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Crystallization of N,N′-dimethyl­pyrazinediium bis­(tetra­fluoro­borate), C6H10N22+·2BF4, (I), and N,N′-diethyl­pyrazinediium bis­(tetra­fluoro­borate), C8H14N22+·2BF4, (II), from dried acetonitrile under argon protection has permitted their single-crystal studies. In both crystal structures, the pyra­zine­diium dications are located about an inversion center (located at the ring center) and each pyrazinediium aromatic ring is π-bonded to two centrosymmetrically related BF4 anions. Strong anion–π inter­actions, as well as weak C—H...F hydrogen bonds, between BF4 and pyrazinediium ions are present in both salts.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270109005277/gg3186sup1.cif
Contains datablocks global, I, II

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270109005277/gg3186Isup2.hkl
Contains datablock I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270109005277/gg3186IIsup3.hkl
Contains datablock II

CCDC references: 735128; 735129

Comment top

Investigations on the supramolecular chemistry of anion–π-acid interactions are relevant to anion binding in biological systems (Gamez et al., 2007), as well as to the design of new anion receptors (Beer et al., 2001; Bianchi et al., 1997). We demonstrated previously the charge-transfer (C–T) nature of anion–π interactions (Rosokha et al., 2004). Such interactions play an important role in the stabilization of ternary anion–π complexes that are responsible for the direction of crystal growth of anions and π-acids into infinite chain structures (wires) (Han et al., 2008; Lu et al., 2009). We also suggested that one-dimensional molecular wires are derived from the ternary synthons of the donor (D, anion) and acceptor (A, aromatic π-acid). We further demonstrated that triad complexes (DAD or ADA triad synthons) can be isolated by charge modulation in cationic π-acid salts (Lu et al., 2009).

In this communication, we turn to the anion–π interactions in N,N'-dimethyldipyrazinium bis(tetrafluoroborate), (I), and N,N'-diethyldipyrazinium bis(tetrafluoroborate), (II), which contain monoanionic tetrafluoroborate donors and dicationic R2Pyz2+ π-acceptors [where R = Me for dimethyldipyrazinium in (I) and R = Et for diethyldipyrazinium in (II)]. N,N'-Dialkylated (diquaternized) dipyraziniums are strong electron acceptors with interesting redox properties (Hilgers et al., 1994; Schmittel et al., 2005). They are also important precursors for generating stable radical species (Kaim et al., 1993). However, studies of the C–T behavior between dipyrazinium acceptors and various neutral donors in solution show no stable C–T band. The existence of stable anion–π triads {D-···A2+···D-} could be the main explanation for this observation. Unfortunately, so far, no crystal structures of dialkyldipyrazinium salts have been reported to confirm such an assumption.

Compounds (I) and (II) were prepared according to the literature procedure of Curphey et al. (1972) and were recrystallized in both cases as white crystals from dried accetonitrile. As shown in Fig. 1, the asymmetry unit of each salt contains half the dipyrazinium dication and one BF4- anion. The dipyrazinium dication is located about an inversion center in both salts and the pyrazine rings experience an average increase of the aromatic C—N bond lengths of σim 0.025Å, and the aromatic C—C bonds increase by σim 0.013Å relative to the neutral parent molecule.

The anion–π interaction patterns are illustrated in Fig. 2. In both compounds, every cationic π-acceptor is π-bonded with two BF4- anions, which sit centrosymmetrically above and below the aromatic ring of the cation to form a DAD triad. Careful examination of the modes of approach of the BF4- anions to the π-acceptors reveals some differences. In compound (I), a head-to-face mode can be identified since only one of the four F atoms of the anion (F3) bonds strongly with the π-acceptor ring. In (II), a face-to-face mode can be identified since three F atoms (F1, F2 and F3) of the the anion intimately bond with the π-acceptor ring on the ring surface. The relevant distances (Berryman et al., 2007) of closest F to aromatic C atoms, F to center-of-ring (dcentroid) and F to plane-of-ring (dplane) are summarized in Tables 1 and 3 for (I) and (II), respectively. The closest F to center-of-ring (dcentroid) distances in (I) and (II) are 2.71 and 2.82Å, respectively. From a literature survey (Mooibroek et al., 2008) of all available crystal data involving BF4-π interactions, these two contact distances (dcentroid) represent unique examples of BF4-π strong interactions.

Weak C—H···F hydrogen-bond interactions are also found among these triad units. The anions form several contacts with H atoms of the dipyrazinium group that are less than the sum of the van der Waals radii of hydrogen (1.2Å) and fluorine (1.5Å). The hydrogen-bonding information is summarized in Tables 2 and 4 for (I) and (II), respectively. It is worth noting here that there are bifurcated C—H···F hydrogen bonds in both compounds. For example, in compound (I), atom F2 bonds both to H1(—C1) and H2(—C2) of the same molecule.

In summary, we report here the first crystal structures of dialkyldipyrazinium salts. The preservation of DAD triads is found in both salts owing to weak C—H···F hydrogen bonding as well as the presence of strong electrostatic anion–cation interactions. Strong anion–π bonding in both triads effectively protect the dicationic π-acceptor from forming stable C–T complexes with additional electron donors in solution.

Related literature top

For related literature, see: Rosokha et al. (2004).

Experimental top

The title dialkyldipyrazinium salts were prepared according to the literature procedure of Curphey et al. (1972) and were recrystallized from dried accetonitrile under argon protection. Crystals are extremely sensitive to moisture and turned black after a few hours under ambient conditions. The highest residual electron-density peak in (II) is located on the center of the aromatic C3—N1 bond.

Refinement top

Carbon-bound H atoms were placed in calculated positions (C—H = 0.95–0.99Å) and included in the refinement in the riding-model approximation, with Uiso(H) values set at 1.2–1.5 Ueq(C).

Computing details top

For both compounds, data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003) and SADABS (Bruker, 2003); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: XP (Bruker, 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and XCIF (Bruker, 1999).

Figures top
[Figure 1] Fig. 1. Displacement ellipsoid plots of (I) [left, symmetry code: (i) -x, -y+1, -z+2] and (II) [right, symmetry code: (i) -x+1, -y+2, -z+1] at the 50% probability level. H atoms are drawn as spheres of arbitrary radii.
[Figure 2] Fig. 2. The π-bonding of BF4- anions to Me2Pyz2+ [in (I), top] and Et2Pyz2+ [in (II), bottom].
(I) N,N'-Dimethyldipyrazinium bis(tetrafluoroborate) top
Crystal data top
C6H10N22+·2BF4F(000) = 284
Mr = 283.78Dx = 1.718 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 2068 reflections
a = 5.6227 (14) Åθ = 2.7–29.5°
b = 14.884 (4) ŵ = 0.20 mm1
c = 6.7419 (17) ÅT = 173 K
β = 103.557 (4)°Block, colourless
V = 548.5 (2) Å30.14 × 0.14 × 0.10 mm
Z = 2
Data collection top
Bruker SMART
diffractometer
1617 independent reflections
Radiation source: sealed tube1331 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.029
ω scansθmax = 30.5°, θmin = 2.7°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 77
Tmin = 0.776, Tmax = 1.000k = 2021
5874 measured reflectionsl = 99
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)] = 0.048Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.131H-atom parameters constrained
S = 1.08 w = 1/[σ2(Fo2) + (0.0592P)2 + 0.2138P]
where P = (Fo2 + 2Fc2)/3
1617 reflections(Δ/σ)max < 0.001
83 parametersΔρmax = 0.49 e Å3
0 restraintsΔρmin = 0.34 e Å3
Crystal data top
C6H10N22+·2BF4V = 548.5 (2) Å3
Mr = 283.78Z = 2
Monoclinic, P21/cMo Kα radiation
a = 5.6227 (14) ŵ = 0.20 mm1
b = 14.884 (4) ÅT = 173 K
c = 6.7419 (17) Å0.14 × 0.14 × 0.10 mm
β = 103.557 (4)°
Data collection top
Bruker SMART
diffractometer
1617 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1331 reflections with I > 2σ(I)
Tmin = 0.776, Tmax = 1.000Rint = 0.029
5874 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0480 restraints
wR(F2) = 0.131H-atom parameters constrained
S = 1.08Δρmax = 0.49 e Å3
1617 reflectionsΔρmin = 0.34 e Å3
83 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
C10.1283 (2)0.51841 (10)0.14178 (19)0.0263 (3)
H10.21810.53090.24170.032*
C20.0206 (2)0.56442 (10)0.1367 (2)0.0266 (3)
H20.03570.60940.23300.032*
C30.2166 (3)0.67158 (10)0.0107 (2)0.0329 (3)
H3A0.35470.67870.10760.049*
H3B0.09370.71790.00720.049*
H3C0.27440.67780.13640.049*
N10.1057 (2)0.58116 (8)0.00507 (17)0.0245 (3)
B10.3820 (3)0.63391 (13)0.5878 (3)0.0338 (4)
F10.2778 (2)0.71657 (9)0.6478 (2)0.0583 (4)
F20.2392 (3)0.58902 (10)0.4808 (2)0.0704 (5)
F30.39212 (18)0.58310 (9)0.75906 (16)0.0491 (3)
F40.6186 (2)0.64571 (8)0.47351 (19)0.0572 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0222 (6)0.0356 (7)0.0224 (6)0.0008 (5)0.0082 (4)0.0006 (5)
C20.0240 (6)0.0350 (7)0.0221 (6)0.0004 (5)0.0084 (5)0.0030 (5)
C30.0328 (7)0.0305 (7)0.0371 (8)0.0069 (6)0.0115 (6)0.0015 (6)
N10.0201 (5)0.0301 (6)0.0235 (5)0.0014 (4)0.0059 (4)0.0003 (4)
B10.0326 (8)0.0418 (9)0.0279 (8)0.0097 (6)0.0088 (6)0.0024 (6)
F10.0478 (7)0.0569 (7)0.0644 (8)0.0056 (5)0.0011 (6)0.0073 (6)
F20.0971 (11)0.0701 (9)0.0626 (8)0.0284 (7)0.0564 (8)0.0068 (6)
F30.0307 (5)0.0808 (8)0.0376 (6)0.0085 (5)0.0115 (4)0.0199 (5)
F40.0485 (6)0.0490 (6)0.0578 (7)0.0072 (5)0.0202 (5)0.0032 (5)
Geometric parameters (Å, º) top
C1—N11.3389 (18)C3—H3A0.9800
C1—C2i1.378 (2)C3—H3B0.9800
C1—H10.9500C3—H3C0.9800
C2—N11.3411 (18)B1—F21.373 (2)
C2—C1i1.378 (2)B1—F11.382 (2)
C2—H20.9500B1—F41.383 (2)
C3—N11.4873 (19)B1—F31.393 (2)
N1—C1—C2i119.61 (12)H3B—C3—H3C109.5
N1—C1—H1120.2C1—N1—C2120.83 (12)
C2i—C1—H1120.2C1—N1—C3120.37 (12)
N1—C2—C1i119.56 (12)C2—N1—C3118.78 (12)
N1—C2—H2120.2F2—B1—F1109.10 (16)
C1i—C2—H2120.2F2—B1—F4111.95 (15)
N1—C3—H3A109.5F1—B1—F4109.67 (14)
N1—C3—H3B109.5F2—B1—F3108.31 (14)
H3A—C3—H3B109.5F1—B1—F3109.72 (14)
N1—C3—H3C109.5F4—B1—F3108.06 (14)
H3A—C3—H3C109.5
Symmetry code: (i) x, y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1···F2i0.952.432.973 (2)116
C2—H2···F20.952.262.892 (2)124
C1—H1···F3ii0.952.323.081 (2)136
C2—H2···F4iii0.952.583.053 (2)111
Symmetry codes: (i) x, y+1, z; (ii) x+1, y, z1; (iii) x+1, y, z.
(II) N,N'-Diethyldipyrazinium bis(tetrafluoroborate) top
Crystal data top
C8H14N22+·2BF4F(000) = 316
Mr = 311.83Dx = 1.523 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 117 reflections
a = 9.324 (3) Åθ = 3.7–22.5°
b = 6.2281 (17) ŵ = 0.17 mm1
c = 11.987 (4) ÅT = 173 K
β = 102.346 (7)°Block, colorless
V = 680.0 (4) Å30.20 × 0.14 × 0.12 mm
Z = 2
Data collection top
Bruker SMART
diffractometer
2000 independent reflections
Radiation source: sealed tube1272 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.047
ω scansθmax = 30.5°, θmin = 2.5°
Absorption correction: multi-scan
(SADABS; Bruker, 2003)
h = 1213
Tmin = 0.383, Tmax = 1.000k = 88
7346 measured reflectionsl = 1616
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)] = 0.062Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.167H-atom parameters constrained
S = 1.09 w = 1/[σ2(Fo2) + (0.0852P)2 + 0.0899P]
where P = (Fo2 + 2Fc2)/3
2000 reflections(Δ/σ)max < 0.001
92 parametersΔρmax = 0.45 e Å3
0 restraintsΔρmin = 0.22 e Å3
Crystal data top
C8H14N22+·2BF4V = 680.0 (4) Å3
Mr = 311.83Z = 2
Monoclinic, P21/nMo Kα radiation
a = 9.324 (3) ŵ = 0.17 mm1
b = 6.2281 (17) ÅT = 173 K
c = 11.987 (4) Å0.20 × 0.14 × 0.12 mm
β = 102.346 (7)°
Data collection top
Bruker SMART
diffractometer
2000 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2003)
1272 reflections with I > 2σ(I)
Tmin = 0.383, Tmax = 1.000Rint = 0.047
7346 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0620 restraints
wR(F2) = 0.167H-atom parameters constrained
S = 1.09Δρmax = 0.45 e Å3
2000 reflectionsΔρmin = 0.22 e Å3
92 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 F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > σ(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ 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
N10.60256 (16)0.9015 (2)0.45371 (12)0.0257 (4)
C10.6435 (2)1.0319 (3)0.54395 (15)0.0281 (4)
H10.74481.05460.57540.034*
C20.4600 (2)0.8676 (3)0.40895 (15)0.0281 (4)
H20.43110.77480.34520.034*
C30.7184 (2)0.7926 (3)0.40372 (17)0.0337 (5)
H3A0.79000.90050.38880.040*
H3B0.67220.72470.33010.040*
C40.7970 (2)0.6238 (4)0.4850 (2)0.0437 (6)
H4A0.85060.69310.55500.066*
H4B0.86630.54600.44880.066*
H4C0.72510.52280.50380.066*
B10.0272 (2)0.8102 (4)0.24170 (19)0.0336 (5)
F10.08722 (18)0.6739 (3)0.24404 (14)0.0729 (6)
F20.01751 (16)0.8796 (2)0.13071 (11)0.0527 (4)
F30.15932 (15)0.7041 (2)0.27718 (12)0.0604 (5)
F40.02217 (13)0.9881 (2)0.31250 (11)0.0463 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0273 (8)0.0271 (8)0.0217 (7)0.0017 (6)0.0030 (6)0.0028 (6)
C10.0263 (9)0.0296 (10)0.0254 (9)0.0025 (8)0.0007 (7)0.0020 (7)
C20.0302 (10)0.0286 (10)0.0226 (9)0.0005 (7)0.0006 (7)0.0018 (7)
C30.0316 (10)0.0391 (12)0.0320 (10)0.0065 (8)0.0101 (8)0.0002 (9)
C40.0400 (12)0.0465 (14)0.0426 (12)0.0157 (10)0.0043 (9)0.0012 (10)
B10.0322 (12)0.0384 (13)0.0288 (11)0.0020 (9)0.0034 (9)0.0078 (9)
F10.0751 (11)0.0804 (12)0.0764 (11)0.0469 (9)0.0457 (9)0.0445 (9)
F20.0767 (10)0.0453 (9)0.0332 (7)0.0047 (7)0.0053 (6)0.0009 (6)
F30.0592 (9)0.0533 (9)0.0545 (9)0.0195 (7)0.0193 (7)0.0153 (7)
F40.0429 (7)0.0488 (8)0.0441 (7)0.0025 (6)0.0027 (6)0.0226 (6)
Geometric parameters (Å, º) top
N1—C21.339 (2)C3—H3B0.9900
N1—C11.341 (2)C4—H4A0.9800
N1—C31.504 (2)C4—H4B0.9800
C1—C2i1.370 (3)C4—H4C0.9800
C1—H10.9500B1—F11.369 (3)
C2—C1i1.370 (3)B1—F31.382 (3)
C2—H20.9500B1—F21.383 (3)
C3—C41.512 (3)B1—F41.402 (3)
C3—H3A0.9900
C2—N1—C1120.36 (16)H3A—C3—H3B108.1
C2—N1—C3120.33 (16)C3—C4—H4A109.5
C1—N1—C3119.32 (15)C3—C4—H4B109.5
N1—C1—C2i120.36 (17)H4A—C4—H4B109.5
N1—C1—H1119.8C3—C4—H4C109.5
C2i—C1—H1119.8H4A—C4—H4C109.5
N1—C2—C1i119.28 (17)H4B—C4—H4C109.5
N1—C2—H2120.4F1—B1—F3110.1 (2)
C1i—C2—H2120.4F1—B1—F2108.80 (18)
N1—C3—C4110.33 (16)F3—B1—F2108.42 (17)
N1—C3—H3A109.6F1—B1—F4110.50 (17)
C4—C3—H3A109.6F3—B1—F4109.54 (16)
N1—C3—H3B109.6F2—B1—F4109.38 (19)
C4—C3—H3B109.6
Symmetry code: (i) x+1, y+2, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C2—H2···F2ii0.952.513.090 (2)119
C1—H1···F3i0.952.352.999 (2)126
C2—H2···F30.952.533.082 (2)117
C1—H1···F4i0.952.313.225 (2)161
Symmetry codes: (i) x+1, y+2, z+1; (ii) x+1/2, y1/2, z+1/2.

Experimental details

(I)(II)
Crystal data
Chemical formulaC6H10N22+·2BF4C8H14N22+·2BF4
Mr283.78311.83
Crystal system, space groupMonoclinic, P21/cMonoclinic, P21/n
Temperature (K)173173
a, b, c (Å)5.6227 (14), 14.884 (4), 6.7419 (17)9.324 (3), 6.2281 (17), 11.987 (4)
β (°) 103.557 (4) 102.346 (7)
V3)548.5 (2)680.0 (4)
Z22
Radiation typeMo KαMo Kα
µ (mm1)0.200.17
Crystal size (mm)0.14 × 0.14 × 0.100.20 × 0.14 × 0.12
Data collection
DiffractometerBruker SMART
diffractometer
Bruker SMART
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Multi-scan
(SADABS; Bruker, 2003)
Tmin, Tmax0.776, 1.0000.383, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
5874, 1617, 1331 7346, 2000, 1272
Rint0.0290.047
(sin θ/λ)max1)0.7150.715
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.048, 0.131, 1.08 0.062, 0.167, 1.09
No. of reflections16172000
No. of parameters8392
H-atom treatmentH-atom parameters constrainedH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.49, 0.340.45, 0.22

Computer programs: SMART (Bruker, 2003), SAINT (Bruker, 2003) and SADABS (Bruker, 2003), XP (Bruker, 1999), SHELXTL (Sheldrick, 2008) and XCIF (Bruker, 1999).

Hydrogen-bond geometry (Å, º) for (I) top
D—H···AD—HH···AD···AD—H···A
C1—H1···F2i0.952.432.973 (2)116
C2—H2···F20.952.262.892 (2)124
C1—H1···F3ii0.952.323.081 (2)136
C2—H2···F4iii0.952.583.053 (2)111
Symmetry codes: (i) x, y+1, z; (ii) x+1, y, z1; (iii) x+1, y, z.
F atoms of BF4- π-interaction modes to Me2Pyz2+ top
F atomsClosest F—C distance (Å)dcentroid (Å)dplane(Å)
F23.063.692.93
F33.002.712.69
Hydrogen-bond geometry (Å, º) for (II) top
D—H···AD—HH···AD···AD—H···A
C2—H2···F2i0.952.513.090 (2)119
C1—H1···F3ii0.952.352.999 (2)126
C2—H2···F30.952.533.082 (2)117
C1—H1···F4ii0.952.313.225 (2)161
Symmetry codes: (i) x+1/2, y1/2, z+1/2; (ii) x+1, y+2, z+1.
F atoms of BF4- π-interaction modes to Et2Pyz2+ top
F atomsClosest F—C distance (Å)dcentroid (Å)dplane (Å)
F13.063.382.79
F23.022.822.80
F33.093.572.88
 

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