N-(2-Bromo­ethyl)-4-piperidino-1,8-naphthalimide and N-(3-bromo­propyl)-4-piperidino-1,8-naphthal­imide

N-(2-Bromo­ethyl)-4-piperidino-1,8-naphthalimide, C₁₉H₁₉BrN₂O₂, (I), and N-(3-bromo­propyl)-4-piperidino-1,8-naphthal­imide, C₂₀H₂₁BrN₂O₂, (II), are an homologous pair of 1,8-naphthalimide derivatives. The naphthalimide units are planar and each piperidine substituent adopts a chair conformation. This study emphasizes the importance of [pi]-stacking interactions, often augmented by other contacts, in determining the crystal structures of 1,8-naphthalimide derivatives.

S1. Comment

1,8-Napthlimides find widespread use in materials science, including use as dyes (Hirahara et al., 1993), as markers in biomedical science (Stewart, 1981a,b) and as optical brighteners (Dorlars et al., 1975). Our interest in these compounds centres on the incorporation of fluorescent naphthalimide units into molecular assemblies that contain both redox-active and fluorescent functionalities joined by conductive alkene or alkyne linkages (McAdam et al., 2000, 2003, 2005), enamines (McAdam et al., 2004) or sugar derivatives of the naphthalimides (Cavigiolo et al., 2004), and the incorporation of fluorescent naphthalimides into polymeric systems (Dana et al., 2007). Of particular recent interest is the use of fluorescent naphthalimides or polyaromatic hydrocarbons in the redox-triggered absorption of radiation in the near-IR region of the electromagnetic spectrum (McAdam et al., 2003; Cuffe et al., 2005). We report here the syntheses and crystal structures of an homologous pair of 1,8-naphthalimide derivatives, N-(2-bromoethyl)-4-piperidino-1,8-naphthalimide, (I), and N-(3-bromopropyl)-4-piperidino-1,8-naphthalimide, (II), prepared as precursors to the syntheses of ferrocene–naphthalimide and related poly ad systems (Tagg, 2008).

Each molecule comprises a 1,8-naphthlimide ring system, with a piperidine substituent at the 4-position of the naphthalene ring and with the N atom of the dicarboximide ring carrying a bromoethyl substituent in (I) (Fig. 1) and a bromopropyl substituent in (II) (Fig. 2). Intramolecular C13—H···O interactions generate two S(5) ring motifs (Bernstein et al., 1995) involving both of the dicarboximide O atoms in each compound. These serve to orient the N1—C13—C14 segments of the molecules approximately at right angles to the planes of the naphthalimides, with dihedral angles of 83.48 (10)° for (I) and 82.35 (13)° for (II). The naphthalimide units are essentially planar in each compound, with r.m.s. deviations from the mean planes through all 15 atoms, including the dicarboximide O atoms, of 0.048 Å for (I) and 0.019 Å for (II). The C13 and N2 substituents are displaced only slightly from these planes, by 0.0278 (19) and -0.0807 (17) Å in opposite directions for (I) and somewhat more extensively, by 0.1108 (15) and 0.1224 (14), but both in the same direction, for (II). The piperidine rings each adopt classical chair conformations, with Cremer & Pople (1975) puckering parameters of Q₂ = 0.0447 (15) Å, ϕ₂ = 178 (2)° and Q₃ = -0.5847 (15) Å for the N2/C15–C19 ring in (I), and Q₂ = 0.0186 (17) Å, ϕ₂ = 324 (5)° and Q₃ = 0.5808 (17) Å for the N2/C16–C20 ring in (II).

A search of the Cambridge Structural Database (Version 5.29, updated to January 2008; Allen, 2002) reveals 12 other naphthalimide derivatives with amine substituents in the 4-position and an alkyl chain with two or more C atoms on the dicarboximide N atom (Banthia & Samanta, 2005, 2006; Banthia & Paul, 2005; Bardajee et al., 2006; Baughman et al., 1995; Shi et al., 2005; Gunnlaugsson et al., 2003, 2005; Qin et al., 2007). In contrast, the structures of only two other 4-piperidinonapthalimide derivatives have been reported previously (McAdam et al., 2003, 2005). Bond-length variations within the dicarboximide ring are consistent with significant delocalization over the naphthalimide unit. However, predictably (Easton et al., 1992; Batchelor et al., 1997), delocalization does not extend to the alkyl substituent, as evidenced by N1—C13 bond distances of 1.4667 (17) Å for (I) and 1.472 (2) Å for (II). These values compare with the corresponding average distance of 1.482 Å found for the 12 related naphthalimide derivatives using VISTA (CCDC, 1994). In contrast, the C4—N2 bonds from the naphthalene ring to the piperidine N atom are relatively short [1.4005 (17) Å for (I) and 1.411 (2) Å for (II)], suggesting some delocalization between the naphthalene and piperidine units. However, these distances are somewhat longer than the average value of 1.365 Å in the related N-alkyl-4-amidonaphthalimide derivatives, but compare somewhat more closely with the values of 1.4088 (19) and 1.376 (4) Å found for the two other reported 4-piperidinonaphthalimides (McAdam et al., 2003, 2005).

Naphthalimide compounds are well known to aggregate through π-stacking interactions in the solid state (McAdam et al., 2000; Sarma et al., 2007; Reger et al., 2005) and this often results in poor solubility and difficulty in obtaining crystalline materials (Keeling et al., 2003; Figueiredo et al., 2005). Offset π–π interactions are major contributors to the packing in both (I) and (II). However, such interactions are supported differently, despite the close relationship between these structures.

For (I), offset π–π interactions form head-to-tail dimers via inversion-related Cg1···Cg3ⁱ [3.6442 (8) Å] and Cg3···Cg3ⁱ [3.6923 (8) Å] contacts [symmetry code: (i) -x, 1-y, 1-z; Cg1 and Cg3 are the centroids of the N1/C1/C8/C11/C12 and C5–C10 rings, respectively]. Pairs of dimers are further aggregated through weaker Cg3···Cg1ⁱⁱ [3.9078 (8) Å] contacts [symmetry code: (ii) 1-x, 1-y, 1-z], forming columns down a (Fig. 3). The crystal packing in (I) is further stabilized by non-classical C—H···Br and C—H···O interactions that result in the formation of two sets of inversion-related dimers. C14—H14A···Br1 hydrogen bonds generate an R²₂(6) graph-set motif, while a pair of C15—H15A···O11 contacts forms an R²₂(18) ring (Fig. 4). These dimers combine to form shallow steps along the diagonal of the ac plane (Fig. 5). In the general packing, adjacent molecules in each of the π-stacked columns down a forms rows along c through the C14—H14A···Br1 dimers. The C—H···O dimers link adjacent rows into a three-dimensional network (Fig. 6).

In the crystal packing of (II), pairs of molecules are arranged in an obverse fashion through head-to-head offset π-stacking interactions that involve all three rings of the naphthalimide unit [Cg4···Cg5ⁱⁱⁱ = 3.4956 (9), Cg4···Cg6ⁱⁱⁱ = 3.8629 (9), Cg5···Cg6ⁱⁱⁱ = 3.4896 (9) Å; symmetry code: (iii) x, 1/2-y, 1/2+z; Cg5, Cg6 and Cg7 are the centroids of the N1/C1/C8/C11/C12, C1–C4/C9/C10 and C5–C10 rings, respectively]. These contacts form extended columns down c and are augmented by C15—H15B···O11 interactions (Fig. 7). Pairs of molecules also form centrosymmetric dimers, with an R²₂(10) graph-set motif, through C7—H7···O12 hydrogen bonds (Fig. 8). These link adjacent molecules in each π-stacked column to form zigzag chains along b (Fig. 9). Weak C20—H20A···Br1^iv hydrogen bonds [C20···Br1^iv = 3.6506 (16) Å; symmetry code: (iv) 1 + x, 1/2 - y, 1/2 + z], not shown, appear to be the only links between adjacent chains and may contribute to the overall packing network.

S2. Experimental

N-(2-hydroxyethyl)-4-piperidino-1,8-naphthalimide (Lei et al., 2005) and 4-piperidinonaphthalic anhydride (Kupriyan et al., 2004) were prepared by published or modified literature methods.

PBr₃ (0.87 ml, 9.24 mmol) in tetrahydrofuran (THF, 10 ml) was added to a mixture of N-(2-hydroxyethyl)-4-piperidino-1,8-naphthalimide (1.00 g, 3.08 mmol) and pyridine (0.75 ml, 9.24 mmol) in THF (20 ml) and heated at 323 K for 16 h. The mixture was poured into ice–water, extracted with chloroform and dried over magnesium sulfate. Column chromatography (SiO₂, CH₂Cl₂) yielded 0.71 g (60%) of (I) and recrystallization from CH₂Cl₂–EtOH (1:1, v/v) gave yellow crystals suitable for X-ray analysis. Analysis, calculated for C₁₉H₁₉N₂O₂Br: C 58.93, H 4.95, N 7.23%; found: C 58.94, H 4.98, N 7.12%; ESI-MS: 409.05 [calculated (M+Na)⁺ 409.05]; ¹H NMR (Frequency?, Solvent?, δ, p.p.m.): 1.75 (m, 2H, pip. H), 1.89 (m, 4H, pip. H), 3.24 [t (J = 5 Hz), 4H, pip. H], 3.66 [t (J = 7 Hz), 2H, –CH₂—Br], 4.60 [t (J = 7 Hz), 2H, N—CH₂–], 7.18 [d (J = 8 Hz), naphth. H3], 7.68 [dd (J = 8, 7 Hz), naphth. H6], 8.41 [dd (J = 8, 1 Hz), naphth. H5], 8.51 [d (J = 8 Hz), naphth. H2], 8.58 [dd (J = 7, 1 Hz), naphth. H7]; IR (KBr): ν_C═O 1693, 1654 cm^-1; UV–vis (CH₂Cl₂): λ_max (ε) 414 (11400); emission (CH₂Cl₂): λ_flu 519 nm, ϕ_f 0.46.

4-Piperidinonaphthalic anhydride (1.00 g, 3.55 mmol) and 3-bromopropylamine hydrobromide (1.55 g, 7.10 mmol) were refluxed in propan-2-ol (50 ml) in the presence of Et₃N (2 ml) for 10 h. The mixture was washed with saturated aqueous NaCl and extracted with chloroform. Column chromatography (SiO₂, CH₂Cl₂) yielded 0.42 g (30%) of (II) and recrystallization from CH₂Cl₂–MeOH (1:1 v/v) gave yellow crystals suitable for X-ray analysis. Analysis, calculated for C₂₀H₂₁N₂O₂Br: C 59.86, H 5.28, N 6.98%; found: C 60.09, H 5.32, N 6.99%; ESI-MS: 423.07 [calculated (M+Na)⁺ 423.07]; ¹H NMR (Frequency?, Solvent?, δ, p.p.m.): 1.73 (m, 2H, pip. H), 1.89 (m, 4H, pip. H), 2.32 [qt (J = 7 Hz), 2H, N—CH₂—CH₂–], 3.24 [t (J = 5 Hz), 4H, pip. H], 3.49 [t (J = 7 Hz), 2H, –CH₂—Br], 4.31 [t (J = 7 Hz), 2H, N—CH₂–], 7.18 [d (J = 8 Hz), naphth. H3], 7.68 [dd (J = 9, 8 Hz), naphth. H6], 8.39 [dd (J = 8, 1 Hz), naphth. H5], 8.50 [d (J = 8 Hz), naphth. H2], 8.57 [dd (J = 7, 1 Hz), naphth. H7]; IR (KBr): ν_C═O 1686, 1648 cm^-1; UV–vis (CH₂Cl₂): λ_max (ε) 412 (11400); emission (CH₂Cl₂): λ_flu 518 nm, ϕ_f 0.51.

S3. Refinement

All H atoms for both structures were positioned geometrically and refined using a riding model, with C—H = 0.95–0.99 Å and U_iso(H) = 1.2U_eq(C).

Computing details

For both compounds, data collection: APEX2 (Bruker 2005); cell refinement: APEX2 (Bruker 2005) and SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008) and TITAN2000 (Hunter & Simpson, 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and TITAN2000 (Hunter & Simpson, 1999); molecular graphics: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), enCIFer (Allen et al., 2004) and PLATON (Spek, 2003).

Figures

Fig. 1. The structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Intramolecular hydrogen bonds are shown as dashed lines. Fig. 2. The structure of (II), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Intramolecular hydrogen bonds are shown as dashed lines. Fig. 3. The π-stacking along a for (I). Spheres represent ring centroids and centroid-to-centroid interactions are shown as dotted lines. Fig. 4. Dimer formation in the structure of (II), with hydrogen bonds shown as dashed lines. Fig 5. Part of the structure of (I), showing the formation of shallow steps along the bc diagonal. Hydrogen bonds are shown as dashed lines. Fig. 6. The crystal packing of (I), viewed down a, showing the three-dimensional network structure generated by π–π stacking interactions and C—H···O(Br) hydrogen bonds (dashed lines). Fig. 7. The π–π stacking of (II), augmented by C—H···O hydrogen bonds (dashed lines). Spheres represent ring centroids and centroid-to-centroid interactions are shown as dotted lines. Fig. 8. Centrosymmetric dimers of (II) formed by C—H···O hydrogen bonds (dashed lines). Fig. 9. Columns of π-stacked molecules of (II), viewed down the c axis, with hydrogen bonds shown as dashed lines.

(I) N-(2-bromoethyl)-4-piperidino-1,8-naphthalimide

Crystal data

C19H19BrN2O2	Z = 2
Mr = 387.27	F(000) = 396
Triclinic, P1	Dx = 1.601 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.3476 (4) Å	Cell parameters from 5259 reflections
b = 9.3218 (5) Å	θ = 5.3–65.7°
c = 12.2905 (6) Å	µ = 2.57 mm^−1
α = 82.039 (3)°	T = 90 K
β = 84.205 (2)°	Plate, yellow
γ = 74.937 (3)°	0.56 × 0.46 × 0.12 mm
V = 803.19 (7) Å^3

Data collection

Bruker Nonius APEXII CCD diffractometer	4650 independent reflections
Radiation source: fine-focus sealed tube	4402 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
ω scans	θmax = 30.0°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Bruker 2005)	h = −10→10
Tmin = 0.326, Tmax = 0.734	k = −10→13
13527 measured reflections	l = −17→17

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)] = 0.025	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.067	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0325P)^2 + 0.3733P] where P = (Fo^2 + 2Fc^2)/3
4650 reflections	(Δ/σ)max = 0.002
217 parameters	Δρmax = 0.54 e Å^−3
0 restraints	Δρmin = −0.71 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
Br1	0.229787 (18)	0.629162 (15)	1.007839 (10)	0.01702 (5)
O11	0.32682 (17)	0.21282 (12)	0.78655 (9)	0.0227 (2)
O12	0.29384 (16)	0.69204 (12)	0.63628 (9)	0.0201 (2)
N1	0.32272 (16)	0.44977 (13)	0.70847 (9)	0.0130 (2)
N2	0.20463 (16)	0.15410 (12)	0.28282 (9)	0.0126 (2)
C1	0.28358 (17)	0.26533 (14)	0.59499 (10)	0.0118 (2)
C2	0.27453 (19)	0.12217 (15)	0.58289 (11)	0.0139 (2)
H2	0.2869	0.0484	0.6451	0.017*
C3	0.24740 (19)	0.08385 (14)	0.48035 (11)	0.0139 (2)
H3	0.2416	−0.0154	0.4745	0.017*
C4	0.22886 (17)	0.18830 (14)	0.38699 (10)	0.0115 (2)
C5	0.18684 (17)	0.45735 (14)	0.31113 (11)	0.0120 (2)
H5	0.1613	0.4357	0.2418	0.014*
C6	0.18378 (19)	0.60254 (15)	0.32538 (11)	0.0142 (2)
H6	0.1566	0.6796	0.2657	0.017*
C7	0.22051 (19)	0.63675 (14)	0.42711 (11)	0.0139 (2)
H7	0.2205	0.7364	0.4358	0.017*
C8	0.25680 (17)	0.52573 (14)	0.51481 (11)	0.0114 (2)
C9	0.25821 (16)	0.37629 (13)	0.50255 (10)	0.0103 (2)
C10	0.22759 (17)	0.34038 (14)	0.39879 (10)	0.0104 (2)
C11	0.31183 (18)	0.30231 (15)	0.70320 (11)	0.0138 (2)
C12	0.29129 (18)	0.56542 (15)	0.62160 (11)	0.0136 (2)
C13	0.36250 (18)	0.48749 (16)	0.81410 (11)	0.0153 (2)
H13A	0.4409	0.5608	0.8012	0.018*
H13B	0.4334	0.3965	0.8578	0.018*
C14	0.17800 (18)	0.55310 (15)	0.87669 (11)	0.0136 (2)
H14A	0.1075	0.4753	0.8986	0.016*
H14B	0.0993	0.6354	0.8290	0.016*
C15	0.36388 (18)	0.15987 (15)	0.19907 (11)	0.0144 (2)
H15A	0.4694	0.0704	0.2138	0.017*
H15B	0.4098	0.2496	0.2037	0.017*
C16	0.3002 (2)	0.16551 (16)	0.08421 (11)	0.0176 (3)
H16A	0.4085	0.1656	0.0293	0.021*
H16B	0.2016	0.2590	0.0673	0.021*
C17	0.2214 (2)	0.03070 (17)	0.07635 (12)	0.0208 (3)
H17A	0.1678	0.0417	0.0040	0.025*
H17B	0.3248	−0.0619	0.0820	0.025*
C18	0.0684 (2)	0.01861 (15)	0.16836 (12)	0.0180 (3)
H18A	−0.0430	0.1042	0.1562	0.022*
H18B	0.0283	−0.0746	0.1668	0.022*
C19	0.1405 (2)	0.01786 (15)	0.28051 (12)	0.0164 (2)
H19A	0.0383	0.0128	0.3388	0.020*
H19B	0.2465	−0.0713	0.2951	0.020*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.01930 (7)	0.02308 (8)	0.01071 (7)	−0.00550 (5)	−0.00212 (5)	−0.00766 (5)
O11	0.0362 (6)	0.0187 (5)	0.0122 (5)	−0.0031 (4)	−0.0076 (4)	−0.0012 (4)
O12	0.0311 (5)	0.0184 (5)	0.0158 (5)	−0.0136 (4)	0.0017 (4)	−0.0077 (4)
N1	0.0137 (5)	0.0170 (5)	0.0101 (5)	−0.0044 (4)	−0.0014 (4)	−0.0057 (4)
N2	0.0185 (5)	0.0128 (5)	0.0095 (5)	−0.0086 (4)	0.0000 (4)	−0.0037 (4)
C1	0.0128 (5)	0.0135 (5)	0.0091 (5)	−0.0025 (4)	−0.0014 (4)	−0.0026 (4)
C2	0.0176 (6)	0.0133 (5)	0.0106 (6)	−0.0035 (4)	−0.0025 (4)	−0.0005 (4)
C3	0.0199 (6)	0.0109 (5)	0.0122 (6)	−0.0052 (4)	−0.0023 (4)	−0.0023 (4)
C4	0.0132 (5)	0.0129 (5)	0.0098 (5)	−0.0050 (4)	−0.0008 (4)	−0.0034 (4)
C5	0.0129 (5)	0.0141 (5)	0.0096 (5)	−0.0045 (4)	−0.0004 (4)	−0.0020 (4)
C6	0.0179 (6)	0.0126 (5)	0.0119 (6)	−0.0042 (4)	−0.0001 (4)	−0.0004 (4)
C7	0.0184 (6)	0.0112 (5)	0.0133 (6)	−0.0056 (4)	0.0018 (4)	−0.0037 (4)
C8	0.0123 (5)	0.0132 (5)	0.0102 (5)	−0.0048 (4)	0.0008 (4)	−0.0044 (4)
C9	0.0099 (5)	0.0120 (5)	0.0099 (5)	−0.0035 (4)	−0.0004 (4)	−0.0033 (4)
C10	0.0109 (5)	0.0116 (5)	0.0098 (5)	−0.0039 (4)	0.0000 (4)	−0.0031 (4)
C11	0.0141 (5)	0.0156 (6)	0.0113 (6)	−0.0011 (4)	−0.0022 (4)	−0.0044 (4)
C12	0.0141 (5)	0.0171 (6)	0.0117 (6)	−0.0066 (4)	0.0014 (4)	−0.0050 (5)
C13	0.0139 (5)	0.0220 (6)	0.0118 (6)	−0.0043 (5)	−0.0022 (4)	−0.0079 (5)
C14	0.0150 (5)	0.0182 (6)	0.0098 (5)	−0.0055 (4)	−0.0013 (4)	−0.0060 (4)
C15	0.0158 (5)	0.0159 (6)	0.0123 (6)	−0.0043 (4)	0.0007 (4)	−0.0047 (5)
C16	0.0214 (6)	0.0211 (6)	0.0100 (6)	−0.0041 (5)	0.0012 (5)	−0.0047 (5)
C17	0.0284 (7)	0.0207 (7)	0.0148 (6)	−0.0040 (5)	−0.0043 (5)	−0.0092 (5)
C18	0.0264 (7)	0.0142 (6)	0.0171 (6)	−0.0083 (5)	−0.0076 (5)	−0.0033 (5)
C19	0.0265 (6)	0.0130 (6)	0.0137 (6)	−0.0109 (5)	−0.0044 (5)	−0.0014 (5)

Geometric parameters (Å, º)

Br1—C14	1.9561 (13)	C7—H7	0.9500
O11—C11	1.2230 (17)	C8—C9	1.4191 (17)
O12—C12	1.2236 (17)	C8—C12	1.4745 (18)
N1—C12	1.3990 (17)	C9—C10	1.4157 (17)
N1—C11	1.4082 (17)	C13—C14	1.5140 (18)
N1—C13	1.4667 (17)	C13—H13A	0.9900
N2—C4	1.4004 (17)	C13—H13B	0.9900
N2—C19	1.4694 (16)	C14—H14A	0.9900
N2—C15	1.4852 (17)	C14—H14B	0.9900
C1—C2	1.3822 (18)	C15—C16	1.5216 (19)
C1—C9	1.4186 (17)	C15—H15A	0.9900
C1—C11	1.4666 (18)	C15—H15B	0.9900
C2—C3	1.4028 (19)	C16—C17	1.532 (2)
C2—H2	0.9500	C16—H16A	0.9900
C3—C4	1.3916 (17)	C16—H16B	0.9900
C3—H3	0.9500	C17—C18	1.526 (2)
C4—C10	1.4425 (17)	C17—H17A	0.9900
C5—C6	1.3828 (18)	C17—H17B	0.9900
C5—C10	1.4174 (17)	C18—C19	1.524 (2)
C5—H5	0.9500	C18—H18A	0.9900
C6—C7	1.4003 (19)	C18—H18B	0.9900
C6—H6	0.9500	C19—H19A	0.9900
C7—C8	1.3819 (18)	C19—H19B	0.9900
C12—N1—C11	125.02 (11)	N1—C13—C14	109.26 (10)
C12—N1—C13	117.07 (11)	N1—C13—H13A	109.8
C11—N1—C13	117.86 (11)	C14—C13—H13A	109.8
C4—N2—C19	116.27 (10)	N1—C13—H13B	109.8
C4—N2—C15	115.52 (10)	C14—C13—H13B	109.8
C19—N2—C15	110.29 (11)	H13A—C13—H13B	108.3
C2—C1—C9	119.08 (12)	C13—C14—Br1	109.52 (9)
C2—C1—C11	120.03 (11)	C13—C14—H14A	109.8
C9—C1—C11	120.84 (12)	Br1—C14—H14A	109.8
C1—C2—C3	121.20 (11)	C13—C14—H14B	109.8
C1—C2—H2	119.4	Br1—C14—H14B	109.8
C3—C2—H2	119.4	H14A—C14—H14B	108.2
C4—C3—C2	121.32 (12)	N2—C15—C16	110.23 (11)
C4—C3—H3	119.3	N2—C15—H15A	109.6
C2—C3—H3	119.3	C16—C15—H15A	109.6
C3—C4—N2	123.14 (12)	N2—C15—H15B	109.6
C3—C4—C10	118.44 (12)	C16—C15—H15B	109.6
N2—C4—C10	118.38 (11)	H15A—C15—H15B	108.1
C6—C5—C10	120.80 (12)	C15—C16—C17	110.55 (11)
C6—C5—H5	119.6	C15—C16—H16A	109.5
C10—C5—H5	119.6	C17—C16—H16A	109.5
C5—C6—C7	120.46 (12)	C15—C16—H16B	109.5
C5—C6—H6	119.8	C17—C16—H16B	109.5
C7—C6—H6	119.8	H16A—C16—H16B	108.1
C8—C7—C6	120.11 (12)	C18—C17—C16	110.45 (12)
C8—C7—H7	119.9	C18—C17—H17A	109.6
C6—C7—H7	119.9	C16—C17—H17A	109.6
C7—C8—C9	120.43 (12)	C18—C17—H17B	109.6
C7—C8—C12	118.97 (12)	C16—C17—H17B	109.6
C9—C8—C12	120.59 (11)	H17A—C17—H17B	108.1
C10—C9—C1	120.53 (11)	C19—C18—C17	110.93 (12)
C10—C9—C8	119.58 (11)	C19—C18—H18A	109.5
C1—C9—C8	119.85 (12)	C17—C18—H18A	109.5
C9—C10—C5	118.55 (11)	C19—C18—H18B	109.5
C9—C10—C4	119.28 (11)	C17—C18—H18B	109.5
C5—C10—C4	122.09 (12)	H18A—C18—H18B	108.0
O11—C11—N1	119.69 (13)	N2—C19—C18	109.93 (11)
O11—C11—C1	123.66 (13)	N2—C19—H19A	109.7
N1—C11—C1	116.65 (11)	C18—C19—H19A	109.7
O12—C12—N1	120.01 (13)	N2—C19—H19B	109.7
O12—C12—C8	123.23 (12)	C18—C19—H19B	109.7
N1—C12—C8	116.76 (11)	H19A—C19—H19B	108.2

(II) N-(3-bromopropyl)-4-piperidino-1,8-naphthalimide

Crystal data

C20H21BrN2O2	F(000) = 824
Mr = 401.30	Dx = 1.522 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 9183 reflections
a = 12.4165 (3) Å	θ = 2.3–31.9°
b = 17.7709 (5) Å	µ = 2.36 mm^−1
c = 7.9618 (2) Å	T = 90 K
β = 94.569 (1)°	Plate, yellow
V = 1751.21 (8) Å^3	0.62 × 0.14 × 0.04 mm
Z = 4

Data collection

Bruker Nonius APEXII CCD diffractometer	5571 independent reflections
Radiation source: fine-focus sealed tube	4434 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.052
ω scans	θmax = 31.0°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker 2005)	h = −17→17
Tmin = 0.201, Tmax = 0.911	k = −25→25
30759 measured reflections	l = −11→11

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.098	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0407P)^2 + 1.4674P] where P = (Fo^2 + 2Fc^2)/3
5571 reflections	(Δ/σ)max < 0.001
226 parameters	Δρmax = 1.12 e Å^−3
0 restraints	Δρmin = −0.99 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
Br1	−0.527590 (16)	0.344479 (14)	−0.08936 (3)	0.03387 (8)
C1	−0.07010 (12)	0.21710 (9)	0.13372 (19)	0.0101 (3)
C2	−0.05950 (13)	0.13995 (9)	0.1262 (2)	0.0117 (3)
H2	−0.1127	0.1087	0.1699	0.014*
C3	0.02862 (12)	0.10695 (9)	0.0549 (2)	0.0119 (3)
H3	0.0339	0.0537	0.0508	0.014*
C4	0.10850 (12)	0.15060 (9)	−0.00995 (19)	0.0106 (3)
C5	0.17083 (13)	0.28019 (9)	−0.0824 (2)	0.0123 (3)
H5	0.2295	0.2597	−0.1371	0.015*
C6	0.15774 (13)	0.35695 (9)	−0.0764 (2)	0.0139 (3)
H6	0.2083	0.3888	−0.1248	0.017*
C7	0.07062 (13)	0.38882 (9)	0.0005 (2)	0.0128 (3)
H7	0.0628	0.4420	0.0047	0.015*
C8	−0.00351 (13)	0.34286 (9)	0.07011 (19)	0.0107 (3)
C9	0.00834 (12)	0.26353 (9)	0.06657 (18)	0.0095 (3)
C10	0.09767 (12)	0.23118 (9)	−0.00795 (19)	0.0101 (3)
C11	−0.16305 (12)	0.24960 (9)	0.21211 (19)	0.0112 (3)
O11	−0.23120 (10)	0.21141 (7)	0.27405 (16)	0.0172 (2)
C12	−0.09637 (13)	0.37712 (9)	0.1471 (2)	0.0125 (3)
O12	−0.10989 (10)	0.44520 (7)	0.15472 (17)	0.0187 (3)
N1	−0.17076 (11)	0.32831 (7)	0.21262 (17)	0.0112 (2)
C13	−0.26345 (13)	0.36280 (9)	0.2877 (2)	0.0143 (3)
H13A	−0.2389	0.4087	0.3501	0.017*
H13B	−0.2914	0.3272	0.3694	0.017*
C14	−0.35487 (14)	0.38371 (10)	0.1556 (2)	0.0178 (3)
H14A	−0.4106	0.4126	0.2104	0.021*
H14B	−0.3258	0.4165	0.0693	0.021*
C15	−0.40682 (15)	0.31494 (11)	0.0701 (2)	0.0203 (3)
H15A	−0.4332	0.2809	0.1562	0.024*
H15B	−0.3524	0.2874	0.0097	0.024*
N2	0.19869 (11)	0.11816 (8)	−0.07946 (17)	0.0114 (2)
C16	0.18654 (13)	0.03899 (9)	−0.1283 (2)	0.0133 (3)
H16A	0.1158	0.0316	−0.1928	0.016*
H16B	0.1881	0.0073	−0.0259	0.016*
C17	0.27673 (13)	0.01469 (9)	−0.2355 (2)	0.0156 (3)
H17A	0.2711	0.0432	−0.3426	0.019*
H17B	0.2688	−0.0395	−0.2627	0.019*
C18	0.38716 (14)	0.02853 (10)	−0.1428 (2)	0.0188 (3)
H18A	0.4446	0.0166	−0.2179	0.023*
H18B	0.3966	−0.0048	−0.0430	0.023*
C19	0.39682 (13)	0.11066 (10)	−0.0871 (2)	0.0179 (3)
H19A	0.4664	0.1185	−0.0195	0.022*
H19B	0.3956	0.1437	−0.1874	0.022*
C20	0.30362 (13)	0.13121 (10)	0.0176 (2)	0.0148 (3)
H20A	0.3077	0.1004	0.1215	0.018*
H20B	0.3095	0.1848	0.0510	0.018*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.01854 (10)	0.05145 (16)	0.03016 (12)	0.00572 (9)	−0.00723 (8)	−0.00056 (9)
C1	0.0093 (6)	0.0119 (7)	0.0089 (6)	−0.0008 (5)	0.0000 (5)	0.0002 (5)
C2	0.0116 (7)	0.0118 (7)	0.0120 (7)	−0.0018 (5)	0.0017 (5)	0.0007 (5)
C3	0.0127 (7)	0.0093 (6)	0.0137 (7)	−0.0003 (5)	0.0016 (5)	−0.0012 (5)
C4	0.0102 (6)	0.0124 (7)	0.0088 (6)	0.0006 (5)	−0.0011 (5)	−0.0007 (5)
C5	0.0111 (6)	0.0151 (7)	0.0109 (7)	−0.0011 (5)	0.0018 (5)	0.0002 (5)
C6	0.0127 (7)	0.0158 (7)	0.0132 (7)	−0.0039 (6)	0.0021 (5)	0.0023 (6)
C7	0.0143 (7)	0.0118 (7)	0.0122 (7)	−0.0016 (5)	0.0006 (5)	0.0010 (5)
C8	0.0109 (6)	0.0116 (7)	0.0096 (6)	−0.0004 (5)	0.0003 (5)	−0.0003 (5)
C9	0.0096 (6)	0.0115 (7)	0.0071 (6)	−0.0008 (5)	−0.0007 (5)	0.0001 (5)
C10	0.0098 (6)	0.0118 (7)	0.0085 (6)	−0.0013 (5)	0.0001 (5)	0.0001 (5)
C11	0.0111 (6)	0.0114 (7)	0.0109 (7)	0.0001 (5)	0.0003 (5)	0.0003 (5)
O11	0.0151 (6)	0.0147 (6)	0.0228 (6)	−0.0012 (4)	0.0079 (5)	0.0004 (5)
C12	0.0129 (7)	0.0127 (7)	0.0120 (7)	−0.0001 (5)	0.0010 (5)	0.0011 (5)
O12	0.0200 (6)	0.0111 (5)	0.0260 (7)	0.0010 (4)	0.0070 (5)	0.0012 (5)
N1	0.0107 (6)	0.0106 (6)	0.0124 (6)	0.0004 (5)	0.0023 (5)	−0.0006 (5)
C13	0.0142 (7)	0.0144 (7)	0.0148 (7)	0.0013 (6)	0.0044 (6)	−0.0029 (6)
C14	0.0138 (7)	0.0171 (8)	0.0226 (8)	0.0039 (6)	0.0033 (6)	0.0012 (6)
C15	0.0156 (8)	0.0259 (9)	0.0189 (8)	0.0014 (7)	−0.0019 (6)	−0.0012 (7)
N2	0.0090 (6)	0.0118 (6)	0.0135 (6)	0.0010 (5)	0.0010 (5)	−0.0017 (5)
C16	0.0128 (7)	0.0111 (7)	0.0161 (7)	0.0007 (5)	0.0023 (6)	−0.0002 (6)
C17	0.0147 (7)	0.0140 (7)	0.0184 (8)	0.0027 (6)	0.0040 (6)	−0.0015 (6)
C18	0.0118 (7)	0.0202 (8)	0.0249 (9)	0.0034 (6)	0.0047 (6)	0.0003 (7)
C19	0.0106 (7)	0.0206 (8)	0.0229 (8)	0.0011 (6)	0.0031 (6)	−0.0010 (7)
C20	0.0102 (7)	0.0193 (8)	0.0146 (7)	0.0007 (6)	−0.0007 (5)	−0.0015 (6)

Geometric parameters (Å, º)

Br1—C15	1.9579 (18)	C13—C14	1.531 (2)
C1—C2	1.379 (2)	C13—H13A	0.9900
C1—C9	1.414 (2)	C13—H13B	0.9900
C1—C11	1.473 (2)	C14—C15	1.517 (3)
C2—C3	1.401 (2)	C14—H14A	0.9900
C2—H2	0.9500	C14—H14B	0.9900
C3—C4	1.391 (2)	C15—H15A	0.9900
C3—H3	0.9500	C15—H15B	0.9900
C4—N2	1.411 (2)	N2—C16	1.464 (2)
C4—C10	1.438 (2)	N2—C20	1.479 (2)
C5—C6	1.375 (2)	C16—C17	1.524 (2)
C5—C10	1.422 (2)	C16—H16A	0.9900
C5—H5	0.9500	C16—H16B	0.9900
C6—C7	1.404 (2)	C17—C18	1.525 (2)
C6—H6	0.9500	C17—H17A	0.9900
C7—C8	1.379 (2)	C17—H17B	0.9900
C7—H7	0.9500	C18—C19	1.527 (3)
C8—C9	1.418 (2)	C18—H18A	0.9900
C8—C12	1.479 (2)	C18—H18B	0.9900
C9—C10	1.420 (2)	C19—C20	1.524 (2)
C11—O11	1.2192 (19)	C19—H19A	0.9900
C11—N1	1.402 (2)	C19—H19B	0.9900
C12—O12	1.224 (2)	C20—H20A	0.9900
C12—N1	1.398 (2)	C20—H20B	0.9900
N1—C13	1.472 (2)
C2—C1—C9	119.53 (14)	C15—C14—C13	112.21 (14)
C2—C1—C11	119.27 (14)	C15—C14—H14A	109.2
C9—C1—C11	121.20 (14)	C13—C14—H14A	109.2
C1—C2—C3	120.95 (14)	C15—C14—H14B	109.2
C1—C2—H2	119.5	C13—C14—H14B	109.2
C3—C2—H2	119.5	H14A—C14—H14B	107.9
C4—C3—C2	121.34 (14)	C14—C15—Br1	110.55 (13)
C4—C3—H3	119.3	C14—C15—H15A	109.5
C2—C3—H3	119.3	Br1—C15—H15A	109.5
C3—C4—N2	121.97 (14)	C14—C15—H15B	109.5
C3—C4—C10	118.76 (14)	Br1—C15—H15B	109.5
N2—C4—C10	119.27 (13)	H15A—C15—H15B	108.1
C6—C5—C10	120.79 (14)	C4—N2—C16	115.37 (13)
C6—C5—H5	119.6	C4—N2—C20	115.11 (13)
C10—C5—H5	119.6	C16—N2—C20	110.93 (13)
C5—C6—C7	120.86 (15)	N2—C16—C17	110.87 (13)
C5—C6—H6	119.6	N2—C16—H16A	109.5
C7—C6—H6	119.6	C17—C16—H16A	109.5
C8—C7—C6	119.87 (15)	N2—C16—H16B	109.5
C8—C7—H7	120.1	C17—C16—H16B	109.5
C6—C7—H7	120.1	H16A—C16—H16B	108.1
C7—C8—C9	120.48 (14)	C16—C17—C18	110.85 (14)
C7—C8—C12	119.32 (14)	C16—C17—H17A	109.5
C9—C8—C12	120.20 (13)	C18—C17—H17A	109.5
C1—C9—C8	119.81 (14)	C16—C17—H17B	109.5
C1—C9—C10	120.41 (14)	C18—C17—H17B	109.5
C8—C9—C10	119.77 (13)	H17A—C17—H17B	108.1
C9—C10—C5	118.19 (14)	C17—C18—C19	109.97 (14)
C9—C10—C4	118.97 (13)	C17—C18—H18A	109.7
C5—C10—C4	122.81 (14)	C19—C18—H18A	109.7
O11—C11—N1	120.30 (14)	C17—C18—H18B	109.7
O11—C11—C1	123.06 (14)	C19—C18—H18B	109.7
N1—C11—C1	116.64 (13)	H18A—C18—H18B	108.2
O12—C12—N1	119.83 (14)	C20—C19—C18	110.02 (14)
O12—C12—C8	122.83 (14)	C20—C19—H19A	109.7
N1—C12—C8	117.34 (14)	C18—C19—H19A	109.7
C12—N1—C11	124.79 (13)	C20—C19—H19B	109.7
C12—N1—C13	117.03 (13)	C18—C19—H19B	109.7
C11—N1—C13	118.18 (13)	H19A—C19—H19B	108.2
N1—C13—C14	112.53 (13)	N2—C20—C19	110.61 (14)
N1—C13—H13A	109.1	N2—C20—H20A	109.5
C14—C13—H13A	109.1	C19—C20—H20A	109.5
N1—C13—H13B	109.1	N2—C20—H20B	109.5
C14—C13—H13B	109.1	C19—C20—H20B	109.5
H13A—C13—H13B	107.8	H20A—C20—H20B	108.1

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···O12^i	0.95	2.47	3.250 (2)	140
C15—H15B···O11^ii	0.99	2.50	3.369 (2)	147

Symmetry codes: (i) −x, −y+1, −z; (ii) x, −y+1/2, z−1/2.