Buy article online - an online subscription or single-article purchase is required to access this article.
In the title compound, C5H5Br2N2+·Br-·0.5H2O, 3-amino-2,6-dibromopyridine is protonated on the amine N atom and this cation is planar, excluding the H atoms attached to N. The organic cation, bromide anion and interstitial water molecule are held together by hydrogen bonding, bromine-bromine interactions and by a special type of electrostatic interaction between aryl bromine and the centroids of two pyridine rings, forming a bridge-like non-covalent bond.
Supporting information
CCDC reference: 251644
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.009 Å
- R factor = 0.032
- wR factor = 0.079
- Data-to-parameter ratio = 21.6
checkCIF/PLATON results
No syntax errors found
Alert level B
PLAT431_ALERT_2_B Short Inter HL..A Contact Br4 .. Br5 .. 3.36 Ang.
Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings Differ .... ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............ 0.50 Ratio
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ... 9
PLAT417_ALERT_2_C Short Inter D-H..H-D H1' .. H2B .. 2.13 Ang.
PLAT431_ALERT_2_C Short Inter HL..A Contact Br1 .. Br4 .. 3.44 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H2C .. BR4 .. 3.01 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H2 .. N1 .. 2.87 Ang.
PLAT481_ALERT_4_C Long D...A H-Bond Reported C2 .. N1 .. 3.80 Ang.
Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
correct. If it is not, please give the correct count in the
_publ_section_exptl_refinement section of the submitted CIF.
From the CIF: _diffrn_reflns_theta_max 27.86
From the CIF: _reflns_number_total 2189
Count of symmetry unique reflns 1193
Completeness (_total/calc) 183.49%
TEST3: Check Friedels for noncentro structure
Estimate of Friedel pairs measured 996
Fraction of Friedel pairs measured 0.835
Are heavy atom types Z>Si present yes
0 ALERT level A = In general: serious problem
1 ALERT level B = Potentially serious problem
9 ALERT level C = Check and explain
1 ALERT level G = General alerts; check
3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
3 ALERT type 2 Indicator that the structure model may be wrong or deficient
1 ALERT type 3 Indicator that the structure quality may be low
4 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: CrystalClear (Pflugrath, 1999); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and XP in SHELXTL (Bruker, 1996); software used to prepare material for publication: WinGX (Farrugia, 1999).
'3-ammonium-2,6-dibromopyridine bromide hemihydrate'
top
Crystal data top
C5H5Br2N2+·Br−·0.5H2O | F(000) = 2544 |
Mr = 341.82 | Dx = 2.451 Mg m−3 |
Orthorhombic, Fdd2 | Mo Kα radiation, λ = 0.71070 Å |
Hall symbol: F 2 -2d | Cell parameters from 2190 reflections |
a = 12.123 (5) Å | θ = 0.8–27.9° |
b = 48.809 (17) Å | µ = 13.01 mm−1 |
c = 6.262 (2) Å | T = 293 K |
V = 3705 (2) Å3 | Chunk, colorless |
Z = 16 | 0.20 × 0.20 × 0.20 mm |
Data collection top
Rigaku AFC8 CCD Mercury diffractometer | 2189 independent reflections |
Radiation source: fine-focus sealed tube | 1569 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.059 |
Detector resolution: 14.6306 pixels mm-1 | θmax = 27.9°, θmin = 1.7° |
dtintegrate.ref scans | h = −15→15 |
Absorption correction: numerical (WinGx; Farrugia, 1999) | k = −64→64 |
Tmin = 0.074, Tmax = 0.093 | l = −7→8 |
11841 measured reflections | |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.032 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.079 | w = 1/[σ2(Fo2) + (0.0104P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.84 | (Δ/σ)max = 0.045 |
2161 reflections | Δρmax = 0.52 e Å−3 |
100 parameters | Δρmin = −0.91 e Å−3 |
2 restraints | Absolute structure: Flack (1983), 996 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.04 (3) |
Special details top
Experimental. ???? |
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 | |
Br4 | 0.61856 (6) | 0.225247 (15) | 0.60301 (11) | 0.0379 (2) | |
Br5 | 0.48442 (7) | 0.195369 (14) | 0.01119 (14) | 0.0402 (2) | |
Br1 | 0.37299 (6) | 0.095111 (15) | 0.32640 (12) | 0.0383 (2) | |
O1 | 0.7500 | 0.2500 | 0.1992 (11) | 0.039 (2) | |
H1' | 0.727 (6) | 0.2369 (11) | 0.280 (11) | 0.059* | |
N2 | 0.3683 (4) | 0.21807 (11) | 0.4109 (10) | 0.0358 (16) | |
H2A | 0.4375 | 0.2228 | 0.4402 | 0.054* | |
H2B | 0.3241 | 0.2239 | 0.5150 | 0.054* | |
H2C | 0.3478 | 0.2256 | 0.2879 | 0.054* | |
N1 | 0.4134 (5) | 0.14773 (11) | 0.2026 (9) | 0.0280 (14) | |
C3 | 0.3076 (5) | 0.17264 (14) | 0.5491 (11) | 0.0313 (17) | |
H3 | 0.2719 | 0.1809 | 0.6635 | 0.038* | |
C2 | 0.3088 (5) | 0.14462 (13) | 0.5293 (13) | 0.0337 (17) | |
H2 | 0.2743 | 0.1334 | 0.6291 | 0.040* | |
C4 | 0.3609 (5) | 0.18846 (13) | 0.3943 (11) | 0.0251 (16) | |
C5 | 0.4096 (5) | 0.17485 (14) | 0.2250 (11) | 0.0284 (16) | |
C1 | 0.3634 (6) | 0.13375 (13) | 0.3554 (12) | 0.0289 (15) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Br4 | 0.0463 (4) | 0.0285 (4) | 0.0388 (4) | −0.0099 (3) | 0.0019 (4) | 0.0025 (3) |
Br5 | 0.0570 (5) | 0.0313 (4) | 0.0323 (4) | −0.0042 (4) | 0.0121 (4) | 0.0031 (4) |
Br1 | 0.0406 (4) | 0.0239 (4) | 0.0504 (5) | −0.0044 (3) | −0.0104 (4) | 0.0037 (4) |
O1 | 0.046 (5) | 0.047 (5) | 0.025 (4) | −0.002 (4) | 0.000 | 0.000 |
N2 | 0.047 (4) | 0.029 (4) | 0.032 (4) | −0.003 (3) | 0.010 (3) | 0.000 (3) |
N1 | 0.030 (3) | 0.022 (3) | 0.031 (3) | 0.001 (3) | 0.002 (3) | −0.001 (3) |
C3 | 0.029 (4) | 0.040 (4) | 0.025 (4) | 0.007 (3) | −0.001 (3) | 0.004 (3) |
C2 | 0.033 (4) | 0.030 (4) | 0.038 (4) | −0.014 (3) | −0.005 (4) | 0.010 (4) |
C4 | 0.028 (4) | 0.017 (3) | 0.030 (4) | 0.001 (3) | 0.000 (3) | 0.001 (3) |
C5 | 0.023 (3) | 0.035 (4) | 0.026 (4) | −0.008 (3) | 0.004 (3) | 0.004 (3) |
C1 | 0.036 (4) | 0.021 (3) | 0.030 (4) | 0.000 (3) | −0.004 (3) | 0.000 (3) |
Geometric parameters (Å, º) top
Br5—C5 | 1.902 (6) | C3—C2 | 1.373 (8) |
Br1—C1 | 1.898 (6) | C3—C4 | 1.398 (9) |
N2—C4 | 1.452 (8) | C2—C1 | 1.380 (10) |
N1—C1 | 1.323 (9) | C4—C5 | 1.383 (9) |
N1—C5 | 1.332 (7) | | |
| | | |
C1—N1—C5 | 114.9 (6) | N1—C5—C4 | 125.0 (6) |
C2—C3—C4 | 118.8 (7) | N1—C5—Br5 | 115.6 (5) |
C3—C2—C1 | 117.4 (7) | C4—C5—Br5 | 119.3 (5) |
C5—C4—C3 | 117.6 (6) | N1—C1—C2 | 126.3 (6) |
C5—C4—N2 | 120.5 (6) | N1—C1—Br1 | 114.5 (5) |
C3—C4—N2 | 121.9 (6) | C2—C1—Br1 | 119.1 (5) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1′···Br4 | 0.86 (6) | 2.48 (5) | 3.224 (5) | 144 (7) |
N2—H2A···Br4 | 0.89 | 2.42 | 3.282 (6) | 163 |
N2—H2B···O1i | 0.89 | 1.94 | 2.783 (7) | 158 |
N2—H2C···Br4ii | 0.89 | 2.69 | 3.376 (6) | 134 |
N2—H2C···Br4iii | 0.89 | 3.01 | 3.606 (6) | 126 |
C2—H2···N1iv | 0.93 | 2.87 | 3.795 (9) | 176 |
Symmetry codes: (i) x−1/2, y, z+1/2; (ii) −x+1, −y+1/2, z−1/2; (iii) x−1/2, y, z−1/2; (iv) x−1/4, −y+1/4, z+3/4. |
Subscribe to Acta Crystallographica Section E: Crystallographic Communications
The full text of this article is available to subscribers to the journal.
If you have already registered and are using a computer listed in your registration details, please email
support@iucr.org for assistance.