Crystal structure and photoluminescent properties of a new EuIII-phthalate-acetate coordination polymer.

A new coordination polymer, poly[(acetato)aqua(μ3-phthalato)europium(III)], [Eu(C8H4O4)(CH3O2)(H2O)] n or [EuIII(phth)(OAc)(H2O)] (phth2- = phthalate and OAc- = acetate) was synthesized and characterized, revealing it to be a supra-molecular assembly of one-dimensional [EuIII(phth)(OAc)(H2O)] chains. Each chain is built up of edge-sharing distorted tricapped trigonal-prismatic TPRS-{EuIIIO9} building motifs and assembled in a regular fashion through hydrogen-bonding and aromatic π-π inter-actions. The fully deprotonated phth2- ligand was shown to be an effective sensitizer, promoting the characteristic 5 D 0→7 FJ (J = 1-4) emissions of EuIII even in the presence of the non-sensitizing OAc- group. © Jittipiboonwat et al. 2022.

Chemical context

Inter­est in crystal engineering of lanthanide coordination polymers has been driven by the unique coordination chemistry and electronic properties of trivalent lanthanides (Ln III), which bring about a wide variety of potential applications ranging from, for instance, luminescence sensing (Hasegawa & Kitagawa, 2022 ▸), magnetism (Hu et al., 2021 ▸), catalysis (Sinchow et al., 2021 ▸), gas storage and separation (Li & Chen, 2014 ▸), to drug delivery (Wei et al., 2020 ▸) and biomolecular imaging (Miller et al., 2016 ▸). However, the high coordination numbers, flexible coordination geometries and lack of directionality of Ln—O bonds complicate prediction of the designed polymeric frameworks, which are also greatly influenced by differences in synthetic parameters, i.e. reaction temperature and time, solvent, pH of reaction, etc (Bünzli, 2014 ▸; Qiu & Zhu, 2009 ▸). The study of structure–property relationships, which is an essence of property design, is consequently limited.

Unlike transition-metal-based coordination polymers in which the preferred coordination geometries of the transition-metal ions play an important role in directing the framework architecture (Kitagawa et al., 2004 ▸), those based on Ln III are principally governed by the organic ligands. Polycarb­oxy­lic acids are notably the most commonly utilized, facilitating diversity through their modes of coordination such as those found for phthalic acid (H2phth) (Fig. 1 ▸). These coordination modes can also be diversified through the presence of the other ligands such as those found in, for instance, [Ln II(bdc)0.5(phth)(H2O)2] (Ln III = EuIII, TbIII, HoIII, ErIII and TmIII, H2bdc = terephthalic acid; Chuasaard et al., 2020 ▸), [Ln III(abdc)0.5(phth)(H2O)2]·2H2O (Ln III = EuIII, GdIII and TbIII, H2abdc = azo­benzene-4,4′-di­carb­oxy­lic acid; Chuasaard et al., 2022 ▸) and [Ln III(ox)(phth)(H2O)2]·0.5H2O (Ln III = SmIII and TbIII, H2ox = oxalic acid; Wang et al., 2010 ▸).

Figure 1

Coordination modes of phth2− and Hphth− found in lanthanide coordination compounds deposited to the CSD (Groom et al., 2016 ▸) with frequency of appearance in parentheses.

With respect to photoluminescence, phth2− is acknowledged as a good sensitizer and can effectively promote f–f emissions in, for example, [EuIII 2(phth)3(H2O)] (Wan et al., 2002 ▸). The apparent photoluminescence can, nonetheless, be modulated by the other ligands such as ad2− in [Ln III(ad)0.5(phth)(H2O)2] (Chuasaard et al., 2018 ▸) and bdc2− in [Ln III(bdc)0.5(phth)(H2O)2] (Chuasaard et al., 2020 ▸).

Structural commentary

The asymmetric unit of the title compound, [EuIII(phth)(OAc)(H2O)], is composed of one crystallographically unique EuIII ion, a whole mol­ecule of phth2−, and the coordinating OAc− and water mol­ecules (Fig. 2 ▸). The EuIII ion is ninefold coordinated to O atoms from three phth2−, two OAc− and one water mol­ecule, which define a distorted tricapped trigonal–prismatic TPRS-{EuIIIO9} building motif. The Eu—O bond distances are in the range 2.352 (2)-2.605 (2) Å (Table 1 ▸), which are consistent with those reported for other EuIII frameworks of phth2− and OAc−, viz. [EuIII(abdc)0.5(phth)(H2O)2]·2H2O (Chuasaard et al., 2022 ▸), [EuIII(phth)(STP)] (NaSTP = sodium 2-(2,2′:6′,2′′-terpyridin-4′-yl)benzene­sulfonate; Hu et al., 2019 ▸) and [C2mim]2[Eu2(OAc)8] (C2mim = 1-ethyl-3-methyl­imidazolium; Bousrez et al., 2021 ▸). The TPRS-{EuIIIO9} motifs are fused through the μ 2-O atoms of phth2−, forming an infinite one-dimensional zigzag chain of edge-sharing TPRS-{EuIIIO9} motifs extending along the b-axis direction. Not only phth2−, which helps facilitating the formation of the one-dimensional chain through the overall μ3-η1:η2:η2:η1 mode of coordination (mode i in Fig. 1 ▸), but also the smaller OAc− link adjacent EuIII centers in a bridging μ2-η1:η1 coord­ination mode.

Figure 2

Extended asymmetric unit of the title compound drawn using 50% probability for ellipsoids (hydrogen atoms are omitted for clarity). Symmetry codes: (i)  − x,  + y,  − z; (ii)  − x, −  + y,  − z.

Table 1

Selected bond lengths (Å)

Eu1—O1i	2.570 (2)	Eu1—O4ii	2.605 (2)
Eu1—O1	2.397 (2)	Eu1—O5	2.352 (2)
Eu1—O2i	2.474 (2)	Eu1—O6i	2.434 (3)
Eu1—O3	2.381 (2)	Eu1—O7	2.446 (2)
Eu1—O3ii	2.484 (2)

Symmetry codes: (i) ; (ii) .

Supra­molecular features

The three-dimensional supra­molecular assembly of [EuIII(phth)(OAc)(H2O)] chains are facilitated by hydrogen bonding and aromatic π–π inter­actions (Fig. 3 ▸). The hydrogen-bonding inter­actions can be divided into the inter­chain O7—H7A⋯O4 and the intra­chain O7—H7B⋯O6 and C3—H3⋯O2 inter­actions (Table 2 ▸). The π–π inter­action between neighboring chains is considered to be of the displaced-stacking type (Banerjee et al., 2019 ▸; Yao et al., 2018 ▸), with an inter­planar angle of 0°, an offset distance of ca 1.0 Å and a centroid-to-centroid distance of ca 3.6 Å.

Figure 3

Depiction of (a) intra­chain and (b) inter­chain hydrogen-bonding inter­actions, and (c) π–π inter­actions.

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O7—H7A⋯O4iii	0.85	2.17	2.9384	149
O7—H7B⋯O6iv	0.85	2.28	3.0438	150
C3—H3⋯O2	0.93	2.46	2.7741	100

Symmetry codes: (iii) ; (iv) .

Photoluminescent properties

The emission spectrum of ground crystals of the title compound was recorded at room temperature. Upon the excitation at 370 nm, the characteristic red emission originating from the 5 D 0→7 F (J = 1–4) transitions of EuIII were displayed (Fig. 4 ▸). This indicates the efficiency of phth2− as a good sensitizer, even in the presence of the non-sensitizing OAc−. A split of the very intense 5 D 0→7 F 2 emission suggests that the EuIII ion is not located at a site with a center of symmetry (Binnemans, 2015 ▸), which is consistent with its distorted tricapped trigonal–prismatic coordination geometry. The split of the 5 D 0→7 F 4 emission, on the other hand, should be due to the ligand-field effect (Gupta et al., 2015 ▸; Okayasu & Yuasa, 2021 ▸; Puntus et al., 2010 ▸).

Figure 4

Room-temperature photoluminescent emission spectrum of the title compound.

Database survey

A search of the CSD database (CSD version 5.43, update of November 2021; Groom et al., 2016 ▸) using the ConQuest software (version 2021.3.0; Bruno et al., 2002 ▸), found 115 structures of lanthanide compounds including phth2−. In six of these structures, phth2− adopts the same μ3-η1:η2:η2:η1 mode of coordination as in the title compound. This mode of coordination apparently promotes the formation of a one-dimensional coordination framework, as, for example, in [Pr3(phen)2(phth)4(NO3)]·H2O (phen = 1,10-phenanthroline) (refcode: LAXWOX; Thirumurugan & Natarajan, 2005 ▸), [Nd(Nphgly)(phth)(H2O)]·2H2O (Nphgly = N-phthaloylglycine) (refcode: TOHJEH; Yang et al., 2014 ▸), and [Gd2Ni(2,5-pdc)2(phth)2(H2O)4]·8H2O (2,5-H2pdc = 2,5-pyridinedi­carb­oxy­lic acid) (refcode: XOZYER; Mahata et al., 2009 ▸).

Regarding OAc−, there are 566 structures containing this deposited in the CSD, none of which also contains phth2−. There are, however, structures containing both OAc− and isophthalate (iso-phth2−), e.g. [Sm2(iso-phth)2(OAc)2(H2O)4]·H2O (refcode: VOJNAK; Jin et al., 2008 ▸), and [Dy4(iso-phth)4(OAc)4(H2O)8]·2H2O (refcode: DIBZEU; Hu et al., 2007 ▸).

Synthesis and crystallization

All chemicals used in this work were obtained commercially and used without purification: Eu2O3 (Strategic Elements, 99.99%), phthalic acid (H2phth; C8H6O4, BDH laboratory, 99%), NaOH (RCI Labscan, 99.0%), glacial acetic acid (AcOH; CH3COOH, QRëC, 99.8%), tetra­hydro­furan (THF; C4H8O, RCI Labscan, 99.8%), ethanol (EtOH; C2H5OH, RCI Labscan, 99.7%). Eu(OAc)3·4H2O, was prepared by dissolving Eu2O3 (2.5000 g, 7.1038 mmol) in 50.0 mL of deionized water with a few drops of glacial acetic acid (HOAc). After the pH of the suspension was adjusted to 3 using HOAc, the mixture was gently heated and a colorless homogeneous solution was attained. The white powder of Eu(OAc)3·4H2O was then recovered through slow evaporation of the solvent.

To synthesize the title compound, Eu(OAc)3·4H2O (0.16 g, 0.40 mmol) was dissolved in 2.0 mL of deionized water to prepare solution A. Solution B was separately prepared by dissolving Na2phth (84 mg, 0.40 mmol) and NaOAc (33 mg, 0.4 mmol) in a mixed solvent prepared from 1.0 mL of deionized water and 5.0 mL of tetra­hydro­furan (THF). Solutions A and B were then mixed in a 15 mL glass vial. The volume of the reaction was adjusted to 10.0 mL using deionized water and the pH of the solution was adjusted to 4 using HOAc. The reaction was left under stirring at room temperature for 2 h, after which the solvent was slowly evaporated, leading to the crystallization of colorless block-shaped crystals of [Eu(phth)(OAc)(H2O)] (78% yield based on EuIII). The crystals were characterized using FT–IR spectroscopy (PerkinElmer/Frontier FT–IR instrument; ATR mode; cm−1): 3541(br), 3419(br), 2978(w), 1548(w), 1402(m), 1373(m), 804(s), 754(s), 707(s), 650(s), 543(m), 503(m). The room-temperature photoluminescent spectrum was collected using a ASEQ LR-1T broad-range spectrophotometer equipped with an Ultrafire G60 UV LED Flashlight Torch excitation source (5 W, 370 nm)

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3 ▸. All H atoms were positioned geometrically and refined isotropically using a riding model. The C—H bond lengths in the aromatic phth2− linker and in OAc− were restrained to 0.93 Å [U iso(H) = 1.2U eq(C)] and 0.96 Å [U iso(H) = 1.5U eq(C)], respectively. The O—H bond lengths in the coordinated water mol­ecule were restrained to 0.85 Å with U iso(H) = 1.5U eq(O).

Table 3

Experimental details

Crystal data
Chemical formula	[Eu(C8H4O4)(CH3O2)(H2O)]
M r	393.13
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	293
a, b, c (Å)	26.5184 (15), 7.2632 (2), 15.3622 (8)
β (°)	130.906 (9)
V (Å3)	2236.3 (3)
Z	8
Radiation type	Mo Kα
μ (mm−1)	5.63
Crystal size (mm)	0.2 × 0.1 × 0.1
Data collection
Diffractometer	Rigaku SuperNova, single source at offset/far, HyPix3000
Absorption correction	Multi-scan (CrysAlis PRO; Rigaku OD, 2019 ▸)
T min, T max	0.218, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	9923, 2393, 2138
R int	0.032
(sin θ/λ)max (Å−1)	0.648
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.024, 0.052, 1.05
No. of reflections	2393
No. of parameters	167
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	0.64, −0.79

Computer programs: CrysAlis PRO (Rigaku OD, 2019 ▸), SHELXT2018/2 (Sheldrick, 2015a ▸), SHELXL2018/3 (Sheldrick, 2015b ▸) and OLEX2 (Dolomanov et al., 2009 ▸).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989022004339/zn2019sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989022004339/zn2019Isup2.hkl

CCDC reference: 2168116

Additional supporting information: crystallographic information; 3D view; checkCIF report

[Eu(C8H4O4)(CH3O2)(H2O)]	F(000) = 1504
Mr = 393.13	Dx = 2.335 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 26.5184 (15) Å	Cell parameters from 7078 reflections
b = 7.2632 (2) Å	θ = 2.0–27.4°
c = 15.3622 (8) Å	µ = 5.63 mm−1
β = 130.906 (9)°	T = 293 K
V = 2236.3 (3) Å3	Block, clear light colourless
Z = 8	0.2 × 0.1 × 0.1 mm

Rigaku SuperNova, Single source at offset/far, HyPix3000 diffractometer	2393 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Mo) X-ray Source	2138 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.032
Detector resolution: 10.0000 pixels mm-1	θmax = 27.4°, θmin = 2.0°
ω scans	h = −33→33
Absorption correction: multi-scan (CrysAlisPro; Rigaku OD, 2019)	k = −9→9
Tmin = 0.218, Tmax = 1.000	l = −19→18
9923 measured reflections

Refinement on F2	Primary atom site location: dual
Least-squares matrix: full	Hydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.024	H-atom parameters constrained
wR(F2) = 0.052	w = 1/[σ2(Fo2) + (0.0235P)2 + 1.2859P] where P = (Fo2 + 2Fc2)/3
S = 1.05	(Δ/σ)max = 0.001
2393 reflections	Δρmax = 0.64 e Å−3
167 parameters	Δρmin = −0.79 e Å−3
1 restraint

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.

	x	y	z	Uiso*/Ueq
Eu1	0.75770 (2)	0.36927 (2)	0.71208 (2)	0.01709 (7)
O1	0.69745 (10)	0.1993 (3)	0.7522 (2)	0.0219 (5)
O4	0.68510 (12)	0.6542 (3)	0.8366 (2)	0.0264 (6)
O3	0.68174 (10)	0.5756 (3)	0.69468 (19)	0.0185 (5)
O6	0.69030 (12)	−0.0954 (3)	0.5869 (2)	0.0290 (6)
O2	0.62648 (11)	−0.0281 (3)	0.6844 (2)	0.0273 (6)
O7	0.72235 (14)	0.5336 (4)	0.5410 (2)	0.0422 (7)
H7A	0.697069	0.483288	0.474914	0.063*
H7B	0.708422	0.643920	0.528604	0.063*
O5	0.67155 (11)	0.2044 (3)	0.5460 (2)	0.0308 (6)
C7	0.59568 (15)	0.4602 (4)	0.6922 (3)	0.0185 (7)
C2	0.58415 (15)	0.2718 (4)	0.6633 (3)	0.0185 (7)
C8	0.65937 (15)	0.5624 (4)	0.7479 (3)	0.0181 (7)
C9	0.66224 (16)	0.0380 (5)	0.5165 (3)	0.0257 (8)
C1	0.63844 (17)	0.1403 (4)	0.7002 (3)	0.0196 (8)
C10	0.61510 (19)	−0.0007 (5)	0.3902 (3)	0.0412 (10)
H10A	0.616586	−0.129448	0.377789	0.062*
H10B	0.627783	0.070141	0.354452	0.062*
H10C	0.570626	0.032152	0.357152	0.062*
C6	0.54332 (17)	0.5698 (5)	0.6621 (3)	0.0282 (8)
H6	0.551117	0.692945	0.683999	0.034*
C3	0.52024 (16)	0.2027 (5)	0.6028 (3)	0.0257 (8)
H3	0.512351	0.077936	0.585067	0.031*
C4	0.46810 (17)	0.3156 (5)	0.5685 (3)	0.0301 (9)
H4	0.425093	0.268326	0.524046	0.036*
C5	0.47994 (17)	0.4983 (5)	0.6002 (3)	0.0318 (9)
H5	0.445276	0.573408	0.579933	0.038*

	U11	U22	U33	U12	U13	U23
Eu1	0.01881 (11)	0.01068 (11)	0.02213 (12)	0.00003 (6)	0.01356 (9)	−0.00015 (6)
O1	0.0190 (12)	0.0157 (11)	0.0322 (14)	0.0006 (10)	0.0173 (11)	0.0032 (11)
O4	0.0294 (14)	0.0245 (14)	0.0270 (14)	−0.0045 (10)	0.0191 (12)	−0.0049 (11)
O3	0.0205 (12)	0.0112 (11)	0.0261 (13)	−0.0006 (9)	0.0162 (11)	0.0012 (10)
O6	0.0311 (14)	0.0253 (14)	0.0243 (14)	0.0014 (11)	0.0154 (12)	0.0038 (11)
O2	0.0255 (13)	0.0127 (12)	0.0439 (15)	−0.0017 (10)	0.0228 (12)	−0.0027 (11)
O7	0.0635 (19)	0.0265 (15)	0.0297 (15)	−0.0021 (14)	0.0275 (15)	0.0026 (12)
O5	0.0299 (14)	0.0218 (13)	0.0312 (14)	−0.0048 (11)	0.0158 (12)	−0.0053 (11)
C7	0.0202 (17)	0.0164 (17)	0.0204 (17)	0.0005 (13)	0.0139 (15)	0.0027 (14)
C2	0.0191 (17)	0.0157 (17)	0.0214 (17)	0.0006 (13)	0.0136 (15)	0.0012 (14)
C8	0.0174 (16)	0.0097 (16)	0.0256 (18)	0.0063 (13)	0.0135 (15)	0.0054 (14)
C9	0.0231 (18)	0.028 (2)	0.0270 (19)	−0.0079 (16)	0.0168 (17)	−0.0048 (17)
C1	0.0243 (19)	0.0166 (18)	0.0210 (19)	0.0015 (13)	0.0161 (16)	0.0041 (13)
C10	0.049 (3)	0.037 (2)	0.023 (2)	−0.0107 (19)	0.017 (2)	−0.0014 (18)
C6	0.029 (2)	0.0200 (18)	0.041 (2)	0.0016 (16)	0.0257 (18)	0.0003 (17)
C3	0.0239 (18)	0.0208 (18)	0.0279 (19)	−0.0018 (15)	0.0149 (16)	0.0013 (16)
C4	0.0168 (18)	0.033 (2)	0.035 (2)	−0.0030 (16)	0.0143 (17)	0.0025 (18)
C5	0.0228 (19)	0.027 (2)	0.044 (2)	0.0075 (15)	0.0213 (18)	0.0055 (18)

Eu1—O1i	2.570 (2)	Eu1—O4ii	2.605 (2)
Eu1—O1	2.397 (2)	Eu1—O5	2.352 (2)
Eu1—O2i	2.474 (2)	Eu1—O6i	2.434 (3)
Eu1—O3	2.381 (2)	Eu1—O7	2.446 (2)
Eu1—O3ii	2.484 (2)
O1—Eu1—Eu1i	100.62 (6)	Eu1—O3—Eu1i	107.20 (8)
O1i—Eu1—Eu1i	36.44 (5)	C8—O3—Eu1i	95.16 (19)
O1—Eu1—O1i	135.94 (6)	C8—O3—Eu1	126.05 (19)
O1—Eu1—O4ii	112.11 (8)	C9—O6—Eu1ii	133.7 (2)
O1i—Eu1—O4ii	110.21 (7)	C1—O2—Eu1ii	96.9 (2)
O1—Eu1—O3ii	72.40 (7)	Eu1—O7—H7A	121.4
O1—Eu1—O6i	69.36 (8)	Eu1—O7—H7B	120.3
O1—Eu1—O2i	138.23 (8)	H7A—O7—H7B	104.5
O1—Eu1—O7	132.57 (9)	C9—O5—Eu1	134.6 (2)
O4ii—Eu1—Eu1i	146.65 (5)	C2—C7—C8	126.3 (3)
O3—Eu1—Eu1i	37.29 (5)	C6—C7—C2	119.2 (3)
O3ii—Eu1—Eu1i	141.16 (5)	C6—C7—C8	114.4 (3)
O3—Eu1—O1i	71.11 (7)	C7—C2—C1	123.0 (3)
O3—Eu1—O1	72.28 (8)	C3—C2—C7	118.7 (3)
O3ii—Eu1—O1i	130.07 (7)	C3—C2—C1	118.3 (3)
O3ii—Eu1—O4ii	51.12 (7)	O4—C8—Eu1i	63.93 (18)
O3—Eu1—O4ii	162.55 (8)	O4—C8—O3	120.3 (3)
O3—Eu1—O3ii	141.75 (4)	O4—C8—C7	119.7 (3)
O3—Eu1—O6i	79.11 (8)	O3—C8—Eu1i	58.54 (16)
O3—Eu1—O2i	119.05 (7)	O3—C8—C7	119.3 (3)
O3—Eu1—O7	82.61 (9)	C7—C8—Eu1i	156.5 (2)
O6i—Eu1—Eu1i	66.91 (5)	O6—C9—C10	119.2 (3)
O6i—Eu1—O1i	80.35 (8)	O5—C9—O6	124.1 (3)
O6i—Eu1—O4ii	118.34 (8)	O5—C9—C10	116.7 (3)
O6i—Eu1—O3ii	75.15 (8)	O1—C1—Eu1ii	62.34 (16)
O6i—Eu1—O2i	73.70 (8)	O1—C1—C2	120.2 (3)
O6i—Eu1—O7	144.26 (8)	O2—C1—Eu1ii	57.86 (16)
O2i—Eu1—Eu1i	81.77 (5)	O2—C1—O1	120.1 (3)
O2i—Eu1—O1i	51.37 (7)	O2—C1—C2	119.6 (3)
O2i—Eu1—O4ii	69.76 (7)	C2—C1—Eu1ii	174.1 (2)
O2i—Eu1—O3ii	79.99 (7)	C9—C10—H10A	109.5
O7—Eu1—Eu1i	79.97 (7)	C9—C10—H10B	109.5
O7—Eu1—O1i	64.69 (8)	C9—C10—H10C	109.5
O7—Eu1—O4ii	82.51 (9)	H10A—C10—H10B	109.5
O7—Eu1—O3ii	133.38 (9)	H10A—C10—H10C	109.5
O7—Eu1—O2i	89.12 (9)	H10B—C10—H10C	109.5
O5—Eu1—Eu1i	125.35 (6)	C7—C6—H6	119.5
O5—Eu1—O1	71.29 (8)	C5—C6—C7	120.9 (3)
O5—Eu1—O1i	133.75 (8)	C5—C6—H6	119.5
O5—Eu1—O4ii	73.60 (8)	C2—C3—H3	119.3
O5—Eu1—O3	92.82 (8)	C4—C3—C2	121.3 (3)
O5—Eu1—O3ii	89.44 (7)	C4—C3—H3	119.3
O5—Eu1—O6i	140.44 (9)	C3—C4—H4	120.1
O5—Eu1—O2i	139.98 (8)	C5—C4—C3	119.8 (3)
O5—Eu1—O7	70.49 (9)	C5—C4—H4	120.1
Eu1—O1—Eu1ii	104.00 (8)	C6—C5—H5	120.0
C1—O1—Eu1ii	91.53 (18)	C4—C5—C6	119.9 (3)
C1—O1—Eu1	139.6 (2)	C4—C5—H5	120.0
C8—O4—Eu1i	90.7 (2)
Eu1—O1—C1—Eu1ii	113.9 (3)	C7—C2—C3—C4	1.7 (5)
Eu1ii—O1—C1—O2	−3.0 (3)	C7—C6—C5—C4	0.7 (6)
Eu1—O1—C1—O2	110.9 (3)	C2—C7—C8—Eu1i	140.5 (5)
Eu1ii—O1—C1—C2	174.0 (3)	C2—C7—C8—O4	−127.1 (3)
Eu1—O1—C1—C2	−72.1 (4)	C2—C7—C8—O3	62.7 (4)
Eu1i—O4—C8—O3	16.5 (3)	C2—C7—C6—C5	−2.9 (5)
Eu1i—O4—C8—C7	−153.6 (2)	C2—C3—C4—C5	−3.9 (5)
Eu1—O3—C8—Eu1i	115.7 (2)	C8—C7—C2—C1	8.9 (5)
Eu1—O3—C8—O4	98.2 (3)	C8—C7—C2—C3	−174.4 (3)
Eu1i—O3—C8—O4	−17.4 (3)	C8—C7—C6—C5	173.7 (3)
Eu1—O3—C8—C7	−91.6 (3)	C1—C2—C3—C4	178.4 (3)
Eu1i—O3—C8—C7	152.8 (2)	C6—C7—C2—C1	−174.9 (3)
Eu1ii—O6—C9—O5	21.5 (5)	C6—C7—C2—C3	1.7 (5)
Eu1ii—O6—C9—C10	−158.7 (3)	C6—C7—C8—Eu1i	−35.8 (7)
Eu1ii—O2—C1—O1	3.1 (3)	C6—C7—C8—O4	56.7 (4)
Eu1ii—O2—C1—C2	−173.9 (3)	C6—C7—C8—O3	−113.6 (3)
Eu1—O5—C9—O6	23.5 (5)	C3—C2—C1—O1	177.3 (3)
Eu1—O5—C9—C10	−156.3 (3)	C3—C2—C1—O2	−5.7 (5)
C7—C2—C1—O1	−6.1 (5)	C3—C4—C5—C6	2.7 (5)
C7—C2—C1—O2	170.9 (3)

D—H···A	D—H	H···A	D···A	D—H···A
O7—H7A···O4iii	0.85	2.17	2.9384	149
O7—H7B···O6iv	0.85	2.28	3.0438	150
C3—H3···O2	0.93	2.46	2.7741	100