5-[2-Methyl-1-(4-methyl­phen­yl)-2-nitro­prop­yl]-4-phenyl-1,2,3-selenadiazole

In the title compound, C₁₉H₁₉N₃O₂Se, the heterocyclic ring makes dihedral angles of 40.74 (12) and 70.38 (15)° with the phenyl and methyl­phenyl rings, respectively. The mol­ecular structure is stabilized by weak intra­molecular C—H...Se inter­actions, and the crystal packing is stabilized by weak C—H...π inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 290 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.051
• wR factor = 0.119
• Data-to-parameter ratio = 19.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.95
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.12
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         N1
PLAT322_ALERT_2_C Check Hybridisation of  Se1    in Main Residue .          ?

Alert level G
PLAT793_ALERT_1_G Check the Absolute Configuration of C4     = ...          R

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 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
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Selenium containing compounds like 1,2,3-selenadiazole possess various beneficial activities like antifungal (Kuroda et al., 2001), antibacterial (El-Kashef et al., 1986), antimicrobial (El-Bahaie et al., 1990) and insecticidal (Padmavathi et al., 2002) activities. As naturally occurring nitro compounds exhibit broad antibiotic activity and certain alkyl nitro compounds exhibit antitumor activity, it was decided to synthesize and structurally characterize a set of 1,2,3- selenadiazoles with a nitro group in the side chain (Saravanan et al., 2006).

The geometric parameters in the compound agree with the values of similar structures (Mellini & Merlino, 1976a; Mellini & Merlino, 1976b; Bertini et al., 1984; Gunasekaran et al., 2007). The phenyl ring makes a dihedral angle of 40.74 (12) ° with the heterocyclic ring. The methylphenyl ring makes a dihedral angle of 70.38 (15)° with the heterocyclic ring (Fig 1.). The heterocyclic ring is planar. The molecular structure is stabilized by weak intramolecular C—H···Se interactions and the crystal packing is stabilized by weak C—H···π interactions (Table 1; Cg is the centre of gravity of the heterocyclic ring).

Related literature

For related literature see: Mellini & Merlino (1976a, 1976b); Bertini et al. (1984); El-Kashef et al. (1986); El-Bahaie et al. (1990); Kuroda et al. (2001); Padmavathi et al. (2002); Saravanan et al. (2006). A similar compound with a chlorophenyl ring has been reported recently (Gunasekaran et al., 2007).

S2. Experimental

A solution of 0.005 mol of 2-[(E)-4-methyl-3-(4-methylphenyl)-4-nitro-1- phenylpentylidene]-1-hydrazine carboxamide and 0.05 mol of powdered selenium dioxide in dry THF was gently heated on a water bath for two hours. The selenium deposited on cooling was removed by filtration, and the filtrate was poured onto crushed ice, extracted with chloroform, and purified by column chromatography using silica gel (60–120 mesh) with 97:3 petroleum ether: ethyl acetate as eluent to give the title compound, which were recrystallized from ethyl alcohol.

S3. Refinement

H atoms were positioned geometrically and refined using riding model with C—H = 0.93Å and U_iso(H) = 1.2Ueq(C) for aromatic C—H, C—H = 0.96Å and U_iso(H) = 1.5Ueq(C) for methyl groups, C—H = 0.98° A and U_iso(H) = 1.2Ueq(C) for tertiary CH.

Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: PLATON (Spek, 2003).

Figures

Fig. 1. The molecular structure of the title compound with atom labels and 50% probability displacement ellipsoids for non-H atoms.

5-[2-Methyl-1-(4-methylphenyl)-2-nitropropyl]-4-phenyl-1,2,3-selenadiazole

Crystal data

C19H19N3O2Se	F(000) = 816
Mr = 400.34	Dx = 1.442 Mg m^−3
Monoclinic, P21/c	Melting point: 96 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 10.184 (3) Å	θ = 2.5–26.5°
b = 10.592 (3) Å	µ = 2.06 mm^−1
c = 17.408 (4) Å	T = 290 K
β = 101.637 (4)°	Rectangular, colourless
V = 1839.1 (9) Å^3	0.38 × 0.32 × 0.26 mm
Z = 4

Data collection

Bruker APEXII CCD diffractometer	4343 independent reflections
Radiation source: fine focus sealed tube	2586 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.047
ω scans	θmax = 28.1°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −13→13
Tmin = 0.512, Tmax = 0.621	k = −14→13
15748 measured reflections	l = −21→22

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)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.119	H-atom parameters constrained
S = 0.99	w = 1/[σ^2(Fo^2) + (0.0548P)^2 + 0.2894P] where P = (Fo^2 + 2Fc^2)/3
4343 reflections	(Δ/σ)max = 0.001
229 parameters	Δρmax = 0.53 e Å^−3
0 restraints	Δρmin = −0.25 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
Se1	0.62856 (4)	0.97210 (4)	0.21983 (2)	0.06318 (17)
C12	0.6830 (3)	0.8384 (3)	0.28730 (17)	0.0411 (7)
C6	0.5378 (3)	0.7007 (3)	0.44772 (17)	0.0431 (7)
H6	0.6177	0.6715	0.4781	0.052*
C14	0.7937 (3)	0.6240 (3)	0.27483 (17)	0.0400 (7)
C7	0.4183 (3)	0.6583 (3)	0.46331 (19)	0.0482 (8)
H7	0.4191	0.6017	0.5043	0.058*
N2	0.7293 (3)	0.7725 (3)	0.16744 (16)	0.0554 (7)
C13	0.7322 (3)	0.7463 (3)	0.24593 (17)	0.0409 (7)
C4	0.6769 (3)	0.8331 (3)	0.37373 (17)	0.0410 (7)
H4	0.7424	0.7688	0.3965	0.049*
C5	0.5421 (3)	0.7858 (3)	0.38795 (17)	0.0390 (7)
C19	0.7418 (4)	0.5485 (3)	0.3259 (2)	0.0508 (8)
H19	0.6659	0.5744	0.3436	0.061*
N1	0.8566 (4)	0.9935 (3)	0.40256 (18)	0.0628 (9)
C8	0.2964 (3)	0.6981 (3)	0.41917 (19)	0.0487 (8)
C16	0.9658 (4)	0.4693 (3)	0.2746 (2)	0.0617 (10)
H16	1.0416	0.4427	0.2570	0.074*
C9	0.3006 (4)	0.7811 (3)	0.3593 (2)	0.0562 (9)
H9	0.2204	0.8092	0.3286	0.067*
N3	0.6823 (3)	0.8769 (3)	0.14081 (16)	0.0649 (8)
C15	0.9056 (4)	0.5814 (3)	0.2484 (2)	0.0524 (8)
H15	0.9402	0.6295	0.2125	0.063*
C1	0.7206 (4)	0.9554 (3)	0.4213 (2)	0.0513 (9)
C10	0.4205 (4)	0.8243 (3)	0.3432 (2)	0.0536 (9)
H10	0.4193	0.8800	0.3017	0.064*
C17	0.9146 (4)	0.3968 (3)	0.3265 (2)	0.0658 (11)
H17	0.9566	0.3217	0.3450	0.079*
O1	0.9395 (3)	0.9132 (3)	0.40488 (18)	0.0858 (9)
O2	0.8748 (4)	1.1026 (3)	0.3878 (2)	0.1088 (11)
C2	0.7536 (4)	0.9262 (4)	0.5097 (2)	0.0724 (11)
H2A	0.7923	0.9995	0.5380	0.109*
H2B	0.8162	0.8574	0.5195	0.109*
H2C	0.6729	0.9033	0.5269	0.109*
C11	0.1656 (4)	0.6533 (4)	0.4359 (2)	0.0720 (11)
H11A	0.1432	0.7026	0.4778	0.108*
H11B	0.1731	0.5661	0.4510	0.108*
H11C	0.0967	0.6627	0.3897	0.108*
C3	0.6242 (4)	1.0648 (4)	0.4045 (3)	0.0777 (12)
H3A	0.5382	1.0395	0.4137	0.117*
H3B	0.6156	1.0904	0.3509	0.117*
H3C	0.6576	1.1341	0.4384	0.117*
C18	0.8018 (4)	0.4346 (3)	0.3511 (2)	0.0628 (10)
H18	0.7653	0.3837	0.3850	0.075*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Se1	0.0819 (3)	0.0553 (2)	0.0553 (3)	0.0203 (2)	0.0209 (2)	0.01726 (18)
C12	0.0446 (18)	0.0381 (16)	0.0396 (17)	0.0023 (14)	0.0059 (14)	0.0001 (13)
C6	0.049 (2)	0.0409 (16)	0.0386 (17)	0.0052 (15)	0.0060 (15)	−0.0009 (14)
C14	0.0472 (19)	0.0373 (16)	0.0348 (16)	−0.0038 (14)	0.0067 (14)	−0.0086 (13)
C7	0.061 (2)	0.0426 (18)	0.0430 (19)	−0.0002 (16)	0.0157 (17)	−0.0007 (15)
N2	0.071 (2)	0.0576 (18)	0.0373 (16)	0.0006 (15)	0.0096 (14)	0.0016 (13)
C13	0.0470 (19)	0.0411 (16)	0.0330 (17)	−0.0029 (14)	0.0042 (14)	−0.0020 (13)
C4	0.052 (2)	0.0338 (15)	0.0379 (17)	0.0035 (14)	0.0098 (15)	−0.0023 (13)
C5	0.0476 (19)	0.0370 (16)	0.0328 (16)	0.0038 (14)	0.0088 (14)	−0.0037 (13)
C19	0.059 (2)	0.044 (2)	0.052 (2)	0.0020 (16)	0.0180 (17)	−0.0061 (15)
N1	0.071 (2)	0.066 (2)	0.0539 (19)	−0.0185 (18)	0.0177 (17)	−0.0116 (16)
C8	0.051 (2)	0.0513 (19)	0.044 (2)	−0.0050 (16)	0.0109 (17)	−0.0120 (16)
C16	0.062 (2)	0.059 (2)	0.067 (2)	0.0095 (19)	0.020 (2)	−0.009 (2)
C9	0.050 (2)	0.065 (2)	0.049 (2)	0.0069 (18)	−0.0016 (17)	−0.0024 (18)
N3	0.082 (2)	0.070 (2)	0.0415 (17)	0.0073 (18)	0.0117 (16)	0.0077 (15)
C15	0.060 (2)	0.0431 (18)	0.057 (2)	−0.0012 (17)	0.0196 (18)	−0.0035 (17)
C1	0.060 (2)	0.050 (2)	0.048 (2)	−0.0101 (16)	0.0203 (17)	−0.0112 (15)
C10	0.058 (2)	0.0506 (19)	0.049 (2)	0.0029 (17)	0.0047 (17)	0.0088 (16)
C17	0.088 (3)	0.044 (2)	0.062 (2)	0.016 (2)	0.009 (2)	−0.0048 (18)
O1	0.0616 (18)	0.092 (2)	0.107 (2)	−0.0078 (17)	0.0265 (17)	−0.015 (2)
O2	0.121 (3)	0.072 (2)	0.148 (3)	−0.0319 (19)	0.062 (2)	0.009 (2)
C2	0.092 (3)	0.082 (3)	0.049 (2)	−0.026 (2)	0.025 (2)	−0.022 (2)
C11	0.062 (2)	0.088 (3)	0.067 (3)	−0.011 (2)	0.017 (2)	−0.009 (2)
C3	0.094 (3)	0.047 (2)	0.099 (3)	0.003 (2)	0.035 (3)	−0.023 (2)
C18	0.094 (3)	0.0431 (19)	0.057 (2)	0.000 (2)	0.027 (2)	0.0017 (17)

Geometric parameters (Å, º)

Se1—C12	1.852 (3)	C8—C9	1.370 (5)
Se1—N3	1.874 (3)	C8—C11	1.497 (5)
C12—C13	1.366 (4)	C16—C17	1.367 (5)
C12—C4	1.519 (4)	C16—C15	1.371 (5)
C6—C7	1.375 (4)	C16—H16	0.9300
C6—C5	1.384 (4)	C9—C10	1.385 (5)
C6—H6	0.9300	C9—H9	0.9300
C14—C19	1.378 (4)	C15—H15	0.9300
C14—C15	1.387 (4)	C1—C3	1.508 (5)
C14—C13	1.482 (4)	C1—C2	1.540 (5)
C7—C8	1.387 (5)	C10—H10	0.9300
C7—H7	0.9300	C17—C18	1.364 (5)
N2—N3	1.256 (4)	C17—H17	0.9300
N2—C13	1.389 (4)	C2—H2A	0.9600
C4—C5	1.528 (4)	C2—H2B	0.9600
C4—C1	1.553 (4)	C2—H2C	0.9600
C4—H4	0.9800	C11—H11A	0.9600
C5—C10	1.385 (4)	C11—H11B	0.9600
C19—C18	1.383 (5)	C11—H11C	0.9600
C19—H19	0.9300	C3—H3A	0.9600
N1—O1	1.193 (4)	C3—H3B	0.9600
N1—O2	1.207 (4)	C3—H3C	0.9600
N1—C1	1.540 (5)	C18—H18	0.9300
C12—Se1—N3	87.69 (13)	C8—C9—H9	119.0
C13—C12—C4	126.0 (3)	C10—C9—H9	119.0
C13—C12—Se1	107.9 (2)	N2—N3—Se1	110.4 (2)
C4—C12—Se1	126.1 (2)	C16—C15—C14	121.0 (3)
C7—C6—C5	121.7 (3)	C16—C15—H15	119.5
C7—C6—H6	119.2	C14—C15—H15	119.5
C5—C6—H6	119.2	C3—C1—N1	109.6 (3)
C19—C14—C15	118.2 (3)	C3—C1—C2	110.5 (3)
C19—C14—C13	122.4 (3)	N1—C1—C2	103.9 (3)
C15—C14—C13	119.5 (3)	C3—C1—C4	115.6 (3)
C6—C7—C8	121.3 (3)	N1—C1—C4	106.2 (2)
C6—C7—H7	119.3	C2—C1—C4	110.3 (3)
C8—C7—H7	119.3	C5—C10—C9	120.9 (3)
N3—N2—C13	118.1 (3)	C5—C10—H10	119.6
C12—C13—N2	116.0 (3)	C9—C10—H10	119.6
C12—C13—C14	128.3 (3)	C18—C17—C16	120.0 (3)
N2—C13—C14	115.6 (3)	C18—C17—H17	120.0
C12—C4—C5	113.0 (2)	C16—C17—H17	120.0
C12—C4—C1	115.6 (2)	C1—C2—H2A	109.5
C5—C4—C1	110.9 (2)	C1—C2—H2B	109.5
C12—C4—H4	105.4	H2A—C2—H2B	109.5
C5—C4—H4	105.4	C1—C2—H2C	109.5
C1—C4—H4	105.4	H2A—C2—H2C	109.5
C6—C5—C10	117.0 (3)	H2B—C2—H2C	109.5
C6—C5—C4	120.1 (3)	C8—C11—H11A	109.5
C10—C5—C4	122.9 (3)	C8—C11—H11B	109.5
C14—C19—C18	120.6 (3)	H11A—C11—H11B	109.5
C14—C19—H19	119.7	C8—C11—H11C	109.5
C18—C19—H19	119.7	H11A—C11—H11C	109.5
O1—N1—O2	123.6 (4)	H11B—C11—H11C	109.5
O1—N1—C1	117.8 (3)	C1—C3—H3A	109.5
O2—N1—C1	118.6 (4)	C1—C3—H3B	109.5
C9—C8—C7	117.1 (3)	H3A—C3—H3B	109.5
C9—C8—C11	121.1 (3)	C1—C3—H3C	109.5
C7—C8—C11	121.9 (3)	H3A—C3—H3C	109.5
C17—C16—C15	120.1 (3)	H3B—C3—H3C	109.5
C17—C16—H16	120.0	C17—C18—C19	120.1 (3)
C15—C16—H16	120.0	C17—C18—H18	119.9
C8—C9—C10	122.0 (3)	C19—C18—H18	119.9
N3—Se1—C12—C13	0.5 (2)	C6—C7—C8—C11	−179.5 (3)
N3—Se1—C12—C4	179.3 (3)	C7—C8—C9—C10	−0.2 (5)
C5—C6—C7—C8	0.6 (5)	C11—C8—C9—C10	179.5 (3)
C4—C12—C13—N2	−179.2 (3)	C13—N2—N3—Se1	0.6 (4)
Se1—C12—C13—N2	−0.3 (4)	C12—Se1—N3—N2	−0.6 (3)
C4—C12—C13—C14	−2.1 (5)	C17—C16—C15—C14	1.1 (5)
Se1—C12—C13—C14	176.7 (3)	C19—C14—C15—C16	−2.3 (5)
N3—N2—C13—C12	−0.2 (5)	C13—C14—C15—C16	179.3 (3)
N3—N2—C13—C14	−177.6 (3)	O1—N1—C1—C3	−172.3 (3)
C19—C14—C13—C12	42.8 (5)	O2—N1—C1—C3	9.0 (5)
C15—C14—C13—C12	−138.9 (3)	O1—N1—C1—C2	69.6 (4)
C19—C14—C13—N2	−140.2 (3)	O2—N1—C1—C2	−109.1 (4)
C15—C14—C13—N2	38.1 (4)	O1—N1—C1—C4	−46.7 (4)
C13—C12—C4—C5	−94.5 (4)	O2—N1—C1—C4	134.6 (3)
Se1—C12—C4—C5	86.9 (3)	C12—C4—C1—C3	72.0 (4)
C13—C12—C4—C1	136.2 (3)	C5—C4—C1—C3	−58.3 (4)
Se1—C12—C4—C1	−42.4 (4)	C12—C4—C1—N1	−49.9 (4)
C7—C6—C5—C10	−1.5 (4)	C5—C4—C1—N1	179.8 (3)
C7—C6—C5—C4	178.5 (3)	C12—C4—C1—C2	−161.8 (3)
C12—C4—C5—C6	137.4 (3)	C5—C4—C1—C2	67.9 (3)
C1—C4—C5—C6	−90.9 (3)	C6—C5—C10—C9	1.5 (5)
C12—C4—C5—C10	−42.6 (4)	C4—C5—C10—C9	−178.5 (3)
C1—C4—C5—C10	89.1 (3)	C8—C9—C10—C5	−0.7 (5)
C15—C14—C19—C18	1.2 (5)	C15—C16—C17—C18	1.3 (6)
C13—C14—C19—C18	179.6 (3)	C16—C17—C18—C19	−2.3 (6)
C6—C7—C8—C9	0.2 (5)	C14—C19—C18—C17	1.0 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3B···Se1	0.96	2.63	3.371 (4)	134
C10—H10···Se1	0.93	2.96	3.659 (4)	133
C16—H16···Cg^i	0.93	2.88	3.712	150

Symmetry code: (i) −x+2, y−1/2, −z+1/2.