Poly[[diaqua-μ3-citrato-praseodymium(III)] monohydrate]

Han, L.-J.; Deng, Y.-F.; Ng, S.W.

doi:10.1107/S1600536811023804

metal-organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 67| Part 7| July 2011| Page m981

doi:10.1107/S1600536811023804

Open

access

Poly[[diaqua-μ₃-citrato-praseodymium(III)] monohydrate]

Li-Jun Han,^a Yuan-Fu Deng ^a and Seik Weng Ng ^b ^*

^aSchool of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, People's Republic of China, and ^bDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
^*Correspondence e-mail: seikweng@um.edu.my

(Received 14 June 2011; accepted 17 June 2011; online 25 June 2011)

In the coordination polymer, {[Pr(C₆H₅O₇)(H₂O)₂]·H₂O}_n, seven of the nine coordination sites of the monocapped square-antiprismatic geometry are occupied by three O atoms of the same citrate trianion (an O atom of the hydroxy unit and the formally single-bond O atoms from two carboxyl units). Two other coordination sites are occupied by the O atoms of a chelating carboxyl unit of another citrate; one of these atoms is additionally involved in bridging. The seventh coordination site is occupied by the O atom of the formally double-bond O atom of a neighboring citrate. The remaining two coordination sites are occupied by water molecules. The citrate functions in a μ₃-bridging mode, connecting the metal atoms into a ribbon structure parallel to [010]. The structure is consolidated into a three-dimensional network by O—H⋯O hydrogen bonds.

Related literature

For isotypic [Eu(C₆H₅O₇)(H₂O)₂]·H₂O, see: Tang et al. (2011 ).

Experimental

Crystal data

[Pr(C₆H₅O₇)(H₂O)₂]·H₂O
M_r = 384.06
Monoclinic, P 2₁ /n
a = 6.2645 (3) Å
b = 9.7356 (7) Å
c = 17.0425 (10) Å
β = 91.0672 (18)°
V = 1039.22 (11) Å³
Z = 4
Mo Kα radiation
μ = 4.74 mm⁻¹
T = 293 K
0.30 × 0.15 × 0.10 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ) T_min = 0.331, T_max = 0.649
9596 measured reflections
2366 independent reflections
2182 reflections with I > 2σ(I)
R_int = 0.038

Refinement

R[F² > 2σ(F²)] = 0.026
wR(F²) = 0.050
S = 1.18
2366 reflections
175 parameters
10 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.76 e Å⁻³
Δρ_min = −0.81 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O7—H7⋯O2ⁱ	0.83 (1)	1.72 (1)	2.536 (3)	167 (4)
O1w—H11⋯O2ⁱⁱ	0.84 (1)	1.84 (1)	2.666 (3)	169 (4)
O1w—H12⋯O3ⁱⁱⁱ	0.84 (1)	1.89 (2)	2.692 (3)	159 (3)
O2w—H21⋯O1w^iv	0.84 (1)	2.09 (2)	2.854 (4)	151 (4)
O2w—H22⋯O3w	0.84 (1)	1.89 (1)	2.718 (4)	168 (4)
O3w—H31⋯O6^v	0.84 (1)	2.05 (2)	2.856 (4)	160 (6)
Symmetry codes: (i) $[-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (ii) $[x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (iii) x-1, y, z; (iv) -x, -y, -z+1; (v) x, y-1, z.

Data collection: RAPID-AUTO (Rigaku, 1998 ); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001 ); software used to prepare material for publication: publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811023804/si2362sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811023804/si2362Isup2.hkl

checkCIF report

Comment top

A recent report describes the synthesis of Eu(H₂O)₂(C₆H₅O₇)^.H₂O, a citrate(3-) based coordination polymer that exhibits useful luminescence; the ribbon motif propagates along the a-axis and adjacent chains are linked by O–H···O hydrogen bonds into a three-dimensional network. The presence of manganese dichloride is crucial to the synthesis (Tang et al., 2011). The present Pr analog (Scheme I) is isostructural, the two compounds crystallizing with matching cell dimensions. In the coordination polymer, Pr(H₂O)₂(C₆H₅O₇)^.H₂O (Fig. 1), seven of the nine coordination sites a mono-capped square-antiprismatic geometry (Fig. 2) are occupied by three O atoms of the same citrate trianion (an O atom of the hydroxy unit and the formally single-bond O atoms from two carboxyl units). Two other coordination sites are occupied by the O atoms of a chelating carboxyl unit of another citrate; one of these atoms is additionally involved in bridging. The seventh coordination site is occupied by the O atom of the formally double-bond O atom of a neighboring citrate. The remaining two coordination sites of the are occupied by water molecules. The citrate functions in a µ₃– bridging mode to connect the metal atoms into a ribbon structure. The structure is consolidated into a three-dimensional network by O–H···O hydrogen bonds (Table 1).

Related literature top

For isotypic Eu(H₂O)₂(C₆H₅O₇)^.H₂O, see: Tang et al. (2011).

Experimental top

Praseodymium oxide, Pr₆O₁₁ (0.341 g), was suspended in water (20 ml) and to the suspension was added manganese dichloride tetrahydrate (0.395 g, 2.0 mmol) and citric acid monohydrate (0.841 g, 4.0 mmol). The mixture was placed in a 25 ml, teflon-lined, stainless-steel Parr bomb. The bomb was heated at 393 K for 72 h. It was cooled to room temperature at 30 K an hour. Green crystals were isolated in 75% yield based on Pr₆O₁₁.

Computing details top

Data collection: RAPID-AUTO (Rigaku, 1998); cell refinement: RAPID-AUTO (Rigaku, 1998); data reduction: CrystalStructure (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top

	Fig. 1. Thermal ellipsoid plot (Barbour, 2001) of a portion of polymeric Pr(H₂O)₂(C₆H₅O₇)^.H₂O with the 70% probability level; hydrogen atoms are drawn as spheres of arbitrary radius.
	Fig. 2. Nine-coordinate geometry of Pr^III.

Poly[[diaqua-µ₃-citrato-praseodymium(III)] monohydrate] top

Crystal data top

[Pr(C₆H₅O₇)(H₂O)₂]·H₂O	F(000) = 744
M_r = 384.06	D_x = 2.455 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 8369 reflections
a = 6.2645 (3) Å	θ = 3.2–27.4°
b = 9.7356 (7) Å	µ = 4.74 mm⁻¹
c = 17.0425 (10) Å	T = 293 K
β = 91.0672 (18)°	Prism, light green
V = 1039.22 (11) Å³	0.30 × 0.15 × 0.10 mm
Z = 4

Data collection top

Rigaku R-AXIS RAPID diffractometer	2366 independent reflections
Radiation source: fine-focus sealed tube	2182 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.038
Detector resolution: 10.000 pixels mm^-1	θ_max = 27.4°, θ_min = 3.2°
ω scans	h = −8→8
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	k = −12→10
T_min = 0.331, T_max = 0.649	l = −22→22
9596 measured reflections

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)] = 0.026	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.050	H atoms treated by a mixture of independent and constrained refinement
S = 1.18	w = 1/[σ²(F_o²) + (0.P)² + 1.4664P] where P = (F_o² + 2F_c²)/3
2366 reflections	(Δ/σ)_max = 0.001
175 parameters	Δρ_max = 0.76 e Å⁻³
10 restraints	Δρ_min = −0.81 e Å⁻³

Crystal data top

[Pr(C₆H₅O₇)(H₂O)₂]·H₂O	V = 1039.22 (11) Å³
M_r = 384.06	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 6.2645 (3) Å	µ = 4.74 mm⁻¹
b = 9.7356 (7) Å	T = 293 K
c = 17.0425 (10) Å	0.30 × 0.15 × 0.10 mm
β = 91.0672 (18)°

Data collection top

Rigaku R-AXIS RAPID diffractometer	2366 independent reflections
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	2182 reflections with I > 2σ(I)
T_min = 0.331, T_max = 0.649	R_int = 0.038
9596 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.026	10 restraints
wR(F²) = 0.050	H atoms treated by a mixture of independent and constrained refinement
S = 1.18	Δρ_max = 0.76 e Å⁻³
2366 reflections	Δρ_min = −0.81 e Å⁻³
175 parameters

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

	x	y	z	U_iso*/U_eq
Pr1	0.11415 (2)	0.319324 (16)	0.566983 (9)	0.01012 (6)
O1	0.2224 (4)	0.2466 (3)	0.70094 (14)	0.0212 (5)
O2	0.3108 (4)	0.2315 (3)	0.82649 (14)	0.0245 (5)
O3	0.5035 (3)	0.2913 (2)	0.56851 (14)	0.0195 (5)
O4	0.7923 (3)	0.2852 (2)	0.64591 (13)	0.0150 (4)
O5	0.8717 (3)	0.5316 (2)	0.55742 (13)	0.0166 (4)
O6	0.7309 (4)	0.7354 (2)	0.57242 (13)	0.0185 (5)
O7	0.3381 (3)	0.5013 (2)	0.63152 (13)	0.0138 (4)
H7	0.297 (6)	0.574 (2)	0.652 (2)	0.021*
O1W	−0.1683 (3)	0.2119 (3)	0.47949 (14)	0.0192 (5)
H11	−0.172 (5)	0.219 (4)	0.4305 (6)	0.029*
H12	−0.289 (3)	0.230 (4)	0.4971 (18)	0.029*
O2W	0.1834 (4)	0.0691 (3)	0.56804 (16)	0.0277 (6)
H21	0.147 (6)	−0.001 (3)	0.543 (2)	0.042*
H22	0.300 (4)	0.054 (4)	0.591 (2)	0.042*
O3W	0.5632 (6)	−0.0132 (4)	0.6318 (2)	0.0564 (10)
H31	0.617 (8)	−0.092 (2)	0.626 (4)	0.085*
H32	0.635 (8)	0.042 (4)	0.605 (3)	0.085*
C1	0.3229 (5)	0.2872 (3)	0.76032 (18)	0.0146 (6)
C2	0.4742 (5)	0.4089 (3)	0.75574 (17)	0.0141 (6)
H2A	0.6066	0.3849	0.7829	0.017*
H2B	0.4118	0.4855	0.7836	0.017*
C3	0.6141 (5)	0.3355 (3)	0.62538 (18)	0.0125 (6)
C4	0.5269 (4)	0.4564 (3)	0.67268 (17)	0.0109 (6)
C5	0.6919 (5)	0.5734 (3)	0.67823 (17)	0.0130 (6)
H5A	0.6285	0.6513	0.7046	0.016*
H5B	0.8134	0.5429	0.7097	0.016*
C6	0.7682 (4)	0.6185 (3)	0.59874 (17)	0.0120 (6)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Pr1	0.00959 (9)	0.01080 (10)	0.00997 (9)	0.00001 (6)	0.00066 (6)	0.00069 (6)
O1	0.0237 (12)	0.0235 (13)	0.0161 (12)	−0.0102 (10)	−0.0060 (9)	0.0049 (9)
O2	0.0360 (13)	0.0230 (13)	0.0142 (12)	−0.0143 (11)	−0.0037 (10)	0.0078 (10)
O3	0.0124 (11)	0.0235 (13)	0.0226 (13)	0.0015 (9)	−0.0010 (9)	−0.0123 (10)
O4	0.0116 (10)	0.0164 (11)	0.0171 (11)	0.0030 (9)	0.0016 (8)	0.0017 (9)
O5	0.0217 (11)	0.0133 (11)	0.0149 (11)	0.0037 (9)	0.0072 (8)	0.0010 (9)
O6	0.0234 (12)	0.0155 (12)	0.0167 (12)	0.0033 (9)	0.0039 (9)	0.0031 (9)
O7	0.0144 (10)	0.0114 (11)	0.0157 (11)	0.0035 (8)	−0.0022 (8)	−0.0017 (8)
O1W	0.0158 (11)	0.0267 (13)	0.0151 (12)	−0.0010 (10)	0.0013 (8)	−0.0025 (10)
O2W	0.0334 (14)	0.0158 (13)	0.0336 (15)	0.0004 (11)	−0.0102 (11)	−0.0021 (11)
O3W	0.056 (2)	0.0331 (18)	0.079 (3)	0.0182 (16)	−0.0212 (18)	−0.0082 (18)
C1	0.0145 (14)	0.0156 (16)	0.0138 (15)	−0.0021 (12)	0.0009 (11)	0.0016 (12)
C2	0.0154 (14)	0.0160 (16)	0.0110 (14)	−0.0034 (12)	0.0018 (11)	−0.0004 (12)
C3	0.0107 (14)	0.0129 (15)	0.0141 (15)	−0.0025 (11)	0.0045 (11)	0.0029 (11)
C4	0.0116 (13)	0.0104 (14)	0.0105 (14)	0.0000 (11)	0.0001 (10)	−0.0005 (11)
C5	0.0155 (14)	0.0117 (15)	0.0118 (14)	−0.0040 (12)	0.0022 (10)	−0.0006 (11)
C6	0.0092 (13)	0.0133 (16)	0.0134 (14)	−0.0026 (11)	−0.0005 (10)	−0.0009 (11)

Geometric parameters (Å, º) top

Pr1—O1	2.473 (2)	O6—Pr1ⁱⁱ	2.637 (2)
Pr1—O3	2.454 (2)	O7—C4	1.432 (3)
Pr1—O4ⁱ	2.467 (2)	O7—H7	0.834 (10)
Pr1—O5ⁱ	2.568 (2)	O1W—H11	0.84 (1)
Pr1—O5ⁱⁱ	2.572 (2)	O1W—H12	0.84 (1)
Pr1—O6ⁱⁱ	2.637 (2)	O2W—H21	0.84 (1)
Pr1—O7	2.502 (2)	O2W—H22	0.84 (1)
Pr1—O1W	2.520 (2)	O3W—H31	0.84 (1)
Pr1—O2W	2.474 (3)	O3W—H32	0.85 (1)
O1—C1	1.246 (4)	C1—C2	1.520 (4)
O2—C1	1.255 (4)	C2—C4	1.531 (4)
O3—C3	1.257 (4)	C2—H2A	0.9700
O4—C3	1.262 (4)	C2—H2B	0.9700
O4—Pr1ⁱⁱⁱ	2.467 (2)	C3—C4	1.533 (4)
O5—C6	1.284 (4)	C4—C5	1.540 (4)
O5—Pr1ⁱⁱⁱ	2.568 (2)	C5—C6	1.510 (4)
O5—Pr1ⁱⁱ	2.572 (2)	C5—H5A	0.9700
O6—C6	1.244 (4)	C5—H5B	0.9700

O3—Pr1—O4ⁱ	143.27 (8)	C6—O5—Pr1ⁱⁱ	96.06 (18)
O3—Pr1—O1	72.72 (8)	Pr1ⁱⁱⁱ—O5—Pr1ⁱⁱ	118.48 (8)
O4ⁱ—Pr1—O1	70.79 (7)	C6—O6—Pr1ⁱⁱ	94.03 (18)
O3—Pr1—O2W	73.53 (8)	C4—O7—Pr1	116.75 (17)
O4ⁱ—Pr1—O2W	90.48 (8)	C4—O7—H7	108 (3)
O1—Pr1—O2W	70.50 (9)	Pr1—O7—H7	128 (3)
O3—Pr1—O7	61.63 (7)	Pr1—O1W—H11	124 (3)
O4ⁱ—Pr1—O7	108.24 (7)	Pr1—O1W—H12	109 (3)
O1—Pr1—O7	69.83 (7)	H11—O1W—H12	109 (2)
O2W—Pr1—O7	126.67 (8)	Pr1—O2W—H21	139 (3)
O3—Pr1—O1W	130.32 (7)	Pr1—O2W—H22	109 (3)
O4ⁱ—Pr1—O1W	72.22 (7)	H21—O2W—H22	110 (2)
O1—Pr1—O1W	127.21 (8)	H31—O3W—H32	107 (2)
O2W—Pr1—O1W	73.54 (8)	O1—C1—O2	123.7 (3)
O7—Pr1—O1W	159.37 (8)	O1—C1—C2	120.8 (3)
O3—Pr1—O5ⁱ	132.58 (7)	O2—C1—C2	115.5 (3)
O4ⁱ—Pr1—O5ⁱ	69.79 (7)	C1—C2—C4	115.4 (2)
O1—Pr1—O5ⁱ	116.15 (8)	C1—C2—H2A	108.4
O2W—Pr1—O5ⁱ	153.65 (8)	C4—C2—H2A	108.4
O7—Pr1—O5ⁱ	77.53 (7)	C1—C2—H2B	108.4
O1W—Pr1—O5ⁱ	83.60 (7)	C4—C2—H2B	108.4
O3—Pr1—O5ⁱⁱ	91.25 (8)	H2A—C2—H2B	107.5
O4ⁱ—Pr1—O5ⁱⁱ	124.51 (7)	O3—C3—O4	123.6 (3)
O1—Pr1—O5ⁱⁱ	155.43 (7)	O3—C3—C4	118.1 (3)
O2W—Pr1—O5ⁱⁱ	123.56 (8)	O4—C3—C4	118.3 (3)
O7—Pr1—O5ⁱⁱ	86.28 (7)	O7—C4—C2	110.8 (2)
O1W—Pr1—O5ⁱⁱ	77.36 (8)	O7—C4—C3	106.0 (2)
O5ⁱ—Pr1—O5ⁱⁱ	61.52 (8)	C2—C4—C3	109.8 (2)
O3—Pr1—O6ⁱⁱ	66.72 (7)	O7—C4—C5	110.6 (2)
O4ⁱ—Pr1—O6ⁱⁱ	141.46 (7)	C2—C4—C5	108.8 (2)
O1—Pr1—O6ⁱⁱ	132.42 (8)	C3—C4—C5	110.8 (2)
O2W—Pr1—O6ⁱⁱ	74.95 (8)	C6—C5—C4	112.5 (2)
O7—Pr1—O6ⁱⁱ	109.04 (7)	C6—C5—H5A	109.1
O1W—Pr1—O6ⁱⁱ	69.47 (7)	C4—C5—H5A	109.1
O5ⁱ—Pr1—O6ⁱⁱ	109.42 (7)	C6—C5—H5B	109.1
O5ⁱⁱ—Pr1—O6ⁱⁱ	49.65 (7)	C4—C5—H5B	109.1
C1—O1—Pr1	141.7 (2)	H5A—C5—H5B	107.8
C3—O3—Pr1	120.28 (19)	O6—C6—O5	119.9 (3)
C3—O4—Pr1ⁱⁱⁱ	121.60 (19)	O6—C6—C5	122.0 (3)
C6—O5—Pr1ⁱⁱⁱ	143.1 (2)	O5—C6—C5	118.1 (3)

O3—Pr1—O1—C1	67.4 (4)	Pr1—O3—C3—O4	152.9 (2)
O4ⁱ—Pr1—O1—C1	−116.8 (4)	Pr1—O3—C3—C4	−26.6 (4)
O2W—Pr1—O1—C1	145.6 (4)	Pr1ⁱⁱⁱ—O4—C3—O3	72.0 (4)
O7—Pr1—O1—C1	2.0 (3)	Pr1ⁱⁱⁱ—O4—C3—C4	−108.5 (3)
O1W—Pr1—O1—C1	−164.6 (3)	Pr1—O7—C4—C2	−83.4 (2)
O5ⁱ—Pr1—O1—C1	−62.1 (4)	Pr1—O7—C4—C3	35.7 (3)
O5ⁱⁱ—Pr1—O1—C1	16.1 (5)	Pr1—O7—C4—C5	155.86 (18)
O6ⁱⁱ—Pr1—O1—C1	99.8 (4)	C1—C2—C4—O7	61.8 (3)
O4ⁱ—Pr1—O3—C3	−49.7 (3)	C1—C2—C4—C3	−55.0 (3)
O1—Pr1—O3—C3	−43.1 (2)	C1—C2—C4—C5	−176.4 (3)
O2W—Pr1—O3—C3	−117.3 (2)	O3—C3—C4—O7	−6.7 (4)
O7—Pr1—O3—C3	32.9 (2)	O4—C3—C4—O7	173.7 (2)
O1W—Pr1—O3—C3	−167.6 (2)	O3—C3—C4—C2	113.0 (3)
O5ⁱ—Pr1—O3—C3	66.8 (3)	O4—C3—C4—C2	−66.5 (3)
O5ⁱⁱ—Pr1—O3—C3	118.0 (2)	O3—C3—C4—C5	−126.7 (3)
O6ⁱⁱ—Pr1—O3—C3	162.4 (3)	O4—C3—C4—C5	53.7 (4)
O3—Pr1—O7—C4	−35.86 (18)	O7—C4—C5—C6	−63.2 (3)
O4ⁱ—Pr1—O7—C4	105.51 (18)	C2—C4—C5—C6	175.0 (2)
O1—Pr1—O7—C4	44.86 (18)	C3—C4—C5—C6	54.1 (3)
O2W—Pr1—O7—C4	0.7 (2)	Pr1ⁱⁱ—O6—C6—O5	6.0 (3)
O1W—Pr1—O7—C4	−166.6 (2)	Pr1ⁱⁱ—O6—C6—C5	−173.0 (2)
O5ⁱ—Pr1—O7—C4	169.07 (19)	Pr1ⁱⁱⁱ—O5—C6—O6	153.9 (2)
O5ⁱⁱ—Pr1—O7—C4	−129.30 (19)	Pr1ⁱⁱ—O5—C6—O6	−6.2 (3)
O6ⁱⁱ—Pr1—O7—C4	−84.44 (19)	Pr1ⁱⁱⁱ—O5—C6—C5	−27.1 (4)
Pr1—O1—C1—O2	164.9 (2)	Pr1ⁱⁱ—O5—C6—C5	172.8 (2)
Pr1—O1—C1—C2	−16.3 (5)	Pr1ⁱⁱⁱ—O5—C6—Pr1ⁱⁱ	160.0 (3)
O1—C1—C2—C4	−11.9 (4)	C4—C5—C6—O6	114.9 (3)
O2—C1—C2—C4	167.0 (3)	C4—C5—C6—O5	−64.0 (3)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O7—H7···O2^iv	0.83 (1)	1.72 (1)	2.536 (3)	167 (4)
O1w—H11···O2^v	0.84 (1)	1.84 (1)	2.666 (3)	169 (4)
O1w—H12···O3ⁱ	0.84 (1)	1.89 (2)	2.692 (3)	159 (3)
O2w—H21···O1w^vi	0.84 (1)	2.09 (2)	2.854 (4)	151 (4)
O2w—H22···O3w	0.84 (1)	1.89 (1)	2.718 (4)	168 (4)
O3w—H31···O6^vii	0.84 (1)	2.05 (2)	2.856 (4)	160 (6)

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

Experimental details

Crystal data
Chemical formula	[Pr(C₆H₅O₇)(H₂O)₂]·H₂O
M_r	384.06
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	293
a, b, c (Å)	6.2645 (3), 9.7356 (7), 17.0425 (10)
β (°)	91.0672 (18)
V (Å³)	1039.22 (11)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	4.74
Crystal size (mm)	0.30 × 0.15 × 0.10

Data collection
Diffractometer	Rigaku R-AXIS RAPID diffractometer
Absorption correction	Multi-scan (ABSCOR; Higashi, 1995)
T_min, T_max	0.331, 0.649
No. of measured, independent and observed [I > 2σ(I)] reflections	9596, 2366, 2182
R_int	0.038
(sin θ/λ)_max (Å⁻¹)	0.648

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.026, 0.050, 1.18
No. of reflections	2366
No. of parameters	175
No. of restraints	10
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.76, −0.81

Computer programs: RAPID-AUTO (Rigaku, 1998), CrystalStructure (Rigaku/MSC, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O7—H7···O2ⁱ	0.83 (1)	1.72 (1)	2.536 (3)	167 (4)
O1w—H11···O2ⁱⁱ	0.84 (1)	1.84 (1)	2.666 (3)	169 (4)
O1w—H12···O3ⁱⁱⁱ	0.84 (1)	1.89 (2)	2.692 (3)	159 (3)
O2w—H21···O1w^iv	0.84 (1)	2.09 (2)	2.854 (4)	151 (4)
O2w—H22···O3w	0.84 (1)	1.89 (1)	2.718 (4)	168 (4)
O3w—H31···O6^v	0.84 (1)	2.05 (2)	2.856 (4)	160 (6)

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

Acknowledgements

We thank South China University of Technology and the University of Malaya for supporting this study.

References

Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan. Google Scholar
Rigaku (1998). RAPID-AUTO. Rigaku Corporation, Tokyo, Japan. Google Scholar
Rigaku/MSC (2002). CrystalStructure. Rigaku/MSC, The Woodlands, Texas, USA. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Tang, S.-D., Deng, Y.-F. & Zhan, S.-Z. (2011). Chin. J. Struct. Chem. 30, 424–430. CAS Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar