3,5-Bis(4-methoxy­benzyl­idene)-1-methyl-4-piperidone and 3,5-bis(4-methoxy­benzyl­idene)-1-methyl-4-oxopiperidinium chloride: potential biophotonic materials

In the title compound 3,5-bis(4-methoxy­benzyl­idene)-1-methyl-4-piperidone, C₂₂H₂₃NO₃, (I), the central heterocyclic ring adopts a flattened boat conformation, while in the related salt 3,5-bis(4-methoxy­benzyl­idene)-1-methyl-4-oxopiperidin­ium chloride, C₂₂H₂₄NO₃⁺·Cl⁻, (II), the ring exhibits a `sofa' conformation in which the N atom deviates from the planar fragment. The pendant benzene rings are twisted from the heterocyclic ring planes in both mol­ecules in the same direction, the range of dihedral angles between the ring planes being 24.5 (2)–32.7 (2)°. The dominant packing motif in (I) involves centrosymmetric dimers bound by weak intermolecular C—H...O hydrogen bonds. In (II), cations and anions are linked by strong N—H...Cl hydrogen bonds, while weak C—H...O and C—H...Cl hydrogen bonds link the cations and anions into a three-dimensional framework.

S1. Comment

The present investigation is a continuation of our work that includes the syntheses and structural investigation of nonlinear optical organic compounds with two-photon absorption properties, such compounds being potential biophotonic materials (Nesterov et al., 2003; Peterson et al., 2004a,2004b). Comparison of the structures of the investigated molecules with related compounds found in the literature that possess anticancer activities has shown that these compounds are very similar (Jia et al., 1988, 1989; Dimmock et al., 1992a, 1992b; Dimmock et al., 1994a, 1994b; Dimmock et al., 2001). The compounds that we are investigating may find applications as agents for locating cancer cells with two-photon exited fluorescence and have potential as agents for a photodynamic treatment of cancer (Nesterov et al., 2003; Peterson et al., 2004a,2004b). The syntheses and structural investigation of 3,5-bis(4-methoxybenzylidene)-1-methyl-4-piperidone, (I) (Fig. 1), and the salt, (II) (Fig. 2), that was obtained from (I) are presented here. Their two-photon absorption properties and fluorescence activity will be published elsewhere.

Both compounds contain two p-methoxyphenyl donor groups connected to the central acceptor heterocyclic ring via conjugated bridges, but the compounds have slightly different structures. In (I), the heterocyclic ring adopts a flattened boat conformation; atoms N1 and C4 are out of the C2/C3/C5/C6 plane [planar within 0.027 (3) Å] by −0.714 (3) and −0.190 (3) Å, respectively. In (II), the conformation of this ring can be described as sofa; atom N1 is out of the C2–C6 plane [planar within 0.013 (3) Å] by 0.686 (3) Å. We have previously described a conformation of the heterocyclic ring in related compounds (Nesterov et al., 2003). As seen in Figs. 1 and 2, the methyl substituents of the methoxy groups have different orientations relative to the phenyl rings. In both cases, these substituents almost lie in the planes of the aromatic rings [C10—C11—O2—C14 = −175.8 (3) and −7.8 (5)°, and C18—C19—O3—C22 = 174.0 (3) and 3.0 (5)°, in (I) and (II), respectively], with geometric parameters in good agreement with the literature data (Gallagher et al., 2001). According to these results, it is possible to predict the existence of other polymorphic modifications of (I) and (II) corresponding to other orientations of these flexible substituents.

Both molecules are non-planar; the dihedral angles between the flat part of the heterocycle and the two almost flat fragments that include the phenyl ring and the bridging atom are 24.5 (2) and 32.7 (2)° in (I), and 25.1 (2) and 31.0 (2)° in (II). The differences in a mutual orientation of these fragments and the flatness of the heterocyclic rings [especially in (II)] lead to H···H intramolecular steric interactions [H2A···H21A = 2.32 and 2.23 Å, and H6B···H13A = 2.32 and 2.09 Å, in (I) and (II), respectively]. These contacts are very close to or shorter than the sum of the van der Waals radii of H atoms (Rowland & Taylor, 1996). Nevertheless, it is possible to predict conjugation between the donor and acceptor parts of the molecules. The bond length distributions in the bridges show a small alternation of single C—C and double C=C bond lengths (Tables 1 and 3) around standard distances (Allen et al., 1987). Most of the geometric parameters in the investigated molecules are very similar to those reported in our previous studies (Nesterov et al., 2003).

In the crystal structure of (I), there is an intermolecular steric contact (H22C···O1 = 2.51 Å) that, according to literature data (Desiraju & Steiner 1999), can be considered as a weak hydrogen bond. Such hydrogen bonds link the molecules into centrosymmetric dimers (Fig. 3 and Table 2). In the crystal of (II), cations and anions are linked by strong N1—H1···Cl1 hydrogen bonds. In addition, weak H1B···O1 (2.45 Å) and H18A···O2 (2.52 Å) intermolecular hydrogen bonds link cations into layers parallel to the ac plane (Fig. 4). Moreover, the Cl⁻ anions form very weak intermolecular contacts with the cations (Cl1···H13A = 2.83 Å and Cl1···H21A =2.89 Å), thus completing a three-dimensional framework (Table 4). In salt (II), there are also intermolecular steric contacts between C···C atoms, which are less than the sum of the van der Waals radii of C atoms (Rowland & Taylor, 1996) [C4···C4(1 − x, 1 − y, 1 − z) = 3.228 (4) Å and C7···C15(1 − x, 1 − y,1 − z) = 3.376 (4) Å]. The remaining geometric parameters in the investigated molecules have normal values (Allen et al., 1987).

S2. Experimental

Compound (I) was obtained according to the procedure described by Nesterov et al. (2003). The precipitate was isolated and recrystallized from tetrahydrofurane (m.p. 477 K, yield 76%). Compound (II) was synthesized on the base (I) and recrystallized from ethanol (m.p. 484 K, yield 91%). Crystals of the two compounds were grown by isothermal evaporation of acetonitrile and ethanol solutions of (I) and (II), respectively. The compounds were characterized by ¹H and ¹³C NMR spectroscopy.

Computing details

For both compounds, data collection: CAD-4 Software (Enraf–Nonuis, 1989); cell refinement: CAD-4 Software; data reduction: SHELXTL (Sheldrick, 1994); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. : A view of (I), showing the atom numbering used. Non-H atoms are shown with displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. : A view of (II), showing the atom numbering used. Non-H atoms are shown with displacement ellipsoids drawn at the 50% probability level.
	Fig. 3. : A projection of the crystal packing of (I) along the c axis. Dashed lines are intermolecular C—H···O hydrogen bonds (see Table 2).
	Fig. 4. : A projection of the crystal packing of (II) along the b axis. Dashed lines are intermolecular N—H···Cl and C—H···O hydrogen bonds (see Table 4).

(I) 3,5-bis(4-methoxybenzylidene)-1-methyl-4-piperidone

Crystal data

C22H23NO3	F(000) = 744
Mr = 349.41	Dx = 1.279 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 11.315 (2) Å	Cell parameters from 24 reflections
b = 7.8910 (16) Å	θ = 10–11°
c = 20.356 (4) Å	µ = 0.09 mm^−1
β = 92.87 (3)°	T = 295 K
V = 1815.2 (6) Å^3	Needle, yellow
Z = 4	0.50 × 0.20 × 0.10 mm

Data collection

Enraf-Nonius CAD4 diffractometer	Rint = 0.073
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 2.0°
Graphite monochromator	h = 0→13
θ/2θ scans	k = 0→9
3340 measured reflections	l = −24→24
3167 independent reflections	3 standard reflections every 97 reflections
1398 reflections with I > 2σ(I)	intensity decay: 3%

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)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.128	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.05P)^2] where P = (Fo^2 + 2Fc^2)/3
3167 reflections	(Δ/σ)max < 0.001
238 parameters	Δρmax = 0.16 e Å^−3
0 restraints	Δρmin = −0.20 e Å^−3

Special details

Experimental. (I): ¹H NMR (CDCl₃, 300 MHz) δ 7.77 (s, 2H), 7.37 (d, 4H, J = 8.8 Hz), 6.95 (d, 4H, J = 8.8 Hz), 3.85 (s, 6H), 3.76 (s, 4H), 2.48 (s, 3H) p.p.m.. ¹³C NMR (CDCl₃, 75 MHz) δ 186.8, 160.2, 135.9, 132.3, 131.3, 128.0, 114.0, 57.2, 55.3, 45.9 p.p.m..

(II): ¹H NMR (DMSO-d₆, 300 MHz) δ 11.80 (br s, 1H, NH), 7.83 (s, 2H), 7.53 (d, 4H, J = 8.8 Hz), 7.09 (d, 4H, J = 8.8 Hz), 4.64 (s, 4H), 3.84 (s, 6H), 2.98 (s, 3H) p.p.m.. ¹³C NMR (DMSO-d₆, 75 MHz) δ 181.1, 160.8, 139.1, 133.0, 126.1, 124.8, 114.5, 55.5, 53.1, 42.2 p.p.m..

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. All H atoms were placed in geometrically calculated positions and refined using a riding model with C—H distances of 0.93 Å for aromatic H atoms with U_iso(H) = 1.2U_eq(C), 0.97 Å for CH₂ with U_iso(H) = 1.2U_eq(C) and 0.96 Å for CH₃ groups with U_iso(H) = 1.5U_eq(C).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	−0.03600 (19)	0.1467 (3)	0.67933 (10)	0.0727 (7)
O2	0.12189 (18)	0.3551 (3)	1.07297 (10)	0.0639 (7)
O3	0.1767 (2)	0.4268 (3)	0.30861 (10)	0.0813 (8)
N1	0.30109 (18)	0.2390 (3)	0.69294 (11)	0.0441 (6)
C1	0.4293 (2)	0.2564 (4)	0.69818 (15)	0.0583 (9)
H1A	0.4610	0.1851	0.7330	0.087*
H1B	0.4497	0.3722	0.7076	0.087*
H1C	0.4617	0.2232	0.6574	0.087*
C2	0.2483 (2)	0.3260 (4)	0.63555 (13)	0.0474 (8)
H2A	0.2918	0.2985	0.5971	0.057*
H2B	0.2524	0.4476	0.6423	0.057*
C3	0.1215 (2)	0.2722 (4)	0.62480 (14)	0.0432 (8)
C4	0.0603 (3)	0.2174 (4)	0.68389 (14)	0.0480 (8)
C5	0.1183 (2)	0.2569 (4)	0.74930 (14)	0.0428 (7)
C6	0.2474 (3)	0.2987 (4)	0.75162 (15)	0.0457 (8)
H6A	0.2577	0.4204	0.7554	0.055*
H6B	0.2862	0.2462	0.7900	0.055*
C7	0.0511 (3)	0.2448 (4)	0.80208 (14)	0.0475 (8)
H7A	−0.0267	0.2114	0.7924	0.057*
C8	0.0800 (2)	0.2755 (4)	0.87154 (13)	0.0410 (7)
C9	0.0088 (3)	0.1995 (4)	0.91714 (15)	0.0554 (9)
H9A	−0.0523	0.1284	0.9021	0.066*
C10	0.0261 (3)	0.2263 (4)	0.98307 (15)	0.0593 (9)
H10A	−0.0219	0.1720	1.0123	0.071*
C11	0.1141 (3)	0.3331 (4)	1.00649 (14)	0.0458 (8)
C12	0.1866 (3)	0.4099 (4)	0.96313 (14)	0.0509 (8)
H12A	0.2472	0.4812	0.9786	0.061*
C13	0.1688 (3)	0.3802 (4)	0.89641 (14)	0.0510 (8)
H13A	0.2182	0.4326	0.8674	0.061*
C14	0.2065 (3)	0.4737 (5)	1.09958 (15)	0.0751 (11)
H14A	0.1979	0.4845	1.1461	0.113*
H14B	0.1937	0.5819	1.0789	0.113*
H14C	0.2849	0.4345	1.0917	0.113*
C15	0.0621 (2)	0.2645 (4)	0.56676 (14)	0.0478 (8)
H15A	−0.0139	0.2203	0.5682	0.057*
C16	0.0962 (2)	0.3136 (4)	0.50127 (14)	0.0451 (8)
C17	0.0421 (3)	0.2336 (4)	0.44676 (15)	0.0599 (9)
H17A	−0.0151	0.1513	0.4532	0.072*
C18	0.0708 (3)	0.2729 (5)	0.38355 (16)	0.0659 (10)
H18A	0.0352	0.2144	0.3482	0.079*
C19	0.1521 (3)	0.3988 (4)	0.37257 (15)	0.0546 (9)
C20	0.2046 (2)	0.4836 (4)	0.42576 (13)	0.0494 (8)
H20A	0.2585	0.5700	0.4190	0.059*
C21	0.1773 (2)	0.4408 (4)	0.48852 (14)	0.0488 (8)
H21A	0.2142	0.4985	0.5237	0.059*
C22	0.2508 (3)	0.5651 (5)	0.29362 (16)	0.0776 (12)
H22A	0.2634	0.5657	0.2473	0.116*
H22B	0.3255	0.5539	0.3178	0.116*
H22C	0.2137	0.6693	0.3056	0.116*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0572 (15)	0.100 (2)	0.0612 (15)	−0.0318 (15)	0.0076 (11)	−0.0073 (14)
O2	0.0704 (15)	0.0747 (17)	0.0470 (14)	−0.0021 (13)	0.0060 (11)	−0.0018 (13)
O3	0.120 (2)	0.082 (2)	0.0421 (14)	−0.0178 (17)	0.0054 (13)	−0.0025 (13)
N1	0.0403 (13)	0.0489 (17)	0.0433 (14)	0.0000 (12)	0.0045 (11)	−0.0039 (13)
C1	0.0433 (18)	0.072 (3)	0.060 (2)	0.0001 (17)	0.0060 (14)	−0.0017 (18)
C2	0.0516 (19)	0.048 (2)	0.0423 (18)	−0.0018 (16)	0.0028 (14)	−0.0019 (16)
C3	0.0452 (17)	0.0383 (19)	0.0462 (19)	0.0011 (15)	0.0037 (14)	−0.0022 (15)
C4	0.0442 (18)	0.048 (2)	0.052 (2)	−0.0051 (16)	0.0061 (14)	−0.0013 (16)
C5	0.0472 (17)	0.0342 (18)	0.0475 (18)	−0.0014 (15)	0.0074 (14)	−0.0001 (15)
C6	0.0502 (17)	0.042 (2)	0.0453 (17)	−0.0027 (15)	0.0081 (13)	−0.0024 (15)
C7	0.0464 (18)	0.044 (2)	0.053 (2)	−0.0025 (16)	0.0058 (14)	0.0004 (16)
C8	0.0429 (17)	0.0383 (19)	0.0422 (17)	0.0009 (15)	0.0078 (13)	0.0012 (15)
C9	0.0491 (19)	0.064 (2)	0.054 (2)	−0.0150 (17)	0.0110 (15)	−0.0058 (18)
C10	0.059 (2)	0.070 (3)	0.049 (2)	−0.015 (2)	0.0160 (15)	0.0028 (18)
C11	0.0496 (19)	0.050 (2)	0.0384 (18)	0.0077 (16)	0.0040 (15)	0.0047 (16)
C12	0.0525 (19)	0.048 (2)	0.053 (2)	−0.0072 (16)	0.0081 (15)	−0.0053 (16)
C13	0.059 (2)	0.049 (2)	0.046 (2)	−0.0061 (17)	0.0161 (16)	0.0003 (16)
C14	0.083 (3)	0.082 (3)	0.058 (2)	0.007 (2)	−0.0120 (19)	−0.009 (2)
C15	0.0426 (17)	0.047 (2)	0.054 (2)	0.0025 (15)	0.0032 (14)	−0.0030 (16)
C16	0.0387 (17)	0.051 (2)	0.0449 (19)	0.0030 (15)	−0.0025 (14)	−0.0008 (16)
C17	0.056 (2)	0.067 (3)	0.055 (2)	−0.0136 (18)	−0.0101 (16)	0.0059 (19)
C18	0.079 (2)	0.067 (3)	0.049 (2)	−0.012 (2)	−0.0168 (17)	−0.0043 (19)
C19	0.065 (2)	0.056 (2)	0.042 (2)	0.0030 (18)	−0.0014 (16)	−0.0019 (17)
C20	0.051 (2)	0.050 (2)	0.047 (2)	−0.0015 (16)	−0.0015 (15)	0.0015 (16)
C21	0.054 (2)	0.049 (2)	0.0427 (18)	0.0015 (17)	−0.0025 (14)	−0.0073 (16)
C22	0.093 (3)	0.081 (3)	0.059 (2)	−0.004 (2)	0.010 (2)	0.009 (2)

Geometric parameters (Å, º)

O1—C4	1.223 (3)	C9—H9A	0.9300
O2—C11	1.363 (3)	C10—C11	1.372 (4)
O2—C14	1.426 (4)	C10—H10A	0.9300
O3—C19	1.363 (4)	C11—C12	1.375 (4)
O3—C22	1.419 (4)	C12—C13	1.383 (4)
N1—C6	1.446 (3)	C12—H12A	0.9300
N1—C1	1.455 (3)	C13—H13A	0.9300
N1—C2	1.457 (3)	C14—H14A	0.9600
C1—H1A	0.9600	C14—H14B	0.9600
C1—H1B	0.9600	C14—H14C	0.9600
C1—H1C	0.9600	C15—C16	1.458 (4)
C2—C3	1.503 (4)	C15—H15A	0.9300
C2—H2A	0.9700	C16—C17	1.392 (4)
C2—H2B	0.9700	C16—C21	1.393 (4)
C3—C15	1.331 (4)	C17—C18	1.378 (4)
C3—C4	1.482 (4)	C17—H17A	0.9300
C4—C5	1.488 (4)	C18—C19	1.380 (4)
C5—C7	1.351 (4)	C18—H18A	0.9300
C5—C6	1.495 (4)	C19—C20	1.382 (4)
C6—H6A	0.9700	C20—C21	1.372 (4)
C6—H6B	0.9700	C20—H20A	0.9300
C7—C8	1.455 (4)	C21—H21A	0.9300
C7—H7A	0.9300	C22—H22A	0.9600
C8—C13	1.378 (4)	C22—H22B	0.9600
C8—C9	1.395 (4)	C22—H22C	0.9600
C9—C10	1.363 (4)
C11—O2—C14	118.0 (2)	C11—C10—H10A	119.9
C19—O3—C22	118.8 (3)	O2—C11—C10	115.6 (3)
C6—N1—C1	111.6 (2)	O2—C11—C12	124.8 (3)
C6—N1—C2	109.7 (2)	C10—C11—C12	119.6 (3)
C1—N1—C2	112.4 (2)	C11—C12—C13	119.6 (3)
N1—C1—H1A	109.5	C11—C12—H12A	120.2
N1—C1—H1B	109.5	C13—C12—H12A	120.2
H1A—C1—H1B	109.5	C8—C13—C12	122.0 (3)
N1—C1—H1C	109.5	C8—C13—H13A	119.0
H1A—C1—H1C	109.5	C12—C13—H13A	119.0
H1B—C1—H1C	109.5	O2—C14—H14A	109.5
N1—C2—C3	109.5 (2)	O2—C14—H14B	109.5
N1—C2—H2A	109.8	H14A—C14—H14B	109.5
C3—C2—H2A	109.8	O2—C14—H14C	109.5
N1—C2—H2B	109.8	H14A—C14—H14C	109.5
C3—C2—H2B	109.8	H14B—C14—H14C	109.5
H2A—C2—H2B	108.2	C3—C15—C16	130.9 (3)
C15—C3—C4	118.1 (3)	C3—C15—H15A	114.6
C15—C3—C2	125.3 (3)	C16—C15—H15A	114.6
C4—C3—C2	116.5 (2)	C17—C16—C21	116.5 (3)
O1—C4—C3	121.5 (3)	C17—C16—C15	118.8 (3)
O1—C4—C5	121.0 (3)	C21—C16—C15	124.6 (3)
C3—C4—C5	117.5 (3)	C18—C17—C16	121.8 (3)
C7—C5—C4	117.1 (3)	C18—C17—H17A	119.1
C7—C5—C6	125.3 (3)	C16—C17—H17A	119.1
C4—C5—C6	117.5 (2)	C17—C18—C19	120.2 (3)
N1—C6—C5	110.6 (2)	C17—C18—H18A	119.9
N1—C6—H6A	109.5	C19—C18—H18A	119.9
C5—C6—H6A	109.5	O3—C19—C18	116.2 (3)
N1—C6—H6B	109.5	O3—C19—C20	124.7 (3)
C5—C6—H6B	109.5	C18—C19—C20	119.1 (3)
H6A—C6—H6B	108.1	C21—C20—C19	120.2 (3)
C5—C7—C8	130.8 (3)	C21—C20—H20A	119.9
C5—C7—H7A	114.6	C19—C20—H20A	119.9
C8—C7—H7A	114.6	C20—C21—C16	122.1 (3)
C13—C8—C9	116.6 (3)	C20—C21—H21A	118.9
C13—C8—C7	125.5 (3)	C16—C21—H21A	118.9
C9—C8—C7	117.8 (3)	O3—C22—H22A	109.5
C10—C9—C8	122.0 (3)	O3—C22—H22B	109.5
C10—C9—H9A	119.0	H22A—C22—H22B	109.5
C8—C9—H9A	119.0	O3—C22—H22C	109.5
C9—C10—C11	120.2 (3)	H22A—C22—H22C	109.5
C9—C10—H10A	119.9	H22B—C22—H22C	109.5
C6—N1—C2—C3	−67.6 (3)	C14—O2—C11—C12	3.9 (4)
C1—N1—C2—C3	167.7 (2)	C9—C10—C11—O2	178.2 (3)
N1—C2—C3—C15	−149.9 (3)	C9—C10—C11—C12	−1.6 (5)
N1—C2—C3—C4	27.6 (3)	O2—C11—C12—C13	−178.8 (3)
C15—C3—C4—O1	9.3 (5)	C10—C11—C12—C13	0.9 (5)
C2—C3—C4—O1	−168.4 (3)	C9—C8—C13—C12	−0.3 (4)
C15—C3—C4—C5	−168.6 (3)	C7—C8—C13—C12	176.4 (3)
C2—C3—C4—C5	13.7 (4)	C11—C12—C13—C8	0.0 (5)
O1—C4—C5—C7	−13.5 (4)	C4—C3—C15—C16	177.8 (3)
C3—C4—C5—C7	164.4 (3)	C2—C3—C15—C16	−4.7 (5)
O1—C4—C5—C6	163.6 (3)	C3—C15—C16—C17	154.0 (3)
C3—C4—C5—C6	−18.4 (4)	C3—C15—C16—C21	−28.3 (5)
C1—N1—C6—C5	−171.8 (2)	C21—C16—C17—C18	2.6 (5)
C2—N1—C6—C5	63.0 (3)	C15—C16—C17—C18	−179.5 (3)
C7—C5—C6—N1	157.9 (3)	C16—C17—C18—C19	−2.3 (5)
C4—C5—C6—N1	−19.0 (4)	C22—O3—C19—C18	174.0 (3)
C4—C5—C7—C8	−179.5 (3)	C22—O3—C19—C20	−7.7 (5)
C6—C5—C7—C8	3.6 (5)	C17—C18—C19—O3	178.8 (3)
C5—C7—C8—C13	25.0 (5)	C17—C18—C19—C20	0.4 (5)
C5—C7—C8—C9	−158.3 (3)	O3—C19—C20—C21	−177.1 (3)
C13—C8—C9—C10	−0.3 (5)	C18—C19—C20—C21	1.1 (5)
C7—C8—C9—C10	−177.3 (3)	C19—C20—C21—C16	−0.7 (5)
C8—C9—C10—C11	1.3 (5)	C17—C16—C21—C20	−1.1 (4)
C14—O2—C11—C10	−175.8 (3)	C15—C16—C21—C20	−178.9 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C22—H22C···O1^i	0.96	2.51	3.394 (4)	153

Symmetry code: (i) −x, −y+1, −z+1.

(II) 3,5-bis(4-methoxybenzylidene)-1-methyl-4-oxopiperidinium chloride

Crystal data

C22H24NO3^+·Cl^−	F(000) = 816
Mr = 385.87	Dx = 1.308 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 15.030 (3) Å	Cell parameters from 24 reflections
b = 8.0020 (16) Å	θ = 11–12°
c = 16.585 (3) Å	µ = 0.22 mm^−1
β = 100.81 (3)°	T = 295 K
V = 1959.3 (7) Å^3	Prism, yellow
Z = 4	0.50 × 0.35 × 0.25 mm

Data collection

Enraf-Nonius CAD-4 diffractometer	Rint = 0.047
Radiation source: fine-focus sealed tube	θmax = 26.0°, θmin = 1.4°
Graphite monochromator	h = 0→18
θ/2θ scans	k = 0→9
3962 measured reflections	l = −20→20
3811 independent reflections	3 standard reflections every 97 reflections
2057 reflections with I > 2σ(I)	intensity decay: 3%

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)] = 0.049	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.136	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	w = 1/[σ^2(Fo^2) + (0.067P)^2 + 0.05P] where P = (Fo^2 + 2Fc^2)/3
3811 reflections	(Δ/σ)max < 0.001
251 parameters	Δρmax = 0.27 e Å^−3
0 restraints	Δρmin = −0.24 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. The NH-hydrogen atom was found from a difference Fourier map and refined isotropically. All other H atoms were placed in geometrically calculated positions and refined using a riding model with C—H distances of 0.93 Å for aromatic H atoms with U_iso(H) = 1.2U_eq(C), 0.97 Å for CH₂ with U_iso(H) = 1.2U_eq(C) and 0.96 Å for CH₃ groups with U_iso (H) = 1.5U_eq(C).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.34440 (6)	1.01504 (10)	0.65498 (5)	0.0570 (3)
O1	0.44018 (14)	0.6789 (3)	0.43821 (11)	0.0562 (6)
O2	0.92125 (14)	0.9902 (3)	0.72942 (13)	0.0615 (6)
O3	−0.04136 (14)	0.1980 (3)	0.47422 (14)	0.0633 (7)
N1	0.41077 (14)	0.6641 (3)	0.67577 (12)	0.0323 (5)
C1	0.4061 (2)	0.6411 (4)	0.76422 (15)	0.0459 (8)
H1A	0.3442	0.6254	0.7696	0.069*
H1B	0.4302	0.7383	0.7946	0.069*
H1C	0.4409	0.5448	0.7853	0.069*
C2	0.35872 (18)	0.5350 (4)	0.62259 (15)	0.0367 (7)
H2A	0.2972	0.5313	0.6326	0.044*
H2B	0.3861	0.4264	0.6361	0.044*
C3	0.35701 (17)	0.5721 (4)	0.53373 (15)	0.0354 (7)
C4	0.43614 (18)	0.6578 (4)	0.51014 (16)	0.0382 (7)
C5	0.51096 (17)	0.7126 (3)	0.57632 (15)	0.0331 (6)
C6	0.50611 (17)	0.6673 (4)	0.66320 (15)	0.0361 (6)
H6A	0.5333	0.5583	0.6760	0.043*
H6B	0.5403	0.7481	0.7003	0.043*
C7	0.58041 (18)	0.7956 (3)	0.55504 (16)	0.0368 (7)
H7A	0.5727	0.8224	0.4996	0.044*
C8	0.66576 (17)	0.8507 (4)	0.60415 (15)	0.0338 (6)
C9	0.71451 (19)	0.9752 (4)	0.57254 (16)	0.0411 (7)
H9A	0.6893	1.0245	0.5227	0.049*
C10	0.79824 (19)	1.0275 (4)	0.61230 (17)	0.0453 (7)
H10A	0.8287	1.1116	0.5899	0.054*
C11	0.83679 (19)	0.9541 (4)	0.68600 (17)	0.0445 (7)
C12	0.78991 (18)	0.8318 (4)	0.72028 (16)	0.0437 (7)
H12A	0.8150	0.7855	0.7709	0.052*
C13	0.70675 (18)	0.7794 (4)	0.67970 (16)	0.0410 (7)
H13A	0.6768	0.6950	0.7025	0.049*
C14	0.9772 (2)	1.0947 (5)	0.6922 (2)	0.0742 (12)
H14A	1.0380	1.0902	0.7229	0.111*
H14B	0.9552	1.2074	0.6913	0.111*
H14C	0.9764	1.0576	0.6371	0.111*
C15	0.28741 (19)	0.5319 (4)	0.47365 (16)	0.0394 (7)
H15A	0.2942	0.5655	0.4215	0.047*
C16	0.20278 (18)	0.4444 (4)	0.47620 (16)	0.0374 (7)
C17	0.12804 (19)	0.4780 (4)	0.41567 (18)	0.0486 (8)
H17A	0.1340	0.5547	0.3749	0.058*
C18	0.0455 (2)	0.4027 (4)	0.41332 (19)	0.0499 (8)
H18A	−0.0040	0.4316	0.3731	0.060*
C19	0.03698 (19)	0.2831 (4)	0.47158 (19)	0.0472 (8)
C20	0.1107 (2)	0.2430 (4)	0.53132 (18)	0.0495 (8)
H20A	0.1050	0.1621	0.5703	0.059*
C21	0.19253 (19)	0.3218 (4)	0.53379 (17)	0.0429 (7)
H21A	0.2417	0.2931	0.5743	0.051*
C22	−0.1175 (2)	0.2290 (5)	0.4110 (2)	0.0726 (11)
H22A	−0.1673	0.1604	0.4196	0.109*
H22B	−0.1023	0.2029	0.3588	0.109*
H22C	−0.1343	0.3446	0.4120	0.109*
H1	0.381 (2)	0.767 (4)	0.6571 (18)	0.057 (9)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0725 (6)	0.0483 (5)	0.0438 (4)	0.0182 (4)	−0.0054 (4)	−0.0049 (4)
O1	0.0621 (14)	0.0760 (17)	0.0298 (11)	−0.0187 (12)	0.0065 (9)	0.0029 (11)
O2	0.0437 (12)	0.0814 (18)	0.0549 (13)	−0.0165 (12)	−0.0023 (10)	0.0088 (12)
O3	0.0417 (13)	0.0672 (17)	0.0793 (16)	−0.0094 (12)	0.0068 (11)	−0.0002 (13)
N1	0.0361 (12)	0.0324 (14)	0.0281 (11)	0.0000 (11)	0.0051 (9)	0.0009 (10)
C1	0.0530 (18)	0.056 (2)	0.0301 (14)	−0.0047 (15)	0.0127 (13)	0.0018 (14)
C2	0.0369 (15)	0.0387 (17)	0.0337 (14)	−0.0036 (13)	0.0048 (11)	−0.0015 (12)
C3	0.0393 (16)	0.0335 (16)	0.0325 (14)	0.0033 (13)	0.0048 (12)	−0.0003 (12)
C4	0.0451 (16)	0.0380 (17)	0.0317 (15)	0.0017 (14)	0.0076 (12)	0.0011 (13)
C5	0.0362 (14)	0.0340 (16)	0.0304 (13)	0.0036 (13)	0.0098 (11)	0.0024 (12)
C6	0.0330 (14)	0.0436 (17)	0.0316 (14)	0.0008 (13)	0.0052 (11)	0.0006 (13)
C7	0.0426 (16)	0.0392 (18)	0.0295 (14)	0.0042 (14)	0.0093 (12)	0.0008 (12)
C8	0.0354 (15)	0.0337 (16)	0.0337 (14)	0.0020 (13)	0.0097 (11)	0.0001 (12)
C9	0.0459 (16)	0.0458 (19)	0.0320 (13)	0.0004 (15)	0.0081 (12)	0.0007 (13)
C10	0.0472 (17)	0.047 (2)	0.0425 (16)	−0.0102 (15)	0.0091 (13)	0.0055 (14)
C11	0.0399 (16)	0.053 (2)	0.0404 (15)	−0.0024 (15)	0.0077 (13)	−0.0074 (15)
C12	0.0392 (16)	0.058 (2)	0.0336 (14)	0.0077 (15)	0.0070 (12)	0.0108 (14)
C13	0.0349 (16)	0.0459 (18)	0.0442 (16)	0.0040 (14)	0.0124 (12)	0.0093 (14)
C14	0.053 (2)	0.090 (3)	0.075 (3)	−0.022 (2)	−0.0003 (18)	0.015 (2)
C15	0.0444 (16)	0.0401 (17)	0.0335 (14)	0.0017 (14)	0.0070 (12)	−0.0014 (13)
C16	0.0410 (16)	0.0369 (16)	0.0335 (14)	0.0062 (13)	0.0052 (12)	−0.0038 (12)
C17	0.0462 (17)	0.053 (2)	0.0421 (16)	0.0007 (16)	−0.0038 (13)	0.0045 (15)
C18	0.0403 (18)	0.054 (2)	0.0492 (18)	0.0055 (15)	−0.0075 (14)	−0.0039 (16)
C19	0.0386 (17)	0.048 (2)	0.0540 (18)	0.0018 (15)	0.0059 (14)	−0.0090 (16)
C20	0.0515 (19)	0.045 (2)	0.0512 (18)	−0.0023 (16)	0.0083 (15)	0.0052 (15)
C21	0.0428 (17)	0.0378 (18)	0.0446 (16)	0.0063 (14)	−0.0009 (13)	−0.0003 (14)
C22	0.0410 (19)	0.075 (3)	0.096 (3)	−0.0048 (19)	−0.0004 (18)	−0.016 (2)

Geometric parameters (Å, º)

O1—C4	1.218 (3)	C9—C10	1.372 (4)
O2—C11	1.368 (3)	C9—H9A	0.9300
O2—C14	1.407 (4)	C10—C11	1.382 (4)
O3—C19	1.368 (4)	C10—H10A	0.9300
O3—C22	1.421 (4)	C11—C12	1.388 (4)
N1—C2	1.483 (3)	C12—C13	1.370 (4)
N1—C6	1.487 (3)	C12—H12A	0.9300
N1—C1	1.493 (3)	C13—H13A	0.9300
N1—H1	0.96 (3)	C14—H14A	0.9600
C1—H1A	0.9600	C14—H14B	0.9600
C1—H1B	0.9600	C14—H14C	0.9600
C1—H1C	0.9600	C15—C16	1.459 (4)
C2—C3	1.499 (3)	C15—H15A	0.9300
C2—H2A	0.9700	C16—C17	1.385 (4)
C2—H2B	0.9700	C16—C21	1.398 (4)
C3—C15	1.342 (4)	C17—C18	1.374 (4)
C3—C4	1.487 (4)	C17—H17A	0.9300
C4—C5	1.483 (4)	C18—C19	1.383 (4)
C5—C7	1.339 (4)	C18—H18A	0.9300
C5—C6	1.501 (3)	C19—C20	1.378 (4)
C6—H6A	0.9700	C20—C21	1.377 (4)
C6—H6B	0.9700	C20—H20A	0.9300
C7—C8	1.453 (4)	C21—H21A	0.9300
C7—H7A	0.9300	C22—H22A	0.9600
C8—C9	1.396 (4)	C22—H22B	0.9600
C8—C13	1.409 (4)	C22—H22C	0.9600
C11—O2—C14	117.8 (2)	C9—C10—H10A	120.3
C19—O3—C22	117.9 (3)	C11—C10—H10A	120.3
C2—N1—C6	110.1 (2)	O2—C11—C10	124.7 (3)
C2—N1—C1	112.4 (2)	O2—C11—C12	115.2 (3)
C6—N1—C1	111.4 (2)	C10—C11—C12	120.1 (3)
C2—N1—H1	104.3 (18)	C13—C12—C11	120.1 (3)
C6—N1—H1	109.9 (19)	C13—C12—H12A	120.0
C1—N1—H1	108.6 (18)	C11—C12—H12A	120.0
N1—C1—H1A	109.5	C12—C13—C8	121.3 (3)
N1—C1—H1B	109.5	C12—C13—H13A	119.4
H1A—C1—H1B	109.5	C8—C13—H13A	119.4
N1—C1—H1C	109.5	O2—C14—H14A	109.5
H1A—C1—H1C	109.5	O2—C14—H14B	109.5
H1B—C1—H1C	109.5	H14A—C14—H14B	109.5
N1—C2—C3	110.9 (2)	O2—C14—H14C	109.5
N1—C2—H2A	109.5	H14A—C14—H14C	109.5
C3—C2—H2A	109.5	H14B—C14—H14C	109.5
N1—C2—H2B	109.5	C3—C15—C16	131.0 (3)
C3—C2—H2B	109.5	C3—C15—H15A	114.5
H2A—C2—H2B	108.0	C16—C15—H15A	114.5
C15—C3—C4	117.8 (2)	C17—C16—C21	116.9 (3)
C15—C3—C2	123.4 (3)	C17—C16—C15	118.6 (3)
C4—C3—C2	118.9 (2)	C21—C16—C15	124.4 (2)
O1—C4—C5	120.9 (2)	C18—C17—C16	122.8 (3)
O1—C4—C3	120.7 (2)	C18—C17—H17A	118.6
C5—C4—C3	118.3 (2)	C16—C17—H17A	118.6
C7—C5—C4	118.2 (2)	C17—C18—C19	119.0 (3)
C7—C5—C6	123.6 (2)	C17—C18—H18A	120.5
C4—C5—C6	118.2 (2)	C19—C18—H18A	120.5
N1—C6—C5	111.1 (2)	O3—C19—C20	116.2 (3)
N1—C6—H6A	109.4	O3—C19—C18	124.0 (3)
C5—C6—H6A	109.4	C20—C19—C18	119.8 (3)
N1—C6—H6B	109.4	C21—C20—C19	120.5 (3)
C5—C6—H6B	109.4	C21—C20—H20A	119.7
H6A—C6—H6B	108.0	C19—C20—H20A	119.7
C5—C7—C8	130.7 (2)	C20—C21—C16	120.9 (3)
C5—C7—H7A	114.6	C20—C21—H21A	119.5
C8—C7—H7A	114.6	C16—C21—H21A	119.5
C9—C8—C13	116.8 (2)	O3—C22—H22A	109.5
C9—C8—C7	118.5 (2)	O3—C22—H22B	109.5
C13—C8—C7	124.6 (3)	H22A—C22—H22B	109.5
C10—C9—C8	122.4 (3)	O3—C22—H22C	109.5
C10—C9—H9A	118.8	H22A—C22—H22C	109.5
C8—C9—H9A	118.8	H22B—C22—H22C	109.5
C9—C10—C11	119.4 (3)
C6—N1—C2—C3	−61.1 (3)	C14—O2—C11—C12	170.9 (3)
C1—N1—C2—C3	174.2 (2)	C9—C10—C11—O2	177.0 (3)
N1—C2—C3—C15	−148.3 (3)	C9—C10—C11—C12	−1.7 (5)
N1—C2—C3—C4	31.7 (3)	O2—C11—C12—C13	−176.4 (3)
C15—C3—C4—O1	−5.5 (4)	C10—C11—C12—C13	2.4 (5)
C2—C3—C4—O1	174.5 (3)	C11—C12—C13—C8	−1.9 (5)
C15—C3—C4—C5	176.2 (3)	C9—C8—C13—C12	0.8 (4)
C2—C3—C4—C5	−3.8 (4)	C7—C8—C13—C12	176.2 (3)
O1—C4—C5—C7	4.3 (4)	C4—C3—C15—C16	177.9 (3)
C3—C4—C5—C7	−177.4 (3)	C2—C3—C15—C16	−2.1 (5)
O1—C4—C5—C6	−173.8 (3)	C3—C15—C16—C17	153.2 (3)
C3—C4—C5—C6	4.5 (4)	C3—C15—C16—C21	−30.0 (5)
C2—N1—C6—C5	62.0 (3)	C21—C16—C17—C18	3.4 (5)
C1—N1—C6—C5	−172.6 (2)	C15—C16—C17—C18	−179.6 (3)
C7—C5—C6—N1	148.9 (3)	C16—C17—C18—C19	−2.8 (5)
C4—C5—C6—N1	−33.1 (3)	C22—O3—C19—C20	−176.6 (3)
C4—C5—C7—C8	−173.6 (3)	C22—O3—C19—C18	3.0 (5)
C6—C5—C7—C8	4.4 (5)	C17—C18—C19—O3	−178.8 (3)
C5—C7—C8—C9	−161.6 (3)	C17—C18—C19—C20	0.8 (5)
C5—C7—C8—C13	23.1 (5)	O3—C19—C20—C21	180.0 (3)
C13—C8—C9—C10	−0.2 (4)	C18—C19—C20—C21	0.4 (5)
C7—C8—C9—C10	−175.9 (3)	C19—C20—C21—C16	0.3 (5)
C8—C9—C10—C11	0.6 (5)	C17—C16—C21—C20	−2.1 (4)
C14—O2—C11—C10	−7.8 (5)	C15—C16—C21—C20	−178.9 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl1	0.95 (3)	2.07 (3)	2.978 (3)	160 (2)
C1—H1B···O1^i	0.96	2.45	3.180 (4)	133
C18—H18A···O2^ii	0.93	2.52	3.374 (4)	154
C13—H13A···Cl1^iii	0.93	2.84	3.657 (4)	148
C21—H21A···Cl1^iv	0.93	2.89	3.682 (4)	144

Symmetry codes: (i) x, −y+3/2, z+1/2; (ii) x−1, −y+3/2, z−1/2; (iii) −x+1, y−1/2, −z+3/2; (iv) x, y−1, z.