The crystal structure of the title compound, C
6H
8N
+·C
8HN
4O
2-, is characterized by three independent ion pairs (
A,
B and
C) in the asymmetric unit. Each ion pair consists of an anion and a cation, and the three ion pairs have similar geometric parameters. All the anions are arranged as dianion dimers
via two N-H
O hydrogen bonds and the dimers form one-dimensional columns parallel to the
b axis as a result of
-
interactions. The cations are also stacked, in two different ways: one type of stacking consists of alternating
A and
B cations, while the other type consists of
C cations only. Each dianion dimer stack is surrounded by eight stacks of cations and is not connected directly to other dianion stacks.
Supporting information
CCDC reference: 237953
2,2,3,3-Tetracyanocyclopropanecarboxylic acid was synthesized from α-chloro ketone and TCNE (ethylene-1,1,2,2-tetracarbonitrile). N-methyl-pyridinium 3-cyano-4-(dicyanomethylene)-5-oxo-4,5-dihydro-1H-pyrrol-2-olate was obtained by mixing N-methylpyridinium iodide with 2,2,3,3-tetracyanocyclopropanecarboxylic acid. The reaction was carried out in water/propan-2-ol (1:1) at room temperature. Orange crystals were collected from the reaction mixture by filtration and drying.
Methyl and pyridinium H atoms were placed in idealized positions and constrained to ride on their parent atoms. The positions of the H atoms on atoms N1 were determined from a Fourier difference map and the coordinates were refined freely with isotropic displacement parameters.
Data collection: CAD-4 Software (Enraf–Nonius, 1989; cell refinement: CAD-4 Software (Enraf–Nonius, 1989; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2000; ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.
N-methylpiridinium 3-cyano-4-(dicyanomethylene)-5-oxo-4,5-dihydro-1
H-pyrrol-2-olate
top
Crystal data top
C6H8N+·C8HN4O2− | Dx = 1.359 Mg m−3 |
Mr = 279.26 | Melting point: 195 K |
Monoclinic, P21/c | Cu Kα radiation, λ = 1.54180 Å |
a = 19.854 (2) Å | Cell parameters from 25 reflections |
b = 9.8278 (11) Å | θ = 28–41° |
c = 22.198 (2) Å | µ = 0.80 mm−1 |
β = 109.006 (10)° | T = 293 K |
V = 4095.1 (7) Å3 | Prism, orange |
Z = 12 | 0.10 × 0.07 × 0.05 mm |
F(000) = 1728 | |
Data collection top
Enraf–Nonius CAD-4 diffractometer | Rint = 0.023 |
Radiation source: fine-focus sealed tube | θmax = 72.0°, θmin = 2.4° |
Graphite monochromator | h = −24→23 |
non–profiled ω scan | k = 0→12 |
8264 measured reflections | l = 0→27 |
8037 independent reflections | 2 standard reflections every 120 min |
4686 reflections with I > 2σ(I) | intensity decay: none |
Refinement top
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)] = 0.057 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.153 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | w = 1/[σ2(Fo2) + (0.0627P)2 + 0.7078P] where P = (Fo2 + 2Fc2)/3 |
8037 reflections | (Δ/σ)max = 0.007 |
583 parameters | Δρmax = 0.21 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
Crystal data top
C6H8N+·C8HN4O2− | V = 4095.1 (7) Å3 |
Mr = 279.26 | Z = 12 |
Monoclinic, P21/c | Cu Kα radiation |
a = 19.854 (2) Å | µ = 0.80 mm−1 |
b = 9.8278 (11) Å | T = 293 K |
c = 22.198 (2) Å | 0.10 × 0.07 × 0.05 mm |
β = 109.006 (10)° | |
Data collection top
Enraf–Nonius CAD-4 diffractometer | Rint = 0.023 |
8264 measured reflections | 2 standard reflections every 120 min |
8037 independent reflections | intensity decay: none |
4686 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.057 | 0 restraints |
wR(F2) = 0.153 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | Δρmax = 0.21 e Å−3 |
8037 reflections | Δρmin = −0.24 e Å−3 |
583 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 | x | y | z | Uiso*/Ueq | |
O1A | 0.05301 (9) | 0.3236 (2) | 0.48924 (8) | 0.0514 (5) | |
O2A | 0.19335 (10) | 0.3924 (2) | 0.69514 (9) | 0.0643 (6) | |
N1A | 0.10911 (12) | 0.3585 (3) | 0.59686 (11) | 0.0497 (6) | |
N2A | 0.21761 (13) | 0.3006 (3) | 0.43701 (11) | 0.0574 (6) | |
N3A | 0.38357 (13) | 0.3341 (3) | 0.56120 (13) | 0.0747 (8) | |
N4A | 0.37021 (14) | 0.3828 (3) | 0.74514 (13) | 0.0751 (8) | |
C2A | 0.10801 (13) | 0.3371 (3) | 0.53444 (12) | 0.0420 (6) | |
C3A | 0.18156 (13) | 0.3344 (3) | 0.53642 (11) | 0.0393 (6) | |
C4A | 0.22587 (13) | 0.3526 (3) | 0.59910 (12) | 0.0393 (6) | |
C5A | 0.17648 (14) | 0.3704 (3) | 0.63854 (13) | 0.0457 (6) | |
C6A | 0.20131 (13) | 0.3152 (3) | 0.48147 (12) | 0.0422 (6) | |
C7A | 0.29833 (13) | 0.3566 (3) | 0.62639 (12) | 0.0437 (6) | |
C8A | 0.34469 (14) | 0.3437 (3) | 0.58922 (13) | 0.0514 (7) | |
C9A | 0.33512 (14) | 0.3720 (3) | 0.69318 (14) | 0.0531 (7) | |
O1B | 0.01589 (9) | 0.6104 (2) | 0.37482 (9) | 0.0577 (5) | |
O2B | 0.17161 (10) | 0.6856 (2) | 0.57473 (8) | 0.0513 (5) | |
N1B | 0.07981 (12) | 0.6528 (2) | 0.48093 (10) | 0.0460 (6) | |
N2B | 0.16112 (14) | 0.6062 (3) | 0.30395 (12) | 0.0692 (8) | |
N3B | 0.33819 (14) | 0.6197 (3) | 0.41841 (13) | 0.0735 (8) | |
N4B | 0.34563 (13) | 0.6847 (3) | 0.61110 (12) | 0.0640 (7) | |
C2B | 0.07296 (13) | 0.6287 (3) | 0.41704 (12) | 0.0438 (6) | |
C3B | 0.14354 (13) | 0.6303 (3) | 0.41279 (11) | 0.0402 (6) | |
C4B | 0.19261 (13) | 0.6495 (2) | 0.47309 (11) | 0.0388 (6) | |
C5B | 0.14918 (13) | 0.6658 (3) | 0.51794 (12) | 0.0412 (6) | |
C6B | 0.15487 (13) | 0.6162 (3) | 0.35330 (13) | 0.0466 (6) | |
C7B | 0.26612 (13) | 0.6536 (3) | 0.49465 (12) | 0.0423 (6) | |
C8B | 0.30578 (14) | 0.6350 (3) | 0.45206 (13) | 0.0504 (7) | |
C9B | 0.30773 (14) | 0.6717 (3) | 0.56009 (13) | 0.0469 (6) | |
O1C | 0.03583 (9) | −0.0133 (2) | 0.43218 (8) | 0.0513 (5) | |
O2C | 0.18272 (10) | 0.0249 (2) | 0.63787 (8) | 0.0580 (5) | |
N1C | 0.09487 (12) | 0.0021 (2) | 0.54066 (9) | 0.0443 (5) | |
N2C | 0.19225 (14) | −0.0335 (3) | 0.37208 (11) | 0.0630 (7) | |
N3C | 0.36566 (15) | −0.0102 (3) | 0.49550 (13) | 0.0789 (9) | |
N4C | 0.35689 (14) | 0.0171 (3) | 0.68253 (12) | 0.0717 (8) | |
C2C | 0.09201 (13) | −0.0090 (3) | 0.47731 (11) | 0.0395 (6) | |
C3C | 0.16411 (13) | −0.0126 (3) | 0.47653 (11) | 0.0379 (6) | |
C4C | 0.21070 (13) | −0.0003 (2) | 0.53902 (10) | 0.0370 (5) | |
C5C | 0.16359 (14) | 0.0096 (3) | 0.58061 (11) | 0.0412 (6) | |
C6C | 0.18073 (13) | −0.0241 (3) | 0.41927 (11) | 0.0434 (6) | |
C7C | 0.28353 (13) | 0.0031 (3) | 0.56387 (11) | 0.0406 (6) | |
C8C | 0.32822 (14) | −0.0043 (3) | 0.52481 (13) | 0.0504 (7) | |
C9C | 0.32137 (15) | 0.0116 (3) | 0.63044 (13) | 0.0495 (7) | |
N5B | 0.35050 (13) | 0.8167 (3) | 0.28738 (13) | 0.0666 (7) | |
C10B | 0.40434 (18) | 0.7838 (4) | 0.26621 (15) | 0.0699 (9) | |
H10B | 0.3951 | 0.7414 | 0.2269 | 0.084* | |
C11B | 0.47315 (19) | 0.8128 (4) | 0.30267 (17) | 0.0830 (11) | |
H11B | 0.5110 | 0.7902 | 0.2886 | 0.100* | |
C12B | 0.4847 (2) | 0.8757 (5) | 0.36021 (18) | 0.0949 (13) | |
H12B | 0.5310 | 0.8963 | 0.3856 | 0.114* | |
C13B | 0.4307 (3) | 0.9075 (5) | 0.38006 (18) | 0.0952 (13) | |
H13B | 0.4392 | 0.9505 | 0.4192 | 0.114* | |
C14B | 0.3632 (2) | 0.8779 (4) | 0.3439 (2) | 0.0882 (12) | |
H14B | 0.3255 | 0.9000 | 0.3583 | 0.106* | |
C15B | 0.27670 (19) | 0.7883 (5) | 0.2471 (2) | 0.1186 (17) | |
H15A | 0.2706 | 0.8135 | 0.2039 | 0.178* | |
H15B | 0.2444 | 0.8399 | 0.2623 | 0.178* | |
H15C | 0.2670 | 0.6930 | 0.2490 | 0.178* | |
N5A | 0.36406 (12) | 0.3415 (3) | 0.35437 (11) | 0.0591 (7) | |
C10A | 0.41299 (19) | 0.3979 (4) | 0.33296 (15) | 0.0778 (11) | |
H10A | 0.3997 | 0.4345 | 0.2921 | 0.093* | |
C11A | 0.4818 (2) | 0.4018 (5) | 0.3704 (2) | 0.1094 (17) | |
H11A | 0.5160 | 0.4405 | 0.3554 | 0.131* | |
C12A | 0.5005 (2) | 0.3498 (7) | 0.42925 (19) | 0.142 (3) | |
H12A | 0.5478 | 0.3526 | 0.4555 | 0.171* | |
C13A | 0.4509 (2) | 0.2938 (6) | 0.45010 (19) | 0.135 (2) | |
H13A | 0.4636 | 0.2564 | 0.4908 | 0.162* | |
C14A | 0.3827 (2) | 0.2916 (4) | 0.41231 (18) | 0.0903 (13) | |
H14A | 0.3482 | 0.2541 | 0.4273 | 0.108* | |
C15A | 0.28892 (17) | 0.3421 (5) | 0.31333 (18) | 0.1025 (15) | |
H15D | 0.2691 | 0.2527 | 0.3126 | 0.154* | |
H15E | 0.2860 | 0.3679 | 0.2709 | 0.154* | |
H15F | 0.2627 | 0.4058 | 0.3298 | 0.154* | |
N5C | 0.02240 (13) | 0.8048 (3) | 0.19510 (11) | 0.0591 (7) | |
C10C | −0.04338 (17) | 0.7556 (4) | 0.17227 (15) | 0.0710 (9) | |
H10C | −0.0579 | 0.7122 | 0.1329 | 0.085* | |
C11C | −0.08981 (19) | 0.7677 (4) | 0.20539 (18) | 0.0855 (11) | |
H11C | −0.1352 | 0.7304 | 0.1892 | 0.103* | |
C12C | −0.0698 (2) | 0.8345 (4) | 0.26253 (16) | 0.0787 (11) | |
H12C | −0.1012 | 0.8455 | 0.2855 | 0.094* | |
C13C | −0.0017 (2) | 0.8845 (4) | 0.28463 (16) | 0.0854 (12) | |
H13C | 0.0137 | 0.9294 | 0.3236 | 0.102* | |
C14C | 0.04351 (19) | 0.8700 (4) | 0.25110 (15) | 0.0729 (10) | |
H14C | 0.0894 | 0.9052 | 0.2669 | 0.087* | |
C15C | 0.07173 (19) | 0.7870 (5) | 0.15983 (16) | 0.0914 (13) | |
H15G | 0.0999 | 0.7069 | 0.1747 | 0.137* | |
H15H | 0.1024 | 0.8650 | 0.1661 | 0.137* | |
H15I | 0.0455 | 0.7774 | 0.1153 | 0.137* | |
H1A | 0.0726 (15) | 0.368 (3) | 0.6060 (13) | 0.058 (9)* | |
H1B | 0.0453 (14) | 0.663 (3) | 0.4935 (12) | 0.045 (8)* | |
H1C | 0.0570 (16) | 0.007 (3) | 0.5511 (13) | 0.065 (10)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1A | 0.0397 (10) | 0.0643 (14) | 0.0469 (10) | 0.0000 (9) | 0.0097 (8) | 0.0002 (9) |
O2A | 0.0562 (12) | 0.0933 (17) | 0.0448 (11) | −0.0028 (12) | 0.0187 (9) | −0.0105 (11) |
N1A | 0.0369 (12) | 0.0656 (17) | 0.0492 (13) | 0.0001 (11) | 0.0175 (10) | −0.0031 (11) |
N2A | 0.0655 (16) | 0.0602 (17) | 0.0513 (14) | −0.0016 (13) | 0.0254 (12) | 0.0008 (12) |
N3A | 0.0508 (15) | 0.099 (2) | 0.0817 (19) | 0.0003 (15) | 0.0320 (14) | −0.0035 (17) |
N4A | 0.0639 (17) | 0.091 (2) | 0.0576 (16) | −0.0073 (16) | 0.0023 (13) | −0.0118 (15) |
C2A | 0.0430 (14) | 0.0397 (15) | 0.0457 (14) | 0.0011 (11) | 0.0177 (12) | 0.0015 (11) |
C3A | 0.0393 (13) | 0.0366 (14) | 0.0430 (13) | 0.0004 (11) | 0.0146 (11) | −0.0009 (11) |
C4A | 0.0409 (13) | 0.0331 (14) | 0.0460 (14) | −0.0011 (11) | 0.0172 (11) | 0.0010 (11) |
C5A | 0.0437 (14) | 0.0464 (16) | 0.0484 (15) | −0.0014 (12) | 0.0169 (12) | −0.0022 (12) |
C6A | 0.0414 (14) | 0.0397 (15) | 0.0447 (14) | −0.0003 (11) | 0.0130 (11) | 0.0022 (12) |
C7A | 0.0415 (14) | 0.0426 (16) | 0.0470 (14) | −0.0021 (12) | 0.0143 (11) | −0.0025 (12) |
C8A | 0.0393 (14) | 0.0547 (19) | 0.0567 (17) | 0.0018 (13) | 0.0110 (13) | 0.0002 (14) |
C9A | 0.0444 (15) | 0.0551 (19) | 0.0567 (17) | −0.0035 (13) | 0.0123 (13) | −0.0036 (14) |
O1B | 0.0415 (10) | 0.0793 (15) | 0.0515 (11) | −0.0001 (10) | 0.0138 (9) | −0.0033 (10) |
O2B | 0.0544 (11) | 0.0585 (13) | 0.0438 (10) | 0.0000 (9) | 0.0198 (9) | −0.0036 (9) |
N1B | 0.0391 (12) | 0.0567 (15) | 0.0477 (13) | 0.0011 (11) | 0.0215 (10) | −0.0012 (11) |
N2B | 0.0743 (18) | 0.087 (2) | 0.0529 (15) | −0.0037 (15) | 0.0296 (13) | −0.0098 (14) |
N3B | 0.0632 (17) | 0.088 (2) | 0.0806 (19) | −0.0021 (15) | 0.0396 (15) | −0.0108 (16) |
N4B | 0.0586 (15) | 0.0699 (19) | 0.0554 (15) | 0.0064 (13) | 0.0077 (12) | −0.0015 (13) |
C2B | 0.0405 (14) | 0.0465 (16) | 0.0466 (14) | 0.0018 (12) | 0.0172 (12) | 0.0017 (12) |
C3B | 0.0403 (13) | 0.0412 (15) | 0.0408 (13) | 0.0001 (11) | 0.0156 (11) | −0.0006 (11) |
C4B | 0.0433 (13) | 0.0326 (14) | 0.0446 (14) | 0.0020 (11) | 0.0200 (11) | 0.0016 (11) |
C5B | 0.0434 (14) | 0.0379 (15) | 0.0463 (14) | 0.0001 (11) | 0.0202 (12) | 0.0008 (12) |
C6B | 0.0407 (14) | 0.0522 (17) | 0.0474 (15) | −0.0003 (12) | 0.0149 (12) | −0.0043 (13) |
C7B | 0.0423 (14) | 0.0408 (15) | 0.0446 (14) | 0.0013 (12) | 0.0154 (11) | −0.0011 (11) |
C8B | 0.0418 (14) | 0.0545 (18) | 0.0549 (16) | −0.0011 (13) | 0.0160 (13) | −0.0054 (14) |
C9B | 0.0430 (14) | 0.0429 (16) | 0.0542 (16) | 0.0027 (12) | 0.0151 (12) | 0.0014 (13) |
O1C | 0.0449 (10) | 0.0703 (14) | 0.0372 (9) | 0.0014 (9) | 0.0112 (8) | −0.0056 (9) |
O2C | 0.0621 (12) | 0.0797 (15) | 0.0332 (9) | −0.0008 (11) | 0.0168 (9) | −0.0046 (9) |
N1C | 0.0442 (13) | 0.0573 (15) | 0.0345 (11) | 0.0030 (11) | 0.0170 (10) | 0.0008 (10) |
N2C | 0.0749 (17) | 0.0763 (19) | 0.0427 (13) | −0.0028 (14) | 0.0258 (12) | −0.0042 (13) |
N3C | 0.0683 (18) | 0.107 (3) | 0.0732 (18) | −0.0133 (17) | 0.0389 (15) | −0.0149 (17) |
N4C | 0.0715 (18) | 0.084 (2) | 0.0468 (14) | 0.0006 (15) | 0.0019 (13) | −0.0070 (14) |
C2C | 0.0442 (14) | 0.0407 (15) | 0.0345 (12) | 0.0015 (11) | 0.0139 (11) | −0.0012 (11) |
C3C | 0.0428 (13) | 0.0397 (15) | 0.0322 (11) | −0.0018 (11) | 0.0136 (10) | −0.0027 (10) |
C4C | 0.0481 (14) | 0.0318 (13) | 0.0325 (12) | 0.0001 (11) | 0.0153 (10) | 0.0007 (10) |
C5C | 0.0489 (15) | 0.0412 (15) | 0.0345 (12) | 0.0019 (12) | 0.0150 (11) | −0.0002 (11) |
C6C | 0.0463 (15) | 0.0466 (16) | 0.0359 (13) | −0.0025 (12) | 0.0115 (11) | −0.0030 (11) |
C7C | 0.0441 (14) | 0.0413 (15) | 0.0353 (12) | −0.0009 (12) | 0.0115 (11) | −0.0009 (11) |
C8C | 0.0450 (15) | 0.0565 (19) | 0.0474 (15) | −0.0047 (13) | 0.0120 (12) | −0.0050 (13) |
C9C | 0.0498 (16) | 0.0513 (18) | 0.0438 (15) | 0.0010 (13) | 0.0105 (12) | −0.0032 (13) |
N5B | 0.0578 (16) | 0.0704 (19) | 0.0759 (18) | 0.0037 (14) | 0.0277 (14) | 0.0210 (15) |
C10B | 0.075 (2) | 0.082 (3) | 0.0542 (18) | 0.0101 (19) | 0.0228 (17) | 0.0002 (17) |
C11B | 0.062 (2) | 0.114 (3) | 0.077 (2) | 0.019 (2) | 0.0273 (18) | 0.002 (2) |
C12B | 0.072 (2) | 0.130 (4) | 0.068 (2) | 0.008 (3) | 0.002 (2) | −0.004 (2) |
C13B | 0.113 (4) | 0.112 (4) | 0.059 (2) | 0.009 (3) | 0.026 (2) | 0.000 (2) |
C14B | 0.111 (3) | 0.091 (3) | 0.088 (3) | 0.023 (3) | 0.067 (3) | 0.027 (2) |
C15B | 0.056 (2) | 0.122 (4) | 0.164 (4) | −0.015 (2) | 0.017 (3) | 0.036 (3) |
N5A | 0.0496 (14) | 0.0761 (19) | 0.0553 (14) | 0.0031 (13) | 0.0221 (12) | −0.0120 (13) |
C10A | 0.072 (2) | 0.109 (3) | 0.0542 (19) | −0.006 (2) | 0.0227 (17) | 0.016 (2) |
C11A | 0.062 (2) | 0.186 (5) | 0.082 (3) | −0.032 (3) | 0.025 (2) | 0.003 (3) |
C12A | 0.057 (2) | 0.307 (8) | 0.058 (2) | 0.018 (4) | 0.0123 (19) | 0.001 (4) |
C13A | 0.094 (3) | 0.252 (7) | 0.071 (3) | 0.080 (4) | 0.043 (2) | 0.066 (3) |
C14A | 0.081 (2) | 0.123 (4) | 0.089 (3) | 0.031 (2) | 0.057 (2) | 0.041 (3) |
C15A | 0.052 (2) | 0.162 (4) | 0.089 (3) | 0.003 (2) | 0.0182 (19) | −0.043 (3) |
N5C | 0.0596 (15) | 0.0677 (18) | 0.0455 (13) | 0.0062 (13) | 0.0107 (11) | 0.0025 (12) |
C10C | 0.0561 (19) | 0.088 (3) | 0.0558 (18) | −0.0024 (18) | 0.0007 (15) | −0.0176 (18) |
C11C | 0.059 (2) | 0.104 (3) | 0.090 (3) | −0.002 (2) | 0.0192 (19) | −0.014 (2) |
C12C | 0.087 (3) | 0.086 (3) | 0.059 (2) | 0.019 (2) | 0.0190 (19) | 0.0116 (19) |
C13C | 0.111 (3) | 0.090 (3) | 0.0455 (18) | 0.009 (3) | 0.013 (2) | −0.0117 (19) |
C14C | 0.073 (2) | 0.079 (3) | 0.0497 (18) | −0.0088 (19) | −0.0028 (16) | −0.0129 (17) |
C15C | 0.076 (2) | 0.132 (4) | 0.075 (2) | 0.010 (2) | 0.037 (2) | 0.010 (2) |
Geometric parameters (Å, º) top
O1A—C2A | 1.226 (3) | N5B—C14B | 1.340 (5) |
O2A—C5A | 1.210 (3) | N5B—C10B | 1.340 (4) |
N1A—C5A | 1.361 (3) | N5B—C15B | 1.473 (4) |
N1A—C2A | 1.395 (3) | C10B—C11B | 1.372 (5) |
N1A—H1A | 0.82 (3) | C10B—H10B | 0.9300 |
N2A—C6A | 1.143 (3) | C11B—C12B | 1.370 (5) |
N3A—C8A | 1.142 (3) | C11B—H11B | 0.9300 |
N4A—C9A | 1.142 (3) | C12B—C13B | 1.323 (5) |
C2A—C3A | 1.447 (3) | C12B—H12B | 0.9300 |
C3A—C4A | 1.395 (3) | C13B—C14B | 1.350 (5) |
C3A—C6A | 1.410 (3) | C13B—H13B | 0.9300 |
C4A—C7A | 1.368 (3) | C14B—H14B | 0.9300 |
C4A—C5A | 1.522 (3) | C15B—H15A | 0.9600 |
C7A—C8A | 1.428 (4) | C15B—H15B | 0.9600 |
C7A—C9A | 1.431 (4) | C15B—H15C | 0.9600 |
O1B—C2B | 1.226 (3) | N5A—C14A | 1.312 (4) |
O2B—C5B | 1.208 (3) | N5A—C10A | 1.333 (4) |
N1B—C5B | 1.360 (3) | N5A—C15A | 1.473 (4) |
N1B—C2B | 1.400 (3) | C10A—C11A | 1.348 (5) |
N1B—H1B | 0.82 (3) | C10A—H10A | 0.9300 |
N2B—C6B | 1.146 (3) | C11A—C12A | 1.338 (5) |
N3B—C8B | 1.144 (3) | C11A—H11A | 0.9300 |
N4B—C9B | 1.144 (3) | C12A—C13A | 1.337 (6) |
C2B—C3B | 1.435 (3) | C12A—H12A | 0.9300 |
C3B—C4B | 1.388 (3) | C13A—C14A | 1.340 (5) |
C3B—C6B | 1.417 (3) | C13A—H13A | 0.9300 |
C4B—C7B | 1.381 (3) | C14A—H14A | 0.9300 |
C4B—C5B | 1.523 (3) | C15A—H15D | 0.9600 |
C7B—C8B | 1.425 (4) | C15A—H15E | 0.9600 |
C7B—C9B | 1.429 (4) | C15A—H15F | 0.9600 |
O1C—C2C | 1.234 (3) | N5C—C10C | 1.328 (4) |
O2C—C5C | 1.212 (3) | N5C—C14C | 1.339 (4) |
N1C—C5C | 1.366 (3) | N5C—C15C | 1.450 (4) |
N1C—C2C | 1.393 (3) | C10C—C11C | 1.359 (5) |
N1C—H1C | 0.86 (3) | C10C—H10C | 0.9300 |
N2C—C6C | 1.147 (3) | C11C—C12C | 1.367 (5) |
N3C—C8C | 1.138 (3) | C11C—H11C | 0.9300 |
N4C—C9C | 1.143 (3) | C12C—C13C | 1.372 (5) |
C2C—C3C | 1.438 (3) | C12C—H12C | 0.9300 |
C3C—C4C | 1.400 (3) | C13C—C14C | 1.347 (5) |
C3C—C6C | 1.418 (3) | C13C—H13C | 0.9300 |
C4C—C7C | 1.370 (3) | C14C—H14C | 0.9300 |
C4C—C5C | 1.516 (3) | C15C—H15G | 0.9600 |
C7C—C9C | 1.425 (3) | C15C—H15H | 0.9600 |
C7C—C8C | 1.430 (4) | C15C—H15I | 0.9600 |
| | | |
C5A—N1A—C2A | 112.5 (2) | C11B—C10B—H10B | 120.1 |
C5A—N1A—H1A | 125 (2) | C12B—C11B—C10B | 118.5 (3) |
C2A—N1A—H1A | 122 (2) | C12B—C11B—H11B | 120.8 |
O1A—C2A—N1A | 123.4 (2) | C10B—C11B—H11B | 120.8 |
O1A—C2A—C3A | 130.1 (2) | C13B—C12B—C11B | 120.6 (4) |
N1A—C2A—C3A | 106.5 (2) | C13B—C12B—H12B | 119.7 |
C4A—C3A—C6A | 128.1 (2) | C11B—C12B—H12B | 119.7 |
C4A—C3A—C2A | 109.3 (2) | C12B—C13B—C14B | 120.4 (4) |
C6A—C3A—C2A | 122.6 (2) | C12B—C13B—H13B | 119.8 |
C7A—C4A—C3A | 132.6 (2) | C14B—C13B—H13B | 119.8 |
C7A—C4A—C5A | 121.6 (2) | N5B—C14B—C13B | 120.1 (4) |
C3A—C4A—C5A | 105.9 (2) | N5B—C14B—H14B | 120.0 |
O2A—C5A—N1A | 126.9 (2) | C13B—C14B—H14B | 120.0 |
O2A—C5A—C4A | 127.3 (2) | N5B—C15B—H15A | 109.5 |
N1A—C5A—C4A | 105.9 (2) | N5B—C15B—H15B | 109.5 |
N2A—C6A—C3A | 179.5 (3) | H15A—C15B—H15B | 109.5 |
C4A—C7A—C8A | 121.6 (2) | N5B—C15B—H15C | 109.5 |
C4A—C7A—C9A | 124.8 (2) | H15A—C15B—H15C | 109.5 |
C8A—C7A—C9A | 113.6 (2) | H15B—C15B—H15C | 109.5 |
N3A—C8A—C7A | 177.8 (3) | C14A—N5A—C10A | 119.9 (3) |
N4A—C9A—C7A | 173.6 (3) | C14A—N5A—C15A | 120.9 (3) |
C5B—N1B—C2B | 111.9 (2) | C10A—N5A—C15A | 119.1 (3) |
C5B—N1B—H1B | 125.0 (18) | N5A—C10A—C11A | 120.1 (3) |
C2B—N1B—H1B | 123.0 (18) | N5A—C10A—H10A | 120.0 |
O1B—C2B—N1B | 124.1 (2) | C11A—C10A—H10A | 120.0 |
O1B—C2B—C3B | 129.1 (2) | C12A—C11A—C10A | 119.7 (4) |
N1B—C2B—C3B | 106.9 (2) | C12A—C11A—H11A | 120.2 |
C4B—C3B—C6B | 129.6 (2) | C10A—C11A—H11A | 120.2 |
C4B—C3B—C2B | 109.4 (2) | C13A—C12A—C11A | 119.6 (4) |
C6B—C3B—C2B | 121.0 (2) | C13A—C12A—H12A | 120.2 |
C7B—C4B—C3B | 132.0 (2) | C11A—C12A—H12A | 120.2 |
C7B—C4B—C5B | 122.0 (2) | C12A—C13A—C14A | 119.9 (4) |
C3B—C4B—C5B | 106.0 (2) | C12A—C13A—H13A | 120.1 |
O2B—C5B—N1B | 127.0 (2) | C14A—C13A—H13A | 120.1 |
O2B—C5B—C4B | 127.2 (2) | N5A—C14A—C13A | 120.8 (3) |
N1B—C5B—C4B | 105.8 (2) | N5A—C14A—H14A | 119.6 |
N2B—C6B—C3B | 177.1 (3) | C13A—C14A—H14A | 119.6 |
C4B—C7B—C8B | 121.1 (2) | N5A—C15A—H15D | 109.5 |
C4B—C7B—C9B | 123.5 (2) | N5A—C15A—H15E | 109.5 |
C8B—C7B—C9B | 115.4 (2) | H15D—C15A—H15E | 109.5 |
N3B—C8B—C7B | 179.3 (3) | N5A—C15A—H15F | 109.5 |
N4B—C9B—C7B | 174.7 (3) | H15D—C15A—H15F | 109.5 |
C5C—N1C—C2C | 111.3 (2) | H15E—C15A—H15F | 109.5 |
C5C—N1C—H1C | 126.9 (19) | C10C—N5C—C14C | 120.0 (3) |
C2C—N1C—H1C | 121.7 (19) | C10C—N5C—C15C | 120.2 (3) |
O1C—C2C—N1C | 123.5 (2) | C14C—N5C—C15C | 119.8 (3) |
O1C—C2C—C3C | 129.0 (2) | N5C—C10C—C11C | 121.2 (3) |
N1C—C2C—C3C | 107.5 (2) | N5C—C10C—H10C | 119.4 |
C4C—C3C—C6C | 128.6 (2) | C11C—C10C—H10C | 119.4 |
C4C—C3C—C2C | 109.0 (2) | C10C—C11C—C12C | 120.0 (4) |
C6C—C3C—C2C | 122.4 (2) | C10C—C11C—H11C | 120.0 |
C7C—C4C—C3C | 132.2 (2) | C12C—C11C—H11C | 120.0 |
C7C—C4C—C5C | 122.2 (2) | C11C—C12C—C13C | 117.3 (4) |
C3C—C4C—C5C | 105.6 (2) | C11C—C12C—H12C | 121.4 |
O2C—C5C—N1C | 126.4 (2) | C13C—C12C—H12C | 121.4 |
O2C—C5C—C4C | 127.0 (2) | C14C—C13C—C12C | 121.4 (3) |
N1C—C5C—C4C | 106.6 (2) | C14C—C13C—H13C | 119.3 |
N2C—C6C—C3C | 178.2 (3) | C12C—C13C—H13C | 119.3 |
C4C—C7C—C9C | 123.3 (2) | N5C—C14C—C13C | 120.0 (3) |
C4C—C7C—C8C | 122.5 (2) | N5C—C14C—H14C | 120.0 |
C9C—C7C—C8C | 114.2 (2) | C13C—C14C—H14C | 120.0 |
N3C—C8C—C7C | 177.8 (3) | N5C—C15C—H15G | 109.5 |
N4C—C9C—C7C | 174.2 (3) | N5C—C15C—H15H | 109.5 |
C14B—N5B—C10B | 120.5 (3) | H15G—C15C—H15H | 109.5 |
C14B—N5B—C15B | 120.0 (3) | N5C—C15C—H15I | 109.5 |
C10B—N5B—C15B | 119.4 (3) | H15G—C15C—H15I | 109.5 |
N5B—C10B—C11B | 119.9 (3) | H15H—C15C—H15I | 109.5 |
N5B—C10B—H10B | 120.1 | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H1A···O1Bi | 0.82 (3) | 1.95 (3) | 2.769 (3) | 178 (3) |
N1B—H1B···O1Ai | 0.82 (3) | 2.11 (3) | 2.930 (3) | 171 (2) |
N1C—H1C···O1Cii | 0.86 (3) | 2.00 (3) | 2.851 (3) | 175 (3) |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x, −y, −z+1. |
Experimental details
Crystal data |
Chemical formula | C6H8N+·C8HN4O2− |
Mr | 279.26 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 19.854 (2), 9.8278 (11), 22.198 (2) |
β (°) | 109.006 (10) |
V (Å3) | 4095.1 (7) |
Z | 12 |
Radiation type | Cu Kα |
µ (mm−1) | 0.80 |
Crystal size (mm) | 0.10 × 0.07 × 0.05 |
|
Data collection |
Diffractometer | Enraf–Nonius CAD-4 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8264, 8037, 4686 |
Rint | 0.023 |
(sin θ/λ)max (Å−1) | 0.617 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.057, 0.153, 1.01 |
No. of reflections | 8037 |
No. of parameters | 583 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.21, −0.24 |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H1A···O1Bi | 0.82 (3) | 1.95 (3) | 2.769 (3) | 178 (3) |
N1B—H1B···O1Ai | 0.82 (3) | 2.11 (3) | 2.930 (3) | 171 (2) |
N1C—H1C···O1Cii | 0.86 (3) | 2.00 (3) | 2.851 (3) | 175 (3) |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x, −y, −z+1. |
Selected distances (Å) between atoms of the anions composing one stack topAtoms | Distance |
N1C··· 2 A | 3.309 (4) |
C2A···N1B | 3.305 (3) |
N1B···C2Ciii | 3.336 (4) |
O2B···C5Ciii | 3.193 (3) |
C3A···C5B | 3.320 (4) |
C3C···C6A | 3.299 (4) |
C4C···C3A | 3.337 (4) |
N4B···C9Ciii | 3.297 (4) |
C9B···C7Ciii | 3.297 (4) |
Symmetry code: (iii) x, 1 + y, z. |
The synthesis and structure of the potassium salt of the title anion have recently been reported for the first time (Tafeenko et al., 2003). Organic salts containing this anion are of interest, from both a theoretical and an experimental point of view, because of their π–π interactions, which are due to the planarity of the organic moieties, and their tendency to form stacks. In N,N-dimethyl-N-benzenaminium 3-cyano-4-(dicyanomethylene)-5-oxo-4,5-dihydro −1H-pyrrol-2-olate, (I) (Tafeenko et al., 2004), the distance between the anion and the cation composing one stack is larger than expected (3.5 Å), and it was conjectured that a smaller distance might be possible if the methyl groups located between the anion and the cation were absent.
To investigate this hypothesis and to determine the `minimum' anion–cation distance for the system in question, the title salt, (II), was synthesized. N-methylpyridinium was selected as the cation because its characteristics seemed appropriate; it has a π-system and its dimensions are similar to those of the N,N-dimethyl-N-benzenaminium moiety if the two methyl groups are omitted. Therefore, it was expected that the packing of (II) and (I) would be the same.
Surprisingly, the crystal structure determination of the selected orange crystal of (II)[the color of (I) is yellow] revealed a drastically different packing geometry. The crystal structure of (II) has three independent molecules, viz. A, B and C, in the asymmetric unit (Fig.1). Anions A, B and C have similar geometric parameters.
Each of the anions is linked by two N1—H···O1 hydrogen bonds into a dimer (Fig. 2 and Table 1). Anions A and Bi [symmetry code: (i) −x, −y + 1, −z + 1], B and Ai, and C and Cii (symmetry code: (ii) −x, −y, −z + 1) are held together in approximately parallel planes (the dihedral angle between the C/Cii and A/Bi planes is about 4°) and, as a result of π–π interactions, form di-anion stacks parallel to the b axis. The distances between adjacent planes composing one stack are 3.3, 3.3 and 3.2 Å for C/Cii and A/Bi, A/Bi and B/Ai, and B/Ai and Ci /Ciii [symmetry code: (iii) x, y + 1, z], respectively. The shortest intermolecular distances between atoms of the anions in adjacent planes are presented in Table 2. Each di-anion stack is surrounded by eight cation stacks and is not connected directly to any other di-anion stacks (see Fig. 3 and Fig. 4). Six of the eight cation stacks consist of alternating A and B cations, the angle between the A and B cations composing one stack being about 60° (see Fig. 4). The second type of cation stack consists of C cations only and the dihedral angle between two neighboring C cations in this stack is about 52°. Other differences also exist between the A/B and C/C cation stacks (Fig.3). In contrast to the A/B cation stacks, each C/C cation stack adjoins two di-anion stacks only. Moreover, in each C/C cation stack parallel to the b axis, the methyl groups point in opposite directions, whereas the methyl groups of the A/B stacks are oriented in the same direction (Fig.3).
The crystal packing of the title compound resembles a `multiple-conductor cable', in which the stacks of cations are the `insulator' part (Fig. 3 and Fig. 4).
In conclusion, the crystal structure investigation has revealed novel packing characteristics of the title anion; the anions form dimers via paired hydrogen bonds and adjacent di-anions are linked by π–π stacking interactions, forming one-dimensional columns. With respect to the original goal, a reduction of the cation–anion interstack distance, it is concluded that the anion–cation hydrogen bonding is more important than initially estimated. This topic will be considered in subsequent investigations in more detail.