[5 Amino 6,8 di­chloro 2,3 bis­(2 pyridyl)­quinoxaline]­di­chloro­zinc(II)

metal-organic papers

m436

Structure Reports Online

ISSN 1600-5368

[5-Amino-6,8-dichloro-2,3-bis(2-pyridyl)-quinoxaline]dichlorozinc(II)

Dao-Li An,a_{Miao Du,}a

Xian-He Bu,a_{* Kumar Biradha}b and Mitsuhiko Shionoyac

a_{Department of Chemistry, Nankai University,}

Tianjin 300071, People's Republic of China,

b_{Institute for Molecular Science, Myodaiji,}

Okazaki 444-8585, Japan, andc_{Department of}

Chemistry, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan

Correspondence e-mail: buxh@nankai.edu.cn

Key indicators Single-crystal X-ray study

T= 193 K

Mean(C±C) = 0.007 AÊ

Rfactor = 0.046

wRfactor = 0.088

Data-to-parameter ratio = 13.6

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

#2002 International Union of Crystallography Printed in Great Britain ± all rights reserved

The ZnII_{atom in the title complex, [ZnCl}

2(C18H11N5Cl2)], has

a distorted tetrahedral environment formed by the N atoms of two quinoxalineortho-pyridyl substituents and two terminal chloro ligands. There is a symmetry-independent intermolec-ular hydrogen bond in the crystal, which links one of the H atoms of the aniline group with one of the chloro ligands [Cl N 3.418 (3) AÊ and Cl HÐN 142_{]. This hydrogen bond}

is responsible for the formation of in®nite zigzag chains, which run along thebaxis of the crystal.

Comment

Polypyridyl ligands and their transition metal complexes have attracted much interest owing to their potential as building blocks for supramolecular assemblies, as well as their possible use in optical sensors and probes for nucleic acids (Arkinet al., 1996; Holmlinet al., 1999). 2,3-Bis(2-pyridyl)quinoxaline and its derivatives represent an important class of chelating agents which have been extensively studied over the last two decades (Balzaniet al., 1996; Scottet al., 1999). However, most of the results were obtained for RuII_{, Os}II_{, and Re}I _complexes,

whereas studies on ®rst row transition metals are still quite rare. We report herein the synthesis and crystal structure of the zinc(II) complex [5-amino-6,8-dichloro-2,3-bis(2-pyridyl)-quinoxaline]dichlorozinc(II), (I) (Fig. 1).

The ZnII _{atom has a distorted tetrahedral coordination,}

formed by the N atoms of two ortho-pyridyl groups of the chelate system and two chloro ligands. The ortho-pyridyl substituents in the quinoxaline system can not be coplanar, either with each other or with the quinoxaline moiety, as a planar conformation would cause sterically unacceptable contacts between the pyridyl rings. In fact, the existence of the adjacent pyridyl substituents causes substantial out-of-plane twist, even within the quinoxaline itself, the torsion angle C1AÐC2ÐC3ÐC1B being ÿ4.1 (1)_{; the mean atomic}

displacement from the least-squares quinoxaline plane is 0.0345 (2) AÊ. The two pyridine rings form dihedral angles of

115.1 (3) and 53.3 (2)_{with the mean quinoxaline plane, and a}

dihedral angle of 94.4 (3)_{with each other.}

Selected bond distances and angles are given in Table 1. The C2ÐN1 and C3ÐN2 bond distances [1.318 (6) and 1.315 (6) AÊ, respectively] are noticeably shorter than N1ÐC9 and N2ÐC4 [1.354 (6) and 1.351 (6) AÊ, respectively], which is typical for quinoxaline system geometry (Rasmussen et al., 1990). All NÐC bond lengths are well within the range between the ranges normally considered standard for single CÐN and double C N bonds [1.47 AÊ (Sasada, 1984) and 1.28 AÊ (Wanget al., 1998), respectively].

Although there are two `active' H atoms in the structure, only one of them (H3C) actually takes part in intermolecular hydrogen bonding. The hydrogen bond N3ÐH3C Cl4i

[N3 Cl3i _{3.418 (3) AÊ and N3ÐH3C Cl3}i _{142; symmetry}

code: (i)ÿx, yÿ1/2, 1/2ÿz] links the molecules of the complex into in®nite chains along thebaxis of the crystal (Fig. 2).

Experimental

The title complex was synthesized by the reaction of 1-nitro-2,3-phenylenediamine and 2,20_{-bipyridyl, and then reduced by Pd/C in} the presence of concentrated (36%) HCl under re¯ux. The details will be published elsewhere. A mixture of solutions of equimolecular ZnCl2 (55 mg, 0.4 mmol) in CH3OH (30 ml) and

5-amino-6,8-di-chloro-2,3-bis(2-pyridyl)quinoxaline (147 mg, 0.4 mmol) in CHCl3

(20 ml) was left to stand at room temperature. Yellow crystals precipitated slowly with the evaporation of the solvent. Yield: 75%. FT±IR data (KBr pellet, cmÿ1_{): 3490 (m), 3380 (s), 1602 (vs), 1570}

(m), 1487 (s), 1458 (m), 1349 (vs), 1029 (s), 789 (m), 755 (m). Analysis calculated for the title complex: C 42.85, H 2.20, N 13.89%; found: C 42.81, H 2.40, N 13.83%.

Crystal data

[ZnCl2(C18H11N5Cl2)]

Mr= 504.49

Monoclinic,P21=c

a= 16.097 (9) AÊ b= 8.922 (3) AÊ c= 13.858 (4) AÊ

= 100.04 (3) V= 1959.8 (14) AÊ3

Z= 4

Dx= 1.710 Mg mÿ3

Mo Kradiation

Cell parameters from 10665 re¯ections

= 1.3±25.0 = 1.81 mmÿ1

T= 193 (2) K Prism, yellow 0.300.250.20 mm

Data collection

Bruker SMART 1000 diffractometer

!scans

Absorption correction: multi-scan [SAINT(Bruker, 1998) and SADABS(Sheldrick, 1997)] Tmin= 0.612,Tmax= 0.713

10833 measured re¯ections

3451 independent re¯ections 2107 re¯ections withI> 2(I) Rint= 0.096

max= 25.0

h=ÿ19!10 k=ÿ9!10 l=ÿ13!16

Re®nement

Re®nement onF2

R[F2_{> 2(F}2_{)] = 0.046}

wR(F2_{) = 0.088}

S= 1.04 3451 re¯ections 254 parameters

H-atom parameters constrained w= 1/[2_(F

o2) + (0.0256P)2]

whereP= (Fo2+ 2Fc2)/3

(/)max= 0.006 max= 0.47 e AÊÿ3 min=ÿ0.45 e AÊÿ3

Table 1

Selected geometric parameters (AÊ,_).

ZnÐN1A 2.062 (4)

ZnÐN1B 2.056 (4)

ZnÐCl3 2.2218 (18)

ZnÐCl4 2.2093 (17)

N1ÐC2 1.318 (6)

N1ÐC9 1.354 (6)

N2ÐC3 1.315 (6)

N2ÐC4 1.351 (6)

N3ÐC5 1.371 (6)

N1BÐZnÐN1A 91.32 (15) N1BÐZnÐCl4 113.73 (13) N1AÐZnÐCl4 112.42 (12)

N1BÐZnÐCl3 107.47 (12) N1AÐZnÐCl3 106.32 (13)

Cl4ÐZnÐCl3 121.30 (6)

Table 2

Hydrogen-bonding geometry (AÊ,_).

DÐH A DÐH H A D A DÐH A

N3ÐH3C Cl4i _{0.88 2.68 3.418 (3) 142}

Symmetry code: (i)ÿx;yÿ1 2;12ÿz.

All H atoms were placed in geometrically calculated positions and included in the ®nal re®nement in the riding-model approximation, with displacement parameters derived from the atoms to which they were bonded. TheUisovalues for the H atoms were set at 1.2Ueqof

the parent atom values.

Data collection:SMART(Bruker, 1998); cell re®nement:SMART; data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to re®ne

Acta Cryst.(2002). E58, m436±m438 Dao-Li Anet al. [ZnCl₂(C₁₈H₁₁N₅Cl₂)]

m437

metal-organic papers

Figure 2

View of the zigzag chain in the crystal of the title complex.

Figure 1

metal-organic papers

m438

structure: SHELXL97 (Sheldrick, 1997); molecular graphics:

ORTEPII (Johnson, 1976); software used to prepare material for publication:SHELXTL(Bruker, 1998).

The authors gratefully acknowledge ®nancial support from the National Natural Science Foundation of China (No. 29971019).

References

Arkin, M. R., Stemp, E. D. A., Holmlin, R. E., Barton, J. K., Hormann, A., Olson, E. J. C. & Barbara, P. F. (1996).Science,273, 475±480.

Balzani, V., Juris, A., Venturi, M., Campagna, S. & Serroni, S. (1996).Chem. Rev.96, 759±833.

Bruker (1998).SMART, SAINTandSHELXTL.Bruker AXS Inc., Madison, Wisconsin, USA.

Holmlin, R. E., Yao, J. A. & Barton, J. K. (1999).Inorg. Chem.38, 174± 189.

Johnson, C. K. (1976).ORTEPII. Report ORNL-5138. Oak Ridge National Laboratory, Tennessee, USA.

Rasmussen, S. C., Richter, M. M., Yi, E., Place, H. & Brewer, K. J. (1990). Inorg. Chem.29, 3926±3932.

Sasada, Y. (1984).Molecular and Crystal Structures, inChemistry Handbook, 3rd ed. Tokyo: The Chemical Society of Japan.

Scott, S. M., Gordon, K. C. & Burrell, A. K. (1999).J. Chem. Soc. Dalton Trans.pp. 2669±2673.

Sheldrick, G. M. (1997).SADABS,SHELXS97 andSHELXL97. University of GoÈttingen, Germany.

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Acta Cryst. (2002). E58, m436–m438

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Acta Cryst. (2002). E58, m436–m438 [https://doi.org/10.1107/S1600536802011996]

[5-Amino-6,8-dichloro-2,3-bis(2-pyridyl)quinoxaline]dichlorozinc(II)

Dao-Li An, Miao Du, Xian-He Bu, Kumar Biradha and Mitsuhiko Shionoya

[5-Amino-6,8-dichloro-2,3-bis(2-pyridyl)quinoxaline]dichlorozinc(II)

Crystal data

[ZnCl2(C18H11N5Cl2)] Mr = 504.49

Monoclinic, P21/c a = 16.097 (9) Å b = 8.922 (3) Å c = 13.858 (4) Å β = 100.04 (3)° V = 1959.8 (14) Å3 Z = 4

F(000) = 1008 Dx = 1.710 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 10665 reflections θ = 1.3–25.0°

µ = 1.81 mm−1 T = 193 K Prism, yellow

0.30 × 0.25 × 0.20 mm

Data collection

Bruker SMART 1000 diffractometer ω scans

Absorption correction: multi-scan [SAINT (Bruker 1998) and SADABS (Sheldrick, 1997)]

Tmin = 0.612, Tmax = 0.713 10833 measured reflections

3451 independent reflections 2107 reflections with I > 2σ(I) Rint = 0.096

θmax = 25.0° h = −19→10 k = −9→10 l = −13→16

Refinement

Refinement on F2 R[F2 _{> 2σ(F}2_{)] = 0.046} wR(F2_{) = 0.088} S = 1.04 3451 reflections 254 parameters

H-atom parameters constrained w = 1/[σ2_(Fo2_{) + (0.0256P)}2_]

where P = (Fo2 _{+ 2Fc}2_)/3 (Δ/σ)max = 0.006

Δρmax = 0.47 e Å−3 Δρmin = −0.45 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)

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Acta Cryst. (2002). E58, m436–m438

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

x y z Uiso*/Ueq

Zn 0.33071 (4) 0.47111 (6) 0.25157 (4) 0.02659 (17)

Cl1 −0.18991 (10) 0.55278 (17) 0.34475 (11) 0.0520 (4)

Cl2 0.06455 (10) 0.95320 (16) 0.39969 (11) 0.0530 (4)

Cl3 0.44506 (9) 0.42847 (14) 0.18617 (10) 0.0412 (4)

Cl4 0.21520 (9) 0.56715 (14) 0.16385 (9) 0.0370 (4)

N1 0.1754 (3) 0.6791 (4) 0.4168 (3) 0.0258 (10)

N2 0.1164 (3) 0.3866 (4) 0.3805 (3) 0.0254 (10)

N3 −0.0538 (3) 0.3202 (4) 0.3560 (3) 0.0368 (12)

H3C −0.1080 0.2995 0.3466 0.044*

H3D −0.0167 0.2472 0.3589 0.044*

C2 0.2280 (3) 0.5662 (5) 0.4158 (3) 0.0233 (12)

C3 0.1975 (3) 0.4169 (5) 0.3938 (3) 0.0212 (11)

C4 0.0613 (3) 0.5008 (5) 0.3809 (3) 0.0269 (12)

C5 −0.0271 (3) 0.4662 (6) 0.3661 (3) 0.0290 (12)

C6 −0.0823 (3) 0.5861 (6) 0.3623 (3) 0.0332 (13)

C7 −0.0537 (4) 0.7365 (6) 0.3730 (3) 0.0384 (15)

H7 −0.0936 0.8157 0.3686 0.046*

C8 0.0307 (4) 0.7689 (6) 0.3895 (4) 0.0344 (14)

C9 0.0916 (3) 0.6503 (5) 0.3950 (3) 0.0247 (12)

N1A 0.3706 (3) 0.5888 (4) 0.3793 (3) 0.0254 (10)

C1A 0.3189 (3) 0.6064 (5) 0.4452 (3) 0.0239 (12)

C2A 0.3480 (4) 0.6681 (5) 0.5377 (4) 0.0315 (14)

H2A 0.3112 0.6784 0.5840 0.038*

C3A 0.4306 (4) 0.7137 (5) 0.5606 (4) 0.0356 (15)

H3A 0.4516 0.7552 0.6233 0.043*

C4A 0.4826 (4) 0.6991 (5) 0.4925 (4) 0.0353 (15)

H4A 0.5393 0.7329 0.5063 0.042*

C5A 0.4506 (4) 0.6344 (5) 0.4038 (4) 0.0321 (13)

H5A 0.4872 0.6215 0.3576 0.039*

N1B 0.3092 (3) 0.2828 (4) 0.3291 (3) 0.0238 (10)

C1B 0.2522 (3) 0.2817 (5) 0.3910 (3) 0.0242 (12)

C2B 0.2420 (3) 0.1585 (5) 0.4469 (3) 0.0306 (13)

H2B 0.2026 0.1605 0.4905 0.037*

C3B 0.2895 (4) 0.0313 (5) 0.4393 (4) 0.0386 (14)

H3B 0.2825 −0.0551 0.4772 0.046*

C4B 0.3469 (3) 0.0306 (5) 0.3766 (4) 0.0335 (13)

H4B 0.3802 −0.0556 0.3706 0.040*

C5B 0.3551 (3) 0.1577 (5) 0.3229 (3) 0.0269 (12)

H5B 0.3947 0.1574 0.2795 0.032*

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

Zn 0.0280 (4) 0.0221 (3) 0.0305 (3) 0.0013 (3) 0.0073 (3) 0.0025 (3)

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Cl2 0.0506 (11) 0.0349 (8) 0.0716 (10) 0.0093 (8) 0.0055 (8) −0.0061 (7)

Cl3 0.0381 (10) 0.0358 (8) 0.0551 (9) 0.0064 (7) 0.0232 (8) 0.0039 (6)

Cl4 0.0353 (9) 0.0390 (8) 0.0357 (8) 0.0099 (7) 0.0031 (7) 0.0063 (6)

N1 0.029 (3) 0.026 (2) 0.023 (2) 0.001 (2) 0.006 (2) −0.0032 (17)

N2 0.029 (3) 0.026 (2) 0.023 (2) −0.003 (2) 0.008 (2) 0.0007 (17)

N3 0.023 (3) 0.034 (3) 0.053 (3) −0.002 (2) 0.006 (2) 0.005 (2)

C2 0.030 (3) 0.020 (3) 0.021 (3) −0.001 (2) 0.006 (2) −0.002 (2)

C3 0.021 (3) 0.025 (3) 0.019 (3) −0.001 (2) 0.005 (2) 0.005 (2)

C4 0.030 (3) 0.030 (3) 0.021 (3) 0.001 (3) 0.006 (2) 0.004 (2)

C5 0.025 (3) 0.037 (3) 0.024 (3) 0.002 (3) 0.005 (2) 0.003 (2)

C6 0.029 (4) 0.047 (3) 0.024 (3) 0.004 (3) 0.006 (3) 0.008 (2)

C7 0.036 (4) 0.049 (4) 0.032 (3) 0.017 (3) 0.010 (3) 0.005 (3)

C8 0.034 (4) 0.034 (3) 0.035 (3) 0.007 (3) 0.006 (3) −0.001 (2)

C9 0.029 (4) 0.031 (3) 0.015 (3) 0.006 (3) 0.007 (3) 0.000 (2)

N1A 0.024 (3) 0.018 (2) 0.034 (2) 0.001 (2) 0.005 (2) 0.0027 (17)

C1A 0.028 (4) 0.009 (2) 0.033 (3) 0.001 (2) 0.001 (3) 0.003 (2)

C2A 0.042 (4) 0.019 (3) 0.034 (3) 0.001 (3) 0.007 (3) −0.002 (2)

C3A 0.036 (4) 0.024 (3) 0.040 (3) −0.006 (3) −0.011 (3) −0.007 (2)

C4A 0.033 (4) 0.025 (3) 0.045 (4) −0.002 (3) 0.000 (3) 0.001 (2)

C5A 0.031 (4) 0.022 (3) 0.044 (3) −0.002 (3) 0.007 (3) 0.005 (2)

N1B 0.024 (3) 0.021 (2) 0.026 (2) 0.000 (2) 0.004 (2) −0.0011 (17)

C1B 0.022 (3) 0.022 (3) 0.028 (3) 0.000 (2) 0.003 (3) −0.002 (2)

C2B 0.030 (4) 0.028 (3) 0.036 (3) 0.000 (3) 0.010 (3) 0.008 (2)

C3B 0.049 (4) 0.020 (3) 0.048 (3) 0.001 (3) 0.013 (3) 0.009 (3)

C4B 0.033 (4) 0.020 (2) 0.048 (3) 0.005 (3) 0.009 (3) 0.000 (2)

C5B 0.020 (3) 0.025 (3) 0.036 (3) −0.001 (2) 0.004 (3) −0.004 (2)

Geometric parameters (Å, º)

Zn—N1A 2.062 (4) C6—C5 1.386 (7)

Zn—N1B 2.056 (4) N1A—C5A 1.337 (6)

Zn—Cl3 2.2218 (18) N1A—C1A 1.348 (6)

Zn—Cl4 2.2093 (17) C1A—C2A 1.399 (6)

Cl2—C8 1.730 (5) C2A—C3A 1.373 (7)

Cl1—C6 1.732 (6) C2A—H2A 0.9500

N1—C2 1.318 (6) C3A—C4A 1.373 (7)

N1—C9 1.354 (6) C3A—H3A 0.9500

N2—C3 1.315 (6) C4A—C5A 1.373 (7)

N2—C4 1.351 (6) C4A—H4A 0.9500

N3—C5 1.371 (6) C5A—H5A 0.9500

N3—H3C 0.8800 N1B—C5B 1.349 (6)

N3—H3D 0.8800 N1B—C1B 1.360 (6)

C2—C3 1.434 (6) C1B—C2B 1.371 (6)

C2—C1A 1.492 (7) C2B—C3B 1.383 (7)

C3—C1B 1.498 (6) C2B—H2B 0.9500

C4—C9 1.423 (6) C3B—C4B 1.374 (7)

C4—C5 1.435 (7) C3B—H3B 0.9500

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Acta Cryst. (2002). E58, m436–m438

C8—C7 1.369 (7) C4B—H4B 0.9500

C7—C6 1.417 (7) C5B—H5B 0.9500

C7—H7 0.9500

N1B—Zn—N1A 91.32 (15) C5A—N1A—Zn 121.0 (3)

N1B—Zn—Cl4 113.73 (13) C1A—N1A—Zn 120.2 (3)

N1A—Zn—Cl4 112.42 (12) N1A—C1A—C2A 121.2 (5)

N1B—Zn—Cl3 107.47 (12) N1A—C1A—C2 118.7 (4)

N1A—Zn—Cl3 106.32 (13) C2A—C1A—C2 120.0 (5)

Cl4—Zn—Cl3 121.30 (6) C3A—C2A—C1A 119.0 (5)

C2—N1—C9 118.0 (4) C3A—C2A—H2A 120.5

C3—N2—C4 118.8 (4) C1A—C2A—H2A 120.5

C5—N3—H3C 120.0 C4A—C3A—C2A 119.6 (5)

C5—N3—H3D 120.0 C4A—C3A—H3A 120.2

H3C—N3—H3D 120.0 C2A—C3A—H3A 120.2

N1—C2—C3 121.1 (5) C3A—C4A—C5A 118.5 (6)

N1—C2—C1A 114.5 (4) C3A—C4A—H4A 120.7

C3—C2—C1A 124.4 (4) C5A—C4A—H4A 120.7

N2—C3—C2 121.0 (4) N1A—C5A—C4A 123.3 (5)

N2—C3—C1B 113.9 (4) N1A—C5A—H5A 118.4

C2—C3—C1B 124.9 (5) C4A—C5A—H5A 118.4

N2—C4—C9 119.9 (5) C5B—N1B—C1B 118.1 (4)

N2—C4—C5 118.2 (4) C5B—N1B—Zn 119.9 (3)

C9—C4—C5 121.9 (5) C1B—N1B—Zn 121.9 (3)

N1—C9—C4 120.9 (4) N1B—C1B—C2B 121.5 (4)

N1—C9—C8 121.1 (5) N1B—C1B—C3 118.3 (4)

C4—C9—C8 118.0 (5) C2B—C1B—C3 120.1 (5)

C7—C8—C9 120.1 (5) C1B—C2B—C3B 119.5 (5)

C7—C8—Cl2 120.3 (4) C1B—C2B—H2B 120.3

C9—C8—Cl2 119.6 (4) C3B—C2B—H2B 120.3

C8—C7—C6 120.8 (5) C4B—C3B—C2B 119.6 (5)

C8—C7—H7 119.6 C4B—C3B—H3B 120.2

C6—C7—H7 119.6 C2B—C3B—H3B 120.2

C5—C6—C7 122.1 (5) C3B—C4B—C5B 118.5 (5)

C5—C6—Cl1 119.5 (4) C3B—C4B—H4B 120.7

C7—C6—Cl1 118.4 (4) C5B—C4B—H4B 120.7

N3—C5—C6 122.8 (5) N1B—C5B—C4B 122.8 (5)

N3—C5—C4 120.3 (5) N1B—C5B—H5B 118.6

C6—C5—C4 116.9 (5) C4B—C5B—H5B 118.6

C5A—N1A—C1A 118.3 (4)

Hydrogen-bond geometry (Å, º)

D—H···A D—H H···A D···A D—H···A

N3—H3C···Cl4i _{0.88 2.68 3.418 (3) 142}