Diaqua­bis(1,10-phenanthroline-κ²N,N′)zinc(II) pamoate monohydrate

In the title compound, [Zn(C₁₂H₈N₂)₂(H₂O)₂](C₂₃H₁₄O₆)·H₂O, the Zn^II ion lies on a twofold axis and exhibits an approximately octa­hedral configuration. The pamoate dianion [or 4,4-methyl­enebis(3-hydr­oxy-2-naphthoate)], also lying on a twofold axis, is uncoordinated and balances the charge. In the crystal structure, O—H...O inter­molecular hydrogen bonds link the mononuclear ions into a two-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.084
• wR factor = 0.160
• Data-to-parameter ratio = 11.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT164_ALERT_4_C Nr. of Refined C-H H-Atoms in Heavy-At Struct...          1
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          7
PLAT415_ALERT_2_C Short Inter D-H..H-X       H4B    ..  H17     ..       2.13 Ang.
PLAT731_ALERT_1_C Bond    Calc     0.83(4), Rep   0.832(19) ......       2.11 su-Rat
              O4   -H4A     1.555   1.555
PLAT731_ALERT_1_C Bond    Calc     0.84(5), Rep   0.834(19) ......       2.63 su-Rat
              O4   -H4B     1.555   1.555
PLAT731_ALERT_1_C Bond    Calc     0.84(6), Rep     0.84(2) ......       3.00 su-Rat
              O5   -H5A     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.84(5), Rep     0.83(2) ......       2.50 su-Rat
              O4   -H4B     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.84(6), Rep     0.84(2) ......       3.00 su-Rat
              O5   -H5A     1.555   1.555
PLAT736_ALERT_1_C H...A   Calc     1.83(5), Rep     1.84(2) ......       2.50 su-Rat
              H4B  -O1      1.555   2.655

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   9 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   6 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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S1. Comment

Pamoic acid is a well known aromatic dicarboxylic acid and has been used as a means of masking unpleaseant tastes and for obtaining prolonged therapeutic action by forming slightly soluble salts with certain drugs (Dryden & Ridley, 1999; Jorgensen, 1998; Morovjan et al., 1998). However, in the construction of metal–organic coordination polymers, pamoic acid as a ligand is comparable with other aromatic dicarboxylic acids such as benzene-1,4-dicarboxylic acid and 5-hydroxyisophthalic acid (Hong & You, 2004; Li et al., 2004; Plater et al., 2001; Xiao et al., 2005; Xiao & Zhu, 2003; Zhu et al., 2004), and the complexes are very limited. Here, we report the crystal structure of the title compound [Zn(phen)₂(H₂O)₂]^.(pa)^.(H₂O), (I), where phen is 1,10-phenanthroline and pa is the pamoate dianion.

The title compound, (I), consists of a [Zn(phen)₂(H₂O)₂]⁺ cation, a pamoate dianion and one free water molecule (Fig. 1). The coordination geometry of the Zn^II atom is best described as distorted octahedral, comprising four N atoms of two 1,10-phenanthroline molecules and two O atoms from two coordinated water molecules. The Zn—N bond lengths are in the range of 2.174 (4)–2.222 (4) Å, while the Zn—O bond distance is 2.079 (3) Å (Table 1). The Zn^II ion lies on a crystallographic twofold axis and exhibits an approximately octahedral configuration. The pamoate dianion, which also lies on a crystallographic twofold axis, is free and does not coordinate to the Zn^II atom, balancing the charge. The dihedral angle between the two phen rings is 73.0 (1)°, while the dihedral angle between the two pamoate rings is 74.7 (2)°.

The stability of the solid state structure of (I) is enhanced significantly by hydrogen-bonding interactions (Table 2). An intramolecular hydrogen bond, O3—H3···O2, exists between atom O3 and the uncoordinated carboxylate O2 atom. Two intermolecular hydrogen bonds (O4—H4A···O1ⁱ and O4—H4B···O1ⁱⁱ; symmetry codes are given in Table 2) are formed between O4 of the coordinated water and the uncoordinated carboxylate atom O1. An additional intermolecular hydrogen bond, O5—H5A···O2ⁱ, is formed between O5 of the free water molecule and the uncoordinated carboxylate atomO2. All these intermolecular hydrogen bonds link neighbouring mononuclear units into a two-dimensional networke (Fig. 2).

S2. Experimental

An aqua solution (10 ml) containing Zn(NO₃)₂ ^.6H₂O (0.30 mmol, 0.084 g) was added slowly to a solution (10 ml) of N,N-dimethylformamide containing 1,10-phenanthroline (0.30 mmol, 0.054 g) and pamoic acid (0.30 mmol, 0.110 g). Colourless crystals suitable for X-ray analysis were obtained on allowing the solution to stand at room temperature for 14 d.

S3. Refinement

H atoms of the water molecules were located in a difference map and were refined isotropically, with O—H and H···H distance retraints of 0.84 (1) and 1.37 (2) Å, respectively. The remaining H atoms were positioned geometrically (C–H = 0.93 Å or O–H = 0.82 Å) and allowed to ride on their parent atoms. The U_iso(H) values were set at 1.2U_eq(C) or 1.5U_eq(O).

Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2002); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The structure of (I), showing 30% probability displacement ellipsoids and the atomic numbering scheme. Unlabelled atoms are related to labelled atoms by the symmetry operation (1 − x, y, 1/2 − z) in the cation and (2 − x, y, 1/2 − z) in the anion.
	Fig. 2. The two-dimensional network formed by hydrogen-bonding interactions (dashed lines). For clarity, the 1,10-phenanthroline molecules have been omitted.

{Bis[aqua(1,10-phenanthroline)]zinc(II)}^.pamoato^. monohydrate

Crystal data

[Zn(C12H8N2)2(H2O)2](C23H14O6)·H2O	F(000) = 1792
Mr = 866.17	Dx = 1.552 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1053 reflections
a = 15.6006 (11) Å	θ = 2.6–23.5°
b = 22.8892 (17) Å	µ = 0.73 mm^−1
c = 11.5193 (8) Å	T = 298 K
β = 115.704 (2)°	Prism, yellow
V = 3706.3 (5) Å^3	0.28 × 0.11 × 0.06 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	3375 independent reflections
Radiation source: fine-focus sealed tube	2823 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.060
ϕ and ω scans	θmax = 25.3°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2002)	h = −13→18
Tmin = 0.821, Tmax = 0.952	k = −27→21
9911 measured reflections	l = −13→13

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.084	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.160	H-atom parameters constrained
S = 1.20	w = 1/[σ^2(Fo^2) + (0.0526P)^2 + 6.9583P] where P = (Fo^2 + 2Fc^2)/3
3375 reflections	(Δ/σ)max = 0.001
290 parameters	Δρmax = 0.49 e Å^−3
5 restraints	Δρmin = −0.35 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
Zn1	0.5000	0.89626 (4)	0.2500	0.0287 (3)
O1	0.5935 (2)	0.94989 (16)	−0.0207 (3)	0.0383 (9)
O2	0.6649 (2)	0.89371 (18)	−0.1087 (3)	0.0464 (10)
O3	0.8255 (2)	0.85030 (15)	0.0252 (3)	0.0342 (8)
H3	0.7733	0.8553	−0.0358	0.051*
O4	0.4644 (2)	0.96606 (16)	0.3360 (3)	0.0383 (9)
H4A	0.498 (3)	0.9958 (16)	0.350 (5)	0.057*
H4B	0.444 (4)	0.961 (2)	0.392 (4)	0.057*
O5	0.5000	0.8256 (3)	0.7500	0.123 (4)
H5A	0.4520 (17)	0.8467 (16)	0.732 (12)	0.185*
N1	0.6306 (3)	0.88221 (17)	0.4316 (3)	0.0314 (10)
N2	0.5856 (3)	0.83646 (17)	0.1973 (4)	0.0316 (9)
C1	0.6516 (4)	0.9029 (2)	0.5489 (5)	0.0442 (14)
H1	0.6074	0.9269	0.5595	0.053*
C2	0.7360 (4)	0.8905 (2)	0.6566 (5)	0.0454 (14)
H2	0.7473	0.9055	0.7370	0.054*
C3	0.8014 (4)	0.8560 (2)	0.6418 (5)	0.0420 (14)
H3A	0.8584	0.8476	0.7127	0.050*
C4	0.7838 (3)	0.8331 (2)	0.5210 (5)	0.0325 (11)
C5	0.8485 (3)	0.7969 (2)	0.4971 (5)	0.0407 (13)
H5	0.9073	0.7885	0.5646	0.049*
C6	0.8272 (3)	0.7745 (2)	0.3798 (5)	0.0386 (13)
H6	0.8710	0.7508	0.3675	0.046*
C7	0.7375 (3)	0.7869 (2)	0.2738 (5)	0.0334 (12)
C8	0.7100 (4)	0.7637 (2)	0.1506 (5)	0.0427 (13)
H8	0.7508	0.7391	0.1341	0.051*
C9	0.6234 (4)	0.7774 (2)	0.0551 (5)	0.0445 (14)
H9	0.6046	0.7623	−0.0273	0.053*
C10	0.5633 (4)	0.8141 (2)	0.0811 (5)	0.0383 (13)
H10	0.5047	0.8236	0.0144	0.046*
C11	0.6718 (3)	0.8228 (2)	0.2934 (4)	0.0274 (11)
C12	0.6960 (3)	0.8469 (2)	0.4181 (4)	0.0280 (11)
C13	1.0000	0.8470 (3)	0.2500	0.0279 (15)
H13A	1.018 (3)	0.823 (2)	0.320 (4)	0.034*
C14	0.9141 (3)	0.88224 (19)	0.2399 (4)	0.0237 (10)
C15	0.8319 (3)	0.88348 (19)	0.1264 (4)	0.0233 (10)
C16	0.7513 (3)	0.9185 (2)	0.1117 (4)	0.0231 (10)
C17	0.7566 (3)	0.94962 (19)	0.2150 (4)	0.0257 (10)
H17	0.7062	0.9739	0.2052	0.031*
C18	0.8351 (3)	0.94651 (19)	0.3357 (4)	0.0227 (10)
C19	0.8337 (3)	0.9754 (2)	0.4438 (4)	0.0294 (11)
H19	0.7815	0.9981	0.4336	0.035*
C20	0.9082 (3)	0.9702 (2)	0.5625 (4)	0.0330 (12)
H20	0.9069	0.9893	0.6330	0.040*
C21	0.9865 (3)	0.9360 (2)	0.5772 (4)	0.0334 (12)
H21	1.0371	0.9322	0.6584	0.040*
C22	0.9902 (3)	0.9081 (2)	0.4752 (4)	0.0274 (11)
H22	1.0435	0.8860	0.4881	0.033*
C23	0.9147 (3)	0.91214 (18)	0.3499 (4)	0.0228 (10)
C24	0.6631 (3)	0.9215 (2)	−0.0151 (4)	0.0306 (11)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0269 (4)	0.0357 (5)	0.0236 (4)	0.000	0.0112 (3)	0.000
O1	0.0227 (17)	0.063 (3)	0.0272 (18)	0.0138 (17)	0.0094 (14)	0.0058 (17)
O2	0.0285 (19)	0.077 (3)	0.0299 (19)	0.0086 (18)	0.0096 (15)	−0.011 (2)
O3	0.0229 (17)	0.047 (2)	0.0302 (18)	−0.0002 (16)	0.0092 (14)	−0.0125 (17)
O4	0.035 (2)	0.048 (2)	0.041 (2)	−0.0095 (17)	0.0241 (17)	−0.0101 (18)
O5	0.109 (6)	0.067 (5)	0.095 (6)	0.000	−0.047 (5)	0.000
N1	0.031 (2)	0.037 (3)	0.025 (2)	−0.0005 (18)	0.0113 (18)	−0.0014 (18)
N2	0.029 (2)	0.034 (2)	0.031 (2)	−0.0056 (18)	0.0125 (19)	−0.0029 (19)
C1	0.049 (3)	0.051 (4)	0.036 (3)	0.001 (3)	0.021 (3)	−0.005 (3)
C2	0.065 (4)	0.045 (3)	0.028 (3)	−0.006 (3)	0.021 (3)	−0.002 (3)
C3	0.040 (3)	0.041 (3)	0.032 (3)	−0.010 (3)	0.003 (2)	0.007 (3)
C4	0.034 (3)	0.029 (3)	0.032 (3)	−0.002 (2)	0.012 (2)	0.008 (2)
C5	0.024 (3)	0.036 (3)	0.051 (3)	−0.002 (2)	0.006 (2)	0.012 (3)
C6	0.027 (3)	0.033 (3)	0.054 (3)	0.004 (2)	0.016 (3)	0.007 (3)
C7	0.037 (3)	0.024 (3)	0.045 (3)	−0.004 (2)	0.023 (2)	0.002 (2)
C8	0.039 (3)	0.040 (3)	0.054 (4)	0.004 (3)	0.025 (3)	−0.005 (3)
C9	0.055 (4)	0.046 (3)	0.036 (3)	−0.006 (3)	0.023 (3)	−0.015 (3)
C10	0.041 (3)	0.039 (3)	0.031 (3)	−0.003 (2)	0.012 (2)	−0.009 (2)
C11	0.025 (3)	0.028 (3)	0.030 (3)	−0.002 (2)	0.013 (2)	0.005 (2)
C12	0.026 (3)	0.027 (3)	0.031 (3)	−0.004 (2)	0.013 (2)	0.003 (2)
C13	0.027 (4)	0.023 (4)	0.028 (4)	0.000	0.006 (3)	0.000
C14	0.019 (2)	0.025 (3)	0.028 (2)	0.0013 (19)	0.0114 (19)	0.005 (2)
C15	0.023 (2)	0.027 (3)	0.023 (2)	−0.0042 (19)	0.0121 (19)	−0.003 (2)
C16	0.021 (2)	0.030 (3)	0.023 (2)	−0.0020 (19)	0.0135 (19)	0.002 (2)
C17	0.023 (2)	0.026 (3)	0.030 (2)	0.005 (2)	0.014 (2)	0.002 (2)
C18	0.021 (2)	0.026 (2)	0.024 (2)	−0.0029 (19)	0.0130 (19)	0.001 (2)
C19	0.029 (3)	0.031 (3)	0.032 (3)	0.001 (2)	0.016 (2)	−0.003 (2)
C20	0.035 (3)	0.038 (3)	0.028 (3)	−0.005 (2)	0.016 (2)	−0.008 (2)
C21	0.031 (3)	0.041 (3)	0.024 (2)	−0.004 (2)	0.007 (2)	0.001 (2)
C22	0.021 (2)	0.035 (3)	0.024 (2)	0.000 (2)	0.0084 (19)	0.001 (2)
C23	0.023 (2)	0.022 (2)	0.026 (2)	−0.0083 (18)	0.0123 (19)	−0.0001 (19)
C24	0.023 (3)	0.045 (3)	0.025 (3)	−0.001 (2)	0.013 (2)	0.005 (2)

Geometric parameters (Å, º)

Zn1—O4	2.079 (3)	C7—C8	1.398 (7)
Zn1—O4^i	2.079 (3)	C7—C11	1.405 (6)
Zn1—N2	2.174 (4)	C8—C9	1.358 (7)
Zn1—N2^i	2.174 (4)	C8—H8	0.93
Zn1—N1^i	2.222 (4)	C9—C10	1.386 (7)
Zn1—N1	2.222 (4)	C9—H9	0.93
O1—C24	1.243 (5)	C10—H10	0.93
O2—C24	1.262 (5)	C11—C12	1.429 (6)
O3—C15	1.359 (5)	C13—C14^ii	1.524 (6)
O3—H3	0.82	C13—C14	1.524 (5)
O4—H4A	0.832 (19)	C13—H13A	0.91 (4)
O4—H4B	0.834 (19)	C14—C15	1.378 (6)
O5—H5A	0.84 (2)	C14—C23	1.437 (6)
N1—C1	1.332 (6)	C15—C16	1.438 (6)
N1—C12	1.362 (6)	C16—C17	1.358 (6)
N2—C10	1.330 (6)	C16—C24	1.513 (6)
N2—C11	1.357 (6)	C17—C18	1.400 (6)
C1—C2	1.391 (7)	C17—H17	0.93
C1—H1	0.93	C18—C19	1.418 (6)
C2—C3	1.358 (7)	C18—C23	1.419 (6)
C2—H2	0.93	C19—C20	1.361 (6)
C3—C4	1.399 (7)	C19—H19	0.93
C3—H3A	0.93	C20—C21	1.399 (7)
C4—C12	1.405 (6)	C20—H20	0.93
C4—C5	1.421 (7)	C21—C22	1.360 (6)
C5—C6	1.346 (7)	C21—H21	0.93
C5—H5	0.93	C22—C23	1.416 (6)
C6—C7	1.431 (7)	C22—H22	0.93
C6—H6	0.93
O4—Zn1—O4^i	79.5 (2)	C8—C9—C10	119.6 (5)
O4—Zn1—N2	160.12 (13)	C8—C9—H9	120.2
O4^i—Zn1—N2	91.57 (14)	C10—C9—H9	120.2
O4—Zn1—N2^i	91.57 (14)	N2—C10—C9	123.0 (5)
O4^i—Zn1—N2^i	160.12 (13)	N2—C10—H10	118.5
N2—Zn1—N2^i	102.0 (2)	C9—C10—H10	118.5
O4—Zn1—N1^i	103.56 (14)	N2—C11—C7	122.5 (4)
O4^i—Zn1—N1^i	89.31 (14)	N2—C11—C12	117.8 (4)
N2—Zn1—N1^i	93.99 (14)	C7—C11—C12	119.6 (4)
N2^i—Zn1—N1^i	75.41 (14)	N1—C12—C4	122.8 (4)
O4—Zn1—N1	89.31 (14)	N1—C12—C11	117.4 (4)
O4^i—Zn1—N1	103.56 (14)	C4—C12—C11	119.8 (4)
N2—Zn1—N1	75.41 (14)	C14^ii—C13—C14	116.2 (5)
N2^i—Zn1—N1	93.99 (14)	C14^ii—C13—H13A	109 (3)
N1^i—Zn1—N1	163.4 (2)	C14—C13—H13A	108 (3)
C15—O3—H3	109.5	C15—C14—C23	118.3 (4)
Zn1—O4—H4A	116 (4)	C15—C14—C13	120.6 (4)
Zn1—O4—H4B	122 (4)	C23—C14—C13	121.0 (3)
H4A—O4—H4B	112 (3)	O3—C15—C14	119.6 (4)
C1—N1—C12	117.4 (4)	O3—C15—C16	118.4 (4)
C1—N1—Zn1	128.7 (3)	C14—C15—C16	122.0 (4)
C12—N1—Zn1	113.9 (3)	C17—C16—C15	118.1 (4)
C10—N2—C11	117.8 (4)	C17—C16—C24	120.5 (4)
C10—N2—Zn1	126.8 (3)	C15—C16—C24	121.4 (4)
C11—N2—Zn1	115.4 (3)	C16—C17—C18	122.6 (4)
N1—C1—C2	123.6 (5)	C16—C17—H17	118.7
N1—C1—H1	118.2	C18—C17—H17	118.7
C2—C1—H1	118.2	C17—C18—C19	120.6 (4)
C3—C2—C1	118.6 (5)	C17—C18—C23	119.2 (4)
C3—C2—H2	120.7	C19—C18—C23	120.2 (4)
C1—C2—H2	120.7	C20—C19—C18	120.7 (4)
C2—C3—C4	120.6 (5)	C20—C19—H19	119.7
C2—C3—H3A	119.7	C18—C19—H19	119.7
C4—C3—H3A	119.7	C19—C20—C21	119.4 (4)
C3—C4—C12	117.0 (5)	C19—C20—H20	120.3
C3—C4—C5	124.2 (5)	C21—C20—H20	120.3
C12—C4—C5	118.8 (5)	C22—C21—C20	121.3 (4)
C6—C5—C4	122.0 (5)	C22—C21—H21	119.3
C6—C5—H5	119.0	C20—C21—H21	119.3
C4—C5—H5	119.0	C21—C22—C23	121.5 (4)
C5—C6—C7	120.3 (5)	C21—C22—H22	119.2
C5—C6—H6	119.8	C23—C22—H22	119.2
C7—C6—H6	119.8	C22—C23—C18	117.0 (4)
C8—C7—C11	117.4 (5)	C22—C23—C14	123.6 (4)
C8—C7—C6	123.1 (5)	C18—C23—C14	119.4 (4)
C11—C7—C6	119.4 (5)	O1—C24—O2	124.2 (4)
C9—C8—C7	119.6 (5)	O1—C24—C16	118.8 (4)
C9—C8—H8	120.2	O2—C24—C16	117.1 (4)
C7—C8—H8	120.2

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4B···O1^i	0.83 (2)	1.84 (2)	2.673 (4)	177 (5)
O4—H4A···O1^iii	0.83 (2)	2.01 (3)	2.757 (5)	149 (5)
O5—H5A···O2^i	0.84 (2)	2.06 (6)	2.839 (5)	154 (12)
O3—H3···O2	0.82	1.76	2.508 (4)	150

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