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Tetraaquabis(2,3-dihydro-1,4-benzodioxine-2-carboxyl-
ato)calcium(II)

Esmit B. Camargo-Cortés, Mirna Acosta, Juan C. Martı́nez and Leslie W.
Pineda

IUCrData (2020). 5, x201092

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IUCrData (2020). 5, x201092 https://doi.org/10.1107/S2414314620010925 1 of 3

Tetraaquabis(2,3-dihydro-1,4-benzodioxine-2-
carboxylato)calcium(II)

Esmit B. Camargo-Cortés,a* Mirna Acosta,a Juan C. Martı́neza and Leslie W.

Pinedab,c

aCentro Especializado en Investigaciones en Quı́mica Inorgánica (CEIQUI), Escuela de Quı́mica, Universidad Autónoma

de Chiriquı́, David, Panama, bCentro de Electroquı́mica y Energı́a Quı́mica (CELEQ), Universidad de Costa Rica, 11501-

2060. San José, Costa Rica, and cEscuela de Quı́mica, Universidad de Costa Rica, 11501-2060, San José, Costa Rica.

*Correspondence e-mail: esmit.camargo@unachi.ac.pa

The acid–base reaction of 1,4-benzodioxane 2-carboxylic acid with calcium

carbonate furnished the centrosymmetric title compound,

[Ca(C9H7O4)2(H2O)4], in which the metal ion is octahedrally coordinated by

two monodentate 1,4-benzodioxane 2-carboxylate ligands and four water

molecules. In the crystal, O—H� � �O and C—H� � �O hydrogen bonds link the

molecules into a three-dimensional network.

Structure description

1,4-Benzodioxanes are components of some therapeutic agents used in cardiovascular

treatments, acting as �- and �-adrenergic antagonists (Nelson et al., 1977, 1979; Pigini et

al., 1988). For the latter application, the enantiopure derivatives of chiral 2-substituted

1,4-benzodioxanes lend affinity and selectivity, mainly those derived from 1,4-benzo-

dioxane 2-carboxylic acid (Ennis & Old, 1992; Antus et al., 1993; Khouili et al., 1999;

Jasinski et al., 2009). Naturally ocurring compounds with a similar structure to these

heterocyclic scaffolds are known as 1,4-benzodioxane lignans, which also exhibit a wide

array of biological activities (e.g., anticancer, antioxidant; Pilkington & Barker, 2015).

In this work, we report the synthesis and the structure of the coordination properties of

1,4-benzodioxane 2-carboxylic acid toward calcium carbonate to afford the title

compound Ca(C9H7O4)2(H2O)4.

The crystal structure of the title compound has monoclinic symmetry with half a

molecule in the asymmetric unit, the other half being generated by a crystallographic

inversion center. The calcium ion is bonded to four aqua ligands and two 1,4-benzo-

dioxane 2-carboxylate ligands, whose carboxylate groups link to the central atom in

Received 27 July 2020

Accepted 9 August 2020

Edited by W. T. A. Harrison, University of

Aberdeen, Scotland

Keywords: crystal structure; 1,4-benzodioxane;

calcium atom; carboxylate groups; hydrogen

bonding.

Structural data: full structural data are available

from iucrdata.iucr.org

ISSN 2414-3146

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monodentate mode (Fig. 1). The Ca1—O1, Ca1—O5, and

Ca1—O6 bond lengths are 2.304 (2), 2.358 (2) and 2.317 (2) Å,

respectively. The dioxane ring adopts a half-chair conforma-

tion with the pendant carboxylate group in an axial orienta-

tion. In the arbitrarily chosen asymmetric unit, C2 has an R

configuration but crystal symmetry generates a racemic

mixture.

In the crystal, O—H� � �O hydrogen bonds link the mol-

ecules into (010) sheets with the acceptor O atoms being parts

of carboxylate groups (O1 and O2) and the dioxane ring (O4)

and the packing is consolidated by weak C—H� � �O inter-

actions (Fig. 2, Table 1).

Synthesis and crystallization

In a 100 mL two-necked flask, anhydrous CaCO3 (0.0100 g,

0.100 mmol) was dissolved in deionized water (20 mL) by

heating to 338 K, and a solution of 1,4-benzodioxane-2-carb-

oxylic acid (0.0560 g, 0.200 mmol) dissolved in distilled water

(10 mL) was added dropwise at 353 K. The reaction mixture

was refluxed for 2 h and then concentrated under vacuum to

10 mL. The precipitate obtained upon cooling overnight was

filtered off and washed with cold distilled water. Colorless

crystals suitable for X-ray analysis were grown from a warm

water–methanol mixed solvent mixture (1:1) at room

temperature. Yield: 0.0362 g (55%), m.p. 501–505 K. FTIR

data (KBr, cm�1): 3600 and 3000 (br, m); 3568 (m); 1330 (m);

879 (m); 833 (s); 767 (s); 752 (s); 654 (m); 569 (m); 545 (w); 476

(m). 1H NMR (400 MHz, mix 1:1 D2O: CD4O, 298 K): � 6.87–
6.99 (s, 4H), 4.82 (dd, 1H), 4.35 p.p.m. (qd, 2H). 13C NMR

(400 MHz, 1:1 mix D2O: CD4O, 298 K): � 176, 143, 142, 123,

122, 117, 115, 73.5, 66 p.p.m. The 1H NMR and 13C NMR

spectra for the title compound are included in the supporting

information.

Refinement

Crystal data, data collection and structure refinement details

are summarized in Table 2.

Figure 1
The molecular structure of the title compound with displacement
ellipsoids drawn at the 50% probability level. Unlabeled atoms are
generated by the symmetry operation 1 � x, 1 � y, 2 � z.

Figure 2
Packing of the molecules of the title compound. O—H� � �O and C—
H� � �O hydrogen bonds are shown as green dashed lines.

Table 1
Hydrogen-bond geometry (Å, �).

D—H� � �A D—H H� � �A D� � �A D—H� � �A
O5—H5A� � �O1i 0.84 (2) 1.96 (2) 2.800 (3) 178 (4)
O5—H5B� � �O4ii 0.84 (3) 2.07 (3) 2.828 (3) 149 (4)
O6—H6A� � �O2iii 0.83 (3) 1.93 (2) 2.707 (3) 155 (3)
O6—H6B� � �O2i 0.84 (3) 1.88 (4) 2.715 (3) 176 (3)
C2—H2� � �O2i 1.00 2.53 3.379 (4) 143
C6—H6� � �O3iv 0.95 2.54 3.357 (4) 145

Symmetry codes: (i) x� 1; y; z; (ii) x; y; zþ 1; (iii) �xþ 1;�yþ 1;�z þ 1; (iv)
xþ 1

2;�yþ 3
2; z� 1

2.

Table 2
Experimental details.

Crystal data
Chemical formula [Ca(C9H7O4)2(H2O)4]
Mr 470.44
Crystal system, space group Monoclinic, P21/n
Temperature (K) 100
a, b, c (Å) 5.3477 (4), 26.6084 (18), 7.7367 (5)
� (�) 106.715 (2)
V (Å3) 1054.37 (13)
Z 2
Radiation type Mo K�
� (mm�1) 0.36
Crystal size (mm) 0.35 � 0.25 � 0.15

Data collection
Diffractometer Bruker D8 Venture
Absorption correction Multi-scan (SADABS; Bruker,

2015)
Tmin, Tmax 0.661, 0.746
No. of measured, independent and

observed [I > 2�(I)] reflections
32373, 2384, 2242

Rint 0.036
(sin �/�)max (Å

�1) 0.647

Refinement
R[F 2 > 2�(F 2)], wR(F 2), S 0.057, 0.133, 1.39
No. of reflections 2384
No. of parameters 158
No. of restraints 6
H-atom treatment H atoms treated by a mixture of

independent and constrained
refinement

�	max, �	min (e �3) 0.42, �0.43

Computer programs: APEX3 and SAINT (Bruker, 2015), SHELXT (Sheldrick, 2015a),
SHELXL2014 (Sheldrick, 2015b), Mercury (Macrae et al., 2020) and publCIF (Westrip,
2010).

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IUCrData (2020). 5, x201092 Camargo-Cortés et al. � [Ca(C9H7O4)2(H2O)4] 3 of 3

Acknowledgements

Rectorı́a and Vicerrectorı́a de Investigación, Universidad de

Costa Rica are acknowledged for funding the purchase of a D8

Venture SC XRD. CELEQ is thanked for supporting liquid

nitrogen for the X-ray measurements.

Funding information

Funding for this research was provided by: Centro de Elec-

troquı́mica y Energı́a Quı́mica (CELEQ), Universidad de

Costa Rica; Escuela de Quı́mica, Universidad de Costa Rica;

Vicerrectorı́a de Investigación y Posgrado, Universidad

Autónoma de Chiriquı́, Panamá (grant No. 1.87-205-100-2016-

23-i01).

References

Antus, S., Gottsegen, A., Kajtár, J., Kovács, T., Tóth, T. S. & Wagner,
H. (1993). Tetrahedron Asymmetry, 4, 339–344.

Bruker (2015). APEX3, SAINT and SADABS. Bruker AXS Inc.,
Madison, Wisconsin, USA.

Ennis, M. D. & Old, D. W. (1992). Tetrahedron Lett. 33, 6283–6286.
Jasinski, J. P., Butcher, R. J., Yathirajan, H. S., Narayana, B., Mallesha,
L. & Mohana, K. N. (2009). J. Chem. Crystallogr. 39, 453–457.

Khouili, M., Pujol, M. D., Solans, X., Font-Bardia, M., Souizi, A.,
Coudert, G. & Guillaumet, G. (1999). Acta Cryst. C55, 387–389.

Macrae, C. F., Sovago, I., Cottrell, S. J., Galek, P. T. A., McCabe, P.,
Pidcock, E., Platings, M., Shields, G. P., Stevens, J. S., Towler, M. &
Wood, P. A. (2020). J. Appl. Cryst. 53, 226–235.

Nelson, W. L., Powell, M. L. & Dyer, D. C. (1979). J. Med. Chem. 22,
1125–1127.

Nelson, W. L., Wennerstrom, J. E., Dyer, D. C. & Engel, M. (1977). J.
Med. Chem. 20, 880–885.

Pigini, M., Brasili, L., Giannella, M., Giardinà, D., Gulini, U., Quaglia,
W. & Melchiorre, C. (1988). J. Med. Chem. 31, 2300–2304.

Pilkington, L. I. & Barker, D. (2015). Nat. Prod. Rep. 32, 1369–
1388.

Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8.
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8.
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.

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data reports

data-1IUCrData (2020). 5, x201092    

full crystallographic data

IUCrData (2020). 5, x201092    [https://doi.org/10.1107/S2414314620010925]

Tetraaquabis(2,3-dihydro-1,4-benzodioxine-2-carboxylato)calcium(II)

Esmit B. Camargo-Cortés, Mirna Acosta, Juan C. Martínez and Leslie W. Pineda

Tetraaquabis(2,3-dihydro-1,4-benzodioxine-2-carboxylato)calcium(II) 

Crystal data 

[Ca(C9H7O4)2(H2O)4]
Mr = 470.44
Monoclinic, P21/n
a = 5.3477 (4) Å
b = 26.6084 (18) Å
c = 7.7367 (5) Å
β = 106.715 (2)°
V = 1054.37 (13) Å3

Z = 2

F(000) = 492
Dx = 1.482 Mg m−3

Mo Kα radiation, λ = 0.71073 Å
Cell parameters from 9843 reflections
θ = 2.9–27.4°
µ = 0.36 mm−1

T = 100 K
Block, clear light white
0.35 × 0.25 × 0.15 mm

Data collection 

Bruker D8 Venture 
diffractometer

Mirrors monochromator
Detector resolution: 10.4167 pixels mm-1

ω scans
Absorption correction: multi-scan 

(SADABS; Bruker, 2015)
Tmin = 0.661, Tmax = 0.746

32373 measured reflections
2384 independent reflections
2242 reflections with I > 2σ(I)
Rint = 0.036
θmax = 27.4°, θmin = 2.9°
h = −6→6
k = −34→34
l = −10→8

Refinement 

Refinement on F2

Least-squares matrix: full
R[F2 > 2σ(F2)] = 0.057
wR(F2) = 0.133
S = 1.39
2384 reflections
158 parameters
6 restraints
Primary atom site location: structure-invariant 

direct methods

Secondary atom site location: difference Fourier 
map

Hydrogen site location: mixed
H atoms treated by a mixture of independent 

and constrained refinement
w = 1/[σ2(Fo

2) + 3.3804P] 
where P = (Fo

2 + 2Fc
2)/3

(Δ/σ)max < 0.001
Δρmax = 0.42 e Å−3

Δρmin = −0.43 e Å−3

Special details 

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.

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data reports

data-2IUCrData (2020). 5, x201092    

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) 

x y z Uiso*/Ueq

Ca1 0.5 0.5 1.0 0.0115 (2)
O1 0.6722 (4) 0.55435 (8) 0.8323 (3) 0.0144 (4)
O2 0.8347 (4) 0.54948 (9) 0.5982 (3) 0.0164 (5)
O3 0.5527 (5) 0.66992 (9) 0.6702 (3) 0.0199 (5)
O4 0.4402 (4) 0.60021 (8) 0.3776 (3) 0.0144 (4)
O5 0.2000 (4) 0.56223 (9) 1.0277 (3) 0.0167 (5)
H5A 0.041 (3) 0.5599 (16) 0.972 (4) 0.030 (12)*
H5B 0.210 (7) 0.5750 (15) 1.129 (3) 0.033 (12)*
O6 0.1782 (4) 0.47510 (9) 0.7438 (3) 0.0158 (5)
H6A 0.208 (8) 0.4613 (13) 0.655 (3) 0.028 (12)*
H6B 0.070 (7) 0.4981 (12) 0.703 (5) 0.043 (14)*
C1 0.6624 (6) 0.56196 (11) 0.6687 (4) 0.0116 (6)
C2 0.4144 (6) 0.58769 (12) 0.5516 (4) 0.0121 (6)
H2 0.2671 0.5632 0.5335 0.015*
C3 0.3443 (6) 0.63398 (12) 0.6413 (5) 0.0171 (6)
H3A 0.1807 0.6488 0.5636 0.021*
H3B 0.316 0.6247 0.7582 0.021*
C4 0.6346 (6) 0.67786 (12) 0.5198 (4) 0.0160 (6)
C5 0.7822 (7) 0.72053 (13) 0.5151 (5) 0.0226 (7)
H5 0.8188 0.7437 0.6124 0.027*
C6 0.8762 (7) 0.72926 (13) 0.3682 (5) 0.0261 (8)
H6 0.9784 0.7583 0.3656 0.031*
C7 0.8210 (7) 0.69567 (14) 0.2255 (5) 0.0251 (8)
H7 0.8838 0.702 0.1246 0.03*
C8 0.6745 (6) 0.65272 (13) 0.2289 (4) 0.0191 (7)
H8 0.6373 0.6297 0.1311 0.023*
C9 0.5828 (6) 0.64388 (11) 0.3781 (4) 0.0129 (6)

Atomic displacement parameters (Å2) 

U11 U22 U33 U12 U13 U23

Ca1 0.0075 (4) 0.0198 (4) 0.0070 (4) 0.0002 (3) 0.0018 (3) 0.0016 (3)
O1 0.0118 (10) 0.0243 (12) 0.0078 (10) 0.0001 (8) 0.0037 (8) 0.0026 (8)
O2 0.0128 (10) 0.0270 (12) 0.0100 (10) 0.0058 (9) 0.0041 (8) 0.0011 (9)
O3 0.0215 (12) 0.0206 (12) 0.0194 (12) −0.0010 (9) 0.0089 (9) −0.0046 (9)
O4 0.0146 (10) 0.0181 (11) 0.0091 (10) −0.0028 (8) 0.0013 (8) 0.0012 (8)
O5 0.0087 (10) 0.0279 (12) 0.0125 (11) 0.0006 (9) 0.0015 (8) −0.0042 (9)
O6 0.0144 (11) 0.0227 (12) 0.0095 (10) 0.0042 (9) 0.0022 (8) −0.0015 (9)
C1 0.0105 (13) 0.0133 (13) 0.0107 (13) −0.0024 (10) 0.0025 (11) −0.0008 (10)
C2 0.0080 (13) 0.0196 (15) 0.0090 (13) −0.0004 (11) 0.0027 (10) 0.0020 (11)
C3 0.0113 (14) 0.0227 (16) 0.0209 (16) 0.0027 (12) 0.0103 (12) 0.0029 (13)
C4 0.0125 (14) 0.0164 (15) 0.0179 (15) 0.0035 (11) 0.0023 (12) 0.0026 (12)
C5 0.0173 (16) 0.0154 (15) 0.0330 (19) 0.0005 (12) 0.0039 (14) 0.0005 (14)
C6 0.0172 (17) 0.0210 (17) 0.038 (2) −0.0025 (13) 0.0051 (15) 0.0121 (15)
C7 0.0187 (16) 0.0316 (19) 0.0244 (18) 0.0005 (14) 0.0053 (14) 0.0144 (15)

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data-3IUCrData (2020). 5, x201092    

C8 0.0182 (16) 0.0249 (17) 0.0124 (15) 0.0016 (13) 0.0016 (12) 0.0059 (12)
C9 0.0077 (13) 0.0177 (15) 0.0141 (14) 0.0025 (11) 0.0041 (11) 0.0042 (11)

Geometric parameters (Å, º) 

Ca1—O1i 2.304 (2) O6—H6B 0.839 (10)
Ca1—O1 2.304 (2) C1—C2 1.535 (4)
Ca1—O6i 2.317 (2) C2—C3 1.513 (4)
Ca1—O6 2.317 (2) C2—H2 1.0
Ca1—O5i 2.358 (2) C3—H3A 0.99
Ca1—O5 2.358 (2) C3—H3B 0.99
Ca1—H6B 2.74 (4) C4—C9 1.386 (4)
O1—C1 1.268 (4) C4—C5 1.389 (5)
O2—C1 1.243 (4) C5—C6 1.388 (5)
O3—C4 1.372 (4) C5—H5 0.95
O3—C3 1.437 (4) C6—C7 1.385 (6)
O4—C9 1.389 (4) C6—H6 0.95
O4—C2 1.432 (3) C7—C8 1.390 (5)
O5—H5A 0.838 (10) C7—H7 0.95
O5—H5B 0.838 (10) C8—C9 1.397 (4)
O6—H6A 0.837 (10) C8—H8 0.95

O1i—Ca1—O1 180.0 O1—C1—C2 116.1 (3)
O1i—Ca1—O6i 90.95 (8) O4—C2—C3 110.2 (2)
O1—Ca1—O6i 89.05 (8) O4—C2—C1 111.0 (2)
O1i—Ca1—O6 89.05 (8) C3—C2—C1 112.3 (2)
O1—Ca1—O6 90.95 (8) O4—C2—H2 107.7
O6i—Ca1—O6 180.00 (10) C3—C2—H2 107.7
O1i—Ca1—O5i 90.17 (8) C1—C2—H2 107.7
O1—Ca1—O5i 89.83 (8) O3—C3—C2 109.3 (2)
O6i—Ca1—O5i 85.49 (8) O3—C3—H3A 109.8
O6—Ca1—O5i 94.51 (8) C2—C3—H3A 109.8
O1i—Ca1—O5 89.83 (8) O3—C3—H3B 109.8
O1—Ca1—O5 90.17 (8) C2—C3—H3B 109.8
O6i—Ca1—O5 94.51 (8) H3A—C3—H3B 108.3
O6—Ca1—O5 85.49 (8) O3—C4—C9 122.0 (3)
O5i—Ca1—O5 180.0 O3—C4—C5 118.1 (3)
O1i—Ca1—H6B 94.9 (10) C9—C4—C5 119.9 (3)
O1—Ca1—H6B 85.1 (9) C6—C5—C4 120.0 (3)
O6i—Ca1—H6B 163.5 (6) C6—C5—H5 120.0
O6—Ca1—H6B 16.5 (6) C4—C5—H5 120.0
O5i—Ca1—H6B 109.8 (6) C7—C6—C5 120.0 (3)
O5—Ca1—H6B 70.2 (6) C7—C6—H6 120.0
C1—O1—Ca1 138.9 (2) C5—C6—H6 120.0
C4—O3—C3 113.1 (2) C6—C7—C8 120.5 (3)
C9—O4—C2 113.2 (2) C6—C7—H7 119.7
Ca1—O5—H5A 121 (3) C8—C7—H7 119.7
Ca1—O5—H5B 120 (3) C7—C8—C9 119.2 (3)

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data reports

data-4IUCrData (2020). 5, x201092    

H5A—O5—H5B 107 (2) C7—C8—H8 120.4
Ca1—O6—H6A 124 (3) C9—C8—H8 120.4
Ca1—O6—H6B 112 (3) C4—C9—O4 122.1 (3)
H6A—O6—H6B 106 (2) C4—C9—C8 120.4 (3)
O2—C1—O1 124.9 (3) O4—C9—C8 117.5 (3)
O2—C1—C2 118.9 (3)

Ca1—O1—C1—O2 −102.2 (4) O3—C4—C5—C6 178.0 (3)
Ca1—O1—C1—C2 76.5 (4) C9—C4—C5—C6 0.4 (5)
C9—O4—C2—C3 45.0 (3) C4—C5—C6—C7 0.6 (5)
C9—O4—C2—C1 −79.9 (3) C5—C6—C7—C8 −0.8 (5)
O2—C1—C2—O4 −8.8 (4) C6—C7—C8—C9 0.2 (5)
O1—C1—C2—O4 172.4 (2) O3—C4—C9—O4 1.4 (5)
O2—C1—C2—C3 −132.6 (3) C5—C4—C9—O4 178.9 (3)
O1—C1—C2—C3 48.5 (4) O3—C4—C9—C8 −178.6 (3)
C4—O3—C3—C2 48.5 (3) C5—C4—C9—C8 −1.1 (5)
O4—C2—C3—O3 −63.0 (3) C2—O4—C9—C4 −15.5 (4)
C1—C2—C3—O3 61.3 (3) C2—O4—C9—C8 164.4 (3)
C3—O3—C4—C9 −19.4 (4) C7—C8—C9—C4 0.8 (5)
C3—O3—C4—C5 163.1 (3) C7—C8—C9—O4 −179.1 (3)

Symmetry code: (i) −x+1, −y+1, −z+2.

Hydrogen-bond geometry (Å, º) 

D—H···A D—H H···A D···A D—H···A

O5—H5A···O1ii 0.84 (2) 1.96 (2) 2.800 (3) 178 (4)
O5—H5B···O4iii 0.84 (3) 2.07 (3) 2.828 (3) 149 (4)
O6—H6A···O2iv 0.83 (3) 1.93 (2) 2.707 (3) 155 (3)
O6—H6B···O2ii 0.84 (3) 1.88 (4) 2.715 (3) 176 (3)
C2—H2···O2ii 1.00 2.53 3.379 (4) 143
C6—H6···O3v 0.95 2.54 3.357 (4) 145

Symmetry codes: (ii) x−1, y, z; (iii) x, y, z+1; (iv) −x+1, −y+1, −z+1; (v) x+1/2, −y+3/2, z−1/2.

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