2,2'-{1,1'-[Pentane-1,5-diyl-bis(oxy-nitrilo)]-diethyl-idyne}diphenol.

In the title compound, C(21)H(26)N(2)O(4), there is half a mol-ecule in the asymmetric unit with a crystallographic twofold rotation axis passing through the central C atom of the -CH=N-O-(CH(2))(5)-O-N=CH- bridge. The dihedral angle formed by the two benzene rings is 80.85 (2)°. Strong intra-molecular O-H⋯N and C-H⋯O hydrogen bonds help to establish the molecular conformation. There are also weak inter-molecular π-π stacking inter-actions between neighbouring benzene rings [centroid-centroid separation = 3.502 (3) Å].

Related literature

For general background, see: Bhadbhade & Srinivas (1993 ▶). For related structures, see: Dong et al. (2007 ▶, 2008 ▶); Wang et al. (2007 ▶); Xu et al. (2007 ▶).

Experimental

Crystal data

C21H26N2O4

M = 370.44

Monoclinic,

a = 12.9691 (13) Å

b = 4.601 (1) Å

c = 16.3639 (16) Å

β = 91.621 (1)°

V = 976.1 (3) Å3

Z = 2

Mo Kα radiation

μ = 0.09 mm−1

T = 298 (2) K

0.48 × 0.40 × 0.32 mm

Data collection

Siemens SMART 1000 CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.959, T max = 0.973

2421 measured reflections

972 independent reflections

646 reflections with I > 2σ(I)

R int = 0.038

Refinement

R[F 2 > 2σ(F 2)] = 0.042

wR(F 2) = 0.123

S = 1.04

972 reflections

123 parameters

2 restraints

H-atom parameters constrained

Δρmax = 0.15 e Å−3

Δρmin = −0.12 e Å−3

Data collection: SMART (Siemens, 1996 ▶); cell refinement: SAINT (Siemens, 1996 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680803136X/gw2048sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053680803136X/gw2048Isup2.hkl

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

C21H26N2O4	F(000) = 396
Mr = 370.44	Dx = 1.260 Mg m−3
Monoclinic, C2	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2y	Cell parameters from 813 reflections
a = 12.9691 (13) Å	θ = 2.5–23.2°
b = 4.601 (1) Å	µ = 0.09 mm−1
c = 16.3639 (16) Å	T = 298 K
β = 91.621 (1)°	Needle-like, colourless
V = 976.1 (3) Å3	0.48 × 0.40 × 0.32 mm
Z = 2

Siemens SMART 1000 CCD area-detector diffractometer	972 independent reflections
Radiation source: fine-focus sealed tube	646 reflections with I > 2σ(I)
graphite	Rint = 0.038
φ and ω scans	θmax = 25.0°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −15→15
Tmin = 0.959, Tmax = 0.973	k = −5→5
2421 measured reflections	l = −19→10

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)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.123	H-atom parameters constrained
S = 1.04	w = 1/[σ2(Fo2) + (0.0568P)2 + 0.2844P] where P = (Fo2 + 2Fc2)/3
972 reflections	(Δ/σ)max < 0.001
123 parameters	Δρmax = 0.15 e Å−3
2 restraints	Δρmin = −0.12 e Å−3

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
N1	0.1857 (2)	0.7552 (7)	0.30501 (17)	0.0533 (8)
O1	0.23002 (19)	0.6005 (8)	0.37063 (14)	0.0656 (7)
O2	0.0337 (2)	0.9262 (9)	0.21462 (17)	0.0796 (9)
H2	0.0629	0.8223	0.2488	0.119*
C1	0.1512 (3)	0.4342 (11)	0.4082 (2)	0.0607 (10)
H1A	0.1834	0.2927	0.4447	0.073*
H1B	0.1126	0.3286	0.3662	0.073*
C2	0.0778 (3)	0.6170 (10)	0.4558 (2)	0.0551 (9)
H2A	0.1169	0.7333	0.4952	0.066*
H2B	0.0418	0.7489	0.4186	0.066*
C3	0.0000	0.4391 (13)	0.5000	0.0526 (12)
H3A	0.0361	0.3147	0.5392	0.063*	0.50
H3B	−0.0361	0.3147	0.4608	0.063*	0.50
C4	0.3610 (3)	0.9300 (15)	0.2926 (2)	0.0836 (14)
H4A	0.3736	0.8041	0.3386	0.125*
H4B	0.3787	1.1259	0.3074	0.125*
H4C	0.4023	0.8688	0.2479	0.125*
C5	0.2494 (3)	0.9162 (9)	0.2673 (2)	0.0494 (9)
C6	0.2084 (3)	1.0860 (9)	0.1985 (2)	0.0485 (9)
C7	0.1043 (3)	1.0870 (11)	0.1759 (2)	0.0573 (9)
C8	0.0682 (3)	1.2544 (12)	0.1116 (2)	0.0745 (12)
H8	−0.0017	1.2535	0.0971	0.089*
C9	0.1348 (4)	1.4212 (13)	0.0693 (2)	0.0773 (13)
H9	0.1099	1.5343	0.0260	0.093*
C10	0.2363 (4)	1.4250 (12)	0.0892 (2)	0.0735 (12)
H10	0.2812	1.5389	0.0595	0.088*
C11	0.2732 (3)	1.2605 (10)	0.1533 (2)	0.0610 (11)
H11	0.3433	1.2656	0.1670	0.073*

	U11	U22	U33	U12	U13	U23
N1	0.0547 (18)	0.0514 (18)	0.0545 (16)	0.0036 (18)	0.0125 (14)	−0.0018 (17)
O1	0.0574 (15)	0.0702 (16)	0.0701 (15)	0.0067 (17)	0.0167 (12)	0.0136 (17)
O2	0.0532 (16)	0.0868 (19)	0.099 (2)	−0.006 (2)	0.0049 (14)	0.018 (2)
C1	0.065 (2)	0.053 (2)	0.066 (2)	0.011 (3)	0.0173 (19)	0.009 (2)
C2	0.062 (2)	0.045 (2)	0.059 (2)	−0.001 (2)	0.0143 (17)	−0.002 (2)
C3	0.062 (3)	0.041 (3)	0.054 (3)	0.000	0.009 (2)	0.000
C4	0.055 (2)	0.107 (4)	0.089 (3)	−0.014 (3)	0.004 (2)	0.015 (4)
C5	0.0469 (19)	0.048 (2)	0.0541 (19)	−0.003 (2)	0.0155 (17)	−0.010 (2)
C6	0.053 (2)	0.0447 (19)	0.0478 (18)	−0.011 (2)	0.0105 (16)	−0.010 (2)
C7	0.056 (2)	0.055 (2)	0.062 (2)	−0.004 (3)	0.0132 (18)	−0.005 (3)
C8	0.071 (3)	0.078 (3)	0.074 (3)	−0.001 (3)	−0.004 (2)	0.005 (3)
C9	0.106 (4)	0.067 (3)	0.058 (2)	0.001 (3)	0.000 (2)	0.001 (3)
C10	0.098 (4)	0.066 (3)	0.058 (2)	−0.023 (3)	0.014 (2)	−0.004 (3)
C11	0.063 (2)	0.062 (3)	0.059 (2)	−0.014 (3)	0.013 (2)	−0.012 (3)

N1—C5	1.282 (4)	C4—H4A	0.9600
N1—O1	1.398 (4)	C4—H4B	0.9600
O1—C1	1.430 (5)	C4—H4C	0.9600
O2—C7	1.349 (5)	C5—C6	1.459 (5)
O2—H2	0.8200	C6—C7	1.389 (5)
C1—C2	1.504 (5)	C6—C11	1.390 (5)
C1—H1A	0.9700	C7—C8	1.375 (5)
C1—H1B	0.9700	C8—C9	1.360 (6)
C2—C3	1.501 (5)	C8—H8	0.9300
C2—H2A	0.9700	C9—C10	1.348 (6)
C2—H2B	0.9700	C9—H9	0.9300
C3—C2i	1.501 (5)	C10—C11	1.370 (6)
C3—H3A	0.9700	C10—H10	0.9300
C3—H3B	0.9700	C11—H11	0.9300
C4—C5	1.495 (5)
C5—N1—O1	114.0 (3)	C5—C4—H4C	109.5
N1—O1—C1	108.6 (3)	H4A—C4—H4C	109.5
C7—O2—H2	109.5	H4B—C4—H4C	109.5
O1—C1—C2	113.2 (4)	N1—C5—C6	117.0 (3)
O1—C1—H1A	108.9	N1—C5—C4	121.6 (4)
C2—C1—H1A	108.9	C6—C5—C4	121.3 (4)
O1—C1—H1B	108.9	C7—C6—C11	117.0 (4)
C2—C1—H1B	108.9	C7—C6—C5	122.5 (3)
H1A—C1—H1B	107.7	C11—C6—C5	120.4 (3)
C3—C2—C1	112.9 (3)	O2—C7—C8	116.4 (4)
C3—C2—H2A	109.0	O2—C7—C6	122.7 (4)
C1—C2—H2A	109.0	C8—C7—C6	120.8 (4)
C3—C2—H2B	109.0	C9—C8—C7	119.9 (4)
C1—C2—H2B	109.0	C9—C8—H8	120.1
H2A—C2—H2B	107.8	C7—C8—H8	120.1
C2—C3—C2i	113.9 (5)	C10—C9—C8	121.0 (5)
C2—C3—H3A	108.8	C10—C9—H9	119.5
C2i—C3—H3A	108.8	C8—C9—H9	119.5
C2—C3—H3B	108.8	C9—C10—C11	119.7 (4)
C2i—C3—H3B	108.8	C9—C10—H10	120.2
H3A—C3—H3B	107.7	C11—C10—H10	120.2
C5—C4—H4A	109.5	C10—C11—C6	121.6 (4)
C5—C4—H4B	109.5	C10—C11—H11	119.2
H4A—C4—H4B	109.5	C6—C11—H11	119.2
C5—N1—O1—C1	179.0 (3)	C5—C6—C7—O2	−1.6 (6)
N1—O1—C1—C2	−72.2 (4)	C11—C6—C7—C8	0.0 (6)
O1—C1—C2—C3	−175.9 (3)	C5—C6—C7—C8	178.7 (4)
C1—C2—C3—C2i	−176.9 (4)	O2—C7—C8—C9	−179.6 (4)
O1—N1—C5—C6	−179.5 (3)	C6—C7—C8—C9	0.1 (6)
O1—N1—C5—C4	0.5 (5)	C7—C8—C9—C10	0.2 (7)
N1—C5—C6—C7	2.9 (5)	C8—C9—C10—C11	−0.5 (8)
C4—C5—C6—C7	−177.1 (4)	C9—C10—C11—C6	0.6 (7)
N1—C5—C6—C11	−178.5 (3)	C7—C6—C11—C10	−0.3 (6)
C4—C5—C6—C11	1.5 (6)	C5—C6—C11—C10	−179.1 (4)
C11—C6—C7—O2	179.7 (4)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···N1	0.82	1.84	2.553 (4)	144
C4—H4A···O1	0.96	2.16	2.631 (5)	109

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯N1	0.82	1.84	2.553 (4)	144
C4—H4A⋯O1	0.96	2.16	2.631 (5)	109