.0069 (18)
C90.053 (3)0.088 (3)0.065 (3)0.015 (2)0.001 (2)0.022 (2)
C100.043 (2)0.068 (3)0.105 (4)0.016 (2)0.000 (2)0.001 (2)
C110.084 (4)0.117 (4)0.135 (5)0.006 (3)0.053 (3)0.007 (3)
C120.058 (3)0.054 (2)0.068 (3)0.015 (2)0.012 (2)0.005 (2)
C130.167 (5)0.071 (3)0.076 (4)0.004 (3)0.015 (3)0.022 (3)
Geometric parameters (Å, º) top
N1—C31.356 (4)C2—C71.432 (5)
N1—H1A0.86C3—C41.404 (4)
N1—H1B0.86C4—C51.390 (4)
N2—C71.153 (4)C4—C81.439 (5)
N3—C81.150 (4)C5—C61.388 (4)
N4—C4'1.380 (4)C5—C91.503 (5)
N4—C121.451 (4)C6—H60.93
N4—C101.456 (4)C9—H9A0.96
C1'—C2'1.383 (4)C9—H9B0.96
C1'—C6'1.392 (4)C9—H9C0.96
C1'—C11.479 (4)C10—C111.500 (5)
C2'—C3'1.379 (4)C10—H10A0.97
C2'—H2'0.93C10—H10B0.97
C3'—C4'1.403 (4)C11—H11A0.96
C3'—H3'0.93C11—H11B0.96
C4'—C5'1.390 (4)C11—H11C0.96
C5'—C6'1.374 (4)C12—C131.496 (5)
C5'—H5'0.93C12—H12A0.97
C6'—H6'0.93C12—H12B0.97
C1—C61.391 (4)C13—H13A0.96
C1—C21.400 (4)C13—H13B0.96
C2—C31.411 (4)C13—H13C0.96
C3—N1—H1A120.0C6—C5—C9120.4 (3)
C3—N1—H1B120.0C4—C5—C9121.2 (3)
H1A—N1—H1B120.0C5—C6—C1121.8 (3)
C4'—N4—C12122.0 (3)C5—C6—H6119.1
C4'—N4—C10120.5 (3)C1—C6—H6119.1
C12—N4—C10117.3 (3)N2—C7—C2175.8 (4)
C2'—C1'—C6'116.3 (3)N3—C8—C4178.3 (4)
C2'—C1'—C1122.5 (3)C5—C9—H9A109.5
C6'—C1'—C1121.0 (3)C5—C9—H9B109.5
C3'—C2'—C1'122.0 (3)H9A—C9—H9B109.5
C3'—C2'—H2'119.0C5—C9—H9C109.5
C1'—C2'—H2'119.0H9A—C9—H9C109.5
C2'—C3'—C4'121.4 (3)H9B—C9—H9C109.5
C2'—C3'—H3'119.3N4—C10—C11115.6 (4)
C4'—C3'—H3'119.3N4—C10—H10A108.4
N4—C4'—C5'122.1 (3)C11—C10—H10A108.4
N4—C4'—C3'121.3 (3)N4—C10—H10B108.4
C5'—C4'—C3'116.6 (3)C11—C10—H10B108.4
C6'—C5'—C4'121.2 (3)H10A—C10—H10B107.4
C6'—C5'—H5'119.4C10—C11—H11A109.5
C4'—C5'—H5'119.4C10—C11—H11B109.5
C5'—C6'—C1'122.5 (3)H11A—C11—H11B109.5
C5'—C6'—H6'118.7C10—C11—H11C109.5
C1'—C6'—H6'118.7H11A—C11—H11C109.5
C6—C1—C2118.6 (3)H11B—C11—H11C109.5
C6—C1—C1'119.8 (3)N4—C12—C13113.9 (3)
C2—C1—C1'121.5 (3)N4—C12—H12A108.8
C1—C2—C3121.5 (3)C13—C12—H12A108.8
C1—C2—C7122.1 (3)N4—C12—H12B108.8
C3—C2—C7116.4 (3)C13—C12—H12B108.8
N1—C3—C4122.2 (3)H12A—C12—H12B107.7
N1—C3—C2120.7 (3)C12—C13—H13A109.5
C4—C3—C2117.1 (3)C12—C13—H13B109.5
C5—C4—C3122.5 (3)H13A—C13—H13B109.5
C5—C4—C8118.9 (3)C12—C13—H13C109.5
C3—C4—C8118.6 (3)H13A—C13—H13C109.5
C6—C5—C4118.4 (3)H13B—C13—H13C109.5
C6'—C1'—C2'—C3'0.4 (5)C1'—C1—C2—C76.0 (5)
C1—C1'—C2'—C3'175.9 (3)C1—C2—C3—N1178.1 (3)
C1'—C2'—C3'—C4'1.5 (5)C7—C2—C3—N13.4 (5)
C12—N4—C4'—C5'170.9 (3)C1—C2—C3—C40.6 (5)
C10—N4—C4'—C5'3.0 (5)C7—C2—C3—C4178.0 (3)
C12—N4—C4'—C3'10.3 (5)N1—C3—C4—C5179.6 (3)
C10—N4—C4'—C3'175.8 (3)C2—C3—C4—C51.0 (5)
C2'—C3'—C4'—N4177.5 (3)N1—C3—C4—C81.6 (5)
C2'—C3'—C4'—C5'1.3 (5)C2—C3—C4—C8177.0 (3)
N4—C4'—C5'—C6'178.8 (3)C3—C4—C5—C61.1 (5)
C3'—C4'—C5'—C6'0.0 (5)C8—C4—C5—C6176.8 (3)
C4'—C5'—C6'—C1'1.2 (5)C3—C4—C5—C9179.8 (3)
C2'—C1'—C6'—C5'0.9 (5)C8—C4—C5—C92.3 (5)
C1—C1'—C6'—C5'177.3 (3)C4—C5—C6—C10.3 (5)
C2'—C1'—C1—C6124.0 (4)C9—C5—C6—C1178.8 (3)
C6'—C1'—C1—C652.1 (5)C2—C1—C6—C51.8 (5)
C2'—C1'—C1—C253.5 (5)C1'—C1—C6—C5175.7 (3)
C6'—C1'—C1—C2130.4 (3)C4'—N4—C10—C1183.6 (4)
C6—C1—C2—C31.9 (5)C12—N4—C10—C1190.5 (4)
C1'—C1—C2—C3175.6 (3)C4'—N4—C12—C1377.3 (4)
C6—C1—C2—C7176.5 (3)C10—N4—C12—C1396.8 (4)

Experimental details

Crystal data
Chemical formulaC19H20N4
Mr304.39
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)9.2925 (4), 10.8655 (3), 16.7229 (5)
β (°) 90.367 (2)
V3)1688.44 (10)
Z4
Radiation typeMo Kα
µ (mm1)0.07
Crystal size (mm)0.26 × 0.14 × 0.10
Data collection
DiffractometerSiemens SMART CCD area detector
diffractometer
Absorption correctionEmpirical (using intensity measurements)
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.978, 0.990
No. of measured, independent and
observed [I > 2σ(I)] reflections
10442, 3496, 1313
Rint0.124
(sin θ/λ)max1)0.628
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.068, 0.185, 0.92
No. of reflections3496
No. of parameters209
H-atom treatmentRiding
Δρmax, Δρmin (e Å3)0.19, 0.18

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ZORTEP (Zsolnai, 1997), SHELXL97 and WinGX (Farrugia, 1999).

Selected torsion angles (º) top
C12—N4—C4'—C5'170.9 (3)C6'—C1'—C1—C652.1 (5)
C10—N4—C4'—C5'3.0 (5)C2'—C1'—C1—C253.5 (5)
C12—N4—C4'—C3'10.3 (5)C4'—N4—C10—C1183.6 (4)
C10—N4—C4'—C3'175.8 (3)C4'—N4—C12—C1377.3 (4)
 

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