A linear supramolecular array of {[Mn(H₂O)₂(15-crown-5)]Br₂}_n

Di­aqua(1,4,7,10,14-penta­oxa­cyclo­penta­decane)­manganese(II) dibromide, [Mn(C₁₀H₂₀O₅)(H₂O)₂]Br₂, prepared in a search for emissive Mn^II ions in unusual coordination environments, contains the metal ion encircled by the crown ether ligand, with the water mol­ecules in trans axial positions. Hydro­gen bonding between these and the Br^- counter-ions forms chains of cations running approximately parallel to a.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.024
• wR factor = 0.086
• Data-to-parameter ratio = 14.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

Compounds of Mn²⁺ and 15-crown-5 were prepared in search of crystals with emissive Mn^II ions in environments other than tetrahedral or octahedral geometries (Reid et al., 1998, 1999). In one of these, [Mn(H₂O)₂(15-crown-5)]Br₂, (I), the cation was found to have crystallographically imposed twofold rotation symmetry, with the axis passing through O1, Mn and the midpoint of the C5—C5A bond. The cations are arranged in chains approximately parallel to a and held together by hydrogen bonding between the water molecules and the Br^- ions.

S2. Experimental

MnBr₂·4H₂O (1 mmol) and a slight excess of 15-crown-5 were dissolved in 40 ml of methanol. Vapor diffusion of diethyl ether into this solution at 293 K afforded pale brown columnar crystals of the title compound in 86% yield. Analysis calculated for C₁₀H₂₄Br₂MnO₇: C 25.5, H 5.1, Br 33.9%; found: C 25.3, H 5.1, Br 33.8%.

Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: PROCESS in MolEN (Fair, 1990); program(s) used to solve structure: SIR (Burla et al., 1989); program(s) used to refine structure: LSFM in MolEN (Fair, 1990); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.

Figures

Fig. 1. The hydrogen-bonded cation–anion chain.

Diaqua(1,4,7,10,14-pentaoxacyclopentadecane)manganese(II) dibromide

Crystal data

[Mn(C10H20O5)(H2O)2]Br2	F(000) = 940
Mr = 471.05	Dx = 1.87 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 13.687 (2) Å	Cell parameters from 25 reflections
b = 15.856 (1) Å	θ = 13–17°
c = 7.7761 (9) Å	µ = 5.60 mm^−1
β = 97.936 (9)°	T = 293 K
V = 1671.4 (5) Å^3	Column, pale brown
Z = 4	0.50 × 0.40 × 0.30 mm

Data collection

Enraf-Nonius CAD-4 diffractometer	Rint = 0.018
θ/2θ scans	θmax = 26.0°, θmin = 2.0°
Absorption correction: empirical (using intensity measurements) via ψ scan (North et al., 1968)	h = 0→16
Tmin = 0.084, Tmax = 0.196	k = 0→19
1780 measured reflections	l = −9→9
1644 independent reflections	3 standard reflections every 120 min
1362 reflections with I > 2σ(I)	intensity decay: <1%

Refinement

Refinement on F	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.024	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.086	H-atom parameters not refined
S = 1.28	w = 4Fo^2/[σ^2(Fo^2) + 0.0016Fo^4]
1362 reflections	(Δ/σ)max = 0.004
92 parameters	Δρmax = 0.25 e Å^−3
24 restraints	Δρmin = −0.58 e Å^−3

Special details

Experimental. A pale brown columnar crystal was cut to size and mounted on a thin glass fiber with a coat of epoxy cement. General procedures for crystal orientation, unit cell determination and refinement and data collection have been published (Mague & Lloyd, 1988). The C-centered monoclinic cell indicated by the CAD-4 Software was confirmed by the observation of 2/m diffraction symmetry and the appropriate systematic absences in a limited sample of reciprocal space. Additional systematic absences indicated the space group to be either Cc or C2/c. While intensity statistics did not permit a clear choice between these,they tended to favor the latter and this choice was confirmed by the successful refinement. Attempts to refine the structure in Cc resulted in the persistence of substantial shifts in the positional parameters of those atoms related by symmetry in C2/c, again supporting the original choice.

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

	x	y	z	Uiso*/Ueq
Br	0.26553 (2)	0.09483 (2)	0.50218 (4)	0.04203 (8)
Mn	0.5000	0.26507 (3)	0.2500	0.0272 (1)
O1	0.5000	0.1287 (2)	0.2500	0.0434 (8)
O2	0.3859 (1)	0.2188 (1)	0.0276 (2)	0.0374 (5)
O3	0.4474 (1)	0.3788 (1)	0.0911 (2)	0.0369 (5)
O4	0.3878 (1)	0.2616 (1)	0.4169 (3)	0.0440 (5)
C1	0.4321 (2)	0.0836 (2)	0.1266 (4)	0.0459 (8)
C2	0.4136 (2)	0.1368 (2)	−0.0301 (4)	0.0486 (8)
C3	0.3658 (2)	0.2811 (2)	−0.1066 (4)	0.0512 (9)
C4	0.3558 (2)	0.3635 (2)	−0.0171 (4)	0.0486 (8)
C5	0.4511 (2)	0.4539 (2)	0.1945 (4)	0.0415 (7)
H1w	0.3512	0.3046	0.4389	0.0527*
H2w	0.3526	0.2152	0.4296	0.0527*
H1a	0.3722	0.0738	0.1724	0.0551*
H1b	0.4598	0.0311	0.0994	0.0551*
H2a	0.4716	0.1410	−0.0840	0.0583*
H2b	0.3618	0.1137	−0.1100	0.0583*
H3a	0.3064	0.2679	−0.1798	0.0615*
H3b	0.4186	0.2837	−0.1739	0.0615*
H4a	0.3427	0.4074	−0.1003	0.0583*
H4b	0.3036	0.3605	0.0516	0.0583*
H5a	0.4429	0.5056	0.1200	0.0497*
H5b	0.3919	0.4565	0.2605	0.0497*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br	0.0430 (1)	0.0393 (2)	0.0443 (2)	0.0015 (1)	0.0077 (1)	0.0032 (1)
Mn	0.0248 (2)	0.0331 (2)	0.0225 (3)	0.0000	−0.0003 (2)	0.0000
O1	0.045 (2)	0.034 (1)	0.047 (2)	0.0000	−0.007 (1)	0.0000
O2	0.0374 (9)	0.049 (1)	0.0245 (9)	−0.0010 (9)	−0.0012 (8)	−0.0048 (8)
O3	0.0320 (9)	0.044 (1)	0.033 (1)	0.0042 (8)	−0.0003 (8)	0.0021 (8)
O4	0.041 (1)	0.043 (1)	0.051 (1)	−0.0033 (8)	0.0213 (9)	−0.0054 (9)
C1	0.047 (2)	0.039 (1)	0.054 (2)	−0.008 (1)	0.010 (1)	−0.018 (1)
C2	0.045 (2)	0.061 (2)	0.039 (2)	−0.002 (1)	0.004 (1)	−0.019 (1)
C3	0.047 (2)	0.074 (2)	0.029 (2)	−0.003 (2)	−0.008 (1)	0.007 (2)
C4	0.036 (1)	0.062 (2)	0.043 (2)	0.003 (1)	−0.010 (1)	0.019 (1)
C5	0.049 (1)	0.035 (1)	0.043 (1)	0.007 (1)	0.015 (1)	0.004 (1)

Geometric parameters (Å, º)

Mn—O1	2.162 (3)	O2—C3	1.436 (4)
Mn—O3	2.247 (2)	O3—C4	1.431 (4)
Mn—O4	2.144 (2)	O3—C5	1.434 (3)
O1—C1	1.432 (3)	C1—C2	1.476 (5)
O2—C2	1.443 (4)	C3—C4	1.495 (5)
O1—Mn—O3	143.34 (5)	Mn—O3—C5	111.9 (2)
O1—Mn—O4	88.53 (5)	C4—O3—C5	115.5 (2)
O3—Mn—O4	98.71 (8)	O1—C1—C2	106.8 (3)
Mn—O1—C1	120.0 (2)	O2—C2—C1	106.3 (2)
C2—O2—C3	115.2 (3)	O2—C3—C4	106.5 (3)
Mn—O3—C4	112.1 (2)	O3—C4—C3	107.0 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H1w···Br^i	0.88	2.35	3.216 (2)	172
O4—H2w···Br	0.89	2.36	3.246 (2)	173

Symmetry code: (i) −x+1/2, −y+1/2, −z+1.