supplementary materials


dn2505 scheme

Acta Cryst. (2009). E65, m1495-m1496    [ doi:10.1107/S1600536809045048 ]

Tetra-[mu]-benzoato-bis{[trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene]zinc(II)}

Y. J. Song, S.-W. Lee, K. H. Jang, C. Kim and Y. Kim

Abstract top

The paddle-wheel-type centrosymmetric dinuclear title complex, [Zn2(C7H5O2)4(C12H10N2)2], contains four bridging benzoate groups and two terminal trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene (L) ligands. The inversion center is located between the two ZnII atoms. The octahedral coordination around the ZnII atom, with four O atoms in the equatorial plane, is completed by an N atom of the L molecule [Zn-N = 2.0198 (15) Å] and by the second ZnII atom [Zn...Zn = 2.971 (8) Å]. The ZnII atom is 0.372 Å out of the plane of the four coordinating O atoms.

Comment top

A great attention has been paid to transition metal ions as the major cation contributors to the inorganic composition of natural water and biological fluids (Daniele, et al., 2008; Parkin, 2004; Tshuva & Lippard, 2004). While the main attention was focused on the interaction of transition metal ions with biologically active molecules such as amino acids, proteins, sugars, nucleotides etc, the study on the interaction of the transition metal ions with fulvic acids and humic acids, mainly found in soil, is about to start. As models to examine the interaction, therefore, we have previously used copper(II) and zinc(II) benzoates as building blocks and reported the structures of copper(II) and zinc(II) benzoates with quinoxaline, 6-methylquinoline, 3-methylquinoline, and di-2-pyridyl ketone (Lee, et al., 2008; Yu, et al., 2008; Park, et al., 2008; Shin, et al., 2009; Yu, et al., 2009). The related paddle-wheel type structures for Zn complexes have been previouly reported (Necefoglu et al., 2002; Zeleňák, et al., 2004; Karmakar, et al., 2006; Ohmura, et al., 2005). In this work, we have employed zinc(II) benzoate as a building block and trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene as a ligand. We report hereon the structure of new zinc(II) benzoate with trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene.

Asymmetric unit contains half of whole molecule, and there is an inversion center in the middle of Zn···Zn bond. Symmetric operation (1-x, 1-y , 1-z) produces a paddle-wheel type dinuclear zinc-benzoate complex (Fig. 1). The paddle-wheel type dinuclear complex is constructed by four bridging benzoate groups and two terminal L ligands (L = trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene). The octahedral coordination around the zinc atom, with four O atoms in the equatorial plane, is completed by nitrogen atom of L molecule (Zn—N 2.0198 (15) Å) and by the second zinc atom (Zn···Zn 2.971 (8) Å). The zinc atom is 0.372 Å out of the plane of the four oxygen atoms.

Related literature top

For structures containing [Zn2(O2CPh)4], see: Necefoglu et al. (2002); Zeleňák et al. (2004); Karmakar et al. (2006); Ohmura et al. (2005). For the structures of copper(II) and zinc(II) benzoates with quinoxaline, 6-methylquinoline, 3-methylquinoline, and di-2-pyridyl ketone, see: Lee et al. (2008); Yu et al. (2008, 2009); Park et al. (2008); Shin et al. (2009). For transition metal ions as the major cation contributors to the inorganic composition of natural water and biological fluids, see: Daniele et al. (2008); Parkin (2004); Tshuva & Lippard (2004);

Experimental top

30.4 mg (0.1 mmol) of Zn(NO3)2.6H2O and 28.0 mg (0.2 mmol) of C6H5COONH4 were dissolved in 4 ml H2O and carefully layered by 4 ml me thanol solution of trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene (37.6 mg, 0.2 mmol). Suitable crystals of the title compound for X-ray analysis were obtained in a few weeks.

Refinement top

H atoms were placed in calculated positions with C—H distances of 0.93 Å. They were included in the refinement in a riding-motion approximation with Uĩso~(H) = 1.2U~eq~(C).

Computing details top

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The structure of the title compound showing the atom-labeling scheme. Displacement ellipsoids are shown at the 30% probability level. H atoms have been omitted for clarity. [Symmetry code: (i) -x+1, -y+1, -z+1].
Tetra-µ-benzoato-bis{[trans-1-(2-pyridyl)-2-(4- pyridyl)ethylene]zinc(II)} top
Crystal data top
[Zn2(C7H5O2)4(C12H10N2)2]F(000) = 2016
Mr = 979.66Dx = 1.447 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 1818 reflections
a = 24.919 (6) Åθ = 2.5–19.6°
b = 12.186 (3) ŵ = 1.13 mm1
c = 15.742 (4) ÅT = 293 K
β = 109.857 (4)°Block, colorless
V = 4496.0 (19) Å30.20 × 0.15 × 0.15 mm
Z = 4
Data collection top
Bruker SMART CCD
diffractometer
4416 independent reflections
Radiation source: fine-focus sealed tube2947 reflections with I > 2σ(I)
graphiteRint = 0.039
φ and ω scansθmax = 26.0°, θmin = 1.9°
Absorption correction: multi-scan
(SADABS; Bruker, 1997)
h = 2030
Tmin = 0.816, Tmax = 0.884k = 1515
12326 measured reflectionsl = 1916
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)] = 0.039Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.090H-atom parameters constrained
S = 1.03 w = 1/[σ2(Fo2) + (0.0205P)2 + 1.48P]
where P = (Fo2 + 2Fc2)/3
4416 reflections(Δ/σ)max = 0.001
298 parametersΔρmax = 0.26 e Å3
0 restraintsΔρmin = 0.26 e Å3
Crystal data top
[Zn2(C7H5O2)4(C12H10N2)2]V = 4496.0 (19) Å3
Mr = 979.66Z = 4
Monoclinic, C2/cMo Kα radiation
a = 24.919 (6) ŵ = 1.13 mm1
b = 12.186 (3) ÅT = 293 K
c = 15.742 (4) Å0.20 × 0.15 × 0.15 mm
β = 109.857 (4)°
Data collection top
Bruker SMART CCD
diffractometer
4416 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 1997)
2947 reflections with I > 2σ(I)
Tmin = 0.816, Tmax = 0.884Rint = 0.039
12326 measured reflectionsθmax = 26.0°
Refinement top
R[F2 > 2σ(F2)] = 0.039H-atom parameters constrained
wR(F2) = 0.090Δρmax = 0.26 e Å3
S = 1.03Δρmin = 0.26 e Å3
4416 reflectionsAbsolute structure: ?
298 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

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.

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 > 2sigma(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
Zn10.545232 (12)0.50480 (2)0.590326 (19)0.03852 (11)
O110.48081 (8)0.42174 (16)0.61458 (13)0.0536 (5)
O120.58816 (8)0.58560 (17)0.51974 (13)0.0589 (5)
O210.56818 (8)0.35925 (15)0.54865 (13)0.0549 (5)
O220.50102 (8)0.64874 (15)0.58505 (13)0.0581 (6)
N310.60407 (9)0.52228 (16)0.71558 (14)0.0391 (5)
N320.75201 (11)0.7049 (2)1.18938 (17)0.0710 (8)
C110.43281 (12)0.3906 (2)0.56234 (19)0.0420 (7)
C120.39861 (11)0.3173 (2)0.60095 (18)0.0399 (6)
C130.41930 (13)0.2875 (3)0.6908 (2)0.0584 (8)
H130.45390.31590.72820.070*
C140.38945 (18)0.2165 (3)0.7258 (3)0.0805 (11)
H140.40410.19730.78650.097*
C150.33831 (18)0.1736 (3)0.6724 (3)0.0803 (11)
H150.31840.12510.69630.096*
C160.31681 (14)0.2032 (3)0.5828 (3)0.0747 (10)
H160.28210.17450.54590.090*
C170.34645 (12)0.2755 (2)0.5472 (2)0.0563 (8)
H170.33120.29620.48690.068*
C210.53915 (12)0.3100 (2)0.47807 (19)0.0423 (6)
C220.55306 (11)0.1917 (2)0.46933 (19)0.0450 (7)
C230.51906 (15)0.1303 (3)0.3980 (3)0.0773 (11)
H230.48940.16360.35250.093*
C240.5289 (2)0.0196 (3)0.3940 (4)0.1091 (17)
H240.50510.02180.34640.131*
C250.5726 (2)0.0295 (3)0.4583 (4)0.1087 (17)
H250.57860.10440.45510.130*
C260.6079 (2)0.0306 (3)0.5279 (3)0.0902 (13)
H260.63840.00340.57140.108*
C270.59863 (14)0.1418 (3)0.5344 (2)0.0628 (9)
H270.62280.18260.58200.075*
C310.65674 (12)0.4837 (2)0.73577 (19)0.0531 (8)
H310.66580.44370.69220.064*
C320.69861 (12)0.5004 (2)0.81848 (19)0.0568 (8)
H320.73510.47280.82920.068*
C330.68646 (11)0.5579 (2)0.88547 (17)0.0412 (7)
C340.63111 (11)0.5948 (2)0.86490 (17)0.0473 (7)
H340.62030.63230.90800.057*
C350.59211 (11)0.5760 (2)0.78060 (17)0.0456 (7)
H350.55520.60240.76810.055*
C360.73130 (12)0.5774 (2)0.97322 (18)0.0505 (7)
H360.76800.55400.97940.061*
C370.72419 (12)0.6248 (2)1.04352 (18)0.0509 (8)
H370.68720.64551.03780.061*
C380.76886 (13)0.6485 (2)1.13035 (18)0.0473 (7)
C390.82430 (14)0.6161 (3)1.1499 (2)0.0647 (9)
H390.83520.57701.10770.078*
C3100.86366 (15)0.6418 (3)1.2323 (2)0.0819 (12)
H3100.90140.61941.24670.098*
C3110.84732 (15)0.7006 (3)1.2933 (2)0.0639 (9)
H3110.87350.72011.34910.077*
C3120.79166 (16)0.7295 (3)1.2699 (2)0.0722 (10)
H3120.78020.76841.31160.087*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Zn10.03822 (19)0.04063 (17)0.03006 (17)0.00220 (15)0.00295 (12)0.00148 (14)
O110.0470 (12)0.0593 (12)0.0528 (12)0.0127 (10)0.0146 (10)0.0025 (10)
O120.0622 (13)0.0699 (13)0.0446 (12)0.0098 (11)0.0180 (10)0.0091 (11)
O210.0599 (13)0.0486 (11)0.0522 (13)0.0073 (10)0.0140 (10)0.0082 (10)
O220.0580 (13)0.0474 (11)0.0584 (14)0.0102 (10)0.0063 (11)0.0015 (10)
N310.0405 (13)0.0400 (12)0.0331 (12)0.0012 (10)0.0078 (10)0.0030 (9)
N320.0614 (18)0.105 (2)0.0411 (15)0.0057 (16)0.0108 (13)0.0143 (15)
C110.0491 (18)0.0344 (14)0.0460 (17)0.0026 (13)0.0207 (14)0.0019 (13)
C120.0426 (16)0.0373 (14)0.0431 (16)0.0024 (12)0.0190 (13)0.0015 (12)
C130.062 (2)0.0643 (19)0.052 (2)0.0050 (17)0.0227 (16)0.0023 (16)
C140.100 (3)0.086 (3)0.066 (2)0.002 (2)0.042 (2)0.022 (2)
C150.094 (3)0.057 (2)0.111 (3)0.002 (2)0.062 (3)0.015 (2)
C160.056 (2)0.069 (2)0.102 (3)0.0149 (18)0.031 (2)0.007 (2)
C170.0473 (19)0.0579 (18)0.062 (2)0.0040 (15)0.0168 (16)0.0014 (16)
C210.0444 (17)0.0416 (14)0.0452 (17)0.0015 (13)0.0206 (14)0.0010 (13)
C220.0479 (17)0.0401 (14)0.0545 (18)0.0015 (13)0.0270 (14)0.0016 (13)
C230.068 (2)0.059 (2)0.097 (3)0.0027 (18)0.016 (2)0.0217 (19)
C240.103 (4)0.063 (3)0.163 (5)0.014 (2)0.046 (3)0.050 (3)
C250.123 (4)0.042 (2)0.192 (6)0.007 (2)0.094 (4)0.003 (3)
C260.103 (3)0.064 (2)0.121 (4)0.035 (2)0.061 (3)0.034 (2)
C270.071 (2)0.061 (2)0.062 (2)0.0168 (17)0.0303 (18)0.0140 (16)
C310.0490 (18)0.0643 (19)0.0413 (16)0.0072 (15)0.0093 (13)0.0153 (14)
C320.0391 (16)0.074 (2)0.0488 (18)0.0100 (16)0.0043 (13)0.0124 (17)
C330.0440 (17)0.0416 (15)0.0331 (15)0.0033 (13)0.0067 (12)0.0023 (12)
C340.0447 (17)0.0595 (17)0.0356 (15)0.0031 (14)0.0110 (13)0.0087 (13)
C350.0360 (16)0.0582 (17)0.0374 (16)0.0044 (14)0.0056 (12)0.0004 (14)
C360.0397 (17)0.0608 (18)0.0410 (17)0.0010 (14)0.0009 (13)0.0077 (14)
C370.0445 (18)0.0638 (19)0.0371 (16)0.0022 (14)0.0045 (13)0.0036 (14)
C380.0547 (19)0.0500 (16)0.0324 (16)0.0109 (14)0.0083 (14)0.0012 (13)
C390.059 (2)0.077 (2)0.0444 (18)0.0088 (17)0.0002 (16)0.0159 (16)
C3100.062 (2)0.099 (3)0.062 (2)0.005 (2)0.0074 (19)0.013 (2)
C3110.071 (2)0.069 (2)0.0367 (18)0.0147 (19)0.0020 (16)0.0016 (16)
C3120.079 (3)0.096 (3)0.0382 (18)0.009 (2)0.0162 (17)0.0134 (18)
Geometric parameters (Å, °) top
Zn1—N312.029 (2)C23—C241.376 (5)
Zn1—O122.039 (2)C23—H230.9300
Zn1—O212.0392 (19)C24—C251.349 (6)
Zn1—O112.0407 (19)C24—H240.9300
Zn1—O222.0580 (19)C25—C261.362 (6)
Zn1—Zn1i2.9711 (8)C25—H250.9300
O11—C111.258 (3)C26—C271.385 (4)
O12—C11i1.252 (3)C26—H260.9300
O21—C211.254 (3)C27—H270.9300
O22—C21i1.251 (3)C31—C321.379 (4)
N31—C311.327 (3)C31—H310.9300
N31—C351.331 (3)C32—C331.383 (4)
N32—C381.333 (4)C32—H320.9300
N32—C3121.350 (4)C33—C341.381 (3)
C11—O12i1.252 (3)C33—C361.471 (3)
C11—C121.498 (4)C34—C351.372 (3)
C12—C131.380 (4)C34—H340.9300
C12—C171.385 (4)C35—H350.9300
C13—C141.372 (4)C36—C371.313 (4)
C13—H130.9300C36—H360.9300
C14—C151.370 (5)C37—C381.468 (3)
C14—H140.9300C37—H370.9300
C15—C161.375 (5)C38—C391.368 (4)
C15—H150.9300C39—C3101.371 (4)
C16—C171.385 (4)C39—H390.9300
C16—H160.9300C310—C3111.366 (5)
C17—H170.9300C310—H3100.9300
C21—O22i1.251 (3)C311—C3121.355 (4)
C21—C221.500 (4)C311—H3110.9300
C22—C231.375 (4)C312—H3120.9300
C22—C271.385 (4)
N31—Zn1—O1298.00 (8)C24—C23—H23120.0
N31—Zn1—O21102.41 (8)C22—C23—H23120.0
O12—Zn1—O2189.34 (8)C25—C24—C23120.7 (4)
N31—Zn1—O11103.00 (8)C25—C24—H24119.7
O12—Zn1—O11158.97 (8)C23—C24—H24119.7
O21—Zn1—O1187.31 (8)C24—C25—C26120.1 (4)
N31—Zn1—O2298.62 (8)C24—C25—H25119.9
O12—Zn1—O2286.52 (9)C26—C25—H25119.9
O21—Zn1—O22158.93 (8)C25—C26—C27120.4 (4)
O11—Zn1—O2289.19 (8)C25—C26—H26119.8
N31—Zn1—Zn1i175.50 (6)C27—C26—H26119.8
O12—Zn1—Zn1i82.26 (6)C26—C27—C22119.4 (3)
O21—Zn1—Zn1i82.08 (6)C26—C27—H27120.3
O11—Zn1—Zn1i76.71 (6)C22—C27—H27120.3
O22—Zn1—Zn1i76.89 (5)N31—C31—C32122.9 (3)
C11—O11—Zn1131.38 (19)N31—C31—H31118.5
C11i—O12—Zn1124.19 (18)C32—C31—H31118.5
C21—O21—Zn1124.11 (17)C31—C32—C33120.2 (3)
C21i—O22—Zn1130.32 (18)C31—C32—H32119.9
C31—N31—C35116.8 (2)C33—C32—H32119.9
C31—N31—Zn1121.66 (18)C34—C33—C32116.5 (2)
C35—N31—Zn1121.47 (18)C34—C33—C36123.2 (2)
C38—N32—C312117.7 (3)C32—C33—C36120.3 (3)
O12i—C11—O11125.1 (3)C35—C34—C33119.7 (3)
O12i—C11—C12117.5 (2)C35—C34—H34120.1
O11—C11—C12117.4 (3)C33—C34—H34120.1
C13—C12—C17118.4 (3)N31—C35—C34123.8 (3)
C13—C12—C11120.5 (2)N31—C35—H35118.1
C17—C12—C11121.1 (3)C34—C35—H35118.1
C14—C13—C12120.8 (3)C37—C36—C33125.9 (3)
C14—C13—H13119.6C37—C36—H36117.1
C12—C13—H13119.6C33—C36—H36117.1
C15—C14—C13120.8 (3)C36—C37—C38126.5 (3)
C15—C14—H14119.6C36—C37—H37116.8
C13—C14—H14119.6C38—C37—H37116.8
C14—C15—C16119.1 (3)N32—C38—C39121.7 (3)
C14—C15—H15120.4N32—C38—C37115.6 (3)
C16—C15—H15120.4C39—C38—C37122.8 (3)
C15—C16—C17120.4 (3)C38—C39—C310119.3 (3)
C15—C16—H16119.8C38—C39—H39120.3
C17—C16—H16119.8C310—C39—H39120.3
C16—C17—C12120.4 (3)C311—C310—C39119.8 (3)
C16—C17—H17119.8C311—C310—H310120.1
C12—C17—H17119.8C39—C310—H310120.1
O22i—C21—O21125.2 (2)C312—C311—C310117.8 (3)
O22i—C21—C22117.4 (2)C312—C311—H311121.1
O21—C21—C22117.3 (2)C310—C311—H311121.1
C23—C22—C27119.2 (3)N32—C312—C311123.6 (3)
C23—C22—C21120.0 (3)N32—C312—H312118.2
C27—C22—C21120.8 (3)C311—C312—H312118.2
C24—C23—C22120.1 (4)
O12i—C11—C12—C13179.8 (3)C21—C22—C27—C26175.3 (3)
O11—C11—C12—C131.0 (4)C35—N31—C31—C322.1 (4)
O12i—C11—C12—C171.5 (4)N31—C31—C32—C331.1 (5)
O11—C11—C12—C17177.2 (3)C31—C32—C33—C340.9 (4)
C17—C12—C13—C141.3 (5)C31—C32—C33—C36178.9 (3)
C11—C12—C13—C14177.0 (3)C32—C33—C34—C351.7 (4)
C12—C13—C14—C150.1 (5)C36—C33—C34—C35178.1 (3)
C13—C14—C15—C160.5 (6)C31—N31—C35—C341.3 (4)
C14—C15—C16—C170.1 (6)C33—C34—C35—N310.7 (4)
C15—C16—C17—C121.2 (5)C34—C33—C36—C374.5 (5)
C13—C12—C17—C161.8 (4)C32—C33—C36—C37175.6 (3)
C11—C12—C17—C16176.5 (3)C33—C36—C37—C38177.6 (3)
O22i—C21—C22—C235.7 (4)C312—N32—C38—C390.0 (5)
O21—C21—C22—C23173.3 (3)C312—N32—C38—C37179.4 (3)
O22i—C21—C22—C27176.9 (3)C36—C37—C38—N32175.1 (3)
O21—C21—C22—C274.1 (4)C36—C37—C38—C394.4 (5)
C27—C22—C23—C242.9 (6)N32—C38—C39—C3100.2 (5)
C21—C22—C23—C24174.5 (4)C37—C38—C39—C310179.6 (3)
C22—C23—C24—C251.6 (7)C38—C39—C310—C3110.9 (5)
C23—C24—C25—C260.5 (8)C39—C310—C311—C3121.3 (5)
C24—C25—C26—C271.4 (7)C38—N32—C312—C3110.4 (5)
C25—C26—C27—C220.0 (6)C310—C311—C312—N321.1 (5)
C23—C22—C27—C262.1 (5)
Symmetry codes: (i) −x+1, −y+1, −z+1.
Acknowledgements top

Financial support from the Korean Ministry of the Environment "ET-Human resource development Project" and the Cooperative Research Program for Agricultural Science & Technology Development (20070301–036-019–02) is gratefully acknowledged.

references
References top

Bruker (1997). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.

Daniele, P. G., Foti, C., Gianguzza, A., Prenesti, E. & Sammartano, S. (2008). Coord. Chem. Rev. 252, 1093–1107.

Karmakar, A., Sarma, R. J. & Baruah, J. B. (2006). Inorg. Chem. Commun. 9, 1169-1172.

Lee, E. Y., Park, B. K., Kim, C., Kim, S.-J. & Kim, Y. (2008). Acta Cryst. E64, m286.

Necefoglu, H., Clegg, W. & Scott, A. J. (2002). Acta Cryst. E58, m121–m122.

Ohmura, T., Mori, W., Takei, T., Ikeda, T. & Maeda, A. (2005). Mater. Sci. Pol. 23, 729–736.

Park, B. K., Jang, K.-H., Kim, P.-G., Kim, C. & Kim, Y. (2008). Acta Cryst. E64, m1141.

Parkin, G. (2004). Chem. Rev. 104, 699–767.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Shin, D. H., Han, S.-H., Kim, P.-G., Kim, C. & Kim, Y. (2009). Acta Cryst. E65, m658–m659.

Tshuva, E. Y. & Lippard, S. J. (2004). Chem. Rev. 104, 987. Final page number?

Yu, S. M., Park, C.-H., Kim, P.-G., Kim, C. & Kim, Y. (2008). Acta Cryst. E64, m881–m882.

Yu, S. M., Shin, D. H., Kim, P.-G., Kim, C. & Kim, Y. (2009). Acta Cryst. E65, m1045–m1046.

Zeleňák, V., Sabo, M., Massa, W. & Černák, J. (2004). Acta Cryst. C60, m85–m87.