In the structural motifs of two isomorphous triclinic salts, (C
5H
6Br
2N
3)
2[
MBr
4] (
M = Cd
II and Mn
II), each [
MBr
4]
2− anion interacts with eight surrounding 2,6-diamino-3,5-dibromopyridinium cations through intermolecular C/N—H
Br and Br
Br interactions, leading to a three-dimensional framework structure. The cations show a minor degree of π–π stacking, adding extra stability to the three-dimensional architecture.
Supporting information
CCDC references: 719472; 727525
For the preparation of (I) and (II), 2,6-diaminopyridine (98%; 2 mmol) was
dissolved in EtOH (95%; 25 ml) with heating and stirring. Another flask was
prepared containing the corresponding metal salt, CdBr2 or Mn(OAc)2 (1 mmol), dissolved in EtOH (95%; 10 ml). The two solutions were mixed together
and acidified with HBr (48%, 2–3 ml). Then Br2 (liquid, 2–3 ml) was added
and the mixture heated (363 K) with stirring for 3 h. The solution was left to
evaporate at room temperature, yielding colourless crystal plates (Cd
compound) or colourless crystal chips (Mn compound) in 2 d.
In the vial used to prepare (II), some brown crystals were found and these
proved to be [3,5-DB-2,6-DAPH]Br, one of two polymorphs of the compound
(Haddad et al., 2009).
H atoms were positioned geometrically, with N—H = 0.86 Å (for NH and NH2)
and C—H = 0.93 Å for aromatic H, and constrained to ride on their parent
atoms, with Uiso(H) = 1.2Ueq(C,N).
There are some 16 and 21 missing reflections, respectively, in the two reported
structures as processed. Both samples were small crystals (thicknesses 0.04
and 0.06 mm) and poorly diffracting. Redundant data were collected for both
crystals and long collection times (20 s) exposures were used.
For both compounds, data collection: SMART (Bruker, 2001); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: XS in SHELXTL (Version 6.10; Sheldrick, 2008); program(s) used to refine structure: XL in SHELXTL (Version 6.10; Sheldrick, 2008); molecular graphics: XP in SHELXTL (Version 6.10; Sheldrick, 2008); software used to prepare material for publication: XCIF in SHELXTL (Version 6.10; Sheldrick, 2008).
(I) bis(2,6-diamino-3,5-dibromopyridinium) tetrabromidocadmate(II)
top
Crystal data top
(C5H6Br2N3)2[CdBr4] | Z = 2 |
Mr = 967.87 | F(000) = 884 |
Triclinic, P1 | Dx = 2.751 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 8.8759 (18) Å | Cell parameters from 5431 reflections |
b = 10.720 (2) Å | θ = 2.2–26.9° |
c = 14.137 (3) Å | µ = 14.62 mm−1 |
α = 73.07 (3)° | T = 293 K |
β = 86.87 (3)° | Plate, colourless |
γ = 65.61 (3)° | 0.25 × 0.12 × 0.04 mm |
V = 1168.7 (5) Å3 | |
Data collection top
Bruker SMART APEX diffractometer | 4207 independent reflections |
Radiation source: sealed tube | 3281 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
Detector resolution: 8.3 pixels mm-1 | θmax = 25.3°, θmin = 1.5° |
ω scans | h = −10→10 |
Absorption correction: empirical (using intensity measurements) (SADABS; Bruker, 2001) | k = −12→12 |
Tmin = 0.114, Tmax = 0.557 | l = −16→16 |
11259 measured reflections | |
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)] = 0.034 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.082 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0237P)2] where P = (Fo2 + 2Fc2)/3 |
4207 reflections | (Δ/σ)max < 0.001 |
226 parameters | Δρmax = 0.87 e Å−3 |
0 restraints | Δρmin = −0.90 e Å−3 |
Crystal data top
(C5H6Br2N3)2[CdBr4] | γ = 65.61 (3)° |
Mr = 967.87 | V = 1168.7 (5) Å3 |
Triclinic, P1 | Z = 2 |
a = 8.8759 (18) Å | Mo Kα radiation |
b = 10.720 (2) Å | µ = 14.62 mm−1 |
c = 14.137 (3) Å | T = 293 K |
α = 73.07 (3)° | 0.25 × 0.12 × 0.04 mm |
β = 86.87 (3)° | |
Data collection top
Bruker SMART APEX diffractometer | 4207 independent reflections |
Absorption correction: empirical (using intensity measurements) (SADABS; Bruker, 2001) | 3281 reflections with I > 2σ(I) |
Tmin = 0.114, Tmax = 0.557 | Rint = 0.037 |
11259 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.082 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.87 e Å−3 |
4207 reflections | Δρmin = −0.90 e Å−3 |
226 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 | |
Br1 | 0.39492 (8) | −0.00615 (6) | 0.18038 (4) | 0.05238 (17) | |
C1 | −0.0916 (7) | 0.8311 (5) | 0.0564 (4) | 0.0422 (13) | |
Cd1 | 0.33902 (5) | 0.18867 (4) | 0.26763 (3) | 0.04692 (13) | |
N1 | −0.0183 (6) | 0.7709 (4) | −0.0152 (3) | 0.0434 (11) | |
H1 | −0.0801 | 0.7581 | −0.0530 | 0.052* | |
Br2 | 0.20919 (9) | 0.11228 (7) | 0.43096 (5) | 0.06144 (19) | |
C2 | 0.0091 (8) | 0.8500 (5) | 0.1174 (4) | 0.0464 (14) | |
N2 | −0.2531 (6) | 0.8650 (5) | 0.0628 (4) | 0.0643 (14) | |
H2A | −0.3062 | 0.8483 | 0.0223 | 0.077* | |
H2B | −0.3044 | 0.9035 | 0.1074 | 0.077* | |
Br3 | 0.13316 (8) | 0.41568 (6) | 0.13986 (4) | 0.05545 (18) | |
C3 | 0.1739 (7) | 0.8097 (5) | 0.1028 (4) | 0.0493 (15) | |
H3 | 0.2404 | 0.8237 | 0.1437 | 0.059* | |
N3 | 0.1973 (7) | 0.6715 (5) | −0.1069 (4) | 0.0616 (14) | |
H3A | 0.1287 | 0.6621 | −0.1420 | 0.074* | |
H3B | 0.2999 | 0.6439 | −0.1196 | 0.074* | |
Br4 | 0.60306 (8) | 0.20599 (7) | 0.31560 (5) | 0.05720 (18) | |
C4 | 0.2434 (7) | 0.7491 (6) | 0.0292 (4) | 0.0488 (14) | |
N4 | 0.4346 (6) | 0.7581 (5) | 0.4412 (3) | 0.0463 (11) | |
H4 | 0.4231 | 0.8185 | 0.4729 | 0.056* | |
Br5 | −0.09061 (10) | 0.94130 (7) | 0.21441 (5) | 0.0679 (2) | |
C5 | 0.1445 (7) | 0.7289 (5) | −0.0326 (4) | 0.0427 (13) | |
N5 | 0.6814 (6) | 0.7708 (5) | 0.3978 (4) | 0.0554 (13) | |
H5A | 0.6600 | 0.8329 | 0.4295 | 0.066* | |
H5B | 0.7719 | 0.7453 | 0.3685 | 0.066* | |
Br6 | 0.47031 (9) | 0.69350 (8) | 0.00801 (7) | 0.0813 (2) | |
C6 | 0.5749 (7) | 0.7146 (5) | 0.3940 (4) | 0.0429 (13) | |
N6 | 0.1801 (7) | 0.7689 (6) | 0.4931 (4) | 0.0689 (15) | |
H6A | 0.1768 | 0.8291 | 0.5230 | 0.083* | |
H6B | 0.0994 | 0.7436 | 0.4956 | 0.083* | |
Br7 | 0.78761 (9) | 0.55099 (7) | 0.27713 (5) | 0.06416 (19) | |
C7 | 0.5939 (7) | 0.6171 (5) | 0.3427 (4) | 0.0447 (13) | |
Br8 | 0.16425 (9) | 0.55148 (7) | 0.38951 (5) | 0.0676 (2) | |
C8 | 0.4706 (7) | 0.5712 (5) | 0.3418 (4) | 0.0457 (13) | |
H8 | 0.4829 | 0.5061 | 0.3074 | 0.055* | |
C9 | 0.3310 (7) | 0.6187 (5) | 0.3900 (4) | 0.0434 (13) | |
C10 | 0.3093 (7) | 0.7150 (5) | 0.4432 (4) | 0.0469 (14) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Br1 | 0.0559 (4) | 0.0524 (3) | 0.0560 (3) | −0.0219 (3) | 0.0031 (3) | −0.0269 (3) |
C1 | 0.039 (4) | 0.044 (3) | 0.036 (3) | −0.014 (3) | 0.003 (2) | −0.007 (2) |
Cd1 | 0.0489 (3) | 0.0487 (2) | 0.0454 (2) | −0.0199 (2) | 0.00236 (19) | −0.01755 (19) |
N1 | 0.039 (3) | 0.049 (3) | 0.045 (3) | −0.019 (2) | 0.000 (2) | −0.016 (2) |
Br2 | 0.0739 (5) | 0.0616 (4) | 0.0569 (4) | −0.0317 (3) | 0.0239 (3) | −0.0272 (3) |
C2 | 0.057 (4) | 0.035 (3) | 0.043 (3) | −0.016 (3) | 0.003 (3) | −0.011 (2) |
N2 | 0.046 (4) | 0.081 (4) | 0.063 (3) | −0.020 (3) | 0.006 (3) | −0.027 (3) |
Br3 | 0.0535 (4) | 0.0472 (3) | 0.0587 (4) | −0.0170 (3) | −0.0041 (3) | −0.0102 (3) |
C3 | 0.049 (4) | 0.042 (3) | 0.060 (4) | −0.023 (3) | −0.006 (3) | −0.011 (3) |
N3 | 0.058 (4) | 0.071 (3) | 0.070 (3) | −0.032 (3) | 0.015 (3) | −0.036 (3) |
Br4 | 0.0537 (4) | 0.0707 (4) | 0.0605 (4) | −0.0293 (3) | 0.0045 (3) | −0.0332 (3) |
C4 | 0.043 (4) | 0.044 (3) | 0.066 (4) | −0.022 (3) | 0.009 (3) | −0.020 (3) |
N4 | 0.054 (3) | 0.049 (3) | 0.049 (3) | −0.025 (2) | 0.010 (2) | −0.027 (2) |
Br5 | 0.0945 (6) | 0.0596 (4) | 0.0547 (4) | −0.0319 (4) | 0.0178 (3) | −0.0262 (3) |
C5 | 0.047 (4) | 0.039 (3) | 0.043 (3) | −0.020 (3) | 0.010 (3) | −0.010 (2) |
N5 | 0.050 (3) | 0.066 (3) | 0.069 (3) | −0.034 (3) | 0.011 (2) | −0.033 (3) |
Br6 | 0.0433 (4) | 0.0805 (5) | 0.1327 (7) | −0.0290 (4) | 0.0120 (4) | −0.0457 (5) |
C6 | 0.048 (4) | 0.042 (3) | 0.040 (3) | −0.022 (3) | 0.002 (3) | −0.010 (2) |
N6 | 0.057 (4) | 0.087 (4) | 0.082 (4) | −0.037 (3) | 0.032 (3) | −0.047 (3) |
Br7 | 0.0558 (4) | 0.0737 (4) | 0.0734 (4) | −0.0278 (3) | 0.0215 (3) | −0.0382 (3) |
C7 | 0.048 (4) | 0.043 (3) | 0.046 (3) | −0.019 (3) | 0.007 (3) | −0.018 (2) |
Br8 | 0.0554 (4) | 0.0666 (4) | 0.0915 (5) | −0.0355 (3) | −0.0024 (4) | −0.0218 (4) |
C8 | 0.046 (4) | 0.043 (3) | 0.049 (3) | −0.015 (3) | 0.002 (3) | −0.019 (3) |
C9 | 0.043 (4) | 0.039 (3) | 0.049 (3) | −0.019 (3) | 0.000 (3) | −0.011 (2) |
C10 | 0.049 (4) | 0.041 (3) | 0.048 (3) | −0.017 (3) | 0.001 (3) | −0.011 (3) |
Geometric parameters (Å, º) top
Cd1—Br1 | 2.5896 (10) | C4—C5 | 1.390 (8) |
C1—N2 | 1.331 (7) | C4—Br6 | 1.883 (6) |
C1—N1 | 1.352 (7) | N4—C6 | 1.350 (7) |
C1—C2 | 1.384 (8) | N4—C10 | 1.365 (7) |
Cd1—Br2 | 2.5917 (11) | N4—H4 | 0.8600 |
Cd1—Br3 | 2.5791 (16) | N5—C6 | 1.324 (7) |
Cd1—Br4 | 2.5678 (9) | N5—H5A | 0.8600 |
N1—C5 | 1.357 (7) | N5—H5B | 0.8600 |
N1—H1 | 0.8600 | C6—C7 | 1.389 (7) |
C2—C3 | 1.366 (8) | N6—C10 | 1.322 (7) |
C2—Br5 | 1.886 (6) | N6—H6A | 0.8600 |
N2—H2A | 0.8600 | N6—H6B | 0.8600 |
N2—H2B | 0.8600 | Br7—C7 | 1.876 (6) |
C3—C4 | 1.371 (8) | C7—C8 | 1.376 (7) |
C3—H3 | 0.9300 | Br8—C9 | 1.896 (5) |
N3—C5 | 1.335 (7) | C8—C9 | 1.359 (8) |
N3—H3A | 0.8600 | C8—H8 | 0.9300 |
N3—H3B | 0.8600 | C9—C10 | 1.393 (8) |
| | | |
N2—C1—N1 | 117.1 (5) | C6—N4—C10 | 126.0 (5) |
N2—C1—C2 | 126.0 (6) | C6—N4—H4 | 117.0 |
N1—C1—C2 | 116.9 (5) | C10—N4—H4 | 117.0 |
Br1—Cd1—Br2 | 106.03 (3) | N3—C5—N1 | 118.0 (5) |
Br1—Cd1—Br3 | 101.99 (3) | N3—C5—C4 | 125.2 (6) |
Br1—Cd1—Br4 | 113.61 (4) | N1—C5—C4 | 116.8 (5) |
Br2—Cd1—Br3 | 113.34 (4) | C6—N5—H5A | 120.0 |
Br2—Cd1—Br4 | 107.05 (3) | C6—N5—H5B | 120.0 |
Br3—Cd1—Br4 | 114.59 (4) | H5A—N5—H5B | 120.0 |
C1—N1—C5 | 125.4 (5) | N5—C6—N4 | 117.8 (5) |
C1—N1—H1 | 117.3 | N5—C6—C7 | 125.0 (6) |
C5—N1—H1 | 117.3 | N4—C6—C7 | 117.2 (5) |
C3—C2—C1 | 119.9 (5) | C10—N6—H6A | 120.0 |
C3—C2—Br5 | 121.9 (4) | C10—N6—H6B | 120.0 |
C1—C2—Br5 | 118.1 (5) | H6A—N6—H6B | 120.0 |
C1—N2—H2A | 120.0 | C8—C7—C6 | 119.1 (5) |
C1—N2—H2B | 120.0 | C8—C7—Br7 | 121.8 (4) |
H2A—N2—H2B | 120.0 | C6—C7—Br7 | 119.1 (4) |
C2—C3—C4 | 121.3 (5) | C9—C8—C7 | 121.6 (5) |
C2—C3—H3 | 119.3 | C9—C8—H8 | 119.2 |
C4—C3—H3 | 119.3 | C7—C8—H8 | 119.2 |
C5—N3—H3A | 120.0 | C8—C9—C10 | 120.7 (5) |
C5—N3—H3B | 120.0 | C8—C9—Br8 | 120.8 (4) |
H3A—N3—H3B | 120.0 | C10—C9—Br8 | 118.5 (5) |
C3—C4—C5 | 119.6 (6) | N6—C10—N4 | 118.0 (5) |
C3—C4—Br6 | 121.8 (5) | N6—C10—C9 | 126.5 (6) |
C5—C4—Br6 | 118.6 (5) | N4—C10—C9 | 115.5 (5) |
| | | |
N2—C1—N1—C5 | −179.7 (5) | C10—N4—C6—N5 | 178.2 (5) |
C2—C1—N1—C5 | −0.6 (7) | C10—N4—C6—C7 | 0.0 (8) |
N2—C1—C2—C3 | 179.7 (5) | N5—C6—C7—C8 | −177.5 (5) |
N1—C1—C2—C3 | 0.6 (7) | N4—C6—C7—C8 | 0.5 (7) |
N2—C1—C2—Br5 | −3.6 (7) | N5—C6—C7—Br7 | 2.8 (7) |
N1—C1—C2—Br5 | 177.3 (3) | N4—C6—C7—Br7 | −179.2 (4) |
C1—C2—C3—C4 | −0.6 (8) | C6—C7—C8—C9 | −0.2 (8) |
Br5—C2—C3—C4 | −177.1 (4) | Br7—C7—C8—C9 | 179.5 (4) |
C2—C3—C4—C5 | 0.5 (8) | C7—C8—C9—C10 | −0.7 (8) |
C2—C3—C4—Br6 | 179.8 (4) | C7—C8—C9—Br8 | −179.0 (4) |
C1—N1—C5—N3 | −179.7 (5) | C6—N4—C10—N6 | −179.9 (5) |
C1—N1—C5—C4 | 0.4 (7) | C6—N4—C10—C9 | −0.8 (7) |
C3—C4—C5—N3 | 179.8 (5) | C8—C9—C10—N6 | −179.9 (5) |
Br6—C4—C5—N3 | 0.5 (7) | Br8—C9—C10—N6 | −1.5 (8) |
C3—C4—C5—N1 | −0.4 (7) | C8—C9—C10—N4 | 1.1 (7) |
Br6—C4—C5—N1 | −179.7 (3) | Br8—C9—C10—N4 | 179.4 (3) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Br3i | 0.86 | 2.71 | 3.474 (4) | 150 |
N2—H2A···Br1i | 0.86 | 2.83 | 3.400 (5) | 125 |
N2—H2B···Br1ii | 0.86 | 2.70 | 3.411 (6) | 141 |
N3—H3A···Br3i | 0.86 | 2.77 | 3.516 (5) | 146 |
N4—H4···Br2iii | 0.86 | 2.82 | 3.446 (5) | 131 |
N4—H4···Br4iv | 0.86 | 2.93 | 3.553 (4) | 131 |
N5—H5A···Br2iv | 0.86 | 2.66 | 3.377 (5) | 142 |
N6—H6A···Br4iv | 0.86 | 2.92 | 3.537 (6) | 130 |
C8—H8···Br4 | 0.93 | 2.91 | 3.720 (5) | 147 |
C3—H3···Br1iii | 0.93 | 2.86 | 3.693 (6) | 150 |
N6—H6B···Br2v | 0.86 | 2.84 | 3.387 (6) | 123 |
Symmetry codes: (i) −x, −y+1, −z; (ii) x−1, y+1, z; (iii) x, y+1, z; (iv) −x+1, −y+1, −z+1; (v) −x, −y+1, −z+1. |
(II) bis(2,6-diamino-3,5-dibromopyridinium) tetrabromidomanganate(II)
top
Crystal data top
(C5H6Br2N3)2[MnBr4] | Z = 2 |
Mr = 910.40 | F(000) = 838 |
Triclinic, P1 | Dx = 2.615 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 8.8776 (19) Å | Cell parameters from 4301 reflections |
b = 10.705 (2) Å | θ = 2.3–27.2° |
c = 13.962 (3) Å | µ = 14.40 mm−1 |
α = 72.757 (4)° | T = 296 K |
β = 86.692 (4)° | Chip, colourless |
γ = 66.159 (4)° | 0.17 × 0.12 × 0.06 mm |
V = 1156.2 (4) Å3 | |
Data collection top
Bruker SMART APEX diffractometer | 4154 independent reflections |
Radiation source: sealed tube | 3124 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.033 |
Detector resolution: 8.3 pixels mm-1 | θmax = 25.3°, θmin = 1.5° |
ω scans | h = −10→10 |
Absorption correction: empirical (using intensity measurements) (SADABS; Bruker, 2001) | k = −12→12 |
Tmin = 0.135, Tmax = 0.421 | l = −16→16 |
10998 measured reflections | |
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)] = 0.036 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.089 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0364P)2 + 0.0548P] where P = (Fo2 + 2Fc2)/3 |
4154 reflections | (Δ/σ)max < 0.001 |
226 parameters | Δρmax = 0.85 e Å−3 |
0 restraints | Δρmin = −0.61 e Å−3 |
Crystal data top
(C5H6Br2N3)2[MnBr4] | γ = 66.159 (4)° |
Mr = 910.40 | V = 1156.2 (4) Å3 |
Triclinic, P1 | Z = 2 |
a = 8.8776 (19) Å | Mo Kα radiation |
b = 10.705 (2) Å | µ = 14.40 mm−1 |
c = 13.962 (3) Å | T = 296 K |
α = 72.757 (4)° | 0.17 × 0.12 × 0.06 mm |
β = 86.692 (4)° | |
Data collection top
Bruker SMART APEX diffractometer | 4154 independent reflections |
Absorption correction: empirical (using intensity measurements) (SADABS; Bruker, 2001) | 3124 reflections with I > 2σ(I) |
Tmin = 0.135, Tmax = 0.421 | Rint = 0.033 |
10998 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.036 | 0 restraints |
wR(F2) = 0.089 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.85 e Å−3 |
4154 reflections | Δρmin = −0.61 e Å−3 |
226 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 | |
Br1 | 0.39465 (7) | −0.00191 (6) | 0.18295 (4) | 0.05246 (17) | |
C1 | −0.0902 (7) | 0.8317 (5) | 0.0581 (4) | 0.0426 (12) | |
Mn1 | 0.33366 (10) | 0.18802 (9) | 0.26764 (6) | 0.0458 (2) | |
N1 | −0.0179 (5) | 0.7706 (4) | −0.0147 (3) | 0.0431 (10) | |
H1 | −0.0793 | 0.7577 | −0.0529 | 0.052* | |
Br2 | 0.20300 (9) | 0.11504 (7) | 0.42637 (5) | 0.0643 (2) | |
C2 | 0.0062 (7) | 0.8536 (5) | 0.1190 (4) | 0.0424 (12) | |
N2 | −0.2537 (6) | 0.8681 (6) | 0.0624 (4) | 0.0660 (14) | |
H2A | −0.3063 | 0.8524 | 0.0206 | 0.079* | |
H2B | −0.3057 | 0.9071 | 0.1070 | 0.079* | |
Br3 | 0.13889 (7) | 0.40914 (6) | 0.14204 (5) | 0.05476 (17) | |
C3 | 0.1727 (7) | 0.8117 (5) | 0.1062 (4) | 0.0500 (14) | |
H3 | 0.2393 | 0.8250 | 0.1479 | 0.060* | |
N3 | 0.1965 (6) | 0.6712 (5) | −0.1053 (4) | 0.0608 (13) | |
H3A | 0.1279 | 0.6618 | −0.1407 | 0.073* | |
H3B | 0.2989 | 0.6434 | −0.1181 | 0.073* | |
Br4 | 0.58857 (8) | 0.20637 (7) | 0.31527 (5) | 0.05810 (18) | |
C4 | 0.2406 (7) | 0.7501 (5) | 0.0314 (4) | 0.0460 (13) | |
N4 | 0.4376 (6) | 0.7572 (5) | 0.4429 (3) | 0.0485 (11) | |
H4 | 0.4273 | 0.8159 | 0.4761 | 0.058* | |
Br5 | −0.09296 (9) | 0.94506 (7) | 0.21676 (5) | 0.0676 (2) | |
C5 | 0.1443 (7) | 0.7291 (5) | −0.0308 (4) | 0.0429 (13) | |
N5 | 0.6878 (6) | 0.7678 (5) | 0.4002 (4) | 0.0600 (13) | |
H5A | 0.6691 | 0.8266 | 0.4346 | 0.072* | |
H5B | 0.7777 | 0.7433 | 0.3701 | 0.072* | |
Br6 | 0.46916 (8) | 0.69239 (8) | 0.01240 (7) | 0.0792 (2) | |
C6 | 0.5772 (7) | 0.7145 (5) | 0.3936 (4) | 0.0406 (12) | |
N6 | 0.1837 (7) | 0.7670 (6) | 0.4949 (4) | 0.0663 (14) | |
H6A | 0.1817 | 0.8260 | 0.5259 | 0.080* | |
H6B | 0.1024 | 0.7422 | 0.4971 | 0.080* | |
Br7 | 0.78962 (8) | 0.55023 (7) | 0.27634 (5) | 0.06401 (19) | |
C7 | 0.5938 (6) | 0.6171 (6) | 0.3424 (4) | 0.0419 (12) | |
Br8 | 0.16402 (8) | 0.55394 (7) | 0.38748 (6) | 0.0671 (2) | |
C8 | 0.4710 (7) | 0.5718 (5) | 0.3399 (4) | 0.0440 (13) | |
H8 | 0.4824 | 0.5083 | 0.3040 | 0.053* | |
C9 | 0.3311 (7) | 0.6189 (5) | 0.3896 (4) | 0.0435 (13) | |
C10 | 0.3130 (7) | 0.7137 (5) | 0.4433 (4) | 0.0457 (13) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Br1 | 0.0557 (4) | 0.0523 (3) | 0.0559 (4) | −0.0216 (3) | 0.0021 (3) | −0.0255 (3) |
C1 | 0.044 (3) | 0.038 (3) | 0.038 (3) | −0.014 (3) | 0.005 (3) | −0.005 (2) |
Mn1 | 0.0472 (5) | 0.0470 (5) | 0.0453 (5) | −0.0187 (4) | 0.0004 (4) | −0.0169 (4) |
N1 | 0.043 (3) | 0.050 (3) | 0.043 (3) | −0.023 (2) | 0.004 (2) | −0.018 (2) |
Br2 | 0.0775 (5) | 0.0650 (4) | 0.0593 (4) | −0.0341 (4) | 0.0240 (4) | −0.0271 (3) |
C2 | 0.047 (3) | 0.038 (3) | 0.041 (3) | −0.016 (3) | 0.004 (3) | −0.012 (2) |
N2 | 0.048 (3) | 0.084 (4) | 0.063 (4) | −0.020 (3) | 0.009 (3) | −0.029 (3) |
Br3 | 0.0528 (4) | 0.0462 (3) | 0.0584 (4) | −0.0161 (3) | −0.0061 (3) | −0.0099 (3) |
C3 | 0.057 (4) | 0.044 (3) | 0.057 (4) | −0.028 (3) | −0.005 (3) | −0.015 (3) |
N3 | 0.052 (3) | 0.069 (3) | 0.074 (4) | −0.026 (3) | 0.015 (3) | −0.039 (3) |
Br4 | 0.0529 (4) | 0.0734 (4) | 0.0623 (4) | −0.0289 (3) | 0.0036 (3) | −0.0354 (3) |
C4 | 0.037 (3) | 0.037 (3) | 0.061 (4) | −0.015 (2) | 0.004 (3) | −0.010 (3) |
N4 | 0.058 (3) | 0.047 (3) | 0.050 (3) | −0.025 (2) | 0.006 (2) | −0.024 (2) |
Br5 | 0.0945 (5) | 0.0588 (4) | 0.0532 (4) | −0.0306 (4) | 0.0186 (4) | −0.0251 (3) |
C5 | 0.047 (3) | 0.038 (3) | 0.046 (3) | −0.019 (3) | 0.004 (3) | −0.015 (3) |
N5 | 0.061 (3) | 0.068 (3) | 0.070 (4) | −0.039 (3) | 0.012 (3) | −0.030 (3) |
Br6 | 0.0421 (4) | 0.0799 (5) | 0.1266 (7) | −0.0271 (4) | 0.0103 (4) | −0.0440 (5) |
C6 | 0.043 (3) | 0.039 (3) | 0.040 (3) | −0.018 (3) | 0.000 (2) | −0.009 (2) |
N6 | 0.062 (3) | 0.080 (4) | 0.074 (4) | −0.036 (3) | 0.023 (3) | −0.041 (3) |
Br7 | 0.0563 (4) | 0.0741 (4) | 0.0711 (4) | −0.0276 (3) | 0.0189 (3) | −0.0361 (4) |
C7 | 0.039 (3) | 0.047 (3) | 0.044 (3) | −0.019 (3) | 0.005 (2) | −0.018 (3) |
Br8 | 0.0565 (4) | 0.0663 (4) | 0.0878 (5) | −0.0354 (3) | −0.0044 (3) | −0.0196 (4) |
C8 | 0.053 (4) | 0.039 (3) | 0.040 (3) | −0.016 (3) | −0.003 (3) | −0.014 (2) |
C9 | 0.041 (3) | 0.042 (3) | 0.049 (3) | −0.020 (3) | 0.001 (3) | −0.012 (3) |
C10 | 0.043 (3) | 0.046 (3) | 0.047 (3) | −0.016 (3) | 0.006 (3) | −0.017 (3) |
Geometric parameters (Å, º) top
Mn1—Br1 | 2.5073 (10) | C4—C5 | 1.377 (8) |
Mn1—Br2 | 2.5054 (11) | C4—Br6 | 1.895 (5) |
Mn1—Br3 | 2.4996 (11) | N4—C6 | 1.359 (7) |
Mn1—Br4 | 2.4925 (11) | N4—C10 | 1.362 (6) |
C1—N2 | 1.345 (7) | N4—H4 | 0.8600 |
C1—N1 | 1.360 (6) | N5—C6 | 1.339 (6) |
C1—C2 | 1.370 (8) | N5—H5A | 0.8600 |
N1—C5 | 1.351 (6) | N5—H5B | 0.8600 |
N1—H1 | 0.8600 | C6—C7 | 1.388 (7) |
C2—C3 | 1.378 (7) | N6—C10 | 1.334 (7) |
C2—Br5 | 1.885 (5) | N6—H6A | 0.8600 |
N2—H2A | 0.8600 | N6—H6B | 0.8600 |
N2—H2B | 0.8600 | Br7—C7 | 1.894 (5) |
C3—C4 | 1.379 (8) | C7—C8 | 1.366 (7) |
C3—H3 | 0.9300 | Br8—C9 | 1.881 (5) |
N3—C5 | 1.332 (7) | C8—C9 | 1.372 (7) |
N3—H3A | 0.8600 | C8—H8 | 0.9300 |
N3—H3B | 0.8600 | C9—C10 | 1.387 (7) |
| | | |
N2—C1—N1 | 116.1 (5) | C6—N4—C10 | 124.7 (4) |
N2—C1—C2 | 125.4 (5) | C6—N4—H4 | 117.7 |
N1—C1—C2 | 118.4 (5) | C10—N4—H4 | 117.7 |
Br1—Mn1—Br2 | 106.57 (4) | N3—C5—N1 | 117.1 (5) |
Br1—Mn1—Br3 | 103.34 (4) | N3—C5—C4 | 125.9 (5) |
Br1—Mn1—Br4 | 112.39 (4) | N1—C5—C4 | 117.0 (5) |
Br2—Mn1—Br3 | 112.89 (4) | C6—N5—H5A | 120.0 |
Br2—Mn1—Br4 | 107.63 (4) | C6—N5—H5B | 120.0 |
Br3—Mn1—Br4 | 113.83 (4) | H5A—N5—H5B | 120.0 |
C5—N1—C1 | 124.2 (5) | N5—C6—N4 | 117.3 (5) |
C5—N1—H1 | 117.9 | N5—C6—C7 | 125.8 (5) |
C1—N1—H1 | 117.9 | N4—C6—C7 | 116.9 (4) |
C1—C2—C3 | 119.5 (5) | C10—N6—H6A | 120.0 |
C1—C2—Br5 | 119.2 (4) | C10—N6—H6B | 120.0 |
C3—C2—Br5 | 121.3 (4) | H6A—N6—H6B | 120.0 |
C1—N2—H2A | 120.0 | C8—C7—C6 | 120.4 (5) |
C1—N2—H2B | 120.0 | C8—C7—Br7 | 121.4 (4) |
H2A—N2—H2B | 120.0 | C6—C7—Br7 | 118.2 (4) |
C4—C3—C2 | 120.0 (5) | C7—C8—C9 | 120.8 (5) |
C4—C3—H3 | 120.0 | C7—C8—H8 | 119.6 |
C2—C3—H3 | 120.0 | C9—C8—H8 | 119.6 |
C5—N3—H3A | 120.0 | C8—C9—C10 | 120.0 (5) |
C5—N3—H3B | 120.0 | C8—C9—Br8 | 120.6 (4) |
H3A—N3—H3B | 120.0 | C10—C9—Br8 | 119.4 (4) |
C5—C4—C3 | 120.9 (5) | N6—C10—N4 | 117.0 (5) |
C5—C4—Br6 | 118.6 (4) | N6—C10—C9 | 125.8 (5) |
C3—C4—Br6 | 120.5 (4) | N4—C10—C9 | 117.2 (5) |
| | | |
N2—C1—N1—C5 | 179.1 (5) | C10—N4—C6—N5 | 179.7 (5) |
C2—C1—N1—C5 | 0.3 (7) | C10—N4—C6—C7 | −1.6 (8) |
N2—C1—C2—C3 | −179.6 (5) | N5—C6—C7—C8 | −179.1 (5) |
N1—C1—C2—C3 | −1.0 (8) | N4—C6—C7—C8 | 2.2 (8) |
N2—C1—C2—Br5 | −1.2 (8) | N5—C6—C7—Br7 | 0.6 (8) |
N1—C1—C2—Br5 | 177.5 (3) | N4—C6—C7—Br7 | −178.0 (4) |
C1—C2—C3—C4 | 0.9 (8) | C6—C7—C8—C9 | −1.5 (8) |
Br5—C2—C3—C4 | −177.5 (4) | Br7—C7—C8—C9 | 178.8 (4) |
C2—C3—C4—C5 | −0.3 (8) | C7—C8—C9—C10 | 0.0 (8) |
C2—C3—C4—Br6 | 179.8 (4) | C7—C8—C9—Br8 | −179.0 (4) |
C1—N1—C5—N3 | −179.8 (5) | C6—N4—C10—N6 | −179.4 (5) |
C1—N1—C5—C4 | 0.3 (7) | C6—N4—C10—C9 | 0.1 (8) |
C3—C4—C5—N3 | 179.8 (5) | C8—C9—C10—N6 | −179.8 (6) |
Br6—C4—C5—N3 | −0.3 (8) | Br8—C9—C10—N6 | −0.8 (8) |
C3—C4—C5—N1 | −0.3 (8) | C8—C9—C10—N4 | 0.7 (8) |
Br6—C4—C5—N1 | 179.6 (3) | Br8—C9—C10—N4 | 179.8 (4) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Br3i | 0.86 | 2.68 | 3.456 (4) | 151 |
N2—H2A···Br1i | 0.86 | 2.79 | 3.389 (6) | 128 |
N2—H2B···Br1ii | 0.86 | 2.71 | 3.433 (5) | 143 |
N3—H3A···Br3i | 0.86 | 2.77 | 3.518 (5) | 147 |
N4—H4···Br2iii | 0.86 | 2.90 | 3.485 (4) | 127 |
N4—H4···Br4iv | 0.86 | 2.85 | 3.496 (4) | 133 |
N5—H5A···Br2iv | 0.86 | 2.64 | 3.380 (5) | 144 |
N6—H6A···Br4iv | 0.86 | 2.95 | 3.567 (6) | 131 |
C8—H8···Br4 | 0.93 | 2.93 | 3.737 (5) | 145 |
C3—H3···Br1iii | 0.93 | 2.87 | 3.701 (5) | 149 |
N6—H6B···Br2v | 0.86 | 2.85 | 3.387 (5) | 122 |
Symmetry codes: (i) −x, −y+1, −z; (ii) x−1, y+1, z; (iii) x, y+1, z; (iv) −x+1, −y+1, −z+1; (v) −x, −y+1, −z+1. |
Experimental details
| (I) | (II) |
Crystal data |
Chemical formula | (C5H6Br2N3)2[CdBr4] | (C5H6Br2N3)2[MnBr4] |
Mr | 967.87 | 910.40 |
Crystal system, space group | Triclinic, P1 | Triclinic, P1 |
Temperature (K) | 293 | 296 |
a, b, c (Å) | 8.8759 (18), 10.720 (2), 14.137 (3) | 8.8776 (19), 10.705 (2), 13.962 (3) |
α, β, γ (°) | 73.07 (3), 86.87 (3), 65.61 (3) | 72.757 (4), 86.692 (4), 66.159 (4) |
V (Å3) | 1168.7 (5) | 1156.2 (4) |
Z | 2 | 2 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 14.62 | 14.40 |
Crystal size (mm) | 0.25 × 0.12 × 0.04 | 0.17 × 0.12 × 0.06 |
|
Data collection |
Diffractometer | Bruker SMART APEX diffractometer | Bruker SMART APEX diffractometer |
Absorption correction | Empirical (using intensity measurements) (SADABS; Bruker, 2001) | Empirical (using intensity measurements) (SADABS; Bruker, 2001) |
Tmin, Tmax | 0.114, 0.557 | 0.135, 0.421 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 11259, 4207, 3281 | 10998, 4154, 3124 |
Rint | 0.037 | 0.033 |
(sin θ/λ)max (Å−1) | 0.600 | 0.600 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.082, 1.03 | 0.036, 0.089, 1.05 |
No. of reflections | 4207 | 4154 |
No. of parameters | 226 | 226 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.87, −0.90 | 0.85, −0.61 |
Selected geometric parameters (Å, º) for (I) topCd1—Br1 | 2.5896 (10) | Cd1—Br3 | 2.5791 (16) |
Cd1—Br2 | 2.5917 (11) | Cd1—Br4 | 2.5678 (9) |
| | | |
Br1—Cd1—Br2 | 106.03 (3) | Br2—Cd1—Br3 | 113.34 (4) |
Br1—Cd1—Br3 | 101.99 (3) | Br2—Cd1—Br4 | 107.05 (3) |
Br1—Cd1—Br4 | 113.61 (4) | Br3—Cd1—Br4 | 114.59 (4) |
Hydrogen-bond geometry (Å, º) for (I) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Br3i | 0.86 | 2.71 | 3.474 (4) | 149.5 |
N2—H2A···Br1i | 0.86 | 2.83 | 3.400 (5) | 125.2 |
N2—H2B···Br1ii | 0.86 | 2.70 | 3.411 (6) | 141.4 |
N3—H3A···Br3i | 0.86 | 2.77 | 3.516 (5) | 145.9 |
N4—H4···Br2iii | 0.86 | 2.82 | 3.446 (5) | 130.7 |
N4—H4···Br4iv | 0.86 | 2.93 | 3.553 (4) | 130.9 |
N5—H5A···Br2iv | 0.86 | 2.66 | 3.377 (5) | 141.7 |
N6—H6A···Br4iv | 0.86 | 2.92 | 3.537 (6) | 130.0 |
C8—H8···Br4 | 0.93 | 2.91 | 3.720 (5) | 146.5 |
C3—H3···Br1iii | 0.93 | 2.86 | 3.693 (6) | 149.9 |
N6—H6B···Br2v | 0.86 | 2.84 | 3.387 (6) | 122.6 |
Symmetry codes: (i) −x, −y+1, −z; (ii) x−1, y+1, z; (iii) x, y+1, z; (iv) −x+1, −y+1, −z+1; (v) −x, −y+1, −z+1. |
Selected geometric parameters (Å, º) for (II) topMn1—Br1 | 2.5073 (10) | Mn1—Br3 | 2.4996 (11) |
Mn1—Br2 | 2.5054 (11) | Mn1—Br4 | 2.4925 (11) |
| | | |
Br1—Mn1—Br2 | 106.57 (4) | Br2—Mn1—Br3 | 112.89 (4) |
Br1—Mn1—Br3 | 103.34 (4) | Br2—Mn1—Br4 | 107.63 (4) |
Br1—Mn1—Br4 | 112.39 (4) | Br3—Mn1—Br4 | 113.83 (4) |
Hydrogen-bond geometry (Å, º) for (II) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Br3i | 0.86 | 2.68 | 3.456 (4) | 150.9 |
N2—H2A···Br1i | 0.86 | 2.79 | 3.389 (6) | 127.9 |
N2—H2B···Br1ii | 0.86 | 2.71 | 3.433 (5) | 142.6 |
N3—H3A···Br3i | 0.86 | 2.77 | 3.518 (5) | 146.9 |
N4—H4···Br2iii | 0.86 | 2.90 | 3.485 (4) | 127.3 |
N4—H4···Br4iv | 0.86 | 2.85 | 3.496 (4) | 133.2 |
N5—H5A···Br2iv | 0.86 | 2.64 | 3.380 (5) | 144.3 |
N6—H6A···Br4iv | 0.86 | 2.95 | 3.567 (6) | 130.5 |
C8—H8···Br4 | 0.93 | 2.93 | 3.737 (5) | 145.4 |
C3—H3···Br1iii | 0.93 | 2.87 | 3.701 (5) | 148.9 |
N6—H6B···Br2v | 0.86 | 2.85 | 3.387 (5) | 122.4 |
Symmetry codes: (i) −x, −y+1, −z; (ii) x−1, y+1, z; (iii) x, y+1, z; (iv) −x+1, −y+1, −z+1; (v) −x, −y+1, −z+1. |
Comparative geometric parameters (Å,°) for halogen bonding in (I) and (II) topContacts | (I) | (II) |
Br5···Br4ii | 3.6133 (17) | 3.6261 (10) |
Br3···Br7vi | 3.5482 (16) | 3.5544 (10) |
Angles | | |
C—Br5···Br4ii | 157 | 156 |
Br3···Br7vi—C | 175 | 175 |
Symmetry codes: (ii) x - 1, y + 1, z; (vi) x - 1, y, z. |
Intermolecular interactions are the essence of supramolecular chemistry (Desiraju 1997), and the field of crystal supramolecularity seeks to understand intermolecular interactions by analysis of crystal packing. Dunitz's aphorism (Dunitz 1991; Dunitz, 1996), "the molecular crystal is the supramolecular entity par excellence", captures this view, and inspires research to extract this understanding.
Research in the field of organic–inorganic hybrid compounds is of great interest, because of their special magnetic (Cui et al., 2000), electronic (Lacroix et al., 1994) and optoelectronic properties (Chakravarthy & Guloy 1997). The influence of the features of the organic cations on the packing interactions that govern the crystal organization is expected to affect the packing and thus the specific properties. In the light of our research on hybrid compounds containing metal bromide anions with substituted pyridinium cations (Luque et al., 2001; Haddad et al., 2006; Al-Far & Ali, 2007a,b; Ali & Al-Far, 2007; Ali et al., 2007, 2008), two isomorphous compounds have been investigated containing the 3,5-dibromo-2,6-diaminopyridinium cation, 3,5-DB-2,6-DAPH, namely (C5H6Br2N3)2[MBr4], with M = Cd in compound (I), and M = Mn in compound (II). These complexes were prepared from the reaction of 2,6-diaminopyridine with the corresponding metal(II) salt in the presence of HBr and Br2. The introduction of amino groups at the 2- and 6-positions facilitates the electrophilic aromatic substitution of Br atoms at the 3- and 5-positions, and increases the nucleophilicity at the ring N atom (Al-Far & Ali, 2007b). Therefore, the protonation of the resulting 3,5-dibromo-2,6-diaminopyridine takes place on the pyridine N atom rather than on the amino N atoms. The bromination and protonation of the pyridine ring were expected to create many important centres of interaction with the bromido-metal anions, e.g. N—H···Br, (π)C—H···Br and possibly arl···aryl (π) stacking.
The [MBr4]2- anions in (I) and (II) (Fig. 1) exhibit a slightly distorted tetrahedral arrangement around M, with M—Br bonds in the ranges 2.5678 (9)–2.5917 (11) and 2.4928 (10)–2.5070 (9) Å for atoms Cd and Mn, respectively, giving mean values of of 2.5821 (12) and 2.5011 (11) Å (Tables 1 and 3). The Br—M—Br angles have ranges of 101.99 (3)–114.59 (4) and 103.33 (4)–113.82 (4)°, respectively. These values are in accordance with the corresponding values in the literature (Al-Far & Ali, 2007a; Morawitz et al., 2007). It is noteworthy that the Br—Mn—Br angles are narrower than for bis(dimethylammonium) tetrabromomanganese(II) (Morawitz et al., 2007), which might be due to the extensive packing interactions in the present work between the anion and surrounding cations, compared with the few interactions between the anion and cations (about four short hydrogen-bonding interactions and no Br···Br interactions) in the much less crowded environment of the latter salt.
In the cations of (I) and (II), the bond lengths (Allen et al., 1987) and angles are within normal ranges. The rings in the two independent cations are nearly planar, with the largest deviation from plane 1 (N1/C1–C5) being for atom Br5, which lies 0.0813 (18) and 0.0751 (30) Å out of this plane in (I) and (II), respectively. For plane 2 (N4/C6–C10), atom Br7 has the largest deviation, being 0.0247 (32) and 0.0495 (62) Å out of this plane in (I) and (II), respectively.
The crystal packing involves extensive cation···anion interactions. The packing diagram can be regarded as a three-dimensional array of interacting cations and anions (Fig. 2) in which each anion interacts with eight surrounding cations (Fig. 3). Six of the cations interact via nine N—H···Br—M hydrogen-bonding interactions of types N—H···Br—M and H—N—H···Br—M, and two interactions of type C—H···Br (Fig. 3; Tables 2 and 4). Two of the cations interact with the anion via two C—Br···Br—M short contacts (see Table 5).
The cations also interact to some extent by offset face-to-face interactions, approximately along the (011) direction, adding extra lattice stability. This is evident from their centroid separation distances. In (I), the distance for cation I, Cg1···Cg1(-x, -y + 2, -z), is 3.943 (3) Å, while for cation II, Cg1···Cg1(1 - x, 1 - y, 1 - z) = 3.760 (3) Å. The corresponding values for (II) are 3.922 (3) and 3.733 (3) Å. These separation distances are in accordance with those of calculated and experimentally observed stacked (offset face-to-face) interaction modes (Gould et al., 1985; Hunter & Sanders, 1990; Hunter et al., 1990; Hunter, 1994; Singh & Thornton, 1990). The stability of this type of structure is evident from the crystallization of these two isostructural compounds.