trans-Bis(isoquinoline-3-carboxyl­ato-κ²N,O)bis­(methanol-κO)zinc(II)

In the crystal structure of the title complex, [Zn(C₁₀H₆NO₂)₂(CH₃OH)₂], the Zn atom at a center of inversion has distorted octa­hedral coordination geometry and is bonded to two quinoline N atoms, two carboxyl­ate O atoms and two methanol O atoms. Two isoquinoline-3-carboxyl­ate ligands lie in trans positions, forming the equatorial plane, and the two methanol ligands occupy the axial positions. The complex mol­ecules are linked together by O—H...O hydrogen bonds between the methanol ligands and neighboring carboxyl­ate groups.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.033
• wR factor = 0.086
• Data-to-parameter ratio = 16.0

checkCIF/PLATON results

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Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Zn1    -   O1M     ..       5.42 su

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

   1 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
   0 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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S1. Comment

Transition metal ions are well known to have many biological functions, such as antimicrobial or fungicidal activity (Okide et al., 2000; Patel et al., 1999), or have redox activity such as Fenton-type reactions (Kasprzak, 2002) inducing toxicity or carcinogenesis. Zn^II is well known for its insulinomemetic activity (e.g. Matsumoto et al., 2005). In the previous papers, the crystal structures of the Fe^II (II), Co^II (III), Ni^II (IV) and Cu^II (V) complexes of isoquinoline-3-carboxylate have been reported (Okabe & Muranishi, 2003c; Okabe et al., 2004). We report here the structure of the corresponding Zn^II complex, (I).

The structure of (I) is shown in Fig. 1. It is isomorphous with the analogs (II)–(V), with the metal ion at a center of inversion and a distorted octahedral coordination geometry.

The two bidentate ligands lie trans to each other. They are coordinated to the central metal ion, through the isoquinoline N atoms and the carboxylate O atoms to form five-membered rings in the equatorial plane. Two O atoms of the methanol ligands complete the octahedron at the axial positions. The coordination bond distances of (I) are listed in Table 1, together with those of (II)–(V).

As shown in Table 1, coordination bond distances, M—N, decrease in the order (II) > (III) > (IV) > (V) < (I). The reverse of this order coincides well with the Irving–Williams series, which indicates the general stability sequence of octahedral metal complexes in the order Fe < Co < Ni < Cu > Zn. The longest axial coordination bond distance (M—O1m) of (V) is explained by the Jahn–Teller effect. The bond lengths of both sides of the ring N atom (N1—C1 and N1—C9) and C atom (C1—C2) of all complexes are shorter than those of others in the same pyridine ring, C2—C3, C3—C8 and C8—C9 (Table 1). This indicates that the double-bond character of these three bonds may be a general characteristic of the transition metal complexes of isoquinoline-3-carboxylate.

It is noticed that only the bonds on either side of the N atom have double-bond character in the isoquinoline-1-carboxylate complexes with Fe^II (Muranishi & Okabe, 2003), Co^II and Ni^II (Okabe & Muranishi, 2002), and Zn^II (Okabe & Muranishi, 2003b), and in the quinoline-2-carboxylate complexes with Fe^II (Okabe & Makino, 1998), Co^II (Okabe & Makino, 1999), Ni^II (Odoko et al., 2001) and Zn^II (Okabe & Muranishi, 2003a).

The hydrogen-bonding parameters of (I)–(V) are listed in Table 2 for comparison. All structures are stabilized by a similar intermolecular O—H···O hydrogen-bonding pattern between methanol ligands and the neighbouring carboxylate groups. A stacking interaction is also observed between the ligands with a mean distance of 3.366 (4) Å.

S2. Experimental

Colorless plate crystals of (I) were obtained by slow evapolation of a methanol solution of a mixture of isoquinoline-3-carboxylic acid (5 mg) dissolved in methanol (3 ml) and ZnSO₄ (2.1 mg) dissolved in methanol (2 ml) (molar ratio 4:1) at room temperature.

S3. Refinement

All H atoms were located in difference Fourier maps, and then were regenerated at ideal positions [C—H = 0.96 (methyl), 0.93 Å (other H atoms); U_iso(H) = 1.5U_eq(methyl C) and 1.2U_eq(other C)]. The weighting schemes for both structures were optimized.

Computing details

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1992); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 2000); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: TEXSAN.

Figures

Fig. 1. ORTEPII (Johnson, 1976) drawing of (I), with the atomic numbering scheme. Displacement ellipsoids for non-H atoms correspond to 50% probability. Atoms labeled with an asterisk are at the symmetry position (please supply).

trans-Bis(isoquinoline-3-carboxylato-κ²N,O)bis(methanol-κO)zinc(II)

Crystal data

[Zn(C10H6NO2)2(CH4O)2]	F(000) = 488.0
Mr = 473.79	Dx = 1.577 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.7107 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 10.672 (1) Å	θ = 14.2–15.0°
b = 6.301 (2) Å	µ = 1.27 mm^−1
c = 15.091 (1) Å	T = 296 K
β = 100.567 (9)°	Prism, colorless
V = 997.6 (3) Å^3	0.40 × 0.10 × 0.10 mm
Z = 2

Data collection

Rigaku AFC-5R diffractometer	Rint = 0.025
ω–2θ scans	θmax = 27.5°
Absorption correction: ψ scan (North et al., 1968)	h = 0→13
Tmin = 0.858, Tmax = 0.880	k = 0→8
2627 measured reflections	l = −19→19
2288 independent reflections	3 standard reflections every 150 reflections
1515 reflections with I > 2σ(I)	intensity decay: 0.1%

Refinement

Refinement on F^2	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.033	w = 1/[σ^2(Fo^2) + (0.0297P)^2 + 0.6344P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.086	(Δ/σ)max < 0.001
S = 1.01	Δρmax = 0.30 e Å^−3
2288 reflections	Δρmin = −0.47 e Å^−3
143 parameters

Special details

Refinement. Refinement using reflections with F² > −10.0 σ(F²). The weighted R-factor (wR) and goodness of fit (S) are based on F². R-factor (gt) are based on F. The threshold expression of F² > 2.0 σ(F²) is used only for calculating R-factor (gt).

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

	x	y	z	Uiso*/Ueq
Zn1	0.0000	0.5000	0.5000	0.0314 (1)
O1	0.0368 (2)	0.2152 (3)	0.4428 (1)	0.0352 (4)
O1M	0.0400 (2)	0.6690 (3)	0.3796 (1)	0.0369 (5)
O2	0.1933 (2)	−0.0160 (3)	0.4363 (1)	0.0438 (5)
N1	0.1975 (2)	0.4835 (4)	0.5459 (1)	0.0283 (4)
C1	0.2455 (2)	0.2957 (4)	0.5209 (2)	0.0269 (5)
C2	0.3713 (2)	0.2453 (4)	0.5450 (2)	0.0302 (6)
C3	0.4571 (2)	0.3900 (5)	0.5946 (2)	0.0297 (6)
C4	0.5902 (3)	0.3521 (5)	0.6190 (2)	0.0369 (7)
C5	0.6683 (2)	0.5044 (6)	0.6637 (2)	0.0421 (7)
C6	0.6183 (3)	0.6982 (6)	0.6873 (2)	0.0434 (8)
C7	0.4906 (3)	0.7385 (5)	0.6662 (2)	0.0364 (6)
C8	0.4078 (3)	0.5854 (5)	0.6194 (2)	0.0291 (6)
C9	0.2750 (2)	0.6212 (4)	0.5928 (2)	0.0292 (6)
C10	0.1506 (2)	0.1517 (4)	0.4620 (2)	0.0307 (6)
C11	−0.0523 (3)	0.7327 (7)	0.3043 (2)	0.0604 (10)
H1M	0.0709	0.8038	0.3972	0.0554*
H2	0.4006	0.1146	0.5286	0.0362*
H4	0.6241	0.2235	0.6045	0.0442*
H5	0.7555	0.4795	0.6786	0.0505*
H6	0.6728	0.8003	0.7177	0.0521*
H7	0.4584	0.8668	0.6827	0.0436*
H9	0.2412	0.7482	0.6093	0.0351*
H11A	−0.1101	0.6174	0.2859	0.0906*
H11B	−0.0104	0.7712	0.2555	0.0906*
H11C	−0.0989	0.8524	0.3206	0.0906*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0202 (2)	0.0306 (2)	0.0410 (2)	0.0034 (2)	−0.0008 (2)	−0.0060 (3)
O1	0.0257 (9)	0.033 (1)	0.044 (1)	0.0004 (8)	−0.0005 (8)	−0.0075 (9)
O1M	0.034 (1)	0.032 (1)	0.042 (1)	−0.0016 (9)	0.0004 (8)	0.0009 (9)
O2	0.0323 (10)	0.030 (1)	0.069 (1)	0.0017 (10)	0.0096 (9)	−0.015 (1)
N1	0.0219 (9)	0.030 (1)	0.033 (1)	0.003 (1)	0.0036 (8)	−0.001 (1)
C1	0.024 (1)	0.024 (1)	0.033 (1)	0.001 (1)	0.0059 (10)	0.000 (1)
C2	0.026 (1)	0.030 (1)	0.036 (1)	0.004 (1)	0.009 (1)	−0.002 (1)
C3	0.026 (1)	0.038 (2)	0.026 (1)	0.004 (1)	0.006 (1)	0.002 (1)
C4	0.026 (1)	0.047 (2)	0.037 (2)	0.008 (1)	0.007 (1)	0.002 (1)
C5	0.020 (1)	0.064 (2)	0.041 (1)	0.003 (2)	0.0018 (10)	0.000 (2)
C6	0.028 (1)	0.059 (2)	0.042 (2)	−0.007 (1)	0.002 (1)	−0.009 (2)
C7	0.031 (1)	0.042 (2)	0.035 (1)	−0.003 (1)	0.004 (1)	−0.006 (1)
C8	0.025 (1)	0.037 (1)	0.025 (1)	0.000 (1)	0.005 (1)	0.002 (1)
C9	0.023 (1)	0.031 (1)	0.033 (1)	0.003 (1)	0.004 (1)	−0.002 (1)
C10	0.030 (1)	0.026 (1)	0.038 (1)	−0.002 (1)	0.009 (1)	0.000 (1)
C11	0.052 (2)	0.076 (3)	0.048 (2)	0.001 (2)	−0.006 (2)	0.011 (2)

Geometric parameters (Å, º)

Zn1—O1	2.060 (2)	C3—C4	1.420 (4)
Zn1—O1^i	2.060 (2)	C3—C8	1.416 (4)
Zn1—O1M	2.214 (2)	C4—C5	1.365 (4)
Zn1—O1M^i	2.214 (2)	C4—H4	0.930
Zn1—N1	2.096 (2)	C5—C6	1.405 (5)
Zn1—N1^i	2.096 (2)	C5—H5	0.930
O1—C10	1.261 (3)	C6—C7	1.365 (4)
O1M—C11	1.419 (4)	C6—H6	0.930
O1M—H1M	0.932	C7—C8	1.408 (4)
O2—C10	1.242 (4)	C7—H7	0.930
N1—C1	1.370 (4)	C8—C9	1.419 (4)
N1—C9	1.313 (3)	C9—H9	0.930
C1—C2	1.363 (3)	C11—H11A	0.960
C1—C10	1.519 (4)	C11—H11B	0.960
C2—C3	1.407 (4)	C11—H11C	0.960
C2—H2	0.930
O1···O1^ii	3.383 (4)	O2···C11^iii	3.380 (4)
O1···C10^ii	3.530 (3)	O2···N1^iii	3.558 (3)
O1···O2^ii	3.546 (3)	O2···C6^v	3.592 (4)
O1···O1M^iii	3.573 (3)	C1···C5^v	3.336 (4)
O1M···O2^iv	2.614 (3)	C2···C5^v	3.478 (4)
O1M···C10^iv	3.413 (3)	C2···C6^v	3.546 (4)
O1M···C5^v	3.472 (3)	C3···C3^v	3.446 (6)
O2···C9^iii	3.288 (3)	C3···C4^v	3.563 (4)
O2···C4^vi	3.350 (4)	C4···C7^vii	3.576 (4)
O1—Zn1—O1^i	180.0000 (1)	C2—C3—C8	117.8 (2)
O1—Zn1—O1M	89.73 (7)	C4—C3—C8	118.7 (2)
O1—Zn1—O1M^i	90.27 (7)	C3—C4—C5	120.1 (3)
O1—Zn1—N1	80.67 (8)	C3—C4—H4	120.0
O1—Zn1—N1^i	99.33 (8)	C5—C4—H4	120.0
O1^i—Zn1—O1M	90.27 (7)	C4—C5—C6	120.7 (2)
O1^i—Zn1—O1M^i	89.73 (7)	C4—C5—H5	119.7
O1^i—Zn1—N1	99.33 (8)	C6—C5—H5	119.7
O1^i—Zn1—N1^i	80.67 (8)	C5—C6—C7	120.8 (3)
O1M—Zn1—O1M^i	180.0000 (1)	C5—C6—H6	119.6
O1M—Zn1—N1	87.78 (7)	C7—C6—H6	119.6
O1M—Zn1—N1^i	92.22 (7)	C6—C7—C8	119.8 (3)
O1M^i—Zn1—N1	92.22 (7)	C6—C7—H7	120.1
O1M^i—Zn1—N1^i	87.78 (7)	C8—C7—H7	120.1
N1—Zn1—N1^i	180.0	C3—C8—C7	119.9 (2)
Zn1—O1—C10	115.4 (2)	C3—C8—C9	117.7 (2)
Zn1—O1M—C11	125.7 (2)	C7—C8—C9	122.4 (3)
Zn1—O1M—H1M	108.4	N1—C9—C8	123.1 (2)
C11—O1M—H1M	97.3	N1—C9—H9	118.5
Zn1—N1—C1	110.9 (2)	C8—C9—H9	118.5
Zn1—N1—C9	129.9 (2)	O1—C10—O2	126.3 (2)
C1—N1—C9	119.3 (2)	O1—C10—C1	117.1 (2)
N1—C1—C2	121.9 (2)	O2—C10—C1	116.6 (2)
N1—C1—C10	115.7 (2)	O1M—C11—H11A	109.5
C2—C1—C10	122.4 (2)	O1M—C11—H11B	109.5
C1—C2—C3	120.3 (3)	O1M—C11—H11C	109.5
C1—C2—H2	119.9	H11A—C11—H11B	109.5
C3—C2—H2	119.9	H11A—C11—H11C	109.5
C2—C3—C4	123.4 (3)	H11B—C11—H11C	109.5
Zn1—O1—C10—O2	178.8 (2)	N1—Zn1—O1—C10	3.5 (2)
Zn1—O1—C10—C1	−2.3 (3)	N1—Zn1—O1^i—C10^i	176.5 (2)
Zn1—O1^i—C10^i—O2^i	−178.8 (2)	N1—Zn1—O1M—C11	175.7 (3)
Zn1—O1^i—C10^i—C1^i	2.3 (3)	N1—Zn1—O1M^i—C11^i	4.3 (3)
Zn1—N1—C1—C2	−178.2 (2)	N1—C1—C2—C3	−2.0 (4)
Zn1—N1—C1—C10	4.0 (3)	N1—C9—C8—C3	−0.9 (4)
Zn1—N1—C9—C8	179.6 (2)	N1—C9—C8—C7	177.1 (3)
Zn1—N1^i—C1^i—C2^i	178.2 (2)	C1—N1—C9—C8	0.0 (4)
Zn1—N1^i—C1^i—C10^i	−4.0 (3)	C1—C2—C3—C4	−177.4 (3)
Zn1—N1^i—C9^i—C8^i	−179.6 (2)	C1—C2—C3—C8	1.0 (4)
O1—Zn1—O1M—C11	95.0 (2)	C2—C1—N1—C9	1.5 (4)
O1—Zn1—O1M^i—C11^i	85.0 (2)	C2—C3—C4—C5	177.0 (3)
O1—Zn1—N1—C1	−3.9 (2)	C2—C3—C8—C7	−177.7 (3)
O1—Zn1—N1—C9	176.5 (2)	C2—C3—C8—C9	0.3 (4)
O1—Zn1—N1^i—C1^i	−176.1 (2)	C3—C2—C1—C10	175.7 (2)
O1—Zn1—N1^i—C9^i	3.5 (2)	C3—C4—C5—C6	1.0 (4)
O1—C10—C1—N1	−1.3 (4)	C3—C8—C7—C6	0.3 (4)
O1—C10—C1—C2	−179.1 (3)	C4—C3—C8—C7	0.8 (4)
O1M—Zn1—O1—C10	91.3 (2)	C4—C3—C8—C9	178.8 (3)
O1M—Zn1—O1^i—C10^i	88.7 (2)	C4—C5—C6—C7	0.1 (5)
O1M—Zn1—N1—C1	−94.0 (2)	C5—C4—C3—C8	−1.4 (4)
O1M—Zn1—N1—C9	86.4 (2)	C5—C6—C7—C8	−0.7 (5)
O1M—Zn1—N1^i—C1^i	−86.0 (2)	C6—C7—C8—C9	−177.7 (3)
O1M—Zn1—N1^i—C9^i	93.6 (2)	C9—N1—C1—C10	−176.4 (2)
O2—C10—C1—N1	177.7 (2)	C9—N1—C1—C10	−176.4 (2)
O2—C10—C1—C2	−0.1 (4)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1M—H1M···O2^iv	0.93	1.75	2.613 (3)	153

Symmetry code: (iv) x, y+1, z.