Tris(1,2-dimeth­oxy­ethane-κ2O,O′)iodidocalcium iodide

Ou, S.-W.; Lu, W.-Y.; Chen, H.-Y.

doi:10.1107/S160053681200075X

metal-organic compounds

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ISSN: 2056-9890

Volume 68| Part 2| February 2012| Page m172

doi:10.1107/S160053681200075X

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Tris(1,2-dimethoxyethane-κ²O,O′)iodidocalcium iodide

Siou-Wei Ou,^a Wei-Yi Lu ^b and Hsuan-Ying Chen ^a ^*

^aDepartment of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan, and ^bDepartment of Chemistry, National Chung Hsing University, Taichung 402, Taiwan
^*Correspondence e-mail: hchen@kmu.edu.tw

(Received 6 January 2012; accepted 8 January 2012; online 18 January 2012)

In the title complex, [CaI(C₄H₁₀O₂)₃]I, the Ca^II atom is seven-coordinated by six O atoms from three 1,2-dimethoxyethane (DME) ligands and one iodide anion in a distorted pentagonal–bipyramidal geometry. The I atom and one of the O atoms from a DME ligand lie in the axial positions while the other O atoms lie in the basal plane. The other iodide anion is outside the complex cation.

Related literature

For background to polylactide and its copolymers, see: Ha & Gardella (2005 ); Simpson et al. (2008 ). For ring-opening polymerization of lactides with calcium-based catalysts, see: Chen et al. (2007 ); Chisholm et al. (2003 , 2004 ); Darensbourg et al. (2002 , 2003a ,b ); Zhong et al. (2001 ).

Experimental

Crystal data

[CaI(C₄H₁₀O₂)₃]I
M_r = 564.24
Monoclinic, P 2₁ /c
a = 12.1503 (6) Å
b = 10.7767 (5) Å
c = 16.2295 (8) Å
β = 99.514 (1)°
V = 2095.86 (18) Å³
Z = 4
Mo Kα radiation
μ = 3.26 mm⁻¹
T = 100 K
0.23 × 0.23 × 0.15 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ) T_min = 0.522, T_max = 0.647
14842 measured reflections
4791 independent reflections
4627 reflections with I > 2σ(I)
R_int = 0.017

Refinement

R[F² > 2σ(F²)] = 0.016
wR(F²) = 0.043
S = 1.19
4791 reflections
196 parameters
H-atom parameters constrained
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.91 e Å⁻³

Table 1
Selected bond lengths (Å)

Ca1—O1	2.4046 (12)
Ca1—O2	2.3872 (12)
Ca1—O3	2.4871 (11)
Ca1—O4	2.4415 (11)
Ca1—O5	2.4254 (12)
Ca1—O6	2.5138 (11)
Ca1—I1	3.0525 (3)

Data collection: APEX2 (Bruker, 2007 ); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681200075X/hy2505sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053681200075X/hy2505Isup2.hkl

checkCIF report

Comment top

Polylactide and its copolymers are so popular and have been researched widely because of their diversiform applications in biomaterial fields (Ha & Gardella, 2005; Simpson et al., 2008). The ring-opening polymerization (ROP) is the major way to polymerize lactides. Because of the biomaterial purpose the catalysts with non-cytotoxic character are required and calcium is paid much attention for this reason. Recently, ROP of lactides with calcium-based catalysts has been reported (Chen et al., 2007; Chisholm et al., 2003, 2004; Darensbourg et al., 2002, 2003a,b; Zhong et al., 2001) and calcium bis[bis(trimethylsilyl)amide] or calcium iodide is the common precursor. But the low dissolution of calcium iodide in organic solvent is its problem. In this paper we used 1,2-dimethoxyethane (DME) as ligand and solvent to react with calcium iodide, and the solution was refluxed until it showed clear. When the temperature of the solution was cooled to 0°C, the rectangular crystals, [Ca(DME)₃I]I, appeared. The compound was dissoluble in DME, THF and CH₂Cl₂. The low dissolution problem of calcium iodide in organic solvent was solved through the synthesis of [Ca(DME)₃I]I, if calcium iodide was the necessary precursor.

In the title compound, the Ca^II atom is heptacoordinated with a distorted pentagonal-bipyramidal geometry, in which five O atoms occupied the basal positions are almost coplanar . One Cl atom and one O atom lie on the axial positions. The Ca—O distances are 2.3872 (12)–2.5138 (11) Å and the Ca—I distance is 3.0525 (3) Å (Table 1).

Related literature top

For background to polylactide and its copolymers, see: Ha & Gardella (2005); Simpson et al. (2008). For ring-opening polymerization of lactides with calcium-based catalysts, see: Chen et al. (2007); Chisholm et al. (2003, 2004); Darensbourg et al. (2002, 2003a,b); Zhong et al. (2001).

Experimental top

A suspension of calcium iodide (2.94 g, 10 mmol) in 1,2-dimethoxyethane (10 ml) was stirred and refluxed until it showed clear. When the solution was cooled down to 0°C slowly, the rectangular colorless crystals appeared. The solution was filtered to remove the excess 1,2-dimethoxyethane. Volatile materials were then removed under a vacuum. Yield: 78%.

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

Fig. 1. The molecular structure of the title compound. Displacement ellipsoids are shown at the 40% probability level.

Tris(1,2-dimethoxyethane-κ²O,O')iodidocalcium iodide top

Crystal data top

[CaI(C₄H₁₀O₂)₃]I	F(000) = 1104
M_r = 564.24	D_x = 1.788 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 9874 reflections
a = 12.1503 (6) Å	θ = 2.0–28.0°
b = 10.7767 (5) Å	µ = 3.26 mm⁻¹
c = 16.2295 (8) Å	T = 100 K
β = 99.514 (1)°	Blocks, colourless
V = 2095.86 (18) Å³	0.23 × 0.23 × 0.15 mm
Z = 4

Data collection top

Bruker APEXII CCD diffractometer	4791 independent reflections
Radiation source: fine-focus sealed tube	4627 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.017
ϕ and ω scans	θ_max = 27.5°, θ_min = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −15→15
T_min = 0.522, T_max = 0.647	k = −13→14
14842 measured reflections	l = −21→20

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)] = 0.016	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.043	H-atom parameters constrained
S = 1.19	w = 1/[σ²(F_o²) + (0.0191P)² + 0.9088P] where P = (F_o² + 2F_c²)/3
4791 reflections	(Δ/σ)_max = 0.005
196 parameters	Δρ_max = 0.35 e Å⁻³
0 restraints	Δρ_min = −0.91 e Å⁻³

Crystal data top

[CaI(C₄H₁₀O₂)₃]I	V = 2095.86 (18) Å³
M_r = 564.24	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 12.1503 (6) Å	µ = 3.26 mm⁻¹
b = 10.7767 (5) Å	T = 100 K
c = 16.2295 (8) Å	0.23 × 0.23 × 0.15 mm
β = 99.514 (1)°

Data collection top

Bruker APEXII CCD diffractometer	4791 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2001)	4627 reflections with I > 2σ(I)
T_min = 0.522, T_max = 0.647	R_int = 0.017
14842 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.016	0 restraints
wR(F²) = 0.043	H-atom parameters constrained
S = 1.19	Δρ_max = 0.35 e Å⁻³
4791 reflections	Δρ_min = −0.91 e Å⁻³
196 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	U_iso*/U_eq
Ca1	0.74096 (2)	0.25280 (3)	0.987454 (18)	0.01103 (6)
I1	0.589004 (9)	0.206685 (9)	1.116467 (6)	0.01643 (4)
I2	0.169983 (9)	0.297669 (9)	0.264013 (7)	0.01675 (4)
O1	0.91500 (9)	0.19272 (10)	1.07103 (7)	0.0141 (2)
O2	0.89431 (10)	0.28746 (10)	0.91541 (7)	0.0165 (2)
O3	0.80225 (9)	0.44050 (10)	1.07187 (7)	0.0152 (2)
O4	0.66028 (9)	0.44389 (10)	0.92287 (7)	0.0163 (2)
O5	0.60542 (9)	0.17389 (11)	0.87284 (7)	0.0164 (2)
O6	0.77110 (9)	0.02920 (10)	0.95308 (7)	0.0155 (2)
C1	0.92225 (14)	0.09314 (15)	1.13105 (10)	0.0178 (3)
H1A	0.8532	0.0897	1.1548	0.027*
H1B	0.9857	0.1078	1.1758	0.027*
H1C	0.9328	0.0143	1.1033	0.027*
C2	1.01205 (14)	0.19625 (14)	1.03155 (10)	0.0166 (3)
H2A	1.0198	0.1169	1.0024	0.020*
H2B	1.0797	0.2086	1.0740	0.020*
C3	0.99948 (14)	0.30183 (15)	0.96992 (11)	0.0185 (3)
H3A	1.0016	0.3821	0.9998	0.022*
H3B	1.0613	0.3005	0.9371	0.022*
C4	0.88796 (16)	0.3613 (2)	0.84086 (12)	0.0305 (4)
H4A	0.8171	0.3450	0.8040	0.046*
H4B	0.9500	0.3397	0.8119	0.046*
H4C	0.8925	0.4494	0.8559	0.046*
C5	0.84956 (14)	0.42976 (16)	1.15957 (10)	0.0193 (3)
H5A	0.9184	0.3808	1.1655	0.029*
H5B	0.7960	0.3885	1.1894	0.029*
H5C	0.8663	0.5127	1.1831	0.029*
C6	0.71418 (14)	0.53093 (15)	1.05910 (10)	0.0187 (3)
H6A	0.7380	0.6076	1.0907	0.022*
H6B	0.6471	0.4981	1.0790	0.022*
C7	0.68799 (15)	0.55864 (15)	0.96726 (11)	0.0200 (3)
H7A	0.6244	0.6170	0.9559	0.024*
H7B	0.7534	0.5975	0.9484	0.024*
C8	0.61548 (15)	0.46988 (16)	0.83621 (10)	0.0213 (3)
H8A	0.6066	0.3920	0.8046	0.032*
H8B	0.6668	0.5246	0.8127	0.032*
H8C	0.5427	0.5106	0.8327	0.032*
C9	0.48713 (14)	0.20029 (17)	0.85691 (12)	0.0231 (4)
H9A	0.4718	0.2731	0.8893	0.035*
H9B	0.4460	0.1287	0.8733	0.035*
H9C	0.4635	0.2169	0.7972	0.035*
C10	0.63075 (14)	0.06361 (15)	0.82961 (10)	0.0178 (3)
H10A	0.6216	0.0796	0.7688	0.021*
H10B	0.5797	−0.0045	0.8393	0.021*
C11	0.74998 (14)	0.02824 (15)	0.86297 (10)	0.0179 (3)
H11A	0.7652	−0.0557	0.8427	0.021*
H11B	0.8010	0.0873	0.8417	0.021*
C12	0.71396 (15)	−0.07020 (15)	0.98863 (11)	0.0201 (3)
H12A	0.7403	−0.0744	1.0490	0.030*
H12B	0.7294	−0.1491	0.9628	0.030*
H12C	0.6334	−0.0544	0.9782	0.030*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ca1	0.01102 (14)	0.01151 (14)	0.01052 (13)	−0.00026 (10)	0.00169 (10)	−0.00006 (10)
I1	0.01616 (6)	0.01888 (6)	0.01554 (6)	−0.00274 (3)	0.00641 (4)	0.00003 (3)
I2	0.01794 (6)	0.01398 (6)	0.01738 (6)	−0.00181 (3)	0.00008 (4)	0.00072 (3)
O1	0.0140 (5)	0.0152 (5)	0.0132 (5)	0.0014 (4)	0.0025 (4)	0.0007 (4)
O2	0.0161 (6)	0.0204 (6)	0.0132 (5)	−0.0004 (4)	0.0032 (4)	0.0048 (4)
O3	0.0160 (5)	0.0152 (5)	0.0132 (5)	0.0025 (4)	−0.0010 (4)	−0.0025 (4)
O4	0.0204 (6)	0.0127 (5)	0.0144 (5)	0.0004 (4)	−0.0013 (4)	0.0010 (4)
O5	0.0132 (5)	0.0182 (5)	0.0167 (5)	−0.0002 (4)	−0.0009 (4)	−0.0025 (4)
O6	0.0169 (5)	0.0137 (5)	0.0148 (5)	−0.0023 (4)	−0.0003 (4)	−0.0011 (4)
C1	0.0223 (8)	0.0171 (7)	0.0135 (7)	0.0011 (6)	0.0011 (6)	0.0029 (6)
C2	0.0134 (7)	0.0203 (8)	0.0165 (8)	0.0019 (6)	0.0034 (6)	−0.0010 (6)
C3	0.0142 (8)	0.0198 (8)	0.0216 (8)	−0.0027 (6)	0.0032 (6)	0.0001 (6)
C4	0.0237 (9)	0.0439 (12)	0.0260 (9)	0.0068 (8)	0.0102 (7)	0.0214 (8)
C5	0.0234 (8)	0.0192 (8)	0.0135 (7)	0.0005 (6)	−0.0021 (6)	−0.0037 (6)
C6	0.0186 (8)	0.0149 (7)	0.0216 (8)	0.0035 (6)	0.0007 (6)	−0.0043 (6)
C7	0.0227 (8)	0.0120 (7)	0.0233 (8)	0.0009 (6)	−0.0018 (7)	−0.0007 (6)
C8	0.0242 (9)	0.0237 (8)	0.0147 (8)	0.0015 (7)	−0.0005 (6)	0.0045 (6)
C9	0.0121 (8)	0.0301 (10)	0.0256 (9)	0.0001 (6)	−0.0009 (7)	0.0016 (7)
C10	0.0205 (8)	0.0180 (7)	0.0141 (7)	−0.0037 (6)	−0.0001 (6)	−0.0028 (6)
C11	0.0211 (8)	0.0176 (7)	0.0150 (7)	−0.0011 (6)	0.0032 (6)	−0.0043 (6)
C12	0.0225 (8)	0.0152 (7)	0.0219 (8)	−0.0039 (6)	0.0014 (7)	0.0021 (6)

Geometric parameters (Å, º) top

Ca1—O1	2.4046 (12)	C3—H3B	0.9900
Ca1—O2	2.3872 (12)	C4—H4A	0.9800
Ca1—O3	2.4871 (11)	C4—H4B	0.9800
Ca1—O4	2.4415 (11)	C4—H4C	0.9800
Ca1—O5	2.4254 (12)	C5—H5A	0.9800
Ca1—O6	2.5138 (11)	C5—H5B	0.9800
Ca1—I1	3.0525 (3)	C5—H5C	0.9800
O1—C2	1.4325 (19)	C6—C7	1.502 (2)
O1—C1	1.4421 (18)	C6—H6A	0.9900
O2—C3	1.437 (2)	C6—H6B	0.9900
O2—C4	1.439 (2)	C7—H7A	0.9900
O3—C6	1.4369 (19)	C7—H7B	0.9900
O3—C5	1.4489 (18)	C8—H8A	0.9800
O4—C7	1.4427 (19)	C8—H8B	0.9800
O4—C8	1.4490 (19)	C8—H8C	0.9800
O5—C10	1.4390 (19)	C9—H9A	0.9800
O5—C9	1.446 (2)	C9—H9B	0.9800
O6—C11	1.4425 (19)	C9—H9C	0.9800
O6—C12	1.4473 (19)	C10—C11	1.509 (2)
C1—H1A	0.9800	C10—H10A	0.9900
C1—H1B	0.9800	C10—H10B	0.9900
C1—H1C	0.9800	C11—H11A	0.9900
C2—C3	1.506 (2)	C11—H11B	0.9900
C2—H2A	0.9900	C12—H12A	0.9800
C2—H2B	0.9900	C12—H12B	0.9800
C3—H3A	0.9900	C12—H12C	0.9800

O2—Ca1—O1	68.51 (4)	O2—C4—H4B	109.5
O2—Ca1—O5	99.51 (4)	H4A—C4—H4B	109.5
O1—Ca1—O5	139.51 (4)	O2—C4—H4C	109.5
O2—Ca1—O4	87.03 (4)	H4A—C4—H4C	109.5
O1—Ca1—O4	136.26 (4)	H4B—C4—H4C	109.5
O5—Ca1—O4	78.05 (4)	O3—C5—H5A	109.5
O2—Ca1—O3	87.46 (4)	O3—C5—H5B	109.5
O1—Ca1—O3	75.70 (4)	H5A—C5—H5B	109.5
O5—Ca1—O3	144.21 (4)	O3—C5—H5C	109.5
O4—Ca1—O3	67.23 (4)	H5A—C5—H5C	109.5
O2—Ca1—O6	83.52 (4)	H5B—C5—H5C	109.5
O1—Ca1—O6	73.76 (4)	O3—C6—C7	107.98 (13)
O5—Ca1—O6	66.36 (4)	O3—C6—H6A	110.1
O4—Ca1—O6	140.91 (4)	C7—C6—H6A	110.1
O3—Ca1—O6	149.37 (4)	O3—C6—H6B	110.1
O2—Ca1—I1	166.17 (3)	C7—C6—H6B	110.1
O1—Ca1—I1	98.31 (3)	H6A—C6—H6B	108.4
O5—Ca1—I1	93.32 (3)	O4—C7—C6	108.59 (13)
O4—Ca1—I1	100.74 (3)	O4—C7—H7A	110.0
O3—Ca1—I1	85.10 (3)	C6—C7—H7A	110.0
O6—Ca1—I1	97.06 (3)	O4—C7—H7B	110.0
C2—O1—C1	111.03 (12)	C6—C7—H7B	110.0
C2—O1—Ca1	116.92 (9)	H7A—C7—H7B	108.4
C1—O1—Ca1	122.09 (9)	O4—C8—H8A	109.5
C3—O2—C4	112.11 (13)	O4—C8—H8B	109.5
C3—O2—Ca1	113.70 (9)	H8A—C8—H8B	109.5
C4—O2—Ca1	124.09 (10)	O4—C8—H8C	109.5
C6—O3—C5	111.16 (12)	H8A—C8—H8C	109.5
C6—O3—Ca1	108.91 (9)	H8B—C8—H8C	109.5
C5—O3—Ca1	120.68 (9)	O5—C9—H9A	109.5
C7—O4—C8	109.77 (12)	O5—C9—H9B	109.5
C7—O4—Ca1	117.68 (9)	H9A—C9—H9B	109.5
C8—O4—Ca1	129.75 (9)	O5—C9—H9C	109.5
C10—O5—C9	111.20 (12)	H9A—C9—H9C	109.5
C10—O5—Ca1	119.39 (9)	H9B—C9—H9C	109.5
C9—O5—Ca1	126.65 (10)	O5—C10—C11	107.67 (12)
C11—O6—C12	112.47 (12)	O5—C10—H10A	110.2
C11—O6—Ca1	102.93 (8)	C11—C10—H10A	110.2
C12—O6—Ca1	121.60 (9)	O5—C10—H10B	110.2
O1—C1—H1A	109.5	C11—C10—H10B	110.2
O1—C1—H1B	109.5	H10A—C10—H10B	108.5
H1A—C1—H1B	109.5	O6—C11—C10	111.17 (13)
O1—C1—H1C	109.5	O6—C11—Ca1	50.70 (7)
H1A—C1—H1C	109.5	C10—C11—Ca1	84.46 (9)
H1B—C1—H1C	109.5	O6—C11—H11A	109.4
O1—C2—C3	108.45 (13)	C10—C11—H11A	109.4
O1—C2—H2A	110.0	Ca1—C11—H11A	159.8
C3—C2—H2A	110.0	O6—C11—H11B	109.4
O1—C2—H2B	110.0	C10—C11—H11B	109.4
C3—C2—H2B	110.0	Ca1—C11—H11B	79.7
H2A—C2—H2B	108.4	H11A—C11—H11B	108.0
O2—C3—C2	108.03 (13)	O6—C12—H12A	109.5
O2—C3—H3A	110.1	O6—C12—H12B	109.5
C2—C3—H3A	110.1	H12A—C12—H12B	109.5
O2—C3—H3B	110.1	O6—C12—H12C	109.5
C2—C3—H3B	110.1	H12A—C12—H12C	109.5
H3A—C3—H3B	108.4	H12B—C12—H12C	109.5
O2—C4—H4A	109.5

Experimental details

Crystal data
Chemical formula	[CaI(C₄H₁₀O₂)₃]I
M_r	564.24
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	100
a, b, c (Å)	12.1503 (6), 10.7767 (5), 16.2295 (8)
β (°)	99.514 (1)
V (Å³)	2095.86 (18)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	3.26
Crystal size (mm)	0.23 × 0.23 × 0.15

Data collection
Diffractometer	Bruker APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2001)
T_min, T_max	0.522, 0.647
No. of measured, independent and observed [I > 2σ(I)] reflections	14842, 4791, 4627
R_int	0.017
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.016, 0.043, 1.19
No. of reflections	4791
No. of parameters	196
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.35, −0.91

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXTL (Sheldrick, 2008).

Selected bond lengths (Å) top

Ca1—O1	2.4046 (12)	Ca1—O5	2.4254 (12)
Ca1—O2	2.3872 (12)	Ca1—O6	2.5138 (11)
Ca1—O3	2.4871 (11)	Ca1—I1	3.0525 (3)
Ca1—O4	2.4415 (11)

Acknowledgements

Financial support from the National Science Council of the Republic of China is gratefully appreciated. Helpful comments from the reviewers are also greatly appreciated.

References

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