Crystal structure and Hirshfeld surface analysis of an erbium(III) coordination polymer based on a 2,3,5,6-tetra­bromo­benzene-1,4-di­carboxyl­ate ligand

Jiajaroen, S.; Chainok, K.

doi:10.1107/S2056989026010698

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ISSN: 2056-9890

Volume 82| Part 11| November 2026| Pages 1323-1327

https://doi.org/10.1107/S2056989026010698

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Crystal structure and Hirshfeld surface analysis of an erbium(III) coordination polymer based on a 2,3,5,6-tetrabromobenzene-1,4-dicarboxylate ligand

Suwadee Jiajaroen ^a ^* and Kittipong Chainok ^b

^aDivision of Science and Mathematic, Faculty of Science and Technology, Rajamangala University of Technology Tawan-ok, Bangpra, Sriracha, Chonburi, 20110, Thailand, and ^bThammasat University Research Unit in Multifunctional Crystalline Materials, and Applications (TU-MCMA), Faculty of Science and Technology, Thammasat University, Khlong Luang, Pathum Thani, 12121, Thailand
^*Correspondence e-mail: [email protected]

Edited by L. Van Meervelt, Katholieke Universiteit Leuven, Belgium (Received 15 October 2026; accepted 15 October 2026; online 20 October 2026)

The title polymeric compound, poly[[triaqua(μ₃-2,3,5,6-tetrabromobenzene-1,4-dicarboxylato)hemi(μ₂-2,3,5,6-tetrabromobenzene-1,4-dicarboxylato)erbium(III)] trihydrate], {[Er(C₈Br₄O₄)_1.5(H₂O)₃]·3H₂O}_n or {[Er(Br₄bdc)_1.5(H₂O)₃]·3H₂O}_n (1), was hydrothermally synthesized and structurally characterized. The asymmetric unit contains one Er^III cation, one and a half Br₄bdc^2– dianions, three coordinated H₂O molecules, and three uncoordinated solvent H₂O molecules. The central Er^III cation is seven-coordinated within a distorted capped trigonal-prismatic geometry. The coordination sphere is defined by four carboxylate oxygen atoms from four Br₄bdc^2– ligands and three aqua oxygen atoms. The Br₄bdc^2– ligand occupies a general position, and acts as a μ₃-bridge linking three symmetry-related Er^III cations. It coordinates via μ₃-κO:κO′:κO′′ mode, using its carboxylate oxygen atoms to extend into a two-dimensional polymeric sheet parallel to the bc plane. Meanwhile, the remaining Br₄bdc²⁻ ligand is situated on a crystallographic inversion centre and adopts a μ₂-κO:κO′ coordination mode linking the sheets into a three-dimensional network. The cohesion of the three-dimensional supramolecular framework is enhanced by classical O–H⋯O hydrogen bonds. The crystal packing is further consolidated by intermolecular Br⋯Br and Br⋯O halogen bonding interactions. The analysis of the Hirshfeld surface reveals that the primary contributions arise from Br⋯Br (23.5%) and O⋯H/H⋯O (20.8%) contacts. Additional contributions include Br⋯H/H⋯Br (13.2%), H⋯C/C⋯H (12.5%), Br⋯C/C⋯Br (8.4%), Br⋯O/O⋯Br (7.0%), and O⋯O (5.3%) interactions.>

Keywords: crystal structure; coordination polymer; erbium(III); carboxylate.

CCDC reference: 2595517

1. Chemical context

Lanthanide coordination polymers (LnCPs) have been widely studied and their potential applications, including electronic, optical, and magnetic properties arising from the unique 4f electronic configurations of Ln^III ions (Bünzli, 2010 ; Capelo et al., 2025 ; Shiels et al., 2026 ). Unlike transition-metal ions, Ln^III ions exhibit high and variable coordination numbers together with a wide range of coordination geometries. They possess robust Ln—O bonds and a hard Lewis acid character, resulting in a strong affinity for hard donor atoms, particularly oxygen-containing ligands (Cui et al., 2012 ; Saraci et al., 2020 ; Costanzo et al., 2026 ). These characteristics make Ln^III ions attractive building units and provide flexibility in the assembly of structural diversity (Bünzli, 2014 ; Boone et al., 2024 ). Besides, the selection of ligands plays a crucial role in constructing diverse topologies and properties. Aromatic polycarboxylic acids are widely employed as organic linkers in the design and construction of CPs. In particular, terephthalic acid (H₂bdc) and its functionalized derivatives display versatile coordination modes spanning monodentate, chelating, bridging, and chelating–bridging fashions, yielding structurally diverse networks upon self-assembly (Li et al., 2014 ; Jiajaroen et al., 2022 ; Nisa et al., 2024 ). Among these derivatives, 2,3,5,6-tetrabromobenzene-1,4-dicarboxylic acid (H₂Br₄bdc) is structurally significant; the four bulky, electronegative bromine substituents drastically alter the steric and electronic environment of the central aromatic core, significantly influencing both the primary coordination spheres and the secondary supramolecular interactions. The presence of bromine substituents may influence the opportunities for intermolecular halogen-related interactions, particularly Br⋯Br and other halogen-containing contacts. These may play a crucial role in crystal packing and structural stabilization. Herein, we report the synthesis and crystal structure of a new erbium(III) CP, namely, poly[[triaqua(μ₃-2,3,5,6-tetrabromobenzene-4-dicarboxylato)hemi(μ₂-2,3,5,6-tetrabromobenzene-1,4-dicarboxylato)erbium(III)] trihydrate] (1). The assembly of the polymeric framework and the supramolecular interactions of 1 are thoroughly elucidated and examined. Furthermore, Hirshfeld surface analysis provides a quantitative evaluation of intermolecular contacts and crystal packing interactions of 1.

2. Structural commentary

The asymmetric unit of 1 contains one Er^III atom, one and a half Br₄bdc^2– ligands, three coordinated water molecules, and three uncoordinated water molecules. The Er^III ion adopts an [ErO₇] coordination environment with four oxygen atoms from four different Br₄bdc^2– ligands and three oxygen atoms from coordinated water molecules (Fig. 1), displaying a distorted capped trigonal-prismatic geometry (CTPR-7; value 4.082) (SHAPE 2.1; Llunell et al., 2013 ). The Er—O bond lengths fall in the range of 2.238 (2) to 2.347 (3) Å, mean 2.304 (2) Å. The O—Er—O bond angles range from 73.11 (8) to 155.44 (11)°. The fully deprotonated Br₄bdc^2– ligand exhibits a μ₃-κO:κO′:κO′′ bridging mode, linking three symmetry-related Er^III ions to propagate a two-dimensional sheet parallel to the bc plane (Fig. 2). Within this layer, the shortest Er⋯Er separation is 4.6625 (19) Å. The sheets are further interconnected into a three-dimensional framework along the c-axis direction by the remaining Br₄bdc^2– ligand, which resides on a crystallographic inversion centre and acts as a μ₂-κO:κO′ bridge (Fig. 3).

Figure 1
Molecular structure of 1, showing the asymmetric unit with the atom-labeling scheme and the coordination environment of the Er^III ion. Displacement ellipsoids are drawn at the 40% probability level. Symmetry codes: (i) 1 − x, 1 − y, 2 − z and x, ½ − y, ½ + z.

Figure 2
View of the two-dimensional sheet structure of 1 in the bc plane.

Figure 3
View of the three-dimensional framework of 1 along the c axis.

3. Supramolecular features

In the crystal structure, the coordinated water molecules (O7W, O8W and O9W) act as hydrogen-bond donors, forming robust intermolecular O—H⋯O hydrogen-bonding interactions with the water molecules of crystallization (O10W, O11W and O12W) serving as the hydrogen-bond acceptors (Table 1). Moreover, the carboxylate oxygen atoms of the Br₄bdc^2– ligands serve as hydrogen-bond acceptors for the solvent water molecules, contributing to the cohesion of the supramolecular network (Fig. 4). The crystal packing is further consolidated by intermolecular Br⋯Br and Br⋯O halogen bonding interactions (Table 2) occurring between adjacent Br₄bdc^2– ligands. No significant π–π stacking interactions are observed between neighboring benzene rings, as the centroid-to-centroid separations fall well outside the typical 3.3–3.8 Å range characteristic of such supramolecular contacts (Janiak, 2000 ).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O7—H7A⋯O11	0.86 (3)	2.06 (3)	2.892 (4)	165 (5)
O7—H7B⋯O4ⁱ	0.84 (3)	2.10 (3)	2.931 (4)	168 (4)
O8—H8A⋯O12	0.84 (3)	1.86 (3)	2.705 (4)	174 (3)
O8—H8B⋯O3ⁱⁱ	0.82 (4)	1.96 (3)	2.703 (3)	152 (5)
O9—H9A⋯O10	0.84 (2)	2.05 (4)	2.643 (5)	128 (4)
O10—H10A⋯O12ⁱⁱⁱ	0.85 (3)	2.00 (5)	2.808 (4)	160 (5)
O10—H10B⋯O6ⁱⁱⁱ	0.84 (5)	2.12 (6)	2.948 (5)	171 (6)
O11—H11A⋯O6	0.84 (3)	2.18 (4)	2.989 (4)	161 (5)
O11—H11B⋯O2ⁱ	0.84 (5)	2.31 (5)	3.139 (4)	174 (6)
O12—H12A⋯O3^iv	0.84 (4)	2.06 (4)	2.879 (4)	164 (4)
O12—H12B⋯O6^v	0.84 (4)	1.99 (4)	2.832 (3)	177 (4)
Symmetry codes: (i) $[-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (ii) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (iii) $[-x, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (iv) $[-x, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (v) $[x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]$ .

Table 2
Br⋯X halogen-bond geometry (Å, °)

C—Br⋯X	Br⋯X	C—Br⋯X	Type
C4—Br2⋯Br2ⁱ	3.7489 (14)	129.40 (7)	I
C6—Br3⋯Br6	3.8861 (11)	134.30 (8)	II
C7—Br4⋯Br2ⁱⁱ	3.7048 (13)	120.25 (8)	I
C7—Br4⋯Br5	3.5390 (15)	161.06 (8)	II
C11—Br5⋯Br1ⁱⁱ	3.5739 (15)	174.31 (9)	II
C3—Br1⋯O11ⁱⁱⁱ	3.054 (3)	160.04 (10)
C12—Br6⋯O3^iv	3.265 (3)	175.75 (9)
Symmetry codes: (i) 1 − x, −y, 2 − z; (ii) 1 − x, $[{1\over 2}]$ + y, $[{3\over 2}]$ − z; (iii) 1 − x, 1 − y, 2 − z; (iv) x, $[{1\over 2}]$ − y, − $[{1\over 2}]$ + z.

Figure 4
View of the O—H⋯O hydrogen bonds involving the carboxylate groups of the Br₄bdc^2– ligands and water molecules of 1. Hydrogen-bonding interactions are shown as dashed lines.

4. Hirshfeld surface analysis

A Hirshfeld surface analysis was carried out using CrystalExplorer (Spackman et al., 2021 ) to examine the intermolecular interactions in 1. The 3D Hirshfeld surface mapped over d_norm highlights close intermolecular contacts as red spots, whereas white and blue regions correspond to contacts close to and longer than the sum of the van der Waals radii, respectively (Fig. 5). The analysis of the two-dimensional fingerprint plots (Fig. 6) reveals that the largest contribution arises from Br⋯Br contacts (23.5%), indicating that close halogen⋯halogen contacts constitute a significant feature of the crystal packing. The O⋯H/H⋯O contacts (20.8%) correspond to the extensive network of O–H⋯O hydrogen bonds involving carboxylate oxygen atoms, coordinated aqua ligands, and solvent water molecules. Secondary contributions to the Hirshfeld surface area include Br⋯H/H⋯Br (13.2%) and H⋯C/C⋯H (12.5%) contacts, which further consolidate the supramolecular architecture. Minor packing contributions are attributed to Br⋯C/C⋯Br (8.4%), Br⋯O/O⋯Br (7.0%), O⋯O (5.3%) and O⋯C/C⋯O (4.2%) contacts. Notably, C⋯C contacts account for only 0.7% of the Hirshfeld surface area, corroborating the absence of significant π–π stacking interactions within the crystal structure. Therefore, it can be concluded that halogen and hydrogen bonds are the major intermolecular contacts that contribute to the consolidation of the crystal packing of 1.

Figure 5
View of the Hirshfeld surface for 1 plotted over d_norm.

Figure 6
The two-dimensional fingerprint plots for 1, showing (a) all interactions, and those delineated into (b) Br⋯Br, (c) O⋯H/H⋯O, (d) Br⋯H/H⋯Br, (e) H⋯C/C⋯H, (f) Br⋯C/C⋯Br, (g) Br⋯O/O⋯Br, (h) O⋯O, and (i) O⋯C/C⋯O interactions. The d_e and d_i values represent the closest external and internal distances (Å), respectively, from a given point on the Hirshfeld surface.

5. Database survey

A search of the Cambridge Structural Database (CSD version 6.01, September 2026 update; Groom et al., 2016 ) for the structures of lanthanide complexes incorporating Br₄bdc^2– ligands yielded 47 hits. Among these, thirteen structures, including SITROE and SITROE01 (Wei et al., 2014 ; Smith et al., 2019 ), BIQMAS, BIQMEW, BIQMIA, BIQMUM, BIQNAT, BIQNEX, BIQNIB, and BIQNOH (Smith et al., 2019), FECFOM, FECFUS, and FECGAZ (Jiajaroen et al., 2022), display concurrent μ₂-κO:κO′ and μ₃-κO:κO′:κO′′ coordination modes of the Br₄bdc^2– ligands to bind the Ln^III centres. Furthermore, the complexes BIQNUN, BIQPAV, BIQPEZ, BIQPID, and BIQPOJ (Smith et al., 2019) exclusively exhibit the μ₃-κO:κO′:κO′′ bridging mode, whereas NICZOQ (Lv et al., 2013a ), WIPXUQ, and WIPYAX (Lv et al., 2013b ) display only the μ₂-κO:κO′ coordination mode to bind the Ln^III cations.

6. Synthesis and crystallization

All starting materials and reagents were of analytical grade and were used as received without further purification. A mixture of Er(NO₃)₃·5H₂O (44.3 mg, 0.1 mmol) and H₂Br₄bdc (48.2 mg, 0.1 mmol) was dissolved in a solvent mixture of methanol (1 mL) and distilled water (3 mL) in a 15 mL Teflon-lined reactor. The mixture solution was stirred at room temperature for 10 min, sealed in stainless steel autoclave, and heated under autogenous pressure in a temperature-controlled oven at 373 K for 48 h. After the autoclave had cooled slowly to ambient temperature, the reaction mixture was filtered, and the filtrate was transferred to a glass vial. Slow evaporation of the mother liquor at room temperature over approximately one week yielded pink block-shaped crystals. Yield: 12.4 mg, 28% based on the Er(NO₃)₃·5H₂O.

7. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3. The hydrogen atoms were located from difference electron-density maps. H atoms bonded to O atoms were refined with distance restraints O—H = 0.84 ± 0.02 Å and with U_iso(H) = 1.5U_eq(O) for H9A/B and H10A/B and independently refined for eight other atoms.

Table 3
Experimental details

Crystal data
Chemical formula	[Er(C₈Br₄O₄)_1.5(H₂O)₃]·3H₂O
M_r	994.94
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	296
a, b, c (Å)	12.711 (5), 15.839 (6), 12.906 (5)
β (°)	113.171 (15)
V (Å³)	2388.9 (17)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	13.60
Crystal size (mm)	0.14 × 0.12 × 0.1

Data collection
Diffractometer	Bruker D8 QUEST CMOS PHOTON II
Absorption correction	Multi-scan (SADABS; Krause et al., 2015 )
T_min, T_max	0.571, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	98614, 5854, 5331
R_int	0.055
(sin θ/λ)_max (Å⁻¹)	0.664

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.019, 0.046, 1.17
No. of reflections	5854
No. of parameters	324
No. of restraints	17
H-atom treatment	Only H-atom coordinates refined
Δρ_max, Δρ_min (e Å⁻³)	0.50, −1.21
Computer programs: APEX6 and SAINT (Bruker, 2023 ), SHELXT2014/5 (Sheldrick, 2015a ), SHELXL2018/3 (Sheldrick, 2015b ) and OLEX2 (Dolomanov et al., 2009 ).

Supporting information

CCDC reference: 2595517

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989026010698/vm2337sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989026010698/vm2337Isup2.hkl

checkCIF report

Computing details top

Poly[[triaqua(µ₃-2,3,5,6-tetrabromobenzene-1,4-dicarboxylato)hemi(µ₂-2,3,5,6-tetrabromobenzene-1,4-dicarboxylato)erbium(III)] trihydrate] top

Crystal data top

[Er(C₈Br₄O₄)_1.5(H₂O)₃]·3H₂O	F(000) = 1832
M_r = 994.94	D_x = 2.766 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 12.711 (5) Å	Cell parameters from 8607 reflections
b = 15.839 (6) Å	θ = 3.1–28.1°
c = 12.906 (5) Å	µ = 13.60 mm⁻¹
β = 113.171 (15)°	T = 296 K
V = 2388.9 (17) Å³	Block, pink
Z = 4	0.14 × 0.12 × 0.1 mm

Data collection top

Bruker D8 QUEST CMOS PHOTON II diffractometer	5854 independent reflections
Radiation source: sealed x-ray tube	5331 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.055
Detector resolution: 7.39 pixels mm^-1	θ_max = 28.2°, θ_min = 3.1°
φ and ω scans	h = −16→16
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	k = −21→21
T_min = 0.571, T_max = 0.746	l = −17→17
98614 measured reflections

Refinement top

Refinement on F²	17 restraints
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F² > 2σ(F²)] = 0.019	Only H-atom coordinates refined
wR(F²) = 0.046	w = 1/[σ²(F_o²) + (0.0183P)² + 2.0786P] where P = (F_o² + 2F_c²)/3
S = 1.17	(Δ/σ)_max = 0.002
5854 reflections	Δρ_max = 0.50 e Å⁻³
324 parameters	Δρ_min = −1.21 e Å⁻³

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.

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

	x	y	z	U_iso*/U_eq
Er1	0.30558 (2)	0.53186 (2)	0.91422 (2)	0.01547 (4)
Br1	0.53394 (2)	0.20275 (2)	1.02462 (2)	0.02423 (7)
Br2	0.40531 (3)	0.04112 (2)	0.85749 (3)	0.02935 (7)
Br3	0.22167 (3)	0.26274 (2)	0.48667 (2)	0.02803 (7)
Br4	0.34474 (3)	0.42516 (2)	0.65020 (3)	0.03093 (7)
Br5	0.21775 (3)	0.60657 (2)	0.48962 (3)	0.03010 (7)
Br6	0.08858 (3)	0.45787 (2)	0.29799 (3)	0.03033 (7)
O1	0.4355 (2)	0.43322 (13)	0.91634 (18)	0.0320 (5)
O2	0.60068 (18)	0.37370 (14)	0.94057 (17)	0.0273 (5)
O3	0.16920 (18)	0.07189 (14)	0.5898 (2)	0.0306 (5)
O4	0.33523 (17)	0.05543 (13)	0.56882 (17)	0.0234 (4)
O5	0.18810 (17)	0.60262 (14)	0.76286 (17)	0.0274 (5)
O6	0.09196 (19)	0.70465 (13)	0.64610 (18)	0.0297 (5)
O7	0.42133 (19)	0.60002 (14)	0.83626 (18)	0.0256 (4)
H7A	0.406 (4)	0.6462 (18)	0.799 (3)	0.052 (13)*
H7B	0.4929 (17)	0.594 (3)	0.869 (3)	0.045 (12)*
O8	0.1619 (2)	0.56996 (15)	0.9707 (2)	0.0317 (5)
H8A	0.116 (3)	0.6106 (17)	0.961 (3)	0.031 (10)*
H8B	0.146 (4)	0.536 (2)	1.010 (3)	0.056 (14)*
O9	0.1742 (3)	0.42709 (17)	0.8218 (3)	0.0565 (9)
H9A	0.177 (3)	0.3743 (12)	0.821 (4)	0.085*
H9B	0.1023 (18)	0.429 (2)	0.783 (4)	0.085*
O10	0.0444 (3)	0.2919 (2)	0.7472 (3)	0.0723 (11)
H10A	0.021 (5)	0.274 (4)	0.680 (2)	0.108*
H10B	0.000 (4)	0.271 (4)	0.774 (4)	0.108*
O11	0.3362 (2)	0.7592 (2)	0.7251 (2)	0.0456 (7)
H11A	0.2668 (19)	0.753 (3)	0.713 (4)	0.057 (14)*
H11B	0.348 (5)	0.791 (3)	0.679 (4)	0.10 (2)*
O12	0.0093 (2)	0.69470 (16)	0.9489 (2)	0.0341 (5)
H12A	−0.045 (3)	0.664 (2)	0.948 (4)	0.045 (12)*
H12B	0.032 (4)	0.726 (3)	1.006 (3)	0.076 (17)*
C1	0.4937 (2)	0.37515 (17)	0.8996 (2)	0.0194 (5)
C2	0.4312 (2)	0.30194 (16)	0.8252 (2)	0.0159 (5)
C3	0.4444 (2)	0.21992 (16)	0.8697 (2)	0.0159 (5)
C4	0.3897 (2)	0.15226 (16)	0.8005 (2)	0.0174 (5)
C5	0.3237 (2)	0.16509 (16)	0.6859 (2)	0.0167 (5)
C6	0.3104 (2)	0.24731 (17)	0.6421 (2)	0.0183 (5)
C7	0.3628 (2)	0.31511 (16)	0.7112 (2)	0.0174 (5)
C8	0.2701 (2)	0.09094 (17)	0.6086 (2)	0.0179 (5)
C9	0.1154 (2)	0.62976 (18)	0.6702 (2)	0.0196 (5)
C10	0.0550 (2)	0.56271 (18)	0.5812 (2)	0.0194 (5)
C11	0.0911 (2)	0.54480 (18)	0.4947 (2)	0.0212 (6)
C12	0.0374 (2)	0.48307 (18)	0.4142 (2)	0.0206 (5)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Er1	0.01698 (6)	0.01306 (6)	0.01333 (6)	−0.00005 (4)	0.00272 (4)	0.00077 (4)
Br1	0.02666 (15)	0.02368 (14)	0.01605 (13)	0.00183 (11)	0.00162 (11)	0.00077 (10)
Br2	0.03810 (17)	0.01532 (13)	0.02970 (16)	0.00103 (12)	0.00805 (13)	0.00287 (11)
Br3	0.02991 (16)	0.03137 (16)	0.01536 (13)	−0.00545 (12)	0.00091 (11)	0.00117 (11)
Br4	0.04617 (19)	0.01730 (14)	0.02426 (15)	−0.00146 (13)	0.00843 (13)	0.00352 (11)
Br5	0.02511 (15)	0.03419 (17)	0.03360 (16)	−0.01130 (12)	0.01434 (13)	−0.00158 (13)
Br6	0.02646 (15)	0.04207 (18)	0.02597 (15)	−0.00518 (13)	0.01410 (12)	−0.00478 (13)
O1	0.0503 (15)	0.0217 (11)	0.0255 (11)	0.0102 (10)	0.0164 (10)	−0.0037 (9)
O2	0.0253 (11)	0.0292 (11)	0.0241 (10)	−0.0101 (9)	0.0062 (9)	−0.0075 (9)
O3	0.0215 (11)	0.0304 (12)	0.0410 (13)	−0.0077 (9)	0.0134 (10)	−0.0145 (10)
O4	0.0229 (10)	0.0239 (10)	0.0236 (10)	−0.0031 (8)	0.0093 (8)	−0.0105 (8)
O5	0.0223 (11)	0.0307 (11)	0.0192 (10)	−0.0027 (9)	−0.0025 (8)	0.0075 (8)
O6	0.0333 (12)	0.0235 (11)	0.0253 (11)	0.0019 (9)	0.0039 (9)	0.0034 (9)
O7	0.0238 (11)	0.0264 (11)	0.0267 (11)	0.0011 (9)	0.0101 (9)	0.0051 (9)
O8	0.0308 (12)	0.0286 (12)	0.0410 (13)	0.0127 (10)	0.0198 (11)	0.0143 (10)
O9	0.0589 (19)	0.0343 (15)	0.0499 (17)	−0.0264 (14)	−0.0068 (14)	0.0031 (13)
O10	0.094 (3)	0.075 (2)	0.0420 (17)	−0.057 (2)	0.0201 (17)	−0.0184 (16)
O11	0.0333 (15)	0.0563 (18)	0.0401 (15)	−0.0100 (13)	0.0067 (12)	0.0124 (13)
O12	0.0307 (13)	0.0340 (13)	0.0385 (14)	0.0013 (10)	0.0145 (11)	−0.0060 (11)
C1	0.0285 (15)	0.0143 (12)	0.0145 (12)	−0.0036 (11)	0.0075 (11)	−0.0018 (10)
C2	0.0153 (12)	0.0151 (12)	0.0170 (12)	0.0006 (9)	0.0058 (10)	−0.0041 (10)
C3	0.0151 (12)	0.0173 (12)	0.0141 (12)	0.0040 (10)	0.0044 (10)	−0.0013 (9)
C4	0.0189 (13)	0.0125 (12)	0.0206 (13)	0.0012 (10)	0.0076 (10)	−0.0001 (10)
C5	0.0174 (12)	0.0158 (12)	0.0168 (12)	−0.0017 (10)	0.0067 (10)	−0.0054 (10)
C6	0.0192 (13)	0.0202 (13)	0.0135 (12)	0.0000 (10)	0.0044 (10)	−0.0007 (10)
C7	0.0209 (13)	0.0142 (12)	0.0175 (12)	0.0010 (10)	0.0079 (10)	0.0003 (9)
C8	0.0193 (13)	0.0170 (12)	0.0157 (12)	−0.0014 (10)	0.0051 (10)	−0.0035 (10)
C9	0.0145 (12)	0.0249 (14)	0.0181 (13)	−0.0010 (10)	0.0049 (10)	0.0052 (11)
C10	0.0150 (12)	0.0217 (13)	0.0169 (13)	0.0010 (10)	0.0012 (10)	0.0045 (10)
C11	0.0153 (13)	0.0249 (14)	0.0219 (14)	−0.0029 (11)	0.0055 (11)	0.0042 (11)
C12	0.0192 (13)	0.0258 (14)	0.0158 (12)	−0.0005 (11)	0.0056 (10)	0.0046 (10)

Geometric parameters (Å, º) top

Er1—O1	2.266 (2)	O8—H8B	0.820 (19)
Er1—O2ⁱ	2.326 (2)	O9—H9A	0.837 (18)
Er1—O4ⁱⁱ	2.333 (2)	O9—H9B	0.852 (18)
Er1—O5	2.238 (2)	O10—H10A	0.845 (14)
Er1—O7	2.347 (2)	O10—H10B	0.842 (14)
Er1—O8	2.297 (2)	O11—H11A	0.838 (19)
Er1—O9	2.323 (3)	O11—H11B	0.84 (2)
Br1—C3	1.891 (3)	O12—H12A	0.848 (19)
Br2—C4	1.888 (3)	O12—H12B	0.835 (19)
Br3—C6	1.891 (3)	C1—C2	1.516 (4)
Br4—C7	1.889 (3)	C2—C3	1.404 (4)
Br5—C11	1.906 (3)	C2—C7	1.399 (4)
Br6—C12	1.898 (3)	C3—C4	1.394 (4)
O1—C1	1.251 (3)	C4—C5	1.398 (4)
O2—C1	1.250 (4)	C5—C6	1.403 (4)
O3—C8	1.245 (3)	C5—C8	1.518 (4)
O4—C8	1.265 (3)	C6—C7	1.387 (4)
O5—C9	1.265 (3)	C9—C10	1.531 (4)
O6—C9	1.233 (3)	C10—C11	1.394 (4)
O7—H7A	0.853 (19)	C10—C12ⁱⁱⁱ	1.401 (4)
O7—H7B	0.843 (19)	C11—C12	1.394 (4)
O8—H8A	0.841 (18)

O1—Er1—O2ⁱ	107.08 (8)	O1—C1—C2	118.3 (3)
O1—Er1—O4ⁱⁱ	73.11 (8)	O2—C1—O1	124.0 (3)
O1—Er1—O7	75.24 (9)	O2—C1—C2	117.7 (2)
O1—Er1—O8	147.57 (8)	C3—C2—C1	120.0 (2)
O1—Er1—O9	83.53 (11)	C7—C2—C1	120.4 (2)
O2ⁱ—Er1—O4ⁱⁱ	80.38 (8)	C7—C2—C3	119.6 (2)
O2ⁱ—Er1—O7	80.84 (8)	C2—C3—Br1	119.45 (19)
O4ⁱⁱ—Er1—O7	136.20 (8)	C4—C3—Br1	120.6 (2)
O5—Er1—O1	126.07 (8)	C4—C3—C2	120.0 (2)
O5—Er1—O2ⁱ	109.61 (8)	C3—C4—Br2	121.2 (2)
O5—Er1—O4ⁱⁱ	150.60 (8)	C3—C4—C5	120.5 (2)
O5—Er1—O7	73.20 (8)	C5—C4—Br2	118.37 (19)
O5—Er1—O8	78.73 (9)	C4—C5—C6	119.2 (2)
O5—Er1—O9	79.14 (9)	C4—C5—C8	120.7 (2)
O8—Er1—O2ⁱ	78.15 (9)	C6—C5—C8	120.1 (2)
O8—Er1—O4ⁱⁱ	76.44 (8)	C5—C6—Br3	118.34 (19)
O8—Er1—O7	136.54 (8)	C7—C6—Br3	121.1 (2)
O8—Er1—O9	81.35 (12)	C7—C6—C5	120.5 (2)
O9—Er1—O2ⁱ	155.44 (11)	C2—C7—Br4	119.9 (2)
O9—Er1—O4ⁱⁱ	81.79 (9)	C6—C7—Br4	119.9 (2)
O9—Er1—O7	123.64 (11)	C6—C7—C2	120.2 (2)
C1—O1—Er1	169.2 (2)	O3—C8—O4	127.0 (2)
C1—O2—Er1ⁱ	117.13 (18)	O3—C8—C5	118.5 (2)
C8—O4—Er1^iv	134.39 (18)	O4—C8—C5	114.5 (2)
C9—O5—Er1	169.8 (2)	O5—C9—C10	116.0 (2)
Er1—O7—H7A	127 (3)	O6—C9—O5	125.4 (3)
Er1—O7—H7B	118 (3)	O6—C9—C10	118.6 (2)
H7A—O7—H7B	109 (4)	C11—C10—C9	121.0 (2)
Er1—O8—H8A	137 (2)	C11—C10—C12ⁱⁱⁱ	118.3 (3)
Er1—O8—H8B	116 (3)	C12ⁱⁱⁱ—C10—C9	120.6 (2)
H8A—O8—H8B	107 (4)	C10—C11—Br5	118.2 (2)
Er1—O9—H9A	134 (2)	C12—C11—Br5	120.5 (2)
Er1—O9—H9B	132 (2)	C12—C11—C10	121.3 (3)
H9A—O9—H9B	94 (3)	C10ⁱⁱⁱ—C12—Br6	118.6 (2)
H10A—O10—H10B	106 (4)	C11—C12—Br6	121.1 (2)
H11A—O11—H11B	114 (5)	C11—C12—C10ⁱⁱⁱ	120.3 (3)
H12A—O12—H12B	111 (4)

Er1—O1—C1—O2	150.8 (10)	C1—C2—C7—Br4	−1.6 (4)
Er1—O1—C1—C2	−29.2 (13)	C1—C2—C7—C6	176.8 (2)
Er1ⁱ—O2—C1—O1	13.9 (4)	C2—C3—C4—Br2	−179.92 (19)
Er1ⁱ—O2—C1—C2	−166.12 (17)	C2—C3—C4—C5	1.6 (4)
Er1^iv—O4—C8—O3	19.4 (5)	C3—C2—C7—Br4	−179.82 (19)
Er1^iv—O4—C8—C5	−159.79 (18)	C3—C2—C7—C6	−1.4 (4)
Er1—O5—C9—O6	174.9 (9)	C3—C4—C5—C6	−1.9 (4)
Er1—O5—C9—C10	−6.6 (13)	C3—C4—C5—C8	176.1 (2)
Br1—C3—C4—Br2	−1.4 (3)	C4—C5—C6—Br3	179.5 (2)
Br1—C3—C4—C5	−179.9 (2)	C4—C5—C6—C7	0.6 (4)
Br2—C4—C5—C6	179.6 (2)	C4—C5—C8—O3	95.4 (3)
Br2—C4—C5—C8	−2.5 (3)	C4—C5—C8—O4	−85.4 (3)
Br3—C6—C7—Br4	0.6 (3)	C5—C6—C7—Br4	179.5 (2)
Br3—C6—C7—C2	−177.8 (2)	C5—C6—C7—C2	1.1 (4)
Br5—C11—C12—Br6	0.4 (3)	C6—C5—C8—O3	−86.7 (3)
Br5—C11—C12—C10ⁱⁱⁱ	179.4 (2)	C6—C5—C8—O4	92.6 (3)
O1—C1—C2—C3	−117.9 (3)	C7—C2—C3—Br1	−178.5 (2)
O1—C1—C2—C7	64.0 (4)	C7—C2—C3—C4	0.1 (4)
O2—C1—C2—C3	62.2 (3)	C8—C5—C6—Br3	1.5 (3)
O2—C1—C2—C7	−116.0 (3)	C8—C5—C6—C7	−177.4 (2)
O5—C9—C10—C11	−98.5 (3)	C9—C10—C11—Br5	−0.3 (4)
O5—C9—C10—C12ⁱⁱⁱ	80.6 (3)	C9—C10—C11—C12	179.1 (3)
O6—C9—C10—C11	80.1 (4)	C10—C11—C12—Br6	−179.1 (2)
O6—C9—C10—C12ⁱⁱⁱ	−100.8 (3)	C10—C11—C12—C10ⁱⁱⁱ	0.0 (5)
C1—C2—C3—Br1	3.3 (3)	C12ⁱⁱⁱ—C10—C11—Br5	−179.5 (2)
C1—C2—C3—C4	−178.1 (2)	C12ⁱⁱⁱ—C10—C11—C12	0.0 (5)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O7—H7A···O11	0.86 (3)	2.06 (3)	2.892 (4)	165 (5)
O7—H7B···O4^v	0.84 (3)	2.10 (3)	2.931 (4)	168 (4)
O8—H8A···O12	0.84 (3)	1.86 (3)	2.705 (4)	174 (3)
O8—H8B···O3ⁱⁱ	0.82 (4)	1.96 (3)	2.703 (3)	152 (5)
O9—H9A···O10	0.84 (2)	2.05 (4)	2.643 (5)	128 (4)
O10—H10A···O12^vi	0.85 (3)	2.00 (5)	2.808 (4)	160 (5)
O10—H10B···O6^vi	0.84 (5)	2.12 (6)	2.948 (5)	171 (6)
O11—H11A···O6	0.84 (3)	2.18 (4)	2.989 (4)	161 (5)
O11—H11B···O2^v	0.84 (5)	2.31 (5)	3.139 (4)	174 (6)
O12—H12A···O3^vii	0.84 (4)	2.06 (4)	2.879 (4)	164 (4)
O12—H12B···O6^viii	0.84 (4)	1.99 (4)	2.832 (3)	177 (4)

Symmetry codes: (ii) x, −y+1/2, z+1/2; (v) −x+1, y+1/2, −z+3/2; (vi) −x, y−1/2, −z+3/2; (vii) −x, y+1/2, −z+3/2; (viii) x, −y+3/2, z+1/2.

Br···X halogen-bond geometry (Å, °) top

C—Br···X	Br···X	C—Br···X	Type
C4—Br2···Br2ⁱ	3.7469 (14)	129.40 (7)	I
C6—Br3···Br6	3.8861 (11)	134.30 (8)	II
C7—Br4···Br2ⁱⁱ	3.7048 (13)	120.25 (8)	I
C7—Br4···Br5	3.5390 (15)	161.06 (8)	I
C11—Br5···Br1ⁱⁱ	3.5739 (15)	174.31 (9)	II
C3—Br1···O11ⁱⁱⁱ	3.054 (3)	160.04 (10)	I
C12—Br6···O3^iv	3.265 (3)	175.75 (9)	I

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

Acknowledgements

This project was partially supported by the Thammasat University Research Unit in Multifunctional Crystalline Materials and Applications (TU-MCMA).

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