2,2-Diphenyl-benzo[c]quinoline-1-ox-yl.

In the title compound, C(25)H(18)NO, a stable phenanthridinic nitroxide, the ring containing the nitroxide function assumes a twist-boat conformation and the dihedral angle formed by adjacent benzene rings is 21.78 (5)°. The phenyl substituents at position 2 are approximately orthogonal to each other, forming a dihedral angle of 81.04 (4)°. The crystal structure is stabilized by an intra-molecular C-H⋯O hydrogen bond and by C-H⋯π inter-actions.

Related literature

For applications of nitroxides in biology, see: Carloni et al. (1996 ▶); Greci (1982 ▶); Likhtenshtein et al. (2008 ▶). For their applications in medicine, see: Damiani et al. (2008 ▶); Krishna et al. (1996 ▶). For their use in pharmacology and cosmetics, see: Krishna et al. (1996 ▶); Setjurc et al. (1995 ▶); Greci et al. (2007 ▶). For their applications in chemical processes and materials science, see: Guillaneuf et al. (2007 ▶); Arends et al. (2006 ▶); Franchi et al. (2008 ▶); Bailly et al. (2006 ▶); Bugnon et al. (2007 ▶). For a description of the Cambridge structural Database, see: Allen (2002 ▶); For puckering parameters, see: Cremer & Pople (1975 ▶). For graph-set motifs, see: Etter et al. (1990 ▶). For the synthesis, see: Colonna et al. (1980 ▶).

Experimental

Crystal data

C25H18NO

M = 348.40

Monoclinic,

a = 12.6188 (12) Å

b = 8.8704 (8) Å

c = 16.6083 (15) Å

β = 102.998 (2)°

V = 1811.4 (3) Å3

Z = 4

Mo Kα radiation

μ = 0.08 mm−1

T = 295 K

0.16 × 0.14 × 0.08 mm

Data collection

Bruker SMART 1000 CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 1998 ▶) T min = 0.972, T max = 0.990

18472 measured reflections

3548 independent reflections

2115 reflections with I > 2σ(I)

R int = 0.047

Refinement

R[F 2 > 2σ(F 2)] = 0.037

wR(F 2) = 0.080

S = 1.01

3548 reflections

244 parameters

H-atom parameters constrained

Δρmax = 0.11 e Å−3

Δρmin = −0.14 e Å−3

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT-Plus (Bruker, 1998 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶) and SCHAKAL97 (Keller, 1997 ▶); software used to prepare material for publication: SHELXL97, PARST95 (Nardelli, 1995 ▶) and WinSim (Duling, 1994 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809013476/fb2149sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809013476/fb2149Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C25H18NO	F(000) = 732
Mr = 348.40	Dx = 1.278 Mg m−3
Monoclinic, P21/c	Melting point = 449–450 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 12.6188 (12) Å	Cell parameters from 1226 reflections
b = 8.8704 (8) Å	θ = 3.2–24.8°
c = 16.6083 (15) Å	µ = 0.08 mm−1
β = 102.998 (2)°	T = 295 K
V = 1811.4 (3) Å3	Block, red
Z = 4	0.16 × 0.14 × 0.08 mm

Bruker SMART 1000 CCD diffractometer	3548 independent reflections
Radiation source: fine-focus sealed tube	2115 reflections with I > 2σ(I)
graphite	Rint = 0.047
ω scans	θmax = 26.0°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 1998)	h = −15→15
Tmin = 0.972, Tmax = 0.990	k = −10→10
18472 measured reflections	l = −20→20

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.037	Hydrogen site location: difference Fourier map
wR(F2) = 0.080	H-atom parameters constrained
S = 1.01	w = 1/[σ2(Fo2) + (0.0321P)2] where P = (Fo2 + 2Fc2)/3
3548 reflections	(Δ/σ)max < 0.001
244 parameters	Δρmax = 0.11 e Å−3
0 restraints	Δρmin = −0.14 e Å−3
72 constraints

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.

	x	y	z	Uiso*/Ueq
N1	0.26974 (9)	0.84150 (12)	0.17884 (7)	0.0436 (3)
O1	0.29038 (8)	0.90766 (11)	0.24920 (6)	0.0590 (3)
C2	0.29264 (10)	0.61901 (15)	0.09755 (8)	0.0406 (3)
C20	0.13820 (10)	0.64080 (15)	0.17300 (7)	0.0386 (3)
C13	0.22201 (11)	0.92305 (16)	0.10729 (9)	0.0443 (3)
C8	0.21679 (11)	0.85600 (16)	0.03064 (8)	0.0458 (4)
C14	0.33392 (11)	0.60524 (16)	0.25222 (8)	0.0445 (4)
C1	0.25883 (11)	0.67236 (14)	0.17575 (8)	0.0391 (3)
C7	0.26972 (11)	0.70981 (15)	0.02684 (8)	0.0424 (3)
C6	0.30162 (12)	0.66030 (18)	−0.04392 (9)	0.0526 (4)
H6	0.2896	0.7217	−0.0905	0.063*
C25	0.07658 (13)	0.54387 (17)	0.11658 (9)	0.0550 (4)
H25	0.1075	0.4964	0.0775	0.066*
C3	0.34171 (12)	0.48029 (16)	0.09411 (9)	0.0537 (4)
H3	0.3560	0.4186	0.1406	0.064*
C21	0.08830 (12)	0.71122 (17)	0.22877 (9)	0.0512 (4)
H21	0.1280	0.7785	0.2668	0.061*
C22	−0.01884 (13)	0.68398 (18)	0.22926 (10)	0.0595 (4)
H22	−0.0506	0.7328	0.2675	0.071*
C5	0.35039 (12)	0.52270 (19)	−0.04600 (9)	0.0596 (4)
H5	0.3703	0.4908	−0.0938	0.072*
C23	−0.07899 (13)	0.58527 (19)	0.17372 (10)	0.0610 (4)
H23	−0.1512	0.5656	0.1744	0.073*
C12	0.18124 (13)	1.06672 (18)	0.11352 (10)	0.0621 (4)
H12	0.1884	1.1122	0.1649	0.074*
C15	0.30015 (13)	0.48928 (18)	0.29547 (9)	0.0603 (4)
H15	0.2285	0.4560	0.2807	0.072*
C24	−0.03136 (13)	0.51648 (19)	0.11758 (10)	0.0647 (5)
H24	−0.0718	0.4501	0.0793	0.078*
C9	0.16276 (13)	0.9348 (2)	−0.03924 (10)	0.0646 (5)
H9	0.1562	0.8914	−0.0911	0.078*
C19	0.44123 (12)	0.65176 (19)	0.27533 (9)	0.0614 (4)
H19	0.4658	0.7291	0.2464	0.074*
C4	0.36960 (13)	0.43243 (19)	0.02258 (10)	0.0622 (4)
H4	0.4016	0.3384	0.0210	0.075*
C10	0.11911 (15)	1.0748 (2)	−0.03309 (13)	0.0808 (6)
H10	0.0821	1.1245	−0.0804	0.097*
C11	0.13017 (15)	1.1411 (2)	0.04279 (13)	0.0782 (5)
H11	0.1028	1.2375	0.0465	0.094*
C18	0.51180 (15)	0.5847 (2)	0.34067 (11)	0.0777 (6)
H18	0.5835	0.6178	0.3558	0.093*
C16	0.37243 (17)	0.4214 (2)	0.36115 (10)	0.0838 (6)
H16	0.3491	0.3426	0.3899	0.101*
C17	0.47781 (18)	0.4703 (3)	0.38350 (11)	0.0866 (6)
H17	0.5260	0.4257	0.4277	0.104*

	U11	U22	U33	U12	U13	U23
N1	0.0451 (7)	0.0437 (7)	0.0430 (7)	−0.0050 (5)	0.0120 (5)	−0.0072 (6)
O1	0.0672 (7)	0.0597 (7)	0.0499 (6)	−0.0065 (5)	0.0130 (5)	−0.0191 (5)
C2	0.0382 (8)	0.0459 (9)	0.0375 (8)	−0.0026 (7)	0.0083 (6)	−0.0042 (7)
C20	0.0412 (8)	0.0409 (8)	0.0328 (7)	−0.0012 (6)	0.0067 (6)	0.0045 (6)
C13	0.0407 (8)	0.0414 (9)	0.0518 (9)	−0.0035 (7)	0.0126 (7)	0.0040 (7)
C8	0.0435 (9)	0.0484 (9)	0.0465 (9)	−0.0048 (7)	0.0121 (7)	0.0064 (7)
C14	0.0442 (9)	0.0538 (9)	0.0347 (7)	0.0060 (7)	0.0073 (6)	−0.0024 (7)
C1	0.0428 (8)	0.0391 (8)	0.0350 (7)	−0.0008 (6)	0.0081 (6)	−0.0008 (6)
C7	0.0383 (8)	0.0501 (9)	0.0386 (8)	−0.0081 (7)	0.0085 (6)	−0.0028 (7)
C6	0.0482 (9)	0.0708 (11)	0.0396 (9)	−0.0065 (8)	0.0115 (7)	−0.0004 (8)
C25	0.0578 (10)	0.0598 (10)	0.0492 (9)	−0.0158 (8)	0.0159 (8)	−0.0097 (8)
C3	0.0627 (10)	0.0526 (10)	0.0460 (9)	0.0061 (8)	0.0128 (8)	−0.0018 (7)
C21	0.0474 (9)	0.0599 (10)	0.0467 (9)	−0.0056 (7)	0.0113 (7)	−0.0060 (7)
C22	0.0504 (10)	0.0726 (11)	0.0592 (10)	−0.0016 (8)	0.0205 (8)	−0.0002 (9)
C5	0.0520 (10)	0.0823 (13)	0.0468 (9)	−0.0012 (9)	0.0159 (8)	−0.0138 (9)
C23	0.0452 (9)	0.0765 (12)	0.0610 (10)	−0.0096 (9)	0.0112 (8)	0.0115 (9)
C12	0.0625 (11)	0.0494 (10)	0.0782 (12)	−0.0006 (8)	0.0241 (9)	−0.0012 (9)
C15	0.0582 (10)	0.0713 (11)	0.0513 (9)	0.0106 (8)	0.0119 (8)	0.0165 (8)
C24	0.0612 (11)	0.0725 (12)	0.0577 (10)	−0.0262 (9)	0.0076 (9)	−0.0069 (9)
C9	0.0687 (11)	0.0689 (12)	0.0558 (10)	0.0025 (9)	0.0129 (9)	0.0158 (9)
C19	0.0491 (10)	0.0752 (12)	0.0560 (10)	0.0062 (8)	0.0035 (8)	−0.0030 (9)
C4	0.0652 (11)	0.0634 (11)	0.0591 (10)	0.0113 (8)	0.0164 (8)	−0.0149 (9)
C10	0.0855 (14)	0.0726 (13)	0.0831 (14)	0.0150 (11)	0.0166 (11)	0.0324 (11)
C11	0.0866 (14)	0.0491 (11)	0.0998 (15)	0.0135 (9)	0.0229 (12)	0.0181 (11)
C18	0.0564 (11)	0.0990 (15)	0.0687 (12)	0.0196 (11)	−0.0048 (10)	−0.0123 (12)
C16	0.0889 (16)	0.0997 (15)	0.0638 (12)	0.0323 (12)	0.0192 (11)	0.0338 (11)
C17	0.0782 (15)	0.1184 (18)	0.0552 (11)	0.0486 (13)	−0.0020 (11)	0.0070 (12)

N1—O1	1.2811 (13)	C22—C23	1.371 (2)
N1—C13	1.4057 (17)	C22—H22	0.9300
N1—C1	1.5064 (16)	C5—C4	1.369 (2)
C2—C3	1.3844 (18)	C5—H5	0.9300
C2—C7	1.3994 (18)	C23—C24	1.362 (2)
C2—C1	1.5305 (17)	C23—H23	0.9300
C20—C25	1.3763 (18)	C12—C11	1.375 (2)
C20—C21	1.3810 (18)	C12—H12	0.9300
C20—C1	1.5383 (18)	C15—C16	1.392 (2)
C13—C12	1.387 (2)	C15—H15	0.9300
C13—C8	1.3933 (18)	C24—H24	0.9300
C8—C9	1.3942 (19)	C9—C10	1.372 (2)
C8—C7	1.4665 (19)	C9—H9	0.9300
C14—C15	1.3760 (19)	C19—C18	1.375 (2)
C14—C19	1.385 (2)	C19—H19	0.9300
C14—C1	1.5244 (17)	C4—H4	0.9300
C7—C6	1.3961 (19)	C10—C11	1.369 (2)
C6—C5	1.371 (2)	C10—H10	0.9300
C6—H6	0.9300	C11—H11	0.9300
C25—C24	1.387 (2)	C18—C17	1.363 (3)
C25—H25	0.9300	C18—H18	0.9300
C3—C4	1.3796 (19)	C16—C17	1.368 (3)
C3—H3	0.9300	C16—H16	0.9300
C21—C22	1.375 (2)	C17—H17	0.9300
C21—H21	0.9300
O1—N1—C13	119.72 (11)	C21—C22—H22	119.8
O1—N1—C1	119.05 (10)	C4—C5—C6	119.76 (14)
C13—N1—C1	117.73 (11)	C4—C5—H5	120.1
C3—C2—C7	119.14 (13)	C6—C5—H5	120.1
C3—C2—C1	121.50 (12)	C24—C23—C22	118.95 (15)
C7—C2—C1	119.32 (12)	C24—C23—H23	120.5
C25—C20—C21	117.79 (13)	C22—C23—H23	120.5
C25—C20—C1	122.53 (12)	C11—C12—C13	119.18 (16)
C21—C20—C1	119.68 (12)	C11—C12—H12	120.4
C12—C13—C8	121.22 (14)	C13—C12—H12	120.4
C12—C13—N1	120.37 (13)	C14—C15—C16	120.49 (16)
C8—C13—N1	118.42 (13)	C14—C15—H15	119.8
C13—C8—C9	117.42 (14)	C16—C15—H15	119.8
C13—C8—C7	119.23 (12)	C23—C24—C25	121.02 (15)
C9—C8—C7	123.33 (14)	C23—C24—H24	119.5
C15—C14—C19	118.45 (14)	C25—C24—H24	119.5
C15—C14—C1	121.29 (13)	C10—C9—C8	121.41 (16)
C19—C14—C1	120.02 (13)	C10—C9—H9	119.3
N1—C1—C14	109.01 (10)	C8—C9—H9	119.3
N1—C1—C2	107.22 (10)	C18—C19—C14	120.63 (17)
C14—C1—C2	110.28 (11)	C18—C19—H19	119.7
N1—C1—C20	105.34 (10)	C14—C19—H19	119.7
C14—C1—C20	112.28 (10)	C5—C4—C3	120.32 (15)
C2—C1—C20	112.42 (10)	C5—C4—H4	119.8
C6—C7—C2	118.75 (13)	C3—C4—H4	119.8
C6—C7—C8	122.32 (13)	C11—C10—C9	119.86 (17)
C2—C7—C8	118.88 (12)	C11—C10—H10	120.1
C5—C6—C7	121.16 (14)	C9—C10—H10	120.1
C5—C6—H6	119.4	C10—C11—C12	120.78 (17)
C7—C6—H6	119.4	C10—C11—H11	119.6
C20—C25—C24	120.47 (14)	C12—C11—H11	119.6
C20—C25—H25	119.8	C17—C18—C19	120.67 (18)
C24—C25—H25	119.8	C17—C18—H18	119.7
C4—C3—C2	120.80 (14)	C19—C18—H18	119.7
C4—C3—H3	119.6	C17—C16—C15	120.05 (18)
C2—C3—H3	119.6	C17—C16—H16	120.0
C22—C21—C20	121.45 (14)	C15—C16—H16	120.0
C22—C21—H21	119.3	C18—C17—C16	119.70 (17)
C20—C21—H21	119.3	C18—C17—H17	120.2
C23—C22—C21	120.30 (15)	C16—C17—H17	120.2
C23—C22—H22	119.8

D—H···A	D—H	H···A	D···A	D—H···A
C21—H21···O1	0.93	2.42	3.044 (2)	124
C24—H24···Cg1i	0.93	3.27	3.864 (3)	136
C6—H6···Cg2ii	0.93	3.16	3.932 (4)	142
C10—H10···Cg3iii	0.93	2.97	3.839 (4)	154

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C21—H21⋯O1	0.93	2.42	3.044 (2)	124
C24—H24⋯Cg1i	0.93	3.27	3.864 (3)	136
C6—H6⋯Cg2ii	0.93	3.16	3.932 (4)	142
C10—H10⋯Cg3iii	0.93	2.97	3.839 (4)	154

Symmetry codes: (i) ; (ii) ; (iii) . Cg1, Cg2 and Cg3 are the centroids of the C2–C7, C14–C19 and C20–C25 aromatic rings, respectively.