metal-organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890
Volume 69| Part 4| April 2013| Pages m179-m180

Bromido(1,4,7,10,13-penta­aza­cyclo­hexa­deca­ne)cobalt(III) dibromide dihydrate

aDepartment of Chemistry, Faculty of Science, Fukuoka University, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
*Correspondence e-mail: kurisaki@fukuoka-u.ac.jp

(Received 28 January 2013; accepted 20 February 2013; online 2 March 2013)

The title salt, [CoBr(C11H27N5)]Br2·2H2O, contains a complex cation with mirror symmetry and two Br counter-anions that are likewise located on the mirror plane. The central CoIII atom of the complex cation has one Br ion in an axial position, one N atom of the penta­dentate macrocyclic ligand in the other axial position and four N atoms of the ligand in equatorial positions, defining a distorted octa­hedral coordination geometry. The macrocyclic ligand is coordinated to the CoIII atom within a 5, 6, 5 arrangement of chelate rings in the equatorial plane of the four N atoms. Due to symmetry, the configuration of the chiral N atoms is 1RS, 4SR, 10RS, 13SR. In the crystal, N—H⋯Br, O—H⋯Br and N—H⋯O hydrogen bonds between the complex cation, anions and lattice water mol­ecules generate a three-dimensional network.

Related literature

For background to metal complexes with aza­macrocycles, see: Mewis & Archida (2010[Mewis, R. E. & Archida, S. J. (2010). Coord. Chem. Rev. 254, 1686-1712.]). For related structures, see: Curtis et al. (1987a[Curtis, N. F., Osvath, P. & Weatherburn, D. C. (1987a). Aust. J. Chem. 40, 811-827.],b[Curtis, N. F., Gainsford, G. J., Osvath, P. & Weatherburn, D. C. (1987b). Aust. J. Chem. 40, 829-839.]); Eigenbrot et al. (1988[Eigenbrot, C., Osvath, P., Lappin, A. G., Curtis, N. F. & Weatherburn, D. C. (1988). Acta Cryst. C44, 2085-2087.]); Tahirov et al. (1993[Tahirov, T. H., Lu, T.-H., Chen, B.-H., Lai, C.-Y. & Chung, C.-S. (1993). Acta Cryst. C49, 1910-1912.]); Bombieri et al. (1982[Bombieri, G., Forsellini, E., Delpra, A., Cooksey, C. J., Humanes, M. & Tobe, M. L. (1982). Inorg. Chim. Acta, 61, 43-49.]). For the synthesis of the macrocyclic ligand, see: Richman & Atkins (1974[Richman, J. E. & Atkins, T. J. (1974). J. Am. Chem. Soc. 96, 2268-2270.]).

[Scheme 1]

Experimental

Crystal data
  • [CoBr(C11H27N5)]Br2·2H2O

  • Mr = 564.07

  • Orthorhombic, P n m a

  • a = 13.139 (3) Å

  • b = 9.6674 (18) Å

  • c = 15.393 (3) Å

  • V = 1955.2 (7) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 7.02 mm−1

  • T = 296 K

  • 0.40 × 0.22 × 0.14 mm

Data collection
  • Rigaku Saturn724+ diffractometer

  • Absorption correction: numerical (NUMABS; Rigaku, 1999[Rigaku (1999). NUMABS. Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.189, Tmax = 0.501

  • 28744 measured reflections

  • 2370 independent reflections

  • 1964 reflections with I > 2σ(I)

  • Rint = 0.075

Refinement
  • R[F2 > 2σ(F2)] = 0.031

  • wR(F2) = 0.076

  • S = 1.02

  • 2370 reflections

  • 109 parameters

  • 4 restraints

  • H-atom parameters constrained

  • Δρmax = 0.89 e Å−3

  • Δρmin = −0.88 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯Br2 0.91 2.5 3.303 (3) 147
N2—H2⋯Br3 0.91 2.57 3.415 (2) 155
N3—H3⋯OWi 0.91 2.24 3.060 (4) 150
OW—HW2⋯Br2 0.87 2.64 3.491 (3) 168
OW—HW1⋯Br3ii 0.82 2.67 3.489 (3) 170
Symmetry codes: (i) [x+{\script{1\over 2}}, y, -z+{\script{1\over 2}}]; (ii) [-x+{\script{3\over 2}}, -y, z-{\script{1\over 2}}].

Data collection: CrystalClear (Rigaku, 2008[Rigaku (2008). CrystalClear. Rigaku Corporation, Tokyo, Japan.]); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SIR92 (Altomare et al., 1993[Altomare, A., Cascarano, G., Giacovazzo, C. & Guagliardi, A. (1993). J. Appl. Cryst. 26, 343-350.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]); software used to prepare material for publication: WinGX (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]).

Supporting information


Comment top

Azamacrocycles are popular ligands for the preparation of metal complexes because of their stability and defined geometry. These ligands often possess enough conformational freedom for their intended functionalities (Mewis & Archida, 2010). The coordination of pentaaza macrocycles to the cobalt(III) ion can result in a number of isomeric forms. The complexes formed between cobalt(III) and a series of eight pentaaza macrocycles with ring sizes varying from 15- to 20-membered rings have been investigated (Curtis et al., 1987a,b). These cobalt(III) complexes may exist as three diastereoisomers, i.e. meso-syn, meso-anti, and the racemic isomer. For the cobalt(III) complex of 1,4,7,11,14-pentaazacycloheptadecane ([17]aneN5) it has been reported that two isomeric forms could be isolated. The crystal structures of these two isomers, [CoBr([17]aneN5)][ZnBr4] (Eigenbrot et al., 1988) and [CoCl([17]aneN5)]Cl(ClO4) (Tahirov et al., 1993), have been determined as the racemic and the meso-anti isomer, respectively. Furthermore, the cobalt(III) complex of 1,4,7,11,14-pentaazacyclohexadecane ([16]aneN5), [CoCl([16]aneN5)](ClO4)2, crystallized as the meso-syn isomer (Bombieri et al., 1982).

In the title complex, [CoBr(C11H27N5)]Br2.2H2O, the CoIII atom is surrounded by one Br- anion and N atoms of the macrocyclic ligand to form a distorted octahedral environment (Fig.1). The Co—N(axial) bond in the complex is longer than the Co—N(equatorial) bonds, presumably caused by the trans effect of the Br atom. The average Co—N(equatorial) distance of 1.967 Å is shorter than that in cobalt(III) complexes of 1,4,7,11,14-pentaazacycloheptadecane (Eigenbrot et al., 1988) and 1,4,7,11,15-pentaazacyclooctadecane (Curtis et al., 1987a). The macrocyclic ligand adopts a stable conformation with the one six-membered chelate ring in chair form and four five-membered chelate rings in gauche forms. The macrocyclic ligand is coordinated in a configuration with five-, six-, and five-membered chelate rings in the equatorial plane. The deviation of the CoIII atom from the equatorial plane is 0.03 A. The N3 and N3* atoms have opposite chirality giving the meso-syn diastereoisomer. The macrocyclic ligand coordinates in the meso-syn configuration with hydrogen atoms on N2, N2*, N3, and N3* on the same side of the equatorial plane relative to the axially coordinating bromide anion. Due to mirror symmetry of the entire complec cation, the configurations of the four chiral amine N atoms are 1RS, 4SR, 10RS, and 13SR. Hydrogen bonds between N atoms of the macrocyclic ligand, water molecules and bromide counter anions exists (Fig. 2; Table 1), stabilizing the crystal packing within a three-dimensional network.

Related literature top

For background to metal complexes with azamacrocycles, see: Mewis & Archida (2010). For related structures, see: Curtis et al. (1987a,b); Eigenbrot et al. (1988); Tahirov et al. (1993); Bombieri et al. (1982). For the synthesis of the macrocyclic ligand, see: Richman & Atkins (1974).

Experimental top

The ligand 1,4,7,10,13-pentaazacyclohexadecane pentahydrobromide was prepared according to the literature method (Richman & Atkins, 1974). The ligand (1.26 g, 2 mmol) was dissolved in water and treated with freshly prepared Na3[Co(CO3)3].3H2O (0.72 g, 2 mmol). The mixture was refluxed for 1 h and filtered. To the filtrate was added NH4Br in excess and the solution allowed to stand for several days whereupon dark violet crystals of the title compound were formed.

Refinement top

All H atoms attached to C and N atoms were placed geometrically (C—H = 0.97 and N—H = 0.91 Å) and were refined as riding with Uiso(H) = 1.2Ueq(C,N). The water H atoms were located in difference Fourier maps and were refined initially with restrains O—H = 0.85 (2) Å. In the last cycles of refinement, they were eventually refined as riding, with Uiso(H) = 1.5Ueq(O).

Computing details top

Data collection: CrystalClear (Rigaku, 2008); cell refinement: CrystalClear (Rigaku, 2008); data reduction: CrystalClear (Rigaku, 2008); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, with 50% probability displacement ellipsoids and the atom-numbering scheme.
[Figure 2] Fig. 2. Crystal Structure of the title compound with view along the b axis. Intermolecular hydrogen bonding is shown as dashed lines.
Bromido(1,4,7,10,13-pentaazacyclohexadecane)cobalt(III) dibromide dihydrate top
Crystal data top
[CoBr(C11H27N5)]Br2·2H2OF(000) = 1120
Mr = 564.07Dx = 1.916 Mg m3
Orthorhombic, PnmaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2nCell parameters from 4654 reflections
a = 13.139 (3) Åθ = 3.1–27.5°
b = 9.6674 (18) ŵ = 7.02 mm1
c = 15.393 (3) ÅT = 296 K
V = 1955.2 (7) Å3Prism, dark violet
Z = 40.40 × 0.22 × 0.14 mm
Data collection top
Rigaku Saturn724+
diffractometer
2370 independent reflections
Radiation source: rotating anode1964 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.075
Detector resolution: 28.5714 pixels mm-1θmax = 27.5°, θmin = 3.1°
dtprofit.ref scansh = 1717
Absorption correction: numerical
(NUMABS; Rigaku, 1999)
k = 1212
Tmin = 0.189, Tmax = 0.501l = 1919
28744 measured reflections
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)] = 0.031Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.076H-atom parameters constrained
S = 1.02 w = 1/[σ2(Fo2) + (0.0392P)2]
where P = (Fo2 + 2Fc2)/3
2370 reflections(Δ/σ)max = 0.001
109 parametersΔρmax = 0.89 e Å3
4 restraintsΔρmin = 0.88 e Å3
Crystal data top
[CoBr(C11H27N5)]Br2·2H2OV = 1955.2 (7) Å3
Mr = 564.07Z = 4
Orthorhombic, PnmaMo Kα radiation
a = 13.139 (3) ŵ = 7.02 mm1
b = 9.6674 (18) ÅT = 296 K
c = 15.393 (3) Å0.40 × 0.22 × 0.14 mm
Data collection top
Rigaku Saturn724+
diffractometer
2370 independent reflections
Absorption correction: numerical
(NUMABS; Rigaku, 1999)
1964 reflections with I > 2σ(I)
Tmin = 0.189, Tmax = 0.501Rint = 0.075
28744 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0314 restraints
wR(F2) = 0.076H-atom parameters constrained
S = 1.02Δρmax = 0.89 e Å3
2370 reflectionsΔρmin = 0.88 e Å3
109 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
Br10.97038 (3)0.250.51348 (3)0.04287 (14)
Br20.44795 (3)0.250.38291 (3)0.04299 (14)
Br30.89341 (4)0.250.77417 (3)0.04833 (15)
Co0.78735 (4)0.250.50953 (3)0.02053 (13)
OW0.4692 (2)0.0362 (3)0.20106 (17)0.0743 (9)
HW10.50850.02630.21560.111*
HW20.47010.09860.24160.111*
N10.6374 (2)0.250.5240 (2)0.0227 (7)
H10.60830.250.47030.027*
N20.78844 (16)0.0990 (2)0.59473 (15)0.0272 (5)
H20.83330.12190.63740.033*
N30.79176 (17)0.1035 (2)0.42054 (15)0.0298 (5)
H30.85560.10760.39770.036*
C10.60554 (19)0.1226 (3)0.57002 (19)0.0309 (6)
H1A0.59570.04820.52860.037*
H1B0.54160.13850.59980.037*
C20.6869 (2)0.0825 (3)0.63512 (19)0.0344 (7)
H2A0.68180.14080.68620.041*
H2B0.67730.01290.6530.041*
C30.8268 (2)0.0279 (3)0.5511 (2)0.0395 (7)
H3A0.80630.1090.58380.047*
H3B0.90060.02580.54880.047*
C40.7838 (2)0.0351 (3)0.4602 (2)0.0396 (7)
H4A0.82170.10180.42590.047*
H4B0.71320.06410.46210.047*
C50.7214 (2)0.1176 (3)0.34490 (19)0.0369 (7)
H5A0.65170.11540.36560.044*
H5B0.73090.03920.30640.044*
C60.7384 (4)0.250.2943 (3)0.0452 (12)
H6A0.69320.250.24450.054*
H6B0.80760.250.27240.054*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0225 (2)0.0483 (3)0.0578 (3)00.00093 (19)0
Br20.0392 (3)0.0353 (3)0.0546 (3)00.0198 (2)0
Br30.0605 (3)0.0443 (3)0.0402 (3)00.0220 (2)0
Co0.0186 (3)0.0205 (3)0.0225 (3)00.00025 (19)0
OW0.082 (2)0.087 (2)0.0533 (17)0.0336 (16)0.0023 (14)0.0002 (15)
N10.0247 (16)0.0235 (16)0.0198 (16)00.0005 (13)0
N20.0270 (12)0.0243 (12)0.0301 (13)0.0013 (9)0.0066 (10)0.0031 (10)
N30.0284 (12)0.0313 (13)0.0297 (13)0.0026 (10)0.0031 (10)0.0055 (11)
C10.0261 (14)0.0318 (16)0.0349 (16)0.0057 (11)0.0035 (12)0.0017 (12)
C20.0421 (17)0.0318 (16)0.0293 (16)0.0035 (13)0.0006 (13)0.0094 (13)
C30.0450 (18)0.0248 (15)0.049 (2)0.0108 (13)0.0048 (15)0.0010 (14)
C40.0480 (19)0.0256 (16)0.0451 (18)0.0056 (13)0.0024 (16)0.0090 (14)
C50.0392 (17)0.0436 (18)0.0280 (15)0.0022 (14)0.0001 (13)0.0145 (14)
C60.049 (3)0.062 (3)0.025 (2)00.000 (2)0
Geometric parameters (Å, º) top
Br1—Co2.4056 (8)C1—C21.516 (4)
Co—N2i1.962 (2)C1—H1A0.97
Co—N21.962 (2)C1—H1B0.97
Co—N31.971 (2)C2—H2A0.97
Co—N3i1.971 (2)C2—H2B0.97
Co—N11.982 (3)C3—C41.512 (4)
OW—HW10.8249C3—H3A0.97
OW—HW20.8682C3—H3B0.97
N1—C1i1.482 (3)C4—H4A0.97
N1—C11.482 (3)C4—H4B0.97
N1—H10.91C5—C61.516 (4)
N2—C21.481 (3)C5—H5A0.97
N2—C31.486 (3)C5—H5B0.97
N2—H20.91C6—C5i1.516 (4)
N3—C41.476 (4)C6—H6A0.97
N3—C51.493 (4)C6—H6B0.97
N3—H30.91
N2i—Co—N296.11 (14)N1—C1—H1A109.8
N2i—Co—N3177.03 (10)C2—C1—H1A109.8
N2—Co—N385.97 (10)N1—C1—H1B109.8
N2i—Co—N3i85.97 (10)C2—C1—H1B109.8
N2—Co—N3i177.03 (10)H1A—C1—H1B108.3
N3—Co—N3i91.87 (14)N2—C2—C1109.3 (2)
N2i—Co—N186.12 (9)N2—C2—H2A109.8
N2—Co—N186.12 (9)C1—C2—H2A109.8
N3—Co—N196.15 (9)N2—C2—H2B109.8
N3i—Co—N196.15 (9)C1—C2—H2B109.8
N2i—Co—Br188.61 (6)H2A—C2—H2B108.3
N2—Co—Br188.61 (6)N2—C3—C4109.3 (2)
N3—Co—Br189.32 (7)N2—C3—H3A109.8
N3i—Co—Br189.32 (7)C4—C3—H3A109.8
N1—Co—Br1172.11 (9)N2—C3—H3B109.8
HW1—OW—HW2107.8C4—C3—H3B109.8
C1i—N1—C1112.5 (3)H3A—C3—H3B108.3
C1i—N1—Co109.54 (16)N3—C4—C3108.3 (2)
C1—N1—Co109.54 (16)N3—C4—H4A110
C1i—N1—H1108.4C3—C4—H4A110
C1—N1—H1108.4N3—C4—H4B110
Co—N1—H1108.4C3—C4—H4B110
C2—N2—C3113.9 (2)H4A—C4—H4B108.4
C2—N2—Co110.77 (16)N3—C5—C6112.8 (3)
C3—N2—Co108.34 (18)N3—C5—H5A109
C2—N2—H2107.9C6—C5—H5A109
C3—N2—H2107.9N3—C5—H5B109
Co—N2—H2107.9C6—C5—H5B109
C4—N3—C5111.2 (2)H5A—C5—H5B107.8
C4—N3—Co111.29 (18)C5—C6—C5i115.3 (4)
C5—N3—Co117.28 (17)C5—C6—H6A108.4
C4—N3—H3105.3C5i—C6—H6A108.4
C5—N3—H3105.3C5—C6—H6B108.4
Co—N3—H3105.3C5i—C6—H6B108.4
N1—C1—C2109.2 (2)H6A—C6—H6B107.5
Symmetry code: (i) x, y+1/2, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···Br20.912.53.303 (3)147
N2—H2···Br30.912.573.415 (2)155
N3—H3···OWii0.912.243.060 (4)150
OW—HW2···Br20.872.643.491 (3)168
OW—HW1···Br3iii0.822.673.489 (3)170
Symmetry codes: (ii) x+1/2, y, z+1/2; (iii) x+3/2, y, z1/2.

Experimental details

Crystal data
Chemical formula[CoBr(C11H27N5)]Br2·2H2O
Mr564.07
Crystal system, space groupOrthorhombic, Pnma
Temperature (K)296
a, b, c (Å)13.139 (3), 9.6674 (18), 15.393 (3)
V3)1955.2 (7)
Z4
Radiation typeMo Kα
µ (mm1)7.02
Crystal size (mm)0.40 × 0.22 × 0.14
Data collection
DiffractometerRigaku Saturn724+
diffractometer
Absorption correctionNumerical
(NUMABS; Rigaku, 1999)
Tmin, Tmax0.189, 0.501
No. of measured, independent and
observed [I > 2σ(I)] reflections
28744, 2370, 1964
Rint0.075
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.076, 1.02
No. of reflections2370
No. of parameters109
No. of restraints4
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.89, 0.88

Computer programs: CrystalClear (Rigaku, 2008), SIR92 (Altomare et al., 1993), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012), WinGX (Farrugia, 2012).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···Br20.912.53.303 (3)147.4
N2—H2···Br30.912.573.415 (2)155.3
N3—H3···OWi0.912.243.060 (4)149.7
OW—HW2···Br20.872.643.491 (3)167.7
OW—HW1···Br3ii0.822.673.489 (3)169.9
Symmetry codes: (i) x+1/2, y, z+1/2; (ii) x+3/2, y, z1/2.
 

Acknowledgements

This work was partially supported by Grants-in-Aid for Scientific Research (C) 22550088 and (B) 23300319 from the Japan Society for the Promotion of Science.

References

First citationAltomare, A., Cascarano, G., Giacovazzo, C. & Guagliardi, A. (1993). J. Appl. Cryst. 26, 343–350.  CrossRef Web of Science IUCr Journals
First citationBombieri, G., Forsellini, E., Delpra, A., Cooksey, C. J., Humanes, M. & Tobe, M. L. (1982). Inorg. Chim. Acta, 61, 43–49.  CSD CrossRef CAS Web of Science
First citationCurtis, N. F., Gainsford, G. J., Osvath, P. & Weatherburn, D. C. (1987b). Aust. J. Chem. 40, 829–839.  CSD CrossRef
First citationCurtis, N. F., Osvath, P. & Weatherburn, D. C. (1987a). Aust. J. Chem. 40, 811–827.  CrossRef CAS
First citationEigenbrot, C., Osvath, P., Lappin, A. G., Curtis, N. F. & Weatherburn, D. C. (1988). Acta Cryst. C44, 2085–2087.  CSD CrossRef CAS Web of Science IUCr Journals
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals
First citationMewis, R. E. & Archida, S. J. (2010). Coord. Chem. Rev. 254, 1686–1712.  Web of Science CrossRef CAS
First citationRichman, J. E. & Atkins, T. J. (1974). J. Am. Chem. Soc. 96, 2268–2270.  CrossRef CAS Web of Science
First citationRigaku (1999). NUMABS. Rigaku Corporation, Tokyo, Japan.
First citationRigaku (2008). CrystalClear. Rigaku Corporation, Tokyo, Japan.
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals
First citationTahirov, T. H., Lu, T.-H., Chen, B.-H., Lai, C.-Y. & Chung, C.-S. (1993). Acta Cryst. C49, 1910–1912.  CSD CrossRef CAS Web of Science IUCr Journals

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ISSN: 2056-9890
Volume 69| Part 4| April 2013| Pages m179-m180
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