Crystal structure of (1S,4S)-2,5-diazo­niabi­cyclo[2.2.1]heptane dibromide

The mol­ecular structure of the 2,5-di­aza­bicyclo­[2.2.1]heptane parent ring has been characterized for the first time. The asymmetric unit contains two crystallographically independent cages of 2,5-di­aza­bicyclo­[2.2.1]heptane, each cage being protonated at the two nitro­gen sites. The overall charge balance is maintained by four crystallogrphically independent bromide ions. In the crystal, the components of the structure are linked via a complex three-dimensional network of N—H...Br hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.014
• wR factor = 0.035
• Data-to-parameter ratio = 20.7

checkCIF/PLATON results

No syntax errors found



Datablock: I


Alert level G
PLAT720_ALERT_4_G Number of Unusual/Non-Standard Labels ..........         10 Note
PLAT764_ALERT_4_G Overcomplete CIF Bond List Detected (Rep/Expd) .       1.88 Ratio
PLAT773_ALERT_2_G Check long C-C Bond in CIF: C1     --  C4      .       2.22 Ang.
PLAT773_ALERT_2_G Check long C-C Bond in CIF: C1A    --  C4A     .       2.23 Ang.
PLAT773_ALERT_2_G Check long C-C Bond in CIF: C3     --  C6      .       2.89 Ang.
PLAT773_ALERT_2_G Check long C-C Bond in CIF: C3A    --  C6A     .       2.85 Ang.
PLAT773_ALERT_2_G Check long C-C Bond in CIF: C3     --  C7      .       2.39 Ang.
PLAT773_ALERT_2_G Check long C-C Bond in CIF: C3A    --  C7A     .       2.39 Ang.
PLAT773_ALERT_2_G Check long C-C Bond in CIF: C6     --  C7      .       2.38 Ang.
PLAT773_ALERT_2_G Check long C-C Bond in CIF: C6A    --  C7A     .       2.39 Ang.
PLAT791_ALERT_4_G The Model has Chirality at C1      (Chiral SPGR)          S Verify
PLAT791_ALERT_4_G The Model has Chirality at C1A     (Chiral SPGR)          S Verify
PLAT791_ALERT_4_G The Model has Chirality at C4      (Chiral SPGR)          S Verify
PLAT791_ALERT_4_G The Model has Chirality at C4A     (Chiral SPGR)          S Verify
PLAT802_ALERT_4_G CIF Input Record(s) with more than 80 Characters          1 Info
PLAT960_ALERT_3_G Number of Intensities with I  <   - 2*sig(I) ...          1 Check
PLAT978_ALERT_2_G Number C-C Bonds with Positive Residual Density.          1 Info

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   0 ALERT level C = Check. Ensure it is not caused by an omission or oversight
  17 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   9 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
   7 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

---

Computing details

Data collection: APEX2 (Bruker, 2015); cell refinement: SAINT (Bruker, 2015); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: Mercury (Macrae et al., 2008) and OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: publCIF (Westrip, 2010).

(1S,4S)-2,5-Diazoniabicyclo[2.2.1]heptane dibromide

Crystal data

C5H12N2^2+·2Br^−	Dx = 2.064 Mg m^−3
Mr = 259.99	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 9887 reflections
a = 9.7298 (6) Å	θ = 2.5–31.5°
b = 11.8643 (5) Å	µ = 9.61 mm^−1
c = 14.4933 (7) Å	T = 100 K
V = 1673.07 (15) Å^3	Block, colourless
Z = 8	0.2 × 0.08 × 0.05 mm
F(000) = 1008

Data collection

Bruker APEXII CCD diffractometer	4031 independent reflections
Radiation source: fine focus sealed tube	3959 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.026
φ and ω scans	θmax = 28.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2015)	h = −12→12
	k = −13→15
15838 measured reflections	l = −19→17

Refinement

Refinement on F^2	Hydrogen site location: mixed
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.014	w = 1/[σ^2(Fo^2) + (0.0162P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.035	(Δ/σ)max = 0.001
S = 1.02	Δρmax = 0.53 e Å^−3
4031 reflections	Δρmin = −0.34 e Å^−3
195 parameters	Absolute structure: Flack x determined using 1676 quotients [(I^+)-(I^-)]/[(I^+)+(I^-)] (Parsons et al., 2013)
0 restraints	Absolute structure parameter: 0.009 (5)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.5925 (3)	0.3998 (2)	0.37609 (18)	0.0160 (5)
H1	0.6722	0.4501	0.3797	0.019*
N2	0.4926 (2)	0.4270 (2)	0.29906 (15)	0.0143 (4)
H2A	0.479 (3)	0.505 (3)	0.2960 (18)	0.011 (7)*
H2B	0.519 (4)	0.403 (3)	0.245 (3)	0.038 (11)*
C3	0.3610 (3)	0.3669 (2)	0.32592 (18)	0.0162 (5)
H3A	0.3377	0.3084	0.2818	0.019*
H3B	0.2848	0.4192	0.3310	0.019*
C4	0.3987 (3)	0.3168 (3)	0.41995 (18)	0.0183 (6)
H4	0.3203	0.2983	0.4596	0.022*
N5	0.4954 (2)	0.2198 (2)	0.40090 (17)	0.0167 (5)
H5A	0.454 (3)	0.170 (3)	0.361 (2)	0.024 (9)*
H5B	0.504 (3)	0.186 (3)	0.446 (2)	0.013 (8)*
C6	0.6277 (3)	0.2749 (2)	0.36993 (18)	0.0158 (5)
H6A	0.6511	0.2534	0.3073	0.019*
H6B	0.7033	0.2557	0.4106	0.019*
C7	0.4971 (3)	0.4045 (2)	0.45944 (18)	0.0205 (6)
H7A	0.4546	0.4778	0.4678	0.025*
H7B	0.5411	0.3802	0.5161	0.025*
C1A	0.6072 (3)	0.8241 (2)	0.59473 (17)	0.0139 (5)
H1A	0.6918	0.8624	0.5758	0.017*
N2A	0.4792 (2)	0.8628 (2)	0.54520 (15)	0.0141 (4)
H2AA	0.478 (4)	0.844 (3)	0.486 (2)	0.033 (10)*
H2AB	0.476 (3)	0.935 (3)	0.5432 (19)	0.010 (7)*
C3A	0.3626 (2)	0.8184 (2)	0.60478 (19)	0.0160 (5)
H3AA	0.3103	0.7610	0.5726	0.019*
H3AB	0.3011	0.8786	0.6233	0.019*
C4A	0.4384 (3)	0.7687 (2)	0.68803 (18)	0.0152 (5)
H4A	0.3835	0.7635	0.7446	0.018*
N5A	0.5014 (2)	0.6592 (2)	0.65645 (16)	0.0154 (4)
H5AA	0.437 (3)	0.612 (3)	0.631 (2)	0.019 (8)*
H5AB	0.534 (3)	0.629 (3)	0.698 (2)	0.021 (9)*
C6A	0.6121 (3)	0.6950 (2)	0.58809 (17)	0.0163 (5)
H6AA	0.5907	0.6694	0.5262	0.020*
H6AB	0.7015	0.6662	0.6059	0.020*
C7A	0.5656 (3)	0.8433 (2)	0.69531 (17)	0.0161 (5)
H7AA	0.6328	0.8149	0.7389	0.019*
H7AB	0.5439	0.9214	0.7087	0.019*
Br1	0.52194 (2)	0.62674 (2)	0.88905 (2)	0.01450 (6)
Br2	0.22116 (2)	0.51516 (2)	0.60873 (2)	0.01567 (6)
Br3	0.46504 (3)	0.70005 (2)	0.35710 (2)	0.01494 (6)
Br4	0.26144 (3)	0.04454 (2)	0.32745 (2)	0.01680 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0142 (12)	0.0157 (14)	0.0181 (13)	−0.0018 (10)	−0.0058 (10)	0.0015 (10)
N2	0.0145 (10)	0.0138 (12)	0.0148 (10)	0.0003 (9)	0.0011 (8)	0.0031 (9)
C3	0.0109 (11)	0.0191 (14)	0.0185 (12)	−0.0006 (10)	0.0001 (10)	0.0020 (11)
C4	0.0136 (12)	0.0217 (15)	0.0195 (12)	0.0003 (10)	0.0063 (10)	0.0044 (11)
N5	0.0191 (11)	0.0135 (12)	0.0174 (11)	−0.0037 (9)	−0.0026 (9)	0.0043 (9)
C6	0.0125 (11)	0.0177 (14)	0.0173 (13)	0.0002 (10)	−0.0025 (9)	0.0005 (10)
C7	0.0285 (15)	0.0199 (15)	0.0130 (12)	0.0033 (11)	−0.0022 (10)	−0.0030 (10)
C1A	0.0107 (11)	0.0138 (14)	0.0173 (13)	−0.0008 (9)	−0.0006 (9)	0.0023 (10)
N2A	0.0172 (11)	0.0115 (12)	0.0135 (10)	0.0008 (9)	−0.0007 (8)	0.0004 (8)
C3A	0.0108 (11)	0.0168 (14)	0.0206 (13)	0.0024 (9)	−0.0019 (9)	0.0010 (11)
C4A	0.0143 (12)	0.0164 (14)	0.0150 (12)	−0.0014 (10)	0.0001 (9)	0.0016 (10)
N5A	0.0148 (10)	0.0141 (11)	0.0173 (11)	−0.0008 (9)	−0.0031 (8)	0.0034 (9)
C6A	0.0147 (12)	0.0163 (14)	0.0178 (12)	0.0029 (10)	0.0008 (9)	0.0006 (10)
C7A	0.0173 (12)	0.0147 (14)	0.0162 (12)	−0.0020 (10)	−0.0027 (10)	0.0012 (10)
Br1	0.01665 (12)	0.01277 (12)	0.01407 (12)	−0.00094 (9)	−0.00018 (9)	−0.00022 (9)
Br2	0.01471 (12)	0.01456 (13)	0.01775 (11)	−0.00228 (9)	−0.00073 (10)	0.00003 (10)
Br3	0.01588 (12)	0.01335 (13)	0.01560 (12)	0.00039 (9)	0.00032 (9)	0.00008 (9)
Br4	0.01390 (12)	0.01434 (13)	0.02214 (12)	−0.00278 (9)	0.00270 (9)	−0.00030 (10)

Geometric parameters (Å, º)

C1—H1	0.9800	C3A—H3AA	0.9700
C1—N2	1.516 (3)	C3A—H3AB	0.9700
C1—C6	1.523 (4)	C3A—C4A	1.532 (4)
C1—C7	1.525 (4)	C4A—H4A	0.9800
N2—H2A	0.93 (3)	C4A—N5A	1.508 (3)
N2—H2B	0.87 (4)	C4A—C7A	1.525 (4)
N2—C3	1.516 (3)	N5A—H5AA	0.91 (3)
C3—H3A	0.9700	N5A—H5AB	0.77 (3)
C3—H3B	0.9700	N5A—C6A	1.523 (3)
C3—C4	1.532 (4)	C6A—H6AA	0.9700
C4—H4	0.9800	C6A—H6AB	0.9700
C4—N5	1.512 (4)	C7A—H7AA	0.9700
C4—C7	1.525 (4)	C7A—H7AB	0.9700
N5—H5A	0.92 (3)	N2—N5	2.868 (3)
N5—H5B	0.78 (3)	N2A—N5A	2.912 (3)
N5—C6	1.512 (3)	C1—C4	2.220 (4)
C6—H6A	0.9700	C1A—C4A	2.226 (4)
C6—H6B	0.9700	C3—C6	2.887 (4)
C7—H7A	0.9700	C3A—C6A	2.845 (4)
C7—H7B	0.9700	N2—C7	2.340 (4)
C1A—H1A	0.9800	N2A—C7A	2.344 (3)
C1A—N2A	1.509 (3)	N5—C7	2.350 (4)
C1A—C6A	1.535 (4)	N5A—C7A	2.340 (4)
C1A—C7A	1.530 (3)	C3—C7	2.387 (4)
N2A—H2AA	0.89 (3)	C3A—C7A	2.390 (4)
N2A—H2AB	0.86 (3)	C6—C7	2.380 (4)
N2A—C3A	1.521 (3)	C6A—C7A	2.391 (4)
N2—C1—H1	114.7	N2A—C1A—H1A	114.8
N2—C1—C6	107.9 (2)	N2A—C1A—C6A	107.4 (2)
N2—C1—C7	100.66 (19)	N2A—C1A—C7A	101.0 (2)
C6—C1—H1	114.7	C6A—C1A—H1A	114.8
C6—C1—C7	102.7 (2)	C7A—C1A—H1A	114.8
C7—C1—H1	114.7	C7A—C1A—C6A	102.5 (2)
C1—N2—H2A	109.5 (17)	C1A—N2A—H2AA	113 (2)
C1—N2—H2B	114 (3)	C1A—N2A—H2AB	111 (2)
C1—N2—C3	104.64 (19)	C1A—N2A—C3A	103.90 (18)
H2A—N2—H2B	109 (3)	H2AA—N2A—H2AB	102 (3)
C3—N2—H2A	111.1 (18)	C3A—N2A—H2AA	117 (2)
C3—N2—H2B	109 (3)	C3A—N2A—H2AB	110 (2)
N2—C3—H3A	111.4	N2A—C3A—H3AA	111.2
N2—C3—H3B	111.4	N2A—C3A—H3AB	111.2
N2—C3—C4	102.0 (2)	N2A—C3A—C4A	102.76 (19)
H3A—C3—H3B	109.2	H3AA—C3A—H3AB	109.1
C4—C3—H3A	111.4	C4A—C3A—H3AA	111.2
C4—C3—H3B	111.4	C4A—C3A—H3AB	111.2
C3—C4—H4	114.9	C3A—C4A—H4A	114.9
N5—C4—C3	106.4 (2)	N5A—C4A—C3A	106.7 (2)
N5—C4—H4	114.9	N5A—C4A—H4A	114.9
N5—C4—C7	101.4 (2)	N5A—C4A—C7A	101.0 (2)
C7—C4—C3	102.7 (2)	C7A—C4A—C3A	102.9 (2)
C7—C4—H4	114.9	C7A—C4A—H4A	114.9
C4—N5—H5A	110 (2)	C4A—N5A—H5AA	112 (2)
C4—N5—H5B	108 (2)	C4A—N5A—H5AB	109 (3)
C4—N5—C6	104.7 (2)	C4A—N5A—C6A	104.2 (2)
H5A—N5—H5B	104 (3)	H5AA—N5A—H5AB	108 (3)
C6—N5—H5A	118 (2)	C6A—N5A—H5AA	113.2 (19)
C6—N5—H5B	113 (2)	C6A—N5A—H5AB	110 (2)
C1—C6—H6A	111.3	C1A—C6A—H6AA	111.3
C1—C6—H6B	111.3	C1A—C6A—H6AB	111.3
N5—C6—C1	102.2 (2)	N5A—C6A—C1A	102.4 (2)
N5—C6—H6A	111.3	N5A—C6A—H6AA	111.3
N5—C6—H6B	111.3	N5A—C6A—H6AB	111.3
H6A—C6—H6B	109.2	H6AA—C6A—H6AB	109.2
C1—C7—C4	93.4 (2)	C1A—C7A—H7AA	113.0
C1—C7—H7A	113.0	C1A—C7A—H7AB	113.0
C1—C7—H7B	113.0	C4A—C7A—C1A	93.6 (2)
C4—C7—H7A	113.0	C4A—C7A—H7AA	113.0
C4—C7—H7B	113.0	C4A—C7A—H7AB	113.0
H7A—C7—H7B	110.4	H7AA—C7A—H7AB	110.4
C1—N2—C3—C4	3.2 (3)	C1A—N2A—C3A—C4A	5.5 (3)
N2—C1—C6—N5	−71.1 (2)	N2A—C1A—C6A—N5A	−74.2 (2)
N2—C1—C7—C4	56.3 (2)	N2A—C1A—C7A—C4A	56.7 (2)
N2—C3—C4—N5	−73.1 (2)	N2A—C3A—C4A—N5A	−75.1 (2)
N2—C3—C4—C7	33.0 (3)	N2A—C3A—C4A—C7A	30.8 (3)
C3—C4—N5—C6	71.2 (2)	C3A—C4A—N5A—C6A	67.9 (2)
C3—C4—C7—C1	−55.1 (2)	C3A—C4A—C7A—C1A	−53.4 (2)
C4—N5—C6—C1	0.8 (3)	C4A—N5A—C6A—C1A	4.5 (2)
N5—C4—C7—C1	54.9 (2)	N5A—C4A—C7A—C1A	56.8 (2)
C6—C1—N2—C3	69.0 (2)	C6A—C1A—N2A—C3A	67.2 (2)
C6—C1—C7—C4	−55.1 (2)	C6A—C1A—C7A—C4A	−54.1 (2)
C7—C1—N2—C3	−38.2 (2)	C7A—C1A—N2A—C3A	−39.8 (2)
C7—C1—C6—N5	34.7 (2)	C7A—C1A—C6A—N5A	31.7 (2)
C7—C4—N5—C6	−35.9 (2)	C7A—C4A—N5A—C6A	−39.3 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···Br3	0.93 (3)	2.49 (3)	3.358 (2)	156 (2)
N5—H5A···Br4	0.92 (3)	2.44 (3)	3.261 (2)	148 (3)
N5—H5B···Br1^i	0.78 (3)	2.50 (3)	3.242 (2)	161 (3)
N2A—H2AA···Br3	0.89 (3)	2.53 (4)	3.344 (2)	152 (3)
N2A—H2AB···Br1^ii	0.86 (3)	2.48 (3)	3.273 (2)	155 (2)
N5A—H5AA···Br2	0.91 (3)	2.42 (3)	3.292 (2)	160 (3)
N5A—H5AB···Br1	0.77 (3)	2.77 (3)	3.399 (2)	140 (3)

Symmetry codes: (i) −x+1, y−1/2, −z+3/2; (ii) −x+1, y+1/2, −z+3/2.