On the reaction of nickel(II) ions with thiol­acetic acid

metal-organic papers

m92

Mahmoudkhani and Langer [Ni(C₂H₃S₃)₂] DOI: 101107/S1600536801001994 Acta Cryst.(2001). E57, m92±m94 Acta Crystallographica Section E

Structure Reports Online

ISSN 1600-5368

On the reaction of nickel(II) ions with thiolacetic acid

Amir H. Mahmoudkhania_{* and} Vratislav Langerb

a_{Department of Chemistry, GoÈteborg University,} SE-41296 GoÈteborg, Sweden, andb_Department of Environmental Inorganic Chemistry, Chalmers University of Technology, SE-41296 GoÈteborg, Sweden

Correspondence e-mail: amir@inoc.chalmers.se

Key indicators

Single-crystal X-ray study

T= 297 K

Mean(C±C) = 0.004 AÊ

Rfactor = 0.034

wRfactor = 0.087

Data-to-parameter ratio = 18.7

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

#2001 International Union of Crystallography Printed in Great Britain ± all rights reserved

An unexpected mononuclear nickel thiolate, bis(perthio-acetato-S,S0_{)nickel(II), [Ni(C}

2H3S3)2], has been obtained by

the reaction of NiII_{ions with thiolacetic acid. It consists of a}

planar rectangular NiS4 unit. Weak hydrogen bonds of the

type CÐH Ni form molecular ribbons along the a axis. Among the products,-sulfur is also detected.

Comment

Metal thiolates, including nickel thiolates, are a rich class of compounds and they are relevant to the coordination of metal ions by sulfur-containing amino acids in biological systems. They are also of interest as synthetic models related to metal sul®de catalysis (Krebs & Henkel, 1991). The reaction of NiII

ions with thiolate ligands provides a large variety of structural possibilities ranging from mononuclear to polynuclear complexes including cyclic clusters and chain fragments. So far, several cyclic nickel thiolates have been synthesized and characterized by diffraction techniques; nevertheless, the governing factors of the degree of oligomerization of cyclic or chain nickel thiolates are still unknown. We believe that the study of structural systematics and relationships may lead to an understanding of the architecture of these compounds in order to design new cyclic clusters. Recently, we have reported the synthesis and structures of a pentanuclear and a hexa-nuclear cyclic nickel thiolate where the thiolate ligands differed only by the substituents on the -C atom (Mahmoudkhani & Langer, 1999a,b). In order to understand the effect of electronic modulations on the-C atom of the thiolate ligand, we have undertaken the reaction of NiII_ions

with thiolacetic acid. To our surprise, instead of a cyclic cluster, we obtained a mononuclear nickel thiolate, (I), in which the primary thiolcarboxylate ligand was transformed to a per-thiocarboxylate ligand. This is, to the best of our knowledge, the ®rst example of an alkylperthiocarboxylato±metal complex, although there are some reports on the structure of arylperthiocarboxylate-metal complexes (Coucouvanis et al., 1985; Coucouvanis & Fackler, 1967; Fackler et al., 1968; Lanferdiet al., 1988).

These complexes are in general prepared by an oxidative addition of sulfur to the corresponding dithiocarboxylate±

metal complex. But formation of this mononuclear nickel thiolate from the reaction of NiII _{ions with thiolacetic acid}

seems to be unique. Furthermore, we have also detected the formation of-sulfur by this reaction which makes the inter-pretation much more complicated. Complex (I) crystallizes in the monoclinic system with space groupP21/n. The structure is

centrosymmetric and the asymmetric unit contains only a half of the molecule. The complex consists of a planar rectangular NiS4 unit with no trace of bridging by thiolate±S atom. The

atomic numbering for the complex (I) is presented in Fig. 1. The bond distances and angles are about the same order as for other sulfur-rich nickel thiolates with a similar skeleton. The structure exhibits a hydrogen mediated interaction in the form of weak hydrogen bonds of the type CÐH M forming molecular ribbons along theaaxis (see Fig. 2). The ability of metal centers to be involved in hydrogen bonds and hydrogen mediated interactions has been recently reviewed by Desiraju & Steiner (1999). For complex (I), the interaction CÐH Ni with an H Ni distance of 3.15 AÊ and an angle of 134.3_{, lies}

just in the range 2.5±3.2 AÊ to be regarded as a weak CÐH M hydrogen bond, and is shorter than the sum of van der Waals radii of 3.5 AÊ.

Experimental

Complex (I) was obtained by a microscale reaction of NiCl2H2O (Aldrich) and thiolacetic acid (Aldrich) in the presence of KOH in ethanol according to the method of Mahmoudkhani & Langer (1999a,b). Solvents were removed by vacuum distillation and the products isolated by microextraction with benzene and subsequent crystallization from benzene±acetone solution. Crystals of (I) were obtained after a few days by slow evaporation of the solution in acetone when allowed to stand over silica gel in a desiccator.

Crystal data

[Ni(C2H3S3)2] Mr= 305.16

Monoclinic,P21/n a= 5.3169 (3) AÊ

b= 6.1524 (3) AÊ

c= 15.9722 (8) AÊ

= 92.50 (1)

V= 521.98 (5) AÊ3 Z= 2

Dx= 1.942 Mg mÿ3

MoKradiation Cell parameters from 3360

re¯ections

= 1±25

= 2.99 mmÿ1 T= 297 (2) K

Parallelepiped, dark red 0.300.250.04 mm

Data collection

Siemens SMART CCD diffract-ometer

!scans

Absorption correction: multi-scan (Blessing; 1995)

Tmin= 0.467,Tmax= 0.890 4984 measured re¯ections

992 independent re¯ections 848 re¯ections withI> 2(I)

Rint= 0.047

max= 25.7 h=ÿ6!6

k=ÿ7!7

l=ÿ19!19

Re®nement

Re®nement onF2 R[F2_{> 2(F}2_{)] = 0.033} wR(F2_{) = 0.087} S= 1.02 992 re¯ections 53 parameters

H atoms constrained

w= 1/[2_(F

o2) + (0.0565P)2]

whereP= (Fo2+ 2Fc2)/3

(/)max= 0.001

max= 0.56 e AÊÿ3

min=ÿ0.46 e AÊÿ3

Table 1

Selected geometric parameters (AÊ,_).

Ni1ÐS1 2.1579 (8) Ni1ÐS3 2.1623 (8) S3ÐS2 2.0322 (12)

S2ÐC1 1.668 (3) S1ÐC1 1.667 (3) C2ÐC1 1.496 (4)

S1ÐNi1ÐS3i _{85.75 (3)}

S1ÐNi1ÐS3 94.25 (3) S2ÐS3ÐNi1 107.26 (4) C1ÐS2ÐS3 105.29 (11)

C1ÐS1ÐNi1 110.05 (11) C2ÐC1ÐS1 120.0 (2) C2ÐC1ÐS2 116.8 (2) S1ÐC1ÐS2 123.14 (18)

Symmetry code: (i)ÿx;ÿy;ÿz.

Acta Cryst.(2001). E57, m92±m94 Mahmoudkhani and Langer [Ni(C₂H₃S₃)₂]

m93

metal-organic papers

Figure 1

The molecular structure of (I). Displacement ellipsoids are shown at the 50% probability level.

Figure 2

metal-organic papers

m94

Mahmoudkhani and Langer [Ni(C₂H₃S₃)₂] Acta Cryst.(2001). E57, m92±m94

Table 2

Hydrogen-bonding geometry (AÊ,_).

DÐH A DÐH H A D A DÐH A

C2ÐH2C Ni1i _{0.96 3.15 3.880 (4) 134} Symmetry codes: (i) 1‡x;y;z.

H atoms were constrained to the ideal geometry using an appro-priate riding model. The CÐH distances (0.96 AÊ) and CÐCÐH angles (109.5_{) were kept ®xed, while the torsion angles were allowed} to re®ne with the starting position based on threefold averaged circular Fourier synthesis.

Data collection:SMART(Siemens, 1995); cell re®nement:SAINT

(Siemens, 1995); data reduction:SAINTand SADABS (Sheldrick, 2001); program(s) used to solve structure:SHELXTL(Bruker, 1997); program(s) used to re®ne structure:SHELXTL; molecular graphics:

SHELXTL; software used to prepare material for publication:

SHELXTL.

References

Blessing, R. H. (1995).Acta Cryst.A51, 33±38.

Bruker (1997). SHELXTL (Version 5.10). Bruker AXS Inc., Madison, Wisconsin, USA.

Coucouvanis, D. & Fackler, J. P. Jr (1967).J. Am. Chem. Soc.89, 1346±1351. Coucouvanis, D., Patil, P. R., Kanatzidis, M. G., Deterring, B. & Baenziger, N.

C. (1985).Inorg. Chem.24, 24±31.

Desiraju, G. R. & Steiner, T. (1999). InThe Weak Hydrogen Bond in Structural Chemistry and Biology. New York: Oxford University Press.

Fackler, J. P. Jr, Coucouvanis, D., Fetchin, J. A. & Seidel, W. C. (1968).J. Am. Chem. Soc.90, 2784±2788.

Krebs, B. & Henkel, G. (1991).Angew. Chem. Int. Ed. Engl.30, 769±788. Lanferdi, A. M. M., Tiripicchio, A., Marsich, N. & Camus, A. (1988).Inorg.

Chim. Acta,142, 269±275.

Mahmoudkhani, A. H. & Langer, V. (1999a).Inorg. Chim. Acta,294, 83±86. Mahmoudkhani, A. H. & Langer, V. (1999b).Polyhedron,18, 3407±3410. Sheldrick, G. M. (2001).SADABS(Version 2.02). University of GoÈttingen,

Germany.

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Acta Cryst. (2001). E57, m92–m94

supporting information

Acta Cryst. (2001). E57, m92–m94 [doi:10.1107/S1600536801001994]

On the reaction of nickel(II) ions with thiolacetic acid

Amir H. Mahmoudkhani and Vratislav Langer

S1. Comment

Metal thiolates, including nickel thiolates, are a rich class of compounds and they are relevant to the coordination of

metal ions by sulfur-containing amino acids in biological systems. They are also of interest as synthetic models related to

metal sulfide catalysis (Krebs & Henkel, 1991). The reaction of NiII _{ions with thiolate ligands, provides a large variety of}

structural possibilities ranging from mononuclear to polynuclear complexes including cyclic clusters and chain

fragments. So far, several cyclic nickel thiolates have been synthesized and characterized by diffraction techniques,

nevertheless, the governing factors of the degree of oligomerization of cyclic or chain nickel thiolates are still unknown.

We believe that the study of structural systematics and relationships may lead to an understanding of the architecture of

these compounds in order to design new cyclic clusters. Recently, we have reported the synthesis and structures of a

pentanuclear and a hexanuclear cyclic nickel thiolates where the thiolate ligands were only different by the substituents

on the β-C atom (Mahmoudkhani & Langer, 1999a,b). In order to understand the effect of electronic modulations on α-C

atom of thiolate ligand, we have undertaken the reaction of NiII _{ions with thiolacetic acid. To our surprise, instead of a}

cyclic cluster, we obtained a mononuclear nickel thiolate, (I), in which the primary thiolcarboxylate ligand was

transformed to a perthiocarboxylate ligand. This is to our best knowledge, the first example of an

alkylperthiocarboxyl-ato–metal complex, although there are some reports on the structure of arylperthiocarboxylate-metal complexes

(Coucouvanis et al., 1985; Coucouvanis & Fackler, 1967; Fackler et al., 1968; Lanferdi et al., 1988).

These complexes are in general prepared by an oxidative addition of sulfur to the corresponding dithiocarboxylate–

metal complex. But formation of this mononuclear nickel thiolate from the reaction of NiII _{ions with thiolacetic acid,}

seems to be rather unusual and unique. Furthermore, we have also detected the formation of γ-sulfur by this reaction

which makes the interpretation much more complicated. Complex (I) crystallizes in the monoclinic system with space

group P21/n. The structure is centrosymmetric and the asymmetric unit contains only a half of the molecule. The complex

consists of a planar rectangular NiS4 unit with no trace of bridging by thiolate-S atom. The atomic numbering for the

complex (I) is presented in Fig. 1. The bond distances and angles are about the same order as for other sulfur-rich nickel

thiolates with a similar skeleton. The structure exhibits a hydrogen mediated interaction in the form of a weak hydrogen

bonds of the type C—H···M forming molecular ribbons along a axis (see Fig. 2). The ability of metal centers to be

involved in hydrogen bonds and hydrogen mediated interactions has been recently reviewed by Desiraju & Steiner

(1999). For complex (I), the interaction C—H···Ni with an H···Ni distance of 3.15 Å and an angle of 134.3°, lies just in

the range 2.5–3.2 Å to be regarded as a weak C—H···M hydrogen bond, and is shorter than the sum of van der Waals radii

of 3.5 Å.

S2. Experimental

Complex (I) has been obtained by a microscale reaction of NiCl2.H2O (Aldrich) and thiolacetic acid (Aldrich) in the

supporting information

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Acta Cryst. (2001). E57, m92–m94

Solvents were removed by vacuum distillation·The products were then isolated by microextraction with benzene and

subsequent crystallization from benzene–acetone solution. Crystals of (I) suitable for X-ray diffraction analysis were

obtained after few days by slow evaporation of the solution in acetone when allowed to stand over silica gel in a

desiccator.

S3. Refinement

H atoms were constrained to the ideal geometry using an appropriate riding model. The C—H distances (0.96 Å) and C—

C—H angles (109.5°) were kept fixed, while the torsion angles were allowed to refine with the starting position based on

[image:5.610.125.481.210.424.2]

threefold averaged circular Fourier synthesis.

Figure 1

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[image:6.610.127.490.73.456.2]

Acta Cryst. (2001). E57, m92–m94 Figure 2

The molecular ribbons formed by weak hydrogen bonds in the crystal structure of (I).

(BMN)

Crystal data

[Ni(C2H3S3)2]

Mr = 305.16

Monoclinic, P21/n

a = 5.3169 (3) Å b = 6.1524 (3) Å c = 15.9722 (8) Å β = 92.50 (1)° V = 521.98 (5) Å3

Z = 2

F(000) = 308 Dx = 1.942 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 3360 reflections θ = 1–25°

µ = 2.99 mm−1

T = 297 K

Parallepide, dark red 0.30 × 0.25 × 0.04 mm

Data collection

Siemens SMART CCD diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

Detector resolution: no pixels mm-1

ω scans

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Acta Cryst. (2001). E57, m92–m94 Tmin = 0.467, Tmax = 0.890 4984 measured reflections 992 independent reflections 848 reflections with I > 2σ(I) Rint = 0.047

θmax = 25.7°, θmin = 2.6°

h = −6→6 k = −7→7 l = −19→19

Refinement

Refinement on F2 Least-squares matrix: full R[F2 _{> 2σ(F}2_{)] = 0.034}

wR(F2_{) = 0.087}

S = 1.02 992 reflections 53 parameters 0 restraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

Hydrogen site location: inferred from neighbouring sites

H atoms treated by a mixture of independent and constrained refinement

w = 1/[σ2_(F

o2) + (0.0565P)2] where P = (Fo2 + 2Fc2)/3 (Δ/σ)max = 0.001

Δρmax = 0.56 e Å−3 Δρmin = −0.46 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 F}2_, conventional R-factors R are based on F, with F set to zero for negative F2_{. The threshold expression of F}2 _{> σ(F}2_{) 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 (Å2₎

x y z Uiso*/Ueq

Ni1 0.0000 0.0000 0.0000 0.0387 (2)

S3 0.07836 (17) −0.17320 (15) 0.11602 (5) 0.0607 (3) S2 0.35389 (19) −0.00717 (14) 0.18086 (6) 0.0579 (3) S1 0.27462 (17) 0.25107 (13) 0.02763 (5) 0.0542 (3) C2 0.6249 (6) 0.3537 (6) 0.1523 (2) 0.0622 (9)

H2A 0.6870 0.3053 0.2065 0.093*

H2B 0.5583 0.4981 0.1568 0.093*

H2C 0.7600 0.3541 0.1143 0.093*

C1 0.4217 (6) 0.2036 (5) 0.12013 (18) 0.0464 (7)

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

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Acta Cryst. (2001). E57, m92–m94 Geometric parameters (Å, º)

Ni1—S1 2.1579 (8) S1—C1 1.667 (3)

Ni1—S1i _{2.1579 (8) C2—C1 1.496 (4)}

Ni1—S3i _{2.1623 (8) C2—H2A 0.96}

Ni1—S3 2.1623 (8) C2—H2B 0.96

S3—S2 2.0322 (12) C2—H2C 0.96

S2—C1 1.668 (3)

S1—Ni1—S1i _{180.00 (5) C1—C2—H2A 109.5}

S1—Ni1—S3i _{85.75 (3) C1—C2—H2B 109.5}

S1i_—Ni1—S3i _{94.25 (3) H2A—C2—H2B 109.5}

S1—Ni1—S3 94.25 (3) C1—C2—H2C 109.5

S1i_{—Ni1—S3 85.75 (3) H2A—C2—H2C 109.5}

S3i_{—Ni1—S3 180.00 (5) H2B—C2—H2C 109.5}

S2—S3—Ni1 107.26 (4) C2—C1—S1 120.0 (2)

C1—S2—S3 105.29 (11) C2—C1—S2 116.8 (2)

C1—S1—Ni1 110.05 (11) S1—C1—S2 123.14 (18)

Symmetry code: (i) −x, −y, −z.

Hydrogen-bond geometry (Å, º)

D—H···A D—H H···A D···A D—H···A

C2—H2C···Ni1ii _{0.96 3.15 3.880 (4) 134}