One-dimensional ladder gallium coordination polymer

A one-dimensional ladder-type coordination polymer, poly[[(μ₂-hydroxido)(μ₂-1H-pyrazole-3,5-di­carboxyl­ato)gallium(III)] monohydrate], [Ga(C₅H₂N₂O₄)(OH)(H₂O)]_n or [Ga(HPDC)(OH)(H₂O)]_n, I, isotypic with a V³⁺ coordination polymer previously reported by Chen et al. [J. Coord. Chem. (2008). 61, 3556–3567] was prepared from Ga³⁺ and pyrazole-3,5-di­carb­oxy­lic acid monohydrate (H₃PDC·H₂O). Compound I was isolated using three distinct experimental methods: hydro­thermal (HT), microwave-assisted (MWAS) and one-pot (OP) and the crystallite size should be fine-tuned according to the method employed. The coordination polymeric structure is based on a dimeric Ga³⁺ moiety comprising two μ₂-bridging hydroxide groups, which are inter­connected by HPDC²⁻ anionic organic linkers. The close packing of individual polymers is strongly directed by the supra­molecular inter­actions, namely several O—H⋯O and N—H⋯O hydrogen-bonding inter­actions.

1. Chemical Context

Research on coordination polymers (CPs) and metal–organic frameworks (MOFs) remains a topical area in chemistry, particularly the study of their crystal structures (Cui et al., 2016). These crystalline materials are typically obtained from a combination of metal ions and organic mol­ecules, giving rise to one-, two- or three-dimensional structures (Chaplais et al., 2009). A wide variety of synthetic methods have been reported for the preparation of CPs/MOFs (Stock & Biswas, 2012; Yuan et al., 2018) ranging from ambient-temperature synthesis to conventional [hydro­thermal (HT) and one-pot processes (OP)] and microwave (MWAS) synthesis. In addition, other less common techniques such as electrochemistry (EC), mechanochemistry (MC) and ultrasonic (US) synthesis can be used (Rubio-Martinez et al., 2017; Stock & Biswas, 2012).

A large number of MOF-containing divalent transition-metal ions have been described (Stock & Biswas, 2012; Devic & Serre, 2014). Examples of CPs/MOFs containing main-group elements, such as Al³⁺, Ga³⁺, or In³⁺, remain scarce (Stock, 2014). A search in the Cambridge Structural Database unveils around 100 Ga³⁺-bearing CP/MOF structures, for example. Remarkably, most of these structures were solved using powder X-ray diffraction (PXRD) techniques (Reinsch & De Vos, 2014; Volkringer et al., 2009). Such materials exhibit high thermal and chemical stability and are ideal candidates for a wide variety of applications (Silva et al., 2015; Yuan et al., 2018; Ajoyan et al., 2018; Howarth et al., 2016). As a result of the close similarity of the coordination chemistry of gallium and aluminium, most of the Ga³⁺-CP/MOFs published are isotypic with well-known Al³⁺-CP/MOFs, and also with the much rarer In³⁺-CP/MOFs (Schilling et al., 2016). This may, in part, explain why most of the studies found in the literature of Ga³⁺-CP/MOFs report only their structures. Furthermore, most of the applications that have been studied are related to those that are also found for Al³⁺-CP/MOFs (Banerjee et al., 2011; Zhang et al., 2018; Reinsch & De Vos, 2014; Canivet et al., 2014; Zhou et al., 2012). For certain applications, Ga³⁺-CP/MOFs excel, even surpassing the performance of the Al³⁺-CP/MOFs (Coudert et al., 2014; Ramaswamy et al., 2017; Weber et al., 2016; Gao et al., 2014). Furthermore, gallium materials possess low toxicity and are found in applications such as gas and water adsorption, shock-absorber technology and semiconductors (Ramaswamy et al., 2017; Coudert et al., 2014; Schilling et al., 2016)

Following our inter­est in CP/MOFs, we have attempted the preparation of MOF-303 (Fathieh et al., 2018) with Ga³⁺. In this crystallographic report we describe these studies, which culminated in the isolation of a compact one-dimensional ladder coordination polymer, [Ga(HPDC)(OH)(H₂O)] (I), prepared by the self-assembly of Ga³⁺ and the organic linker 3,5-pyrazoledi­carb­oxy­lic acid monohydrate (H₃PDC·H₂O). Compound I was obtained using a variety of methods (hydro­thermal, microwave and a one-pot process) and a survey of the literature revealed that it is isotypic with a compound published in 2008 (Chen et al., 2008), which is not unprecedented (Volkringer et al., 2009; Finsy et al., 2009; Volkringer et al., 2008).

2. Crystal Morphology and Characterization

Compound I was prepared by hydro­thermal (HT), microwave (MWAS) and one-pot (OP) synthesis. The general experimental conditions were similar (solvent, molar qu­anti­ties and temperature). The compound is isotypic with [V(HPDC)(OH)(H₂O)] (Chen et al., 2008), which was prepared using harsher conditions. Our attempts to obtain the analogous V³⁺-bearing material using the conditions described here were unsuccessful.

MWAS produces phase pure coordination polymers much faster than the HT and OP approaches. PXRD studies have confirmed the same structural features (see Figure S1 in the supporting information). The crystal morphology, however, varied depending on the method employed (Fig. 1). Crystals typically exhibit irregular shapes. MWAS allowed a faster preparation of I when compared to the other methods (a reduction from 24 h to just 1 h) with a significantly smaller average crystal size (ca 3–5 µm) and a more uniform plate-like morphology. The HT method, on the other hand, afforded larger crystals (ca 15–65 µm) with a more block-type morphology, while the OP method resulted mainly in agglomerated particles with a plate-like morphology.

Figure 1 Scanning electron microscopy (SEM) images of bulk [Ga(HPDC)(OH)(H2O)] (I) obtained by microwave-assisted synthesis (MWAS), hydro­thermal synthesis (HT) and a one-pot process (OP).

FT–IR spectroscopy supports the structural features revealed by the X-ray diffraction studies (Figure S2 in the supporting information). Compound I exhibits two broad bands centred at 3280 and 3159 cm⁻¹ attributed to the O—H stretching vibrational modes from the coordinated water mol­ecules and to the N—H stretching vibrations of the pyrazole ring. In the central region of the spectrum, between ca 1700 and 1300 cm⁻¹, it is possible to discern the typical C—O, C—C and C—N stretching vibrational modes arising from the pyrazole rings and the bending vibration of water mol­ecules.

The materials showed similar thermal decomposition profiles between ambient temperature and ca 1000 K (Figure S3 in the supporting information). Between ambient temperature and ca 548 K, there is almost no weight loss, which is indicative of good thermal stability. The weight loss registered between ca 548 and 618 K is 14.9, 14.6 and 14.8% for the OP-, HT- and MWAS-derived materials, respectively, and is attributed to the release of the water of coordination and the decomposition of the hydroxyl group (theoretical weight loss 14.0%). The subsequent weight loss (ca 44.9%) is attributed to the decomposition of the ligand, resulting in the formation of Ga₂O₃.

3. Structural Commentary

Compound I was formulated by single-crystal X-ray diffraction as [Ga(HPDC)(OH)(H₂O)] from a crystal obtained using hydro­thermal synthetic conditions (see Experimental section for further details). This compound crystallizes in the centrosymmetric P space group with the asymmetric unit being composed of one Ga³⁺ metal centre, one HPDC²⁻ anionic organic linker, one hydroxyl group and one coordin­ated water mol­ecule, as depicted in Fig. 2a.

Figure 2 (a) Schematic representation of the asymmetric unit of [Ga(HPDC)(OH)(H2O)] (I) showing all non-H atoms shown with displacement ellipsoids drawn at the 50% probability level and H atoms as small spheres with arbitrary radii. The coordination sphere of the crystallographically independent metal centre was completed by generating the remaining atoms through symmetry. [Symmetry codes: (i) −x, −y, −z + 2; (ii) x, y, z + 1 (b) Ga^3+ dimer formed by two symmetry-related bridging hydroxyl groups.

The anionic organic linker HPDC²⁻ has two distinct coord­ination modes: forming a N,O-chelate with the crystallographically independent Ga³⁺ metal centre [bite angle of 78.02 (11)°], and bridging with an adjacent metal centre through a syn inter­action involving the carboxyl­ate group, imposing a Ga⋯Ga inter­metallic distance of ca 8.52 Å (i.e. the length of the c axis of the unit cell). The octa­hedral {GaNO₅} coordination sphere is completed by one water mol­ecule and two-symmetry related μ₂-bridging hydroxyl groups, which are the responsible for the formation of a centrosymmetric dimer, as depicted in Fig. 2b (inter­metallic distance of ca 2.97 Å).

The Ga—O bond lengths range between 1.903 (3) and 1.988 (3) Å and the Ga—N distance is 2.112 (3) Å (Table 1), in good agreement with those reported for other carboxyl­ate-based materials as witnessed by a search in the Cambridge Structural Database (CSD version of 2019; Groom et al., 2016): mean value of 1.988 Å for the Ga—O bond (CSD range, 1.832–2.475 Å) and 2.023 Å for the Ga—N bond (CSD range 1.798–3.275 Å).

Table 1
Selected geometric parameters (Å, °)

Ga1—O1	1.903 (3)	Ga1—O2^ii	1.987 (3)
Ga1—O5	1.932 (3)	Ga1—O1W	1.988 (3)
Ga1—O1^i	1.974 (3)	Ga1—N2^ii	2.112 (3)
O1—Ga1—O5	101.59 (12)	O1^i—Ga1—O1W	178.65 (12)
O1—Ga1—O1^i	79.94 (13)	O2^ii—Ga1—O1W	91.00 (11)
O5—Ga1—O1^i	93.13 (12)	O1—Ga1—N2^ii	93.94 (12)
O1—Ga1—O2^ii	166.31 (11)	O5—Ga1—N2^ii	164.18 (12)
O5—Ga1—O2^ii	87.28 (11)	O1^i—Ga1—N2^ii	92.49 (12)
O1^i—Ga1—O2^ii	89.26 (11)	O2^ii—Ga1—N2^ii	78.02 (11)
O1—Ga1—O1W	99.60 (12)	O1W—Ga1—N2^ii	86.27 (12)
O5—Ga1—O1W	88.20 (12)
Symmetry codes: (i) -x, -y, -z+2; (ii) x, y, z+1.

The aforementioned connectivity promotes the formation of a one-dimensional ladder-type coordination polymer along the [001] direction (Fig. 3a), which close pack in a parallel fashion in the ab plane of the unit cell mediated by various supra­molecular contacts (see the following section). Although the organic linkers are stacked within these ladders, the inter-centroid distance is 4.442 (3) Å, indicating the absence of significant π–π supra­molecular inter­actions.

Figure 3 Schematic representation of the (a) one-dimensional ladder-type coordination polymer present in I, and (b) the close packing of the polymers viewed along the [010] direction of the unit cell.

4. Supra­molecular Features

Compound I contains several functional groups that can promote the formation of various hydrogen-bonding inter­actions (Fig. 4, Table 2). The coordinated water mol­ecule is engaged in two strong and directional O—H⋯O hydrogen-bonding inter­actions with neighbouring carboxyl­ate groups from adjacent one-dimensional chains: d_D⋯A distances of 2.643 (4) and 2.803 (4) Å and <(DHA) angles in the 164–165° range (Fig. 4, Table 2). These inter­actions may be described by the graph set motifs, R₂²(12) and R₂²(20). The independent μ₂-bridging hydroxyl group also donates a hydrogen atom to a neighbouring carbonyl group (from the N,O-chelated moiety) in a strong inter­action: d_D⋯A distance of 2.751 (4) Å and <(DHA) angle of 175°. This contact leads to the formation of a supra­molecular chain C₁¹(10) across neighbouring polymers. Like the μ₂-bridging hydroxyl group, the pyrazole ring is involved in a N—H⋯O inter­action with a N,O-chelated ligand, leading to the formation of a distinct type of supra­molecular chain, C₁¹(6) [d_D⋯A distance of 2.773 (4) Å and <(DHA) angle of 152°].

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1X⋯O4^iii	0.94	1.73	2.643 (4)	164
O1W—H1Y⋯O2^iv	0.94	1.89	2.803 (4)	165
O1—H1⋯O3^v	0.77	1.99	2.751 (4)	175
N1—H1N⋯O3^vi	0.88	1.96	2.773 (4)	152
Symmetry codes: (iii) -x+1, -y, -z+2; (iv) -x+1, -y+1, -z+1; (v) x, y-1, z+1; (vi) x, y-1, z.

Figure 4 Schematic representation of a portion of the crystal packing of [Ga(HPDC)(OH)(H2O)] (I) depicting the O—H⋯O and N—H⋯O supra­molecular contacts (orange dashed lines) between ladder-type polymers. For geometrical details on the represented inter­actions see Table 2 (the symmetry codes used to generate equivalent atoms have been omitted for clarity).

These supra­molecular inter­actions lead to a close packing of individual polymers and to a compact crystal structure of I, as shown in Fig. 5.

Figure 5 Crystal packing of [Ga(HPDC)(OH)(H2O)] (I) viewed along the [001] direction of the unit cell.

5. Synthesis and Crystallization Procedures

Chemicals were purchased from commercial sources (Merck and TCI) and used without any further purification. The methods and molar qu­anti­ties described here were based on a methodology described by Yaghi and coworkers for the preparation of MOF-303 (Fathieh et al., 2018).

Compound I was prepared by dissolving 147 mg (0.57 mmol) of gallium nitrate hexa­hydrate (Ga(NO₃)₃·6H₂O) and 100 mg (0.57 mmol) of 3,5-pyrazoledi­carb­oxy­lic acid monohydrate (H₃PDC·H₂O) in 9.6 mL of water in the corres­ponding vessel (autoclave for hydro­thermal synthesis, microwave vial for microwave synthesis and a round-bottom flask equipped with a condenser for the one-pot approach). Subsequently, the vessels were heated at 373 K for 24 h (hydro­thermal and one-pot synthesis) or 1 h (microwave synthesis). The resulting white precipitates were separated by filtration, washed three times with water and three times with ethanol, and dried overnight at ambient temperature (yields: 49, 47 and 60% for the one-pot, hydro­thermal and microwave-assisted syntheses, respectively).

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3. Hydrogen atoms bound to carbon and nitro­gen were placed at idealized positions using the HFIX 43 instruction in SHELXL2018/3 and included in subsequent refinement with C—H = 0.95 Å and N—H = 0.88 Å with the isotropic thermal displacement parameters fixed at 1.2U_eq of the atom to which they are attached.

Table 3
Experimental details

Crystal data
Chemical formula	[Ga(C5H2N2O4)(OH)(H2O)]
Mr	258.83
Crystal system, space group	Triclinic, P
Temperature (K)	150
a, b, c (Å)	6.6055 (13), 6.8830 (16), 8.5178 (19)
α, β, γ (°)	94.804 (8), 101.306 (7), 108.596 (7)
V (Å^3)	355.44 (14)
Z	2
Radiation type	Mo Kα
μ (mm^−1)	3.88
Crystal size (mm)	0.13 × 0.10 × 0.07
Data collection
Diffractometer	Bruker D8 QUEST
Absorption correction	Multi-scan (SADABS; Bruker, 2001; Krause et al. 2015)
No. of measured, independent and observed [I > 2σ(I)] reflections	5768, 1303, 1182
Rint	0.034
(sin θ/λ)max (Å^−1)	0.603
Refinement
R[F^2 > 2σ(F^2)], wR(F^2), S	0.031, 0.074, 1.11
No. of reflections	1303
No. of parameters	136
No. of restraints	3
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å^−3)	0.65, −0.47
Computer programs: APEX3 (Bruker, 2016), SAINT (Bruker, 2015), SHELXT2014 (Sheldrick, 2015a), SHELXL2018 (Sheldrick, 2015b), PLATON (Spek, 2009) and DIAMOND (Brandenburg, 1999).

Hydrogen atoms from the coordinated water mol­ecule and the hydroxyl group were directly located from difference-Fourier maps and included in the final structural models with the O—H and H⋯H distances restrained to 0.95 (1) and 1.55 (1) Å, respectively, in order to ensure a chemically reasonable environment. These hydrogen atoms were modelled with the isotropic thermal displacement parameters fixed at 1.5U_eq(O).

Supporting information

Computing details

Data collection: APEX3 (Bruker, 2016); cell refinement: SAINT (Bruker, 2015); data reduction: SAINT (Bruker, 2015); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2018 (Sheldrick, 2015b); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXL2018 (Sheldrick, 2015b) and PLATON (Spek, 2009).

Poly[[(µ₂-hydroxido)(µ₂-1H-pyrazole-3,5-dicarboxylato)gallium(III)] monohydrate]

Crystal data

[Ga(C5H2N2O4)(OH)(H2O)]	Z = 2
Mr = 258.83	F(000) = 256
Triclinic, P1	Dx = 2.418 Mg m^−3
a = 6.6055 (13) Å	Mo Kα radiation, λ = 0.71073 Å
b = 6.8830 (16) Å	Cell parameters from 3255 reflections
c = 8.5178 (19) Å	θ = 2.5–25.4°
α = 94.804 (8)°	µ = 3.88 mm^−1
β = 101.306 (7)°	T = 150 K
γ = 108.596 (7)°	Block, colourless
V = 355.44 (14) Å^3	0.13 × 0.10 × 0.07 mm

Data collection

Bruker D8 QUEST diffractometer	1303 independent reflections
Radiation source: Sealed tube	1182 reflections with I > 2σ(I)
Multi-layer X-ray mirror monochromator	Rint = 0.034
Detector resolution: 10.4167 pixels mm^-1	θmax = 25.4°, θmin = 3.7°
ω / φ scans	h = −7→7
Absorption correction: multi-scan (SADABS; Bruker, 2001; Krause et al. 2015)	k = −8→8
	l = −10→10
5768 measured reflections

Refinement

Refinement on F^2	3 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.031	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.074	w = 1/[σ^2(Fo^2) + (0.0292P)^2 + 1.2151P] where P = (Fo^2 + 2Fc^2)/3
S = 1.11	(Δ/σ)max = 0.001
1303 reflections	Δρmax = 0.65 e Å^−3
136 parameters	Δρmin = −0.47 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.

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

	x	y	z	Uiso*/Ueq
Ga1	0.20874 (7)	0.17985 (7)	1.03804 (5)	0.00844 (15)
O1W	0.5321 (4)	0.2428 (4)	1.0908 (3)	0.0140 (6)
H1X	0.604 (6)	0.162 (6)	1.147 (5)	0.021*
H1Y	0.627 (5)	0.335 (5)	1.040 (5)	0.021*
O1	0.1126 (4)	−0.1152 (4)	1.0094 (3)	0.0100 (6)
H1	0.142 (8)	−0.167 (7)	1.082 (6)	0.015*
N1	0.2437 (5)	0.1027 (5)	0.4128 (4)	0.0102 (7)
H1N	0.249943	−0.023469	0.404671	0.012*
N2	0.2363 (5)	0.2116 (5)	0.2909 (4)	0.0088 (7)
C1	0.2537 (6)	0.1216 (6)	0.7048 (5)	0.0103 (8)
C2	0.2405 (6)	0.2131 (6)	0.5511 (4)	0.0089 (8)
C3	0.2296 (6)	0.4004 (6)	0.5154 (5)	0.0102 (8)
H3	0.223752	0.511146	0.586837	0.012*
C4	0.2289 (6)	0.3927 (6)	0.3507 (4)	0.0074 (8)
C5	0.2388 (6)	0.5450 (6)	0.2360 (5)	0.0087 (8)
O2	0.2500 (4)	0.4783 (4)	0.0937 (3)	0.0098 (6)
O3	0.2423 (5)	0.7207 (4)	0.2790 (3)	0.0137 (6)
O4	0.2886 (5)	−0.0428 (4)	0.7039 (3)	0.0149 (6)
O5	0.2257 (4)	0.2323 (4)	0.8208 (3)	0.0123 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ga1	0.0123 (2)	0.0088 (2)	0.0059 (2)	0.00441 (17)	0.00399 (16)	0.00291 (15)
O1W	0.0120 (14)	0.0172 (16)	0.0176 (15)	0.0074 (13)	0.0071 (12)	0.0109 (12)
O1	0.0142 (14)	0.0097 (14)	0.0078 (14)	0.0050 (12)	0.0032 (11)	0.0044 (11)
N1	0.0164 (17)	0.0109 (16)	0.0069 (16)	0.0069 (14)	0.0057 (13)	0.0056 (13)
N2	0.0110 (17)	0.0093 (16)	0.0061 (15)	0.0025 (13)	0.0034 (13)	0.0029 (12)
C1	0.0076 (19)	0.014 (2)	0.0075 (19)	0.0009 (16)	0.0010 (15)	0.0034 (15)
C2	0.0073 (19)	0.012 (2)	0.0071 (19)	0.0018 (16)	0.0035 (15)	0.0016 (15)
C3	0.011 (2)	0.0117 (19)	0.0100 (19)	0.0053 (16)	0.0060 (16)	0.0018 (15)
C4	0.0066 (18)	0.0077 (18)	0.0084 (18)	0.0020 (15)	0.0034 (14)	0.0024 (15)
C5	0.0071 (19)	0.0087 (19)	0.0112 (19)	0.0040 (15)	0.0015 (15)	0.0018 (15)
O2	0.0158 (14)	0.0064 (13)	0.0086 (13)	0.0043 (11)	0.0048 (11)	0.0022 (10)
O3	0.0205 (16)	0.0120 (15)	0.0110 (14)	0.0084 (12)	0.0036 (12)	0.0033 (11)
O4	0.0203 (16)	0.0171 (16)	0.0125 (14)	0.0100 (13)	0.0076 (12)	0.0072 (12)
O5	0.0182 (15)	0.0139 (14)	0.0052 (13)	0.0050 (12)	0.0036 (11)	0.0028 (11)

Geometric parameters (Å, º)

Ga1—O1	1.903 (3)	N1—H1N	0.8800
Ga1—O5	1.932 (3)	N2—C4	1.326 (5)
Ga1—O1^i	1.974 (3)	C1—O4	1.224 (5)
Ga1—O2^ii	1.987 (3)	C1—O5	1.276 (5)
Ga1—O1W	1.988 (3)	C1—C2	1.499 (5)
Ga1—N2^ii	2.112 (3)	C2—C3	1.369 (6)
Ga1—Ga1^i	2.9716 (10)	C3—C4	1.399 (5)
O1W—H1X	0.943 (10)	C3—H3	0.9500
O1W—H1Y	0.939 (10)	C4—C5	1.487 (5)
O1—H1	0.77 (5)	C5—O3	1.225 (5)
N1—N2	1.333 (4)	C5—O2	1.284 (5)
N1—C2	1.355 (5)
O1—Ga1—O5	101.59 (12)	Ga1—O1—H1	118 (4)
O1—Ga1—O1^i	79.94 (13)	Ga1^i—O1—H1	107 (4)
O5—Ga1—O1^i	93.13 (12)	N2—N1—C2	110.6 (3)
O1—Ga1—O2^ii	166.31 (11)	N2—N1—H1N	124.7
O5—Ga1—O2^ii	87.28 (11)	C2—N1—H1N	124.7
O1^i—Ga1—O2^ii	89.26 (11)	C4—N2—N1	106.8 (3)
O1—Ga1—O1W	99.60 (12)	C4—N2—Ga1^iii	112.3 (2)
O5—Ga1—O1W	88.20 (12)	N1—N2—Ga1^iii	140.7 (3)
O1^i—Ga1—O1W	178.65 (12)	O4—C1—O5	129.1 (4)
O2^ii—Ga1—O1W	91.00 (11)	O4—C1—C2	118.2 (3)
O1—Ga1—N2^ii	93.94 (12)	O5—C1—C2	112.7 (3)
O5—Ga1—N2^ii	164.18 (12)	N1—C2—C3	107.5 (3)
O1^i—Ga1—N2^ii	92.49 (12)	N1—C2—C1	119.5 (3)
O2^ii—Ga1—N2^ii	78.02 (11)	C3—C2—C1	133.0 (4)
O1W—Ga1—N2^ii	86.27 (12)	C2—C3—C4	104.8 (3)
O1—Ga1—Ga1^i	40.86 (8)	C2—C3—H3	127.6
O5—Ga1—Ga1^i	99.50 (8)	C4—C3—H3	127.6
O1^i—Ga1—Ga1^i	39.08 (8)	N2—C4—C3	110.3 (3)
O2^ii—Ga1—Ga1^i	127.84 (8)	N2—C4—C5	115.1 (3)
O1W—Ga1—Ga1^i	140.45 (9)	C3—C4—C5	134.4 (3)
N2^ii—Ga1—Ga1^i	94.18 (9)	O3—C5—O2	124.3 (4)
Ga1—O1W—H1X	124 (2)	O3—C5—C4	121.2 (3)
Ga1—O1W—H1Y	123 (2)	O2—C5—C4	114.5 (3)
H1X—O1W—H1Y	110.8 (16)	C5—O2—Ga1^iii	118.6 (2)
Ga1—O1—Ga1^i	100.06 (13)	C1—O5—Ga1	129.9 (3)
C2—N1—N2—C4	0.2 (4)	N1—N2—C4—C5	175.1 (3)
C2—N1—N2—Ga1^iii	−173.6 (3)	Ga1^iii—N2—C4—C5	−9.2 (4)
N2—N1—C2—C3	0.2 (4)	C2—C3—C4—N2	0.7 (4)
N2—N1—C2—C1	−178.4 (3)	C2—C3—C4—C5	−173.7 (4)
O4—C1—C2—N1	7.0 (5)	N2—C4—C5—O3	−177.0 (3)
O5—C1—C2—N1	−173.1 (3)	C3—C4—C5—O3	−2.8 (7)
O4—C1—C2—C3	−171.2 (4)	N2—C4—C5—O2	1.0 (5)
O5—C1—C2—C3	8.7 (6)	C3—C4—C5—O2	175.2 (4)
N1—C2—C3—C4	−0.5 (4)	O3—C5—O2—Ga1^iii	−173.3 (3)
C1—C2—C3—C4	177.8 (4)	C4—C5—O2—Ga1^iii	8.8 (4)
N1—N2—C4—C3	−0.5 (4)	O4—C1—O5—Ga1	−4.2 (6)
Ga1^iii—N2—C4—C3	175.2 (2)	C2—C1—O5—Ga1	175.8 (2)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1X···O4^iv	0.94	1.73	2.643 (4)	164
O1W—H1Y···O2^v	0.94	1.89	2.803 (4)	165
O1—H1···O3^vi	0.77	1.99	2.751 (4)	175
N1—H1N···O3^vii	0.88	1.96	2.773 (4)	152

Symmetry codes: (iv) −x+1, −y, −z+2; (v) −x+1, −y+1, −z+1; (vi) x, y−1, z+1; (vii) x, y−1, z.