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1,4,10,13-Tetra­oxa-7,16-diazo­nia­cyclo­octa­decane bis­­(1H-pyrrole-2-carboxyl­ate)

aTianjin Key Laboratory of Structure and Performance for Functional Molecules, Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Ministry of Education, College of Chemistry, Tianjin Normal University, Tianjin 300387, People's Republic of China
*Correspondence e-mail: tjyinzm@aliyun.com

(Received 24 May 2013; accepted 11 June 2013; online 15 June 2013)

In the title salt, C12H28N2O42+·2C5H4NO2, the 1,4,10,13-tetra­oxa-7,16-di­aza­cyclo­octa­decane dication possesses inversion symmetry. In the crystal, the pyrrole-carboxyl­ate anions are linked via pairs of N—H⋯O hydrogen bonds, forming inversion dimers. These dimers are linked by the dications, via N—H⋯O hydrogen bonds, forming chains propagating along [110].

Related literature

For background to hydrogen-bonded supra­molecular assemblies, see: Burrows (2004[Burrows, A. D. (2004). Struct. Bond. 108, 55-96.]). For the hydrogen-bonded assemblies of pyrrole-based structures, see: Wang & Yin (2007[Wang, W.-Y. & Yin, Z.-M. (2007). Acta Cryst. E63, o2737-o2738.]); Yin & Li (2006[Yin, Z. & Li, Z. (2006). Tetrahedron Lett. 47, 7875-7879.]); Cui et al. (2009[Cui, Y., Yin, Z., Dong, L. & He, J. (2009). J. Mol. Struct. 938, 322-327.]); Li et al. (2012[Li, C., Zhang, G. & Yin, Z. (2012). Acta Cryst. E68, m323.]).

[Scheme 1]

Experimental

Crystal data
  • C12H28N2O42+·2C5H4NO2

  • Mr = 484.55

  • Triclinic, [P \overline 1]

  • a = 7.8963 (19) Å

  • b = 9.164 (2) Å

  • c = 9.244 (2) Å

  • α = 73.028 (4)°

  • β = 76.547 (4)°

  • γ = 77.824 (4)°

  • V = 614.8 (3) Å3

  • Z = 1

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 294 K

  • 0.24 × 0.22 × 0.18 mm

Data collection
  • Bruker SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 1997[Bruker (1997). SADABS, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.970, Tmax = 0.982

  • 3484 measured reflections

  • 2471 independent reflections

  • 1695 reflections with I > 2σ(I)

  • Rint = 0.017

Refinement
  • R[F2 > 2σ(F2)] = 0.042

  • wR(F2) = 0.113

  • S = 1.03

  • 2471 reflections

  • 166 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.14 e Å−3

  • Δρmin = −0.26 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N2—H2⋯O4i 0.877 (19) 1.94 (2) 2.7741 (19) 158.0 (17)
N1—H1B⋯O3ii 0.91 (2) 2.01 (2) 2.8167 (19) 147.4 (16)
N1—H1A⋯O4 0.94 (2) 2.489 (19) 3.137 (2) 125.9 (14)
N1—H1A⋯O3 0.94 (2) 1.81 (2) 2.7452 (19) 171.1 (17)
Symmetry codes: (i) -x+2, -y, -z+1; (ii) -x+1, -y+1, -z+1.

Data collection: SMART (Bruker, 1997[Bruker (1997). SADABS, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 1997[Bruker (1997). SADABS, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

Hydrogen-bond-mediated self-assembly represents an area of considerable current interest (Burrows, 2004). It has recently been found that pyrrole-based entities are also capable of undergoing self-assembly through hydrogen bonds, especially in the solid state. In our previous works, we have reported the hydrogen-bonded assemblies of 4-pyridylmethyl 1H-pyrrole-2-carboxylate (Wang & Yin, 2007) and some other pyrrole-based compounds (Yin & Li, 2006; Cui et al. 2009; Li et al. 2012) in the solid state. Here we report the self-assembly of the title compound, (I), via conventional N—H···O hydrogen bonds.

The molecular structure of (I) is shown in Fig.1. In the solid state, the compound adopts central symmetrical conformation. Each pyrrole-2-carboxylate group is planar and interact with protonated amino group through two charge assisted N—H···O hydrogen bonds.

In the crystal structure, the molecules of (I) are held together by a pair of N—H···O hydrogen bonds between the pyrrole and carbonyl groups (Fig.2). Consequently, the molecules of (I) form a one-dimensional infinite chain structure.

Related literature top

For background to hydrogen-bonded supramolecular assemblies, see: Burrows (2004). For the hydrogen-bonded assemblies of pyrrole-based structures, see: Wang & Yin (2007); Yin & Li (2006); Cui et al. (2009); Li et al. (2012)

Experimental top

1,4,10,13-Tetraoxa-7,16-diaza-cyclooctadecane (262 mg, 100 mmol), 1H-pyrrole-2-carboxylic acid (222 mg, 200 mmol) were added to alcohol (20 ml), and the mixture was stirred in room temperature for 1 h. The solution was then evaporated and afforded the title compound (colorless crystals, 387 mg, 70%).

Refinement top

The N-bound H atoms were located in a difference map and refined freely. Other H atoms were positioned geometrically (C—H = 0.93 or 0.97 A°) and refined using a riding model, with Uiso(H) =1.2Ueq(C).

Structure description top

Hydrogen-bond-mediated self-assembly represents an area of considerable current interest (Burrows, 2004). It has recently been found that pyrrole-based entities are also capable of undergoing self-assembly through hydrogen bonds, especially in the solid state. In our previous works, we have reported the hydrogen-bonded assemblies of 4-pyridylmethyl 1H-pyrrole-2-carboxylate (Wang & Yin, 2007) and some other pyrrole-based compounds (Yin & Li, 2006; Cui et al. 2009; Li et al. 2012) in the solid state. Here we report the self-assembly of the title compound, (I), via conventional N—H···O hydrogen bonds.

The molecular structure of (I) is shown in Fig.1. In the solid state, the compound adopts central symmetrical conformation. Each pyrrole-2-carboxylate group is planar and interact with protonated amino group through two charge assisted N—H···O hydrogen bonds.

In the crystal structure, the molecules of (I) are held together by a pair of N—H···O hydrogen bonds between the pyrrole and carbonyl groups (Fig.2). Consequently, the molecules of (I) form a one-dimensional infinite chain structure.

For background to hydrogen-bonded supramolecular assemblies, see: Burrows (2004). For the hydrogen-bonded assemblies of pyrrole-based structures, see: Wang & Yin (2007); Yin & Li (2006); Cui et al. (2009); Li et al. (2012)

Computing details top

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT (Bruker, 1997); 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 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), with the numbering scheme and 30% probability displacement ellipsoids. [Symmetry code: (i) 1-x, 1-y, 1-z]
[Figure 2] Fig. 2. The dimer of molecules of (I) connected by N—H···O hydrogen bonds (dashed lines). [Symmetry code: (ii) -x + 2, -y, -z + 1]
1,4,10,13-Tetraoxa-7,16-diazoniacyclooctadecane bis(1H-pyrrole-2-carboxylate) top
Crystal data top
C12H28N2O42+·2C5H4NO2Z = 1
Mr = 484.55F(000) = 260
Triclinic, P1Dx = 1.309 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.8963 (19) ÅCell parameters from 1288 reflections
b = 9.164 (2) Åθ = 2.7–25.6°
c = 9.244 (2) ŵ = 0.10 mm1
α = 73.028 (4)°T = 294 K
β = 76.547 (4)°Block, colourless
γ = 77.824 (4)°0.24 × 0.22 × 0.18 mm
V = 614.8 (3) Å3
Data collection top
Bruker SMART CCD area-detector
diffractometer
2471 independent reflections
Radiation source: fine-focus sealed tube1695 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.017
phi and ω scansθmax = 26.3°, θmin = 2.3°
Absorption correction: multi-scan
(SADABS; Bruker, 1997)
h = 99
Tmin = 0.970, Tmax = 0.982k = 117
3484 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.042Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.113H atoms treated by a mixture of independent and constrained refinement
S = 1.03 w = 1/[σ2(Fo2) + (0.0587P)2 + 0.0353P]
where P = (Fo2 + 2Fc2)/3
2471 reflections(Δ/σ)max < 0.001
166 parametersΔρmax = 0.14 e Å3
0 restraintsΔρmin = 0.26 e Å3
Crystal data top
C12H28N2O42+·2C5H4NO2γ = 77.824 (4)°
Mr = 484.55V = 614.8 (3) Å3
Triclinic, P1Z = 1
a = 7.8963 (19) ÅMo Kα radiation
b = 9.164 (2) ŵ = 0.10 mm1
c = 9.244 (2) ÅT = 294 K
α = 73.028 (4)°0.24 × 0.22 × 0.18 mm
β = 76.547 (4)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
2471 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 1997)
1695 reflections with I > 2σ(I)
Tmin = 0.970, Tmax = 0.982Rint = 0.017
3484 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0420 restraints
wR(F2) = 0.113H atoms treated by a mixture of independent and constrained refinement
S = 1.03Δρmax = 0.14 e Å3
2471 reflectionsΔρmin = 0.26 e Å3
166 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
N10.5212 (2)0.36442 (16)0.71663 (16)0.0346 (3)
H1A0.592 (3)0.369 (2)0.618 (2)0.051 (5)*
H1B0.434 (3)0.447 (2)0.706 (2)0.049 (5)*
N20.99820 (18)0.10017 (16)0.27227 (16)0.0346 (3)
H21.027 (2)0.022 (2)0.348 (2)0.048 (5)*
O10.41888 (15)0.19373 (14)0.53943 (14)0.0462 (3)
O20.55409 (16)0.64120 (13)0.77534 (14)0.0462 (3)
O30.72871 (15)0.40741 (12)0.42918 (12)0.0391 (3)
O40.85227 (16)0.17742 (13)0.55299 (13)0.0439 (3)
C10.4410 (3)0.2209 (2)0.7790 (2)0.0453 (5)
H1C0.37610.21870.88230.054*
H1D0.53420.13260.78570.054*
C20.3194 (2)0.2067 (2)0.6832 (2)0.0457 (5)
H2A0.26240.11630.73320.055*
H2B0.22900.29700.67050.055*
C30.3199 (3)0.1628 (2)0.4441 (2)0.0495 (5)
H3A0.20310.22330.45380.059*
H3B0.30750.05440.47540.059*
C40.6376 (3)0.3752 (2)0.8169 (2)0.0482 (5)
H4A0.73690.29230.81720.058*
H4B0.57290.36360.92160.058*
C50.7031 (2)0.5272 (2)0.7613 (2)0.0486 (5)
H5A0.78510.53130.82300.058*
H5B0.76270.54270.65480.058*
C60.5862 (3)0.7961 (2)0.7188 (2)0.0507 (5)
H6A0.65520.81530.78360.061*
H6B0.47420.86410.72780.061*
C70.8236 (2)0.27649 (18)0.43185 (18)0.0318 (4)
C80.9026 (2)0.24102 (18)0.28271 (18)0.0313 (4)
C90.8985 (2)0.3296 (2)0.13557 (19)0.0432 (4)
H90.84260.43090.10750.052*
C100.9934 (3)0.2405 (2)0.0351 (2)0.0505 (5)
H101.01200.27160.07180.061*
C111.0535 (2)0.0996 (2)0.1224 (2)0.0437 (5)
H111.12090.01740.08540.052*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0400 (8)0.0321 (8)0.0289 (8)0.0031 (7)0.0085 (7)0.0080 (6)
N20.0376 (8)0.0328 (8)0.0310 (8)0.0017 (6)0.0068 (6)0.0091 (6)
O10.0407 (7)0.0546 (8)0.0490 (8)0.0112 (6)0.0072 (6)0.0200 (6)
O20.0475 (7)0.0390 (7)0.0528 (8)0.0051 (6)0.0082 (6)0.0147 (6)
O30.0416 (7)0.0323 (6)0.0401 (7)0.0072 (5)0.0095 (5)0.0115 (5)
O40.0509 (8)0.0387 (7)0.0324 (6)0.0094 (6)0.0086 (6)0.0049 (5)
C10.0548 (12)0.0358 (10)0.0393 (10)0.0065 (8)0.0051 (9)0.0034 (8)
C20.0458 (11)0.0414 (10)0.0467 (11)0.0092 (8)0.0022 (9)0.0096 (8)
C30.0525 (12)0.0437 (11)0.0602 (12)0.0163 (9)0.0190 (10)0.0121 (9)
C40.0646 (13)0.0408 (11)0.0425 (10)0.0004 (9)0.0267 (9)0.0086 (8)
C50.0481 (11)0.0492 (11)0.0541 (12)0.0011 (9)0.0225 (9)0.0157 (9)
C60.0632 (13)0.0426 (11)0.0542 (12)0.0095 (9)0.0155 (10)0.0196 (9)
C70.0281 (9)0.0310 (9)0.0370 (9)0.0019 (7)0.0086 (7)0.0092 (7)
C80.0283 (8)0.0309 (8)0.0337 (9)0.0002 (7)0.0077 (7)0.0082 (7)
C90.0443 (10)0.0405 (10)0.0363 (10)0.0057 (8)0.0095 (8)0.0040 (8)
C100.0497 (11)0.0651 (13)0.0304 (9)0.0053 (10)0.0089 (8)0.0115 (9)
C110.0425 (10)0.0499 (11)0.0404 (10)0.0052 (8)0.0076 (8)0.0225 (9)
Geometric parameters (Å, º) top
N1—C11.483 (2)C3—C6i1.492 (3)
N1—C41.484 (2)C3—H3A0.9700
N1—H1A0.94 (2)C3—H3B0.9700
N1—H1B0.91 (2)C4—C51.495 (3)
N2—C111.354 (2)C4—H4A0.9700
N2—C81.369 (2)C4—H4B0.9700
N2—H20.877 (19)C5—H5A0.9700
O1—C21.402 (2)C5—H5B0.9700
O1—C31.424 (2)C6—C3i1.492 (3)
O2—C51.408 (2)C6—H6A0.9700
O2—C61.417 (2)C6—H6B0.9700
O3—C71.2701 (18)C7—C81.474 (2)
O4—C71.2519 (18)C8—C91.369 (2)
C1—C21.496 (2)C9—C101.397 (2)
C1—H1C0.9700C9—H90.9300
C1—H1D0.9700C10—C111.361 (3)
C2—H2A0.9700C10—H100.9300
C2—H2B0.9700C11—H110.9300
C1—N1—C4111.26 (13)C5—C4—H4A109.5
C1—N1—H1A112.0 (11)N1—C4—H4B109.5
C4—N1—H1A106.5 (11)C5—C4—H4B109.5
C1—N1—H1B109.1 (12)H4A—C4—H4B108.1
C4—N1—H1B111.2 (12)O2—C5—C4106.59 (16)
H1A—N1—H1B106.7 (16)O2—C5—H5A110.4
C11—N2—C8109.53 (15)C4—C5—H5A110.4
C11—N2—H2122.7 (12)O2—C5—H5B110.4
C8—N2—H2127.7 (12)C4—C5—H5B110.4
C2—O1—C3113.17 (14)H5A—C5—H5B108.6
C5—O2—C6115.71 (15)O2—C6—C3i114.91 (15)
N1—C1—C2113.14 (14)O2—C6—H6A108.5
N1—C1—H1C109.0C3i—C6—H6A108.5
C2—C1—H1C109.0O2—C6—H6B108.5
N1—C1—H1D109.0C3i—C6—H6B108.5
C2—C1—H1D109.0H6A—C6—H6B107.5
H1C—C1—H1D107.8O4—C7—O3123.76 (15)
O1—C2—C1108.26 (15)O4—C7—C8118.96 (13)
O1—C2—H2A110.0O3—C7—C8117.28 (14)
C1—C2—H2A110.0N2—C8—C9107.10 (14)
O1—C2—H2B110.0N2—C8—C7122.19 (14)
C1—C2—H2B110.0C9—C8—C7130.70 (15)
H2A—C2—H2B108.4C8—C9—C10107.78 (16)
O1—C3—C6i108.78 (15)C8—C9—H9126.1
O1—C3—H3A109.9C10—C9—H9126.1
C6i—C3—H3A109.9C11—C10—C9107.46 (15)
O1—C3—H3B109.9C11—C10—H10126.3
C6i—C3—H3B109.9C9—C10—H10126.3
H3A—C3—H3B108.3N2—C11—C10108.13 (15)
N1—C4—C5110.60 (14)N2—C11—H11125.9
N1—C4—H4A109.5C10—C11—H11125.9
C4—N1—C1—C2178.78 (15)O4—C7—C8—N23.8 (2)
C3—O1—C2—C1173.64 (14)O3—C7—C8—N2175.99 (14)
N1—C1—C2—O164.80 (19)O4—C7—C8—C9176.92 (17)
C2—O1—C3—C6i160.84 (15)O3—C7—C8—C93.3 (3)
C1—N1—C4—C5174.38 (16)N2—C8—C9—C100.1 (2)
C6—O2—C5—C4176.05 (14)C7—C8—C9—C10179.46 (16)
N1—C4—C5—O263.76 (19)C8—C9—C10—C110.0 (2)
C5—O2—C6—C3i54.4 (2)C8—N2—C11—C100.1 (2)
C11—N2—C8—C90.12 (19)C9—C10—C11—N20.1 (2)
C11—N2—C8—C7179.58 (15)
Symmetry code: (i) x+1, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2···O4ii0.877 (19)1.94 (2)2.7741 (19)158.0 (17)
N1—H1B···O3i0.91 (2)2.01 (2)2.8167 (19)147.4 (16)
N1—H1A···O40.94 (2)2.489 (19)3.137 (2)125.9 (14)
N1—H1A···O30.94 (2)1.81 (2)2.7452 (19)171.1 (17)
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+2, y, z+1.

Experimental details

Crystal data
Chemical formulaC12H28N2O42+·2C5H4NO2
Mr484.55
Crystal system, space groupTriclinic, P1
Temperature (K)294
a, b, c (Å)7.8963 (19), 9.164 (2), 9.244 (2)
α, β, γ (°)73.028 (4), 76.547 (4), 77.824 (4)
V3)614.8 (3)
Z1
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.24 × 0.22 × 0.18
Data collection
DiffractometerBruker SMART CCD area-detector
Absorption correctionMulti-scan
(SADABS; Bruker, 1997)
Tmin, Tmax0.970, 0.982
No. of measured, independent and
observed [I > 2σ(I)] reflections
3484, 2471, 1695
Rint0.017
(sin θ/λ)max1)0.624
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.042, 0.113, 1.03
No. of reflections2471
No. of parameters166
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.14, 0.26

Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2···O4i0.877 (19)1.94 (2)2.7741 (19)158.0 (17)
N1—H1B···O3ii0.91 (2)2.01 (2)2.8167 (19)147.4 (16)
N1—H1A···O40.94 (2)2.489 (19)3.137 (2)125.9 (14)
N1—H1A···O30.94 (2)1.81 (2)2.7452 (19)171.1 (17)
Symmetry codes: (i) x+2, y, z+1; (ii) x+1, y+1, z+1.
 

Acknowledgements

We sincerely thank the Natural Science Foundation of China for financial support (NSFC No. 21172174).

References

First citationBruker (1997). SADABS, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBurrows, A. D. (2004). Struct. Bond. 108, 55–96.  Web of Science CrossRef CAS Google Scholar
First citationCui, Y., Yin, Z., Dong, L. & He, J. (2009). J. Mol. Struct. 938, 322–327.  Web of Science CSD CrossRef CAS Google Scholar
First citationLi, C., Zhang, G. & Yin, Z. (2012). Acta Cryst. E68, m323.  CSD CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationWang, W.-Y. & Yin, Z.-M. (2007). Acta Cryst. E63, o2737–o2738.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationYin, Z. & Li, Z. (2006). Tetrahedron Lett. 47, 7875–7879.  Web of Science CSD CrossRef CAS Google Scholar

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