1,1'-{(Hexane-1,6-di-yl)bis-[(aza-niumylyl-idene)methanylyl-idene]}bis-(naphthalen-2-olate).

The whole molecule of the title Schiff base compound, C28H28N2O2, is generated by inversion symmetry. It is formed from two units of ortho-hy-droxy-naphthaldehyde bridged with 1,6-di-amino-hexane. The N atoms are protonated and, thus, the structure is a bis-zwitterionic compound in the solid state. The zwitterion shows strong intra-molecular N-H⋯O hydrogen bonds between the iminium N and the naphthaleno-late O atoms.

Related literature

For the synthesis of similar compounds, see: Ramos Silva et al. (2009 ▸); Li et al. (2007 ▸); Zhu et al. (2006 ▸); Sampath Kumar et al. (2010 ▸); Bhattacharjee et al. (2012 ▸). For their applications, see: Ourari et al. (2006 ▸, 2008 ▸); Ouari et al. (2010 ▸, 2015 ▸). For related crystal structures, see: Yuan & Li (2013 ▸); Paul & Kubicki (2009 ▸). For the biological activity of Schiff bases, see: Zayed et al. (2015 ▸); Abou-Hussein & Linert (2014 ▸); Sadeek et al. (2013 ▸).

Experimental

Crystal data

C28H28N2O2

M = 424.52

Orthorhombic,

a = 23.722 (1) Å

b = 8.8117 (3) Å

c = 10.3903 (5) Å

V = 2171.90 (16) Å3

Z = 4

Mo Kα radiation

μ = 0.08 mm−1

T = 173 K

0.36 × 0.16 × 0.08 mm

Data collection

Nonius KappaCCD diffractometer

17177 measured reflections

2500 independent reflections

1285 reflections with I > 2σ(I)

R int = 0.082

Refinement

R[F 2 > 2σ(F 2)] = 0.054

wR(F 2) = 0.160

S = 0.99

2500 reflections

150 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.23 e Å−3

Δρmin = −0.28 e Å−3

Data collection: COLLECT (Nonius, 1998 ▸); cell refinement: DENZO (Otwinowski & Minor, 1997 ▸); data reduction: SCALEPACK (Otwinowski & Minor, 1997 ▸); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL2013 (Sheldrick, 200); molecular graphics: PLATON (Spek, 2009 ▸); software used to prepare material for publication: SHELXL2013.

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989014027236/mw2128sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989014027236/mw2128Isup2.hkl

Click here for additional data file.

. DOI: 10.1107/S2056989014027236/mw2128fig1.tif

The mol­ecular geometry of the title compound with displacement ellipsoids drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radii. Hydrogen bonds are shown as dashed lines. Only the non-H atoms of the asymmetric unit are labelled.

Click here for additional data file.

c . DOI: 10.1107/S2056989014027236/mw2128fig2.tif

Crystal packing of the title compound viewed along the c axis.

CCDC reference: 1032693

Additional supporting information: crystallographic information; 3D view; checkCIF report

C28H28N2O2	Dx = 1.298 Mg m−3
Mr = 424.52	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbcn	Cell parameters from 8957 reflections
a = 23.722 (1) Å	θ = 1.0–27.5°
b = 8.8117 (3) Å	µ = 0.08 mm−1
c = 10.3903 (5) Å	T = 173 K
V = 2171.90 (16) Å3	Prism, yellow
Z = 4	0.36 × 0.16 × 0.08 mm
F(000) = 904

Nonius KappaCCD diffractometer	1285 reflections with I > 2σ(I)
Radiation source: sealed tube	Rint = 0.082
Graphite monochromator	θmax = 27.5°, θmin = 2.5°
phi and ω scans	h = −25→30
17177 measured reflections	k = −10→11
2500 independent reflections	l = −13→12

Refinement on F2	Hydrogen site location: mixed
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.054	w = 1/[σ2(Fo2) + (0.0842P)2] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.160	(Δ/σ)max < 0.001
S = 0.99	Δρmax = 0.23 e Å−3
2500 reflections	Δρmin = −0.28 e Å−3
150 parameters	Extinction correction: SHELXL2013 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraints	Extinction coefficient: 0.0047 (14)

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.

	x	y	z	Uiso*/Ueq
C1	0.42177 (9)	0.1531 (2)	0.9435 (2)	0.0314 (5)
C2	0.42703 (9)	0.1083 (2)	1.0765 (2)	0.0336 (5)
H2	0.4575	0.0451	1.1016	0.040*
C3	0.38971 (9)	0.1541 (2)	1.1655 (2)	0.0351 (5)
H3	0.3951	0.1236	1.2524	0.042*
C4	0.34205 (8)	0.2473 (2)	1.1344 (2)	0.0319 (5)
C5	0.30246 (9)	0.2899 (2)	1.2282 (2)	0.0389 (6)
H5	0.3080	0.2583	1.3147	0.047*
C6	0.25612 (9)	0.3759 (2)	1.1985 (2)	0.0411 (6)
H6	0.2297	0.4032	1.2631	0.049*
C7	0.24870 (9)	0.4224 (2)	1.0717 (2)	0.0416 (6)
H7	0.2167	0.4820	1.0497	0.050*
C8	0.28662 (9)	0.3839 (2)	0.9781 (2)	0.0359 (5)
H8	0.2806	0.4182	0.8926	0.043*
C9	0.33434 (8)	0.2945 (2)	1.0054 (2)	0.0294 (5)
C10	0.37521 (8)	0.24816 (18)	0.90863 (19)	0.0283 (5)
C11	0.36924 (9)	0.2932 (2)	0.7794 (2)	0.0311 (5)
H11	0.3382	0.3570	0.7587	0.037*
C12	0.39177 (9)	0.2937 (2)	0.55205 (19)	0.0372 (6)
H12A	0.3640	0.3775	0.5496	0.045*
H12B	0.3747	0.2051	0.5084	0.045*
C13	0.44381 (9)	0.3416 (2)	0.4786 (2)	0.0369 (5)
H13A	0.4324	0.3750	0.3914	0.044*
H13B	0.4689	0.2526	0.4687	0.044*
C14	0.47653 (8)	0.4686 (2)	0.54272 (19)	0.0370 (6)
H14A	0.4932	0.4303	0.6238	0.044*
H14B	0.4502	0.5518	0.5650	0.044*
N1	0.40291 (8)	0.25438 (18)	0.68565 (17)	0.0333 (5)
O1	0.45832 (6)	0.10907 (16)	0.86112 (13)	0.0403 (4)
H1N	0.4349 (11)	0.195 (2)	0.720 (2)	0.064 (7)*

	U11	U22	U33	U12	U13	U23
C1	0.0307 (12)	0.0318 (11)	0.0318 (13)	−0.0016 (8)	0.0006 (10)	−0.0004 (9)
C2	0.0348 (12)	0.0326 (10)	0.0335 (13)	0.0006 (9)	−0.0050 (10)	0.0047 (9)
C3	0.0394 (14)	0.0371 (11)	0.0289 (12)	−0.0057 (9)	−0.0019 (10)	0.0040 (9)
C4	0.0311 (12)	0.0321 (10)	0.0325 (13)	−0.0056 (8)	−0.0003 (10)	−0.0021 (9)
C5	0.0399 (14)	0.0449 (13)	0.0319 (13)	−0.0090 (10)	0.0026 (11)	−0.0056 (9)
C6	0.0307 (13)	0.0495 (13)	0.0431 (15)	−0.0056 (10)	0.0073 (11)	−0.0162 (10)
C7	0.0332 (13)	0.0438 (12)	0.0479 (15)	0.0008 (9)	0.0003 (11)	−0.0105 (11)
C8	0.0347 (13)	0.0363 (11)	0.0367 (13)	0.0009 (9)	−0.0002 (10)	−0.0019 (9)
C9	0.0290 (12)	0.0284 (10)	0.0308 (12)	−0.0039 (8)	−0.0008 (9)	−0.0017 (8)
C10	0.0277 (11)	0.0299 (10)	0.0275 (12)	−0.0009 (8)	−0.0026 (9)	0.0014 (8)
C11	0.0289 (12)	0.0301 (10)	0.0342 (13)	−0.0002 (8)	−0.0012 (10)	−0.0004 (9)
C12	0.0397 (13)	0.0426 (12)	0.0293 (13)	−0.0013 (9)	−0.0026 (10)	0.0060 (9)
C13	0.0398 (13)	0.0430 (12)	0.0281 (12)	0.0014 (10)	0.0010 (10)	0.0041 (9)
C14	0.0413 (13)	0.0409 (11)	0.0288 (13)	0.0008 (10)	0.0005 (10)	0.0027 (9)
N1	0.0349 (10)	0.0380 (10)	0.0271 (11)	0.0018 (8)	0.0010 (9)	0.0042 (7)
O1	0.0383 (9)	0.0474 (8)	0.0352 (9)	0.0120 (7)	0.0035 (7)	0.0006 (7)

C1—O1	1.279 (2)	C8—H8	0.9500
C1—C10	1.433 (3)	C9—C10	1.455 (3)
C1—C2	1.442 (3)	C10—C11	1.408 (3)
C2—C3	1.343 (3)	C11—N1	1.305 (2)
C2—H2	0.9500	C11—H11	0.9500
C3—C4	1.434 (3)	C12—N1	1.455 (2)
C3—H3	0.9500	C12—C13	1.511 (3)
C4—C5	1.405 (3)	C12—H12A	0.9900
C4—C9	1.416 (3)	C12—H12B	0.9900
C5—C6	1.370 (3)	C13—C14	1.516 (3)
C5—H5	0.9500	C13—H13A	0.9900
C6—C7	1.391 (3)	C13—H13B	0.9900
C6—H6	0.9500	C14—C14i	1.528 (4)
C7—C8	1.367 (3)	C14—H14A	0.9900
C7—H7	0.9500	C14—H14B	0.9900
C8—C9	1.408 (3)	N1—H1N	0.99 (3)
O1—C1—C10	122.03 (18)	C11—C10—C1	118.94 (18)
O1—C1—C2	119.99 (18)	C11—C10—C9	120.86 (18)
C10—C1—C2	117.97 (19)	C1—C10—C9	120.19 (18)
C3—C2—C1	121.40 (19)	N1—C11—C10	125.19 (19)
C3—C2—H2	119.3	N1—C11—H11	117.4
C1—C2—H2	119.3	C10—C11—H11	117.4
C2—C3—C4	122.44 (19)	N1—C12—C13	113.56 (17)
C2—C3—H3	118.8	N1—C12—H12A	108.9
C4—C3—H3	118.8	C13—C12—H12A	108.9
C5—C4—C9	119.48 (19)	N1—C12—H12B	108.9
C5—C4—C3	121.6 (2)	C13—C12—H12B	108.9
C9—C4—C3	118.92 (18)	H12A—C12—H12B	107.7
C6—C5—C4	121.9 (2)	C12—C13—C14	113.75 (18)
C6—C5—H5	119.1	C12—C13—H13A	108.8
C4—C5—H5	119.1	C14—C13—H13A	108.8
C5—C6—C7	118.5 (2)	C12—C13—H13B	108.8
C5—C6—H6	120.7	C14—C13—H13B	108.8
C7—C6—H6	120.7	H13A—C13—H13B	107.7
C8—C7—C6	121.1 (2)	C13—C14—C14i	112.7 (2)
C8—C7—H7	119.4	C13—C14—H14A	109.1
C6—C7—H7	119.4	C14i—C14—H14A	109.1
C7—C8—C9	121.7 (2)	C13—C14—H14B	109.1
C7—C8—H8	119.2	C14i—C14—H14B	109.1
C9—C8—H8	119.2	H14A—C14—H14B	107.8
C8—C9—C4	117.29 (18)	C11—N1—C12	122.55 (19)
C8—C9—C10	123.64 (18)	C11—N1—H1N	109.7 (14)
C4—C9—C10	119.06 (17)	C12—N1—H1N	127.7 (14)
O1—C1—C2—C3	179.21 (17)	C3—C4—C9—C10	−0.5 (3)
C10—C1—C2—C3	−0.1 (3)	O1—C1—C10—C11	0.7 (3)
C1—C2—C3—C4	1.1 (3)	C2—C1—C10—C11	180.00 (16)
C2—C3—C4—C5	177.89 (18)	O1—C1—C10—C9	179.50 (17)
C2—C3—C4—C9	−0.8 (3)	C2—C1—C10—C9	−1.2 (3)
C9—C4—C5—C6	0.3 (3)	C8—C9—C10—C11	0.8 (3)
C3—C4—C5—C6	−178.41 (18)	C4—C9—C10—C11	−179.71 (16)
C4—C5—C6—C7	−0.4 (3)	C8—C9—C10—C1	−178.02 (17)
C5—C6—C7—C8	−0.1 (3)	C4—C9—C10—C1	1.5 (3)
C6—C7—C8—C9	0.7 (3)	C1—C10—C11—N1	0.5 (3)
C7—C8—C9—C4	−0.8 (3)	C9—C10—C11—N1	−178.29 (17)
C7—C8—C9—C10	178.74 (17)	N1—C12—C13—C14	−53.7 (2)
C5—C4—C9—C8	0.3 (3)	C12—C13—C14—C14i	−171.2 (2)
C3—C4—C9—C8	179.01 (16)	C10—C11—N1—C12	174.49 (16)
C5—C4—C9—C10	−179.23 (16)	C13—C12—N1—C11	139.58 (19)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1	0.99 (3)	1.74 (3)	2.587 (2)	141 (2)

Table 1

Hydrogen-bond geometry (, )

DHA	DH	HA	D A	DHA
N1H1NO1	0.99(3)	1.74(3)	2.587(2)	141(2)