Optical properties of (Z)-2-(2-phenyl­hydrazinyl­idene)acenaphthen-1(2H)-one: a potential electron donor in organic solar cells

Electron-donating mol­ecules play an important role in the development of organic solar cells. (Z)-2-(2-Phenyl­hydrazinyl­idene)acenaphthen-1(2H)-one (PDAK), C₁₈H₁₂N₂O, was synthesized by a Schiff base reaction. The crystal structure shows that the mol­ecules are planar and are linked together forming `face-to-face' assemblies held together by inter­molecular C—H...O, π–π and C—H...π inter­actions. PDAK exhibits a broadband UV–Vis absorption (200–648 nm) and a low HOMO–LUMO energy gap (1.91 eV; HOMO is the highest occupied mol­ecular orbital and LUMO is the lowest unoccupied mol­ecular orbital), while fluorescence quenching experiments provide evidence for electron transfer from the excited state of PDAK to C₆₀. This suggests that the title mol­ecule may be a suitable donor for use in organic solar cells.

Computing details

Data collection: SMART (Bruker, 2008); cell refinement: SMART (Bruker, 2008); data reduction: SHELXTL (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Bruker, 2008); software used to prepare material for publication: SHELXTL (Bruker, 2008).

(Z)-2-(2-Phenylhydrazinylidene)acenaphthen-1(2H)-one

Crystal data

C18H12N2O	F(000) = 568
Mr = 272.30	Dx = 1.342 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 4257 reflections
a = 13.3040 (11) Å	θ = 2.7–25.0°
b = 5.1796 (4) Å	µ = 0.09 mm^−1
c = 19.6396 (18) Å	T = 298 K
β = 95.143 (1)°	Block, colourless
V = 1347.9 (2) Å^3	0.40 × 0.11 × 0.04 mm
Z = 4

Data collection

Bruker SMART CCD area detector diffractometer	2362 independent reflections
Radiation source: fine-focus sealed tube	1096 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.093
phi and ω scans	θmax = 25.0°, θmin = 2.7°
Absorption correction: multi-scan	h = −15→15
Tmin = 0.967, Tmax = 0.997	k = −6→6
6372 measured reflections	l = −23→18

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)] = 0.057	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.094	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.005P)^2] where P = (Fo^2 + 2Fc^2)/3
2362 reflections	(Δ/σ)max < 0.001
190 parameters	Δρmax = 0.18 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
O1	0.04782 (15)	0.5173 (5)	0.21991 (10)	0.0639 (7)
N2	0.20574 (17)	0.2739 (5)	0.30038 (12)	0.0526 (7)
H2	0.1424	0.2716	0.2871	0.063*
C8	0.2181 (2)	0.9388 (6)	0.14751 (14)	0.0455 (8)
N1	0.26762 (18)	0.4416 (5)	0.27247 (12)	0.0540 (7)
C2	0.1194 (2)	0.6419 (6)	0.20091 (15)	0.0503 (9)
C13	0.2456 (2)	0.1019 (6)	0.35165 (14)	0.0455 (8)
C9	0.2879 (2)	0.7970 (6)	0.19210 (14)	0.0485 (8)
C14	0.3463 (2)	0.1130 (6)	0.37631 (15)	0.0606 (10)
H14	0.3891	0.2337	0.3590	0.073*
C3	0.1181 (2)	0.8561 (6)	0.15021 (14)	0.0488 (9)
C18	0.1824 (2)	−0.0788 (6)	0.37729 (15)	0.0529 (9)
H18	0.1147	−0.0872	0.3608	0.063*
C5	0.0677 (2)	1.1781 (7)	0.06632 (15)	0.0635 (10)
H5	0.0171	1.2588	0.0383	0.076*
C16	0.3208 (3)	−0.2389 (7)	0.45350 (15)	0.0618 (10)
H16	0.3457	−0.3522	0.4877	0.074*
C10	0.3883 (2)	0.8584 (7)	0.19453 (15)	0.0623 (10)
H10	0.4355	0.7681	0.2231	0.075*
C4	0.0415 (2)	0.9760 (7)	0.10998 (15)	0.0591 (10)
H4	−0.0254	0.9257	0.1115	0.071*
C11	0.4192 (2)	1.0632 (7)	0.15244 (17)	0.0663 (10)
H11	0.4873	1.1060	0.1542	0.080*
C7	0.2463 (2)	1.1369 (7)	0.10502 (15)	0.0515 (9)
C12	0.3507 (3)	1.2001 (7)	0.10908 (16)	0.0643 (10)
H12	0.3730	1.3336	0.0826	0.077*
C6	0.1653 (3)	1.2577 (6)	0.06415 (15)	0.0595 (9)
H6	0.1793	1.3934	0.0355	0.071*
C1	0.2280 (2)	0.6048 (6)	0.22689 (15)	0.0496 (9)
C17	0.2212 (2)	−0.2482 (7)	0.42811 (15)	0.0622 (10)
H17	0.1788	−0.3703	0.4452	0.075*
C15	0.3830 (2)	−0.0584 (8)	0.42729 (16)	0.0682 (11)
H15	0.4506	−0.0508	0.4439	0.082*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0685 (15)	0.0556 (17)	0.0678 (16)	−0.0074 (13)	0.0068 (11)	0.0015 (13)
N2	0.0575 (17)	0.045 (2)	0.0544 (18)	−0.0012 (14)	0.0021 (13)	0.0000 (15)
C8	0.058 (2)	0.035 (2)	0.043 (2)	0.0021 (17)	0.0049 (16)	−0.0076 (17)
N1	0.0725 (19)	0.043 (2)	0.0473 (17)	−0.0045 (16)	0.0079 (14)	−0.0012 (15)
C2	0.060 (2)	0.044 (3)	0.047 (2)	−0.0017 (18)	0.0081 (17)	−0.0057 (18)
C13	0.053 (2)	0.040 (2)	0.043 (2)	0.0023 (17)	0.0017 (16)	0.0004 (16)
C9	0.057 (2)	0.041 (2)	0.048 (2)	0.0016 (18)	0.0023 (17)	−0.0067 (17)
C14	0.058 (2)	0.060 (3)	0.063 (2)	−0.0059 (18)	−0.0015 (17)	0.004 (2)
C3	0.058 (2)	0.045 (2)	0.043 (2)	0.0007 (18)	0.0028 (16)	−0.0024 (17)
C18	0.054 (2)	0.050 (3)	0.054 (2)	−0.0028 (18)	0.0017 (16)	−0.0041 (19)
C5	0.069 (2)	0.057 (3)	0.064 (3)	0.009 (2)	0.0011 (19)	0.008 (2)
C16	0.071 (2)	0.057 (3)	0.056 (2)	0.017 (2)	0.003 (2)	0.011 (2)
C10	0.063 (2)	0.058 (3)	0.065 (3)	−0.0009 (19)	0.0016 (17)	0.003 (2)
C4	0.061 (2)	0.051 (3)	0.065 (2)	−0.0004 (18)	0.0014 (18)	−0.002 (2)
C11	0.062 (2)	0.063 (3)	0.074 (3)	−0.007 (2)	0.0085 (19)	0.000 (2)
C7	0.064 (2)	0.042 (2)	0.049 (2)	−0.0002 (18)	0.0064 (17)	−0.0010 (18)
C12	0.083 (3)	0.047 (3)	0.065 (3)	−0.007 (2)	0.0185 (19)	−0.0002 (19)
C6	0.083 (2)	0.040 (2)	0.056 (2)	0.004 (2)	0.0101 (18)	0.0044 (18)
C1	0.065 (2)	0.037 (2)	0.046 (2)	0.0011 (17)	0.0039 (17)	−0.0002 (18)
C17	0.074 (3)	0.049 (3)	0.064 (2)	−0.005 (2)	0.0056 (19)	0.009 (2)
C15	0.054 (2)	0.082 (3)	0.067 (3)	0.010 (2)	−0.0037 (18)	0.002 (2)

Geometric parameters (Å, º)

O1—C2	1.236 (3)	C9—C1	1.481 (4)
N2—N1	1.347 (3)	C14—C15	1.393 (4)
N2—C13	1.412 (3)	C3—C4	1.380 (4)
C8—C7	1.395 (4)	C18—C17	1.393 (4)
C8—C3	1.404 (3)	C5—C6	1.366 (4)
C8—C9	1.422 (4)	C5—C4	1.416 (4)
N1—C1	1.308 (3)	C16—C17	1.374 (3)
C2—C3	1.490 (4)	C16—C15	1.379 (4)
C2—C1	1.500 (4)	C10—C11	1.428 (4)
C13—C18	1.384 (4)	C11—C12	1.386 (4)
C13—C14	1.384 (3)	C7—C12	1.422 (4)
C9—C10	1.369 (3)	C7—C6	1.429 (4)
N1—N2—C13	119.5 (2)	C8—C3—C2	107.3 (3)
C7—C8—C3	123.6 (3)	C13—C18—C17	119.2 (3)
C7—C8—C9	123.5 (3)	C6—C5—C4	121.9 (3)
C3—C8—C9	112.8 (3)	C17—C16—C15	118.7 (3)
C1—N1—N2	118.1 (3)	C9—C10—C11	118.9 (3)
O1—C2—C3	128.8 (3)	C3—C4—C5	118.1 (3)
O1—C2—C1	125.1 (3)	C12—C11—C10	121.8 (3)
C3—C2—C1	106.0 (3)	C8—C7—C12	116.7 (3)
C18—C13—C14	120.1 (3)	C8—C7—C6	115.4 (3)
C18—C13—N2	119.0 (3)	C12—C7—C6	127.9 (3)
C14—C13—N2	120.9 (3)	C11—C12—C7	120.2 (3)
C10—C9—C8	118.9 (3)	C5—C6—C7	121.4 (3)
C10—C9—C1	134.7 (3)	N1—C1—C9	123.3 (3)
C8—C9—C1	106.4 (3)	N1—C1—C2	129.3 (3)
C13—C14—C15	119.4 (3)	C9—C1—C2	107.4 (3)
C4—C3—C8	119.6 (3)	C16—C17—C18	121.5 (3)
C4—C3—C2	133.0 (3)	C16—C15—C14	121.1 (3)
C13—N2—N1—C1	−177.6 (3)	C3—C8—C7—C12	179.1 (3)
N1—N2—C13—C18	−176.5 (3)	C9—C8—C7—C12	−1.7 (4)
N1—N2—C13—C14	3.6 (4)	C3—C8—C7—C6	1.1 (4)
C7—C8—C9—C10	0.8 (5)	C9—C8—C7—C6	−179.7 (3)
C3—C8—C9—C10	−179.9 (3)	C10—C11—C12—C7	−0.6 (5)
C7—C8—C9—C1	−179.2 (3)	C8—C7—C12—C11	1.5 (5)
C3—C8—C9—C1	0.0 (3)	C6—C7—C12—C11	179.2 (3)
C18—C13—C14—C15	−0.3 (5)	C4—C5—C6—C7	1.3 (5)
N2—C13—C14—C15	179.5 (3)	C8—C7—C6—C5	−1.3 (5)
C7—C8—C3—C4	−1.0 (5)	C12—C7—C6—C5	−179.0 (3)
C9—C8—C3—C4	179.7 (3)	N2—N1—C1—C9	−179.5 (3)
C7—C8—C3—C2	179.6 (3)	N2—N1—C1—C2	2.0 (5)
C9—C8—C3—C2	0.3 (3)	C10—C9—C1—N1	0.7 (6)
O1—C2—C3—C4	−0.7 (6)	C8—C9—C1—N1	−179.2 (3)
C1—C2—C3—C4	−179.8 (3)	C10—C9—C1—C2	179.6 (3)
O1—C2—C3—C8	178.6 (3)	C8—C9—C1—C2	−0.4 (3)
C1—C2—C3—C8	−0.6 (3)	O1—C2—C1—N1	0.2 (5)
C14—C13—C18—C17	0.1 (5)	C3—C2—C1—N1	179.3 (3)
N2—C13—C18—C17	−179.7 (3)	O1—C2—C1—C9	−178.6 (3)
C8—C9—C10—C11	0.3 (5)	C3—C2—C1—C9	0.6 (3)
C1—C9—C10—C11	−179.7 (3)	C15—C16—C17—C18	−0.5 (5)
C8—C3—C4—C5	0.9 (5)	C13—C18—C17—C16	0.3 (5)
C2—C3—C4—C5	−179.9 (3)	C17—C16—C15—C14	0.3 (5)
C6—C5—C4—C3	−1.1 (5)	C13—C14—C15—C16	0.1 (5)
C9—C10—C11—C12	−0.4 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C18—H18···O1^i	0.93	2.62	3.496 (3)	157
N2—H2···O1	0.86	2.16	2.812 (3)	133

Symmetry code: (i) −x, y−1/2, −z+1/2.