Assembly of a new family of mercury(II) zwitterionic thiolate complexes from a preformed compound [Hg(Tab)2](PF6)2 [Tab = 4-(trimethylammonio)benzenethiolate]

Article abstract of DOI:10.1021/ic051875n

Reactions of Hg(OAc)₂ with 2 equiv of TabHPF₆ [TabH = 4-(trimethylammonio)benzenethiol] in MeCN/MeOH afforded a mononuclear linear complex [Hg(Tab)₂](PF₆)₂ (1). By using 1 as a precursor, a new family of mercury(II) zwitterionic thiolate complexes, [Hg ₂(Tab)₆](PF₆)₄·2MeCN (2·2MeCN), [Hg(Tab)₂(SCN)](PF₆) (3), [Hg(Tab) ₂(SCN)₂] (4), [Hg-(Tab)I₂] (5), {[Hg(Tab) ₂]₄[HgI₂][Hg₂I₆]}(PF ₆)₂(NO₃)₄ (6), [Hg(Tab) ₂][HgI₄] (7), [Hg(Tab)₂][HgCl ₂(SCN)₂] (8), [Tab-Tab]₂[Hg₃Cl ₁₀] (9), and [Hg₂(Tab)₆]₃(PF ₆)Cl₁₁ (10), were prepared and characterized by elemental analysis, IR spectra, UV-vis spectra, ¹H-NMR, and single-crystal X-ray crystallography. The [Hg₂(Tab)₆]⁴⁺ tetracation of 2 or 10 contains an asymmetrical Hg₂S₂ rhomb with an inversion center lying on the midpoint of the Hg...Hg line. The Hg atom of the [Hg(Tab)₂]²⁺ dication of 3 is coordinated to one SCN^-, forming a rare T-shaped coordination geometry, while in 4, the Hg atom of [Hg(Tab)₂]²⁺ is coordinated to two SCN^-, forming a seesaw-shaped coordination geometry. Through weak secondary Hg...S coordinations, each cation in 3 is further linked to afford a one-dimensional zigzag chain. The trigonal [Hg(Tab)I₂] molecules in 5 are held together by weak secondary Hg...I and Hg...S interactions, forming a one-dimensional chain structure. In 6, the four [Hg(Tab)₂]²⁺ dications, one HgI₂ molecule, one [Hg₂I₆]^2- dianion, one PF₆^-, and four NO₃^- anions are interconnected by complicated secondary Hg...I and Hg...O interactions, forming a scolopendra-like chain structure. The secondary Hg...I interactions, [Hg(Tab)₂]²⁺ and [HgI ₄]^2- in 7, are combined to generate a one-dimensional chain structure, while [Hg(Tab)₂]²⁺ and [HgCl ₂(SCN)₂]^2- in 8 are interconnected by secondary Hg...N interactions to form a one-dimensional zigzag chain structure. Compound 9 consists of two [Tab-Tab]²⁺ dications and one [Hg ₃Cl₁₀]^4- tetraanion. The facile approach to the construction of 2-8 and 10 from 1 may be applicable to the mimicking of a coordination sphere of the Hg sites of metallothioneins.

Full text of DOI:10.1021/ic051875n

Inorg. Chem. 2006, 45, 2568−2580
Assembly of a New Family of Mercury(II) Zwitterionic Thiolate
Complexes from a Preformed Compound [Hg(Tab)2](PF6)2 [Tab
4-(Trimethylammonio)benzenethiolate]
)
Jin-Xiang Chen,† Wen-Hua Zhang,† Xiao-Yan Tang,† Zhi-Gang Ren,† Yong Zhang,† and
Jian-Ping Lang*,†,‡
Key Laboratory of Organic Synthesis of Jiangsu ProVince, School of Chemistry and Chemical
Engineering, Suzhou UniVersity, Suzhou 215123, Jiangsu, People’s Republic of China, and State
Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter
CAS, Fuzhou 350002, Fujian, People’s Republic of China
Received October 28, 2005
Reactions of Hg(OAc)2 with 2 equiv of TabHPF6 [TabH
a mononuclear linear complex [Hg(Tab)2](PF6)2 (1). By using 1 as a precursor, a new family of mercury(II) zwitterionic
thiolate complexes, [Hg2(Tab)6](PF6)4 2MeCN (2 2MeCN), [Hg(Tab)2(SCN)](PF6) (3), [Hg(Tab)2(SCN)2] (4), [Hg-
(Tab)I2] (5), [Hg(Tab)2]4[HgI2][Hg2I6] (PF6)2(NO3)4 (6), [Hg(Tab)2][HgI4] (7), [Hg(Tab)2][HgCl2(SCN)2] (8), [Tab
) 4-(trimethylammonio)benzenethiol] in MeCN/MeOH afforded
‚
‚
{
}
−
Tab]2[Hg3Cl10] (9), and [Hg2(Tab)6]3(PF6)Cl11 (10), were prepared and characterized by elemental analysis, IR spectra,
1
UV
−
vis spectra, H NMR, and single-crystal X-ray crystallography. The [Hg2(Tab)6]4+ tetracation of 2 or 10 contains
an asymmetrical Hg2S2 rhomb with an inversion center lying on the midpoint of the Hg‚‚‚Hg line. The Hg atom of
+
the [Hg(Tab)2]2 dication of 3 is coordinated to one SCN-, forming a rare T-shaped coordination geometry, while
+
in 4, the Hg atom of [Hg(Tab)2]2 is coordinated to two SCN-, forming a seesaw-shaped coordination geometry.
Through weak secondary Hg‚‚‚S coordinations, each cation in 3 is further linked to afford a one-dimensional
zigzag chain. The trigonal [Hg(Tab)I2] molecules in 5 are held together by weak secondary Hg‚‚‚I and Hg‚‚‚
S
+
interactions, forming a one-dimensional chain structure. In 6, the four [Hg(Tab)2]2 dications, one HgI2 molecule,
-
-
one [Hg2I6]2 dianion, one PF6-, and four NO3 anions are interconnected by complicated secondary Hg‚‚‚I and
Hg‚‚‚O interactions, forming a scolopendra-like chain structure. The secondary Hg‚‚‚I interactions, [Hg(Tab)2]2
+
and [HgI4]2- in 7, are combined to generate a one-dimensional chain structure, while [Hg(Tab)2]2+ and [HgCl2(SCN)2]2
-
in 8 are interconnected by secondary Hg‚‚‚N interactions to form a one-dimensional zigzag chain structure. Compound
+
4-
9 consists of two [Tab
−
Tab]2 dications and one [Hg3Cl10
]
tetraanion. The facile approach to the construction of
2
−8 and 10 from 1 may be applicable to the mimicking of a coordination sphere of the Hg sites of metallothioneins.
Introduction
Cys)3}, and tetrahedral {Hg(S-Cys)4} coordination geom-
etries have been proposed for HgII in the mercury metallo-
As in past decades, mercury thiolate complexes have
received much attention as a result of their rich chemistry,1
their application in the resistance response in bacteria at the
level of gene activation,2 their relation to the detoxification
of Hg by metallothioneins,3 and their involvement in a DNA-
binding protein1a and in mercury reductases and related
proteins.1b The linear {Hg(S-Cys)2}, trigonal {Hg(S-
thioneins.1f,4 Studies in these respects have stimulated more
interest in structural probes that might be used to determine
the nature of the coordination of the HgII ion to the proteins.
So far, a large number of mercury thiolate compounds have
been prepared and structurally characterized: mononuclear
Hg(SR)n (n ) 2-4),5 dinuclear Hg2(SR)n (n ) 3 and 6),4a,6
trinuclear Hg3(SR)4,6a tetranuclear Hg4(SR)6,7 pentanuclear
Hg5(SR)8,2 and polynuclear [Hg(SR)n]∞.5c Most of these
compounds have been prepared from a one-pot reaction of
simple HgII salts with RSH or from redox reactions of organic
* To whom correspondence should be addressed. E-mail:
jplang@suda.edu.cn.
† Suzhou University.
‡ Fujian Institute of Research on the Structure of Matter CAS.
2568 Inorganic Chemistry, Vol. 45, No. 6, 2006
10.1021/ic051875n CCC: $33.50
© 2006 American Chemical Society
Published on Web 02/11/2006

Family of Mercury(II) Zwitterionic Thiolate Complexes
disulfides with Hg in organic solvents.8 However, reactions
of the preformed mercury thiolates with other donor ligands
or metal ions seem to be less explored for the preparation
of new mercury(II) thiolate complexes.7b,9
On the other hand, we are interested in the preparation of
metal thiolate complexes from an unique zwitterionic thiolate
TabHPF6 [TabH ) 4-(trimethylammonio)benzenethiol].10
Being that this is an an extension of this study and, especially,
being aware that few examples of mercury(II) zwitterionic
thiolate complexes have been reported,11 we carried out the
reactions of Hg(OAc)2 with TabHPF6 and isolated a mono-
nuclear mercury thiolate complex [Hg(Tab)2](PF6)2 (1). As
discussed later in this paper, the coordination is unsaturated
either for the Hg atom or for the two S atoms of the Tab
ligands in 1, implying that 1 may be used as a precursor for
the preparation of new HgII/Tab complexes. Herein we report
the reactions of 1 with additional donor ligands (e.g., Tab,
SCN-, I-) or metal salts (e.g., Hg2+, Au3+) and the structural
characterization of 1 along with the resulting nine new HgII/
Tab complexes. These represent a new family of mercury(II)
zwitterionic thiolate complexes with interesting structural
motifs and may provide insight into the nature of the
coordination of the HgII ion to the proteins.
Experimental Section
(1) (a) Dance, I. G. Polyhedron 1986, 5, 1037-1104. (b) Blower, P. J.;
Dilworth, J. R. Coord. Chem. ReV. 1987, 76, 121-185. (c) Gruff, E.
S.; Koch, S. A. J. Am. Chem. Soc. 1990, 112, 1245-1247. (d) Block,
E.; Brito, M.; Gernon, M.; McGowty, D.; Kang, H.; Zubieta, J. Inorg.
Chem. 1990, 29, 3172-3181. (e) Ueyama, N.; Taniuchi, K.; Okamura,
T.; Nakamura, A.; Maeda, H.; Emura, S. Inorg. Chem. 1996, 35,
1945-1951. (f) Watton, S. P.; Wright, J. G.; MacDonnell, F. M.;
Bryson, J. W.; Sabat, M.; O’Halloran, T. V. J. Am. Chem. Soc. 1990,
112, 2824-2826. (g) Santos, R. A.; Gruff, E. S.; Koch, S. A.;
Harbison, G. S. J. Am. Chem. Soc. 1991, 113, 3, 469-475. (h)
Brotherton, P. D.; White, A. H. J. Chem. Soc., Dalton Trans. 1973,
23, 2696-2698. (i) Govindaswamy, N.; Moy, J.; Millar, M.; Koch,
S. A. Inorg. Chem. 1992, 31, 5343-5344. (j) Alcock, N. W.; Lampe,
P. A.; Moore, P. J. Chem. Soc., Dalton Trans. 1980, 8, 1471-1474.
(k) Eichho¨fer, A.; Buth, G. Eur. J. Inorg. Chem. 2005, 4160-4167.
(l) Stålhandske, C. M. V.; Persson, I.; Sandstro¨m, M.; A° berg, M. Inorg.
Chem. 1997, 36, 4945-4953. (m) Bharara, M. S.; Bui, T. H.; Parkin,
S.; Atwood, D. A. Inorg. Chem. 2005, 44, 5753-5760.
General Procedures. TabHPF6 was prepared according to the
literature method.12 Tab was obtained from reactions of TabHPF6
with Et3N in MeCN followed by filtration and dried in vacuo. Other
chemicals and reagents were obtained from commercial sources
and used as received. All solvents were predried over activated
molecular sieves and refluxed over the appropriate drying agents
under argon. The IR spectra were recorded on a Nicolet Magna-IR
550 as the KBr disk (4000-400 cm-1). The elemental analyses
for C, H, and N were performed on an EA1110 CHNS elemental
1
analyzer. H NMR spectra were recorded at ambient temperature
1
on a Varian UNITY-400 spectrometer. H NMR chemical shifts
were referenced to the deuterated dimethyl sulfoxide (DMSO-d6)
signal. UV-vis spectra were measured on a Hitachi U-2810
spectrophotometer.
(2) ˆIhalloran, T. V.; Frantz, B.; Shin, M. K.; Ralston, D M.; Wright, J. G.
Cell 1989, 56, 119-129.
Synthesis. [Hg(Tab)2](PF6)2 (1). To a solution containing
TabHPF6 (0.626 g, 2 mmol) in MeCN (5 mL) was added a solution
of Hg(OAc)2 (0.318 g, 1 mmol) in MeOH (5 mL). The resulting
mixture was heated to 70 °C and stirred for 1 h to form a colorless
homogeneous solution. After it was cooled to ambient temperature,
diethyl ether (20 mL) was layered onto the filtrate to form colorless
plates of 1 in several days, which were collected by filtration,
washed by Et2O, and dried in vacuo. Yield: 0.82 g (99.4% based
on Hg). Anal. Calcd for C18H26F12HgN2P2S2: C, 26.20; H, 3.18;
N, 3.40. Found: C, 26.32; H, 3.02; N, 3.12. IR (KBr disk): 1581
(w), 1489 (m), 1126 (w), 1010 (w), 960 (m), 830 (s), 744 (w), 559
(m) cm-1. UV-vis [DMF; λmax, nm (ꢀ, M-1 cm-1)]: 230 (19 700).
1H NMR (400 MHz, (CD3)2SO): δ 7.56-7.65 (m, 4H, Ph), 3.50
(s, 9H, NMe3).
(3) Henkel, G.; Krebs, B. Chem. ReV. 2004, 104, 801-824.
(4) (a) Bowmaker, G. A.; Dance, I. G.; Harris, R. K.; Henderson, W.;
Laban, I.; Scudder, M. L.; Oh, S. W. J. Chem. Soc., Dalton Trans.
1996, 11, 2381-2388. (b) Shewchuk, L. M.; Verdine, G. L.; Walsh,
C. T. Biochemistry 1989, 28, 2331-2339. (c) Shewchuk, L. M.;
Verdine, G. L.; Nash, H.; Walsh, C. T. Biochemistry 1989, 28, 6140-
6145. (d) Moore, M. J.; Distefano, M. D.; Walsh, C. T.; Schiering,
N.; Pai, E. F. J. Biol. Chem. 1989, 264, 14386-14388. (e) Raybuck,
S. A.; Distefano, M. D.; Teo, B. K.; Orme-Johnson, W.; Walsh, C. T.
J. Am. Chem. Soc. 1990, 112, 1983-1989. (f) Helmann, J. D.; Ballard,
B. T.; Walsh, C. T. Science 1990, 247, 946-948.
(5) (a) Hoffmann, G. G.; Steinfatt, I.; Brockner, W.; Kaiser, V. Z.
Naturforsch., Teil B 1999, 54B, 887-894. (b) Tallon, J.; Garcia-
Vazquez, J. A.; Romero, J.; Louro, M. S.; Sousa, A.; Chen, Q.; Chang,
Y. D.; Zubieta, J. Polyhedron 1995, 14, 2309-2317. (c) Alsina, T.;
Clegg, W.; Fraser, K. A.; Sola, J. J. Chem. Soc., Dalton Trans. 1992,
8, 1393-1399. (d) Noth, H.; Beck, W.; Burger, K. Eur. J. Inorg. Chem.
1998, 93-99. (e) Kra¨uter, G.; Neumuller, B.; Goedken, V. L.; Rees,
W. S., Jr. Chem. Mater. 1996, 8, 360-368. (f) Bramlett, J. M.; Im,
H. J.; Yu, X. H.; Chen, T. N.; Cai, H.; Roecker, L. E.; Barnes, C. E.;
Dai, S.; Xue, Z. L. Inorg. Chim. Acta 2004, 357, 243-249.
(6) (a) Henkel, G.; Betz, P.; Krebs, B. J. Chem. Soc., Chem. Commun.
1985, 21, 1498-1499. (b) Bowmaker, G. A.; Dance, I. G.; Dobson,
B. C.; Rogers, D. A. Aust. J. Chem. 1984, 37, 1607-1618.
(7) (a) Vittal, J. J.; Dean, P. A. W.; Payne, N. C. Can. J. Chem. 1993, 71,
2043-2050. (b) Dean, P. A. W.; Vittal, J. J.; Wu, Y. Y. Inorg. Chem.
1994, 33, 2180-2186.
(8) (a) Steinfatt, I.; Hoffmann, G. G. Z. Naturforsch., Teil B 1994, 49B,
1507-1510. (b) Hoffmann, G. G.; Steinfatt, I. Am. Chem. Soc., DiV.
EnViron. Chem., Prepr. Pap. 1997, 37 (1), 298. (c) Hoffmann, G. G.;
Steinfatt, I. Phosphorus, Sulfur, Silicon 1999, 153/154, 423-424. (d)
Hoffmann, G. G. The 218th ACS National Meeting, New Orleans,
LA, 1999; DiV. Inorg. Chem. Abstr. 1999, 336.
(9) Hoffmann, G. G.; Brockner, W.; Steinfatt, I. Inorg. Chem. 2001, 40,
977-985.
(10) (a) Chen, J. X.; Xu, Q. F.; Xu, Y.; Zhang, Y.; Chen, Z. N.; Lang, J.
P. Eur. J. Inorg. Chem. 2004, 4274-4252. (b) Chen, J. X.; Xu, Q. F.;
Zhang, Y.; Chen, Z. N.; Lang, J. P. J. Organomet. Chem. 2004, 689,
1071-1077.
[Hg2(Tab)6](PF6)4 (2). To a solution containing 1 (0.825 g, 1
mmol) in MeCN (15 mL) was added a solution of Tab (0.167 g, 1
mmol) in MeOH (5 mL). The resulting mixture was stirred for 1 h
to form a colorless homogeneous solution. A workup similar to
that used in the isolation of 1 afforded colorless block crystals of
2. Yield: 0.89 g (90.0% based on Hg). Anal. Calcd for C54H78F24-
Hg2N6P4S6: C, 32.68; H, 3.96; N, 4.23. Found: C, 32.62; H, 4.23;
N, 4.59. IR (KBr disk): 1581 (w), 1489 (m), 1126 (w), 1010 (w),
956 (m), 833 (s), 744 (w), 555 (m) cm-1. UV-vis [DMF; λmax
,
1
nm (ꢀ, M-1 cm-1)]: 240 (10 900). H NMR (400 MHz, (CD3)2-
SO): δ 7.47-7.63 (m, 4H, Ph), 3.47 (s, 9H, NMe3).
[Hg(Tab)2(SCN)](PF6) (3). To a solution containing 1 (0.825
g, 1 mmol) in MeCN (15 mL) was added a solution of KSCN (0.097
g, 1 mmol) in MeOH (10 mL). The resulting mixture was stirred
for 0.5 h and filtered. Slow evaporation of solvents from the
colorless filtrate for 1 week produced colorless block crystals of 3.
Yield: 0.657 g (89.0% based on Hg). Anal. Calcd for C19H26F6-
HgN3PS3: C, 30.91; H, 3.55; N, 5.69. Found: C, 30.62; H, 3.42;
(11) (a) Barrera, H.; Bayon, J. C.; Gonzalez-Duarte, P. Polyhedron 1982,
1, 647-654. (b) Casals, I.; Gonzalez-Duarte, P.; Clegg, W. Inorg.
Chim. Acta 1991, 184, 167-175. (c) Casal, I.; Gonzalez-Duarte, P.;
Sola, J. Polyhedron 1988, 24, 2509-2514. (d) Kim, C. H.; Parkin,
S.; Bharara, H.; Atwood, D. A. Polyhedron 2002, 21, 225-228.
(12) DePamphilis, B. V.; Averill, B. A.; Herskovitz, T.; Que, L., Jr.; Holm,
R. H. J. Am. Chem. Soc. 1974, 96, 4159-4167.
Inorganic Chemistry, Vol. 45, No. 6, 2006 2569

Chen et al.
N, 5.46. IR (KBr disk): 2079 (s), 1581 (w), 1489 (m), 1126 (w),
(w), 848 (s), 744 (w), 547 (m) cm-1. UV-vis [DMF; λmax, nm (ꢀ,
1
1010 (w), 952 (m), 830 (s), 740 (w), 555 (m) cm-1. UV-Vis [DMF;
M-1 cm-1)]: 230 (46 000). H NMR (400 MHz, (CD3)2SO): δ
λ
max, nm (ꢀ, M-1 cm-1)]: 235 (22 200). 1H NMR (400 MHz,
7.42-7.59 (m, 4H, Ph), 3.49 (s, 9H, NMe3).
(CD3)2SO): δ 7.53-7.62 (m, 4H, Ph), 3.42 (s, 9H, NMe3).
[Hg(Tab)2(SCN)2] (4). The similar reaction of 1 (0.825 g, 1
mmol) with 2 equiv of KSCN (0.195 g, 2 mmol) in MeOH followed
by a workup similar to that used in the isolation of 3 afforded
colorless triangle crystals of 4. Yield: 0.605 g (92.9% based on
Hg). Anal. Calcd for C20H26HgN4S4: C, 36.88; H, 4.02; N, 8.60.
Found: C, 36.45; H, 4.29; N, 8.72. IR (KBr disk): 2080 (s), 1581
(w), 1489 (m), 1126 (w), 1010 (w), 953 (m), 831 (s), 740 (w), 555
(m) cm-1. UV-vis [DMF; λmax, nm (ꢀ, M-1 cm-1)]: 230 (17 400).
1H NMR (400 MHz, (CD3)2SO): δ 7.51-7.63 (m, 4H, Ph), 3.48
(s, 9H, NMe3).
[Hg(Tab)I2] (5). To a solution containing 1 (0.825 g, 1 mmol)
in MeCN (5 mL) was added a solution of Bu4NI (0.739 g, 2 mmol)
in MeCN (5 mL). The mixture was stirred for 1 h, and a large
amount of yellow precipitate was developed and then filtered. The
resulting solid was redissolved in DMF (5 mL) and filtered again.
A workup similar to that used in the isolation of 1 led to the
formation of yellow block crystals of 5. Yield: 0.590 g (95.0%
based on Hg). Anal. Calcd for C9H13HgI2NS: C, 17.39; H, 2.11;
N, 2.25. Found: C, 17.12; H, 2.53; N, 2.64. IR (KBr disk): 1581
(w), 1481 (m), 1122 (s), 1010 (s), 952 (w), 844 (s), 744 (s), 547
(s) cm-1. UV-vis [DMF; λmax, nm (ꢀ, M-1 cm-1)]: 235 (24 800).
1H NMR (400 MHz, (CD3)2SO): δ 7.51-7.62 (m, 4H, Ph), 3.41
(s, 9H, NMe3).
{[Hg(Tab)2]4[HgI2][Hg2I6]}(PF6)2(NO3)4 (6). To a solution
containing 1 (0.825 g, 1 mmol) in DMF (5 mL) was added a
solution of HgI2 (0.454 g, 1 mmol) in DMF (5 mL). The mixture
was stirred for 1 h, and a large amount of yellow precipitate was
developed. After filtration, the resulting solid was dissolved in 5
mL of hot DMF/H2O (3:2, v/v) containing KNO3 (0.101 g, 1 mmol)
to give rise to a clear solution. A workup similar to that used in
the isolation of 1 afforded yellowish block crystals of 6. Yield:
0.838 g (78.0% based on 1). Anal. Calcd for C72H104F12-
Hg7I8N12O12P2S8: C, 20.13; H, 2.44; N, 3.91. Found: C, 20.54;
H, 2.13; N, 3.79. IR (KBr disk): 1581 (w), 1485 (m), 1350 (s),
1126 (w), 1010 (w), 956 (m), 830 (s), 744 (m), 559 (w) cm-1. UV-
vis [DMF; λmax, nm (ꢀ, M-1 cm-1)]: 235 (96 100). 1H NMR (400
MHz, (CD3)2SO): δ 7.43-7.58 (m, 4H, Ph), 3.42 (s, 9H, NMe3).
[Hg(Tab)2][HgI4] (7). To a solution containing HgI2 (0.454 g,
1 mmol) in DMF (5 mL) was added a solution of Bu4NI (0.739 g,
2 mmol) in DMF (5 mL). The resulting yellow solution was stirred
for 0.5 h and then treated with a solution of 1 (0.825 g, 1 mmol)
in DMF (5 mL). The mixture was stirred for another 2 h and filtered.
A workup similar to that used in the isolation of 1 generated yellow
block crystals of 7. Yield: 1.032 g (83.0% based on Hg). Anal.
Calcd for C18H26Hg2I4N2S2: C, 17.39; H, 2.11; N, 2.25. Found:
C, 17.52; H, 2.13; N, 2.49. IR (KBr disk): 1577 (s), 1481 (m),
1122 (w), 1006 (w), 949 (m), 844 (s), 744 (w), 544 (m) cm-1. UV-
vis [DMF; λmax, nm (ꢀ, M-1 cm-1)]: 235 (17 200). 1H NMR (400
MHz, (CD3)2SO): δ 7.49-7.67 (m, 4H, Ph), 3.45 (s, 9H, NMe3).
[Hg(Tab)2][HgCl2(SCN)2] (8). To a solution containing HgCl2
(0.271 g, 1 mmol) in MeOH (5 mL) was added KSCN (0.194 g, 2
mmol). The resulting colorless solution was stirred for 0.5 h and
then treated with a solution of 1 (0.825 g, 1 mmol) in MeCN (15
mL). The mixture was stirred for another 0.5 h and filtered to give
a colorless solution. A workup analogous to that used in the isolation
of 1 resulted in colorless block crystals of 8. Yield: 0.867 g (94.0%
based on Hg). Anal. Calcd for C20H26Cl2Hg2N4S4: C, 26.03; H,
2.84; N, 6.07. Found: C, 26.12; H, 2.69; N, 5.98. IR (KBr disk):
2114 (s), 1581 (w), 1485 (m), 1126 (w), 1010 (w), 952 (m), 844
[Tab-Tab]2[Hg3Cl10] (9). To a solution containing 1 (0.825 g,
1 mmol) in MeCN (15 mL) was added a solution of HAuCl4‚4H2O
(0.412 g, 1 mmol) in MeOH (5 mL). The resulting mixture was
stirred for 0.5 h and filtered to give a colorless solution. Slow
evaporation of solvents from the filtrate overnight produced
colorless flakes of 9, which were collected by filtration, washed
by Et2O, and dried in vacuo. Yield: 0.341 g (62.9% based on Hg).
Anal. Calcd for C36H52Cl10Hg3N4S4: C, 26.60; H, 3.22; N, 3.45.
Found: C, 26.35; H, 3.38; N, 3.67. IR (KBr disk): 1581 (w), 1481
(m), 1122 (w), 1006 (w), 956 (m), 829 (s), 744 (w), 547 (m), 481
(m) cm-1. UV-vis [DMF; λmax, nm (ꢀ, M-1 cm-1)]: 230 (25 996).
1H NMR (400 MHz, (CD3)2SO): δ 7.73-7.81(m, 4H, Ph), 3.65
(s, 9H, NMe3).
[Hg2(Tab)6]3(PF6)Cl11 (10). To a solution of Tab (0.668 g, 4
mmol) in MeOH (10 mL) was added a solution of HAuCl4‚4H2O
(0.412 g, 1 mmol) in MeOH (5 mL). The resulting colorless solution
was treated with a solution of 1 (0.825 g, 1 mmol) in MeCN (15
mL) and stirred for 0.5 h. After filtration, diethyl ether (40 mL)
was allowed to diffuse into the filtrate at ambient temperature for
2 weeks, forming colorless long block crystals of 10 coupled with
two byproducts, Au(Tab)2(PF6) (colorless blocks) and [Tab-Tab]-
(PF6)2 (light yellow needles), which were separated mechanically
under a microscope. Yield for 10: 0.673 g (85.0% based on Hg).
Anal. Calcd for C162H234Cl11F6Hg6N18PS18: C, 40.97; H, 4.97; N,
5.31. Found: C, 40.83; H, 4.59; N, 4.87. IR (KBr disk): 1581 (w),
1489 (m), 1415 (w), 1126 (w), 1010 (w), 956 (m), 832 (s), 744
(w), 555 (m) cm-1. UV-vis [DMF; λmax, nm (ꢀ, M-1 cm-1)]: 240
1
(62 000). H NMR (400 MHz, (CD3)2SO): δ 7.50-7.65 (m, 4H,
Ph), 3.43 (s, 9H, NMe3). Yield for Au(Tab)2(PF6): 0.523 g. Anal.
Calcd for C18H26AuF6N2PS2: C, 31.96; H, 3.87; N, 4.14. Found:
C, 32.15; H, 3.39; N, 3.81. IR (KBr disk): 1579 (w), 1484 (m),
1409 (w), 1121 (w), 1007 (w), 960 (m), 839 (s), 742 (w), 555 (m)
cm-1. Yield for [Tab-Tab](PF6)2: 0.045 g. Anal. Calcd for
C18H26F12N2P2S2: C, 34.62; H, 4.20; N, 4.49. Found: C, 34.23;
H, 4.18; N, 4.72. IR (KBr disk): 1583 (w), 1482 (m), 1126 (w),
1009 (w), 958 (m), 835 (s), 745 (w), 555 (m), 483 (m) cm-1
.
X-ray Structure Determination. X-ray-quality crystals of 1-10
were obtained directly from the above preparation. All measure-
ments were made on a Rigaku Mercury CCD X-ray diffractometer
by using graphite-monochromated Mo KR (λ ) 0.710 70 Å).
Crystals of 1-10 were mounted with grease at the top of a glass
fiber and cooled at 193 K in a liquid-nitrogen stream. Cell
parameters were refined by using the program CrystalClear (Rigaku
and MSC, version 1.3, 2001). The collected data were reduced by
using the program CrystalClear (Rigaku and MSC, version 3.60,
2004), while an absorption correction (multiscan) was applied. The
reflection data were also corrected for Lorentz and polarization
effects.
The crystal structures of 1-10 were solved by direct methods
and refined on F 2 by full-matrix least-squares methods with the
SHELXTL-97 program.13 All non-H atoms except the Cl atoms in
10 were refined anisotropically. All H atoms were placed in
geometrically idealized positions (C-H ) 0.98 Å for methyl
groups; C-H ) 0.95 Å for phenyl groups) and constrained to ride
on their parent atoms with Uiso(H) ) 1.2Ueq(C) for phenyl groups
and Uiso(H) ) 1.5Ueq(C) for methyl groups. In the final Fourier
(13) Sheldrick, G. M. SHELX-97 and SHELXL-97, Program for Crystal
Structure Refinement; University of Go¨ttingen: Go¨ttingen, Germany,
1997.
2570 Inorganic Chemistry, Vol. 45, No. 6, 2006

Family of Mercury(II) Zwitterionic Thiolate Complexes
Table 1. Crystallographic Data for 1-10
1
2
3
4
5
mol formula
fw
C18H26F12HgN2P2S2
825.08
C58H84F24Hg2N8P4S6
2066.75
C19H26F6HgN3PS3
738.17
C20H26HgN4S4
651.32
C9H13HgI2NS
621.66
cryst syst
space group
size (mm3)
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
Z
triclinic
P1h
triclinic
P1h
monoclinic
P21
orthorhombic
Pccn
monoclinic
Cc
0.15 × 0.15 × 0.10
11.995(2)
15.022(3)
7.9580(11)
0.40 × 0.25 × 0.05
6.165(3)
8.403(4)
13.120(5)
74.77(2)
82.74(3)
88.03(3)
650.6(5)
1
0.22 × 0.19 × 0.12
9.6164(13)
10.8605(14)
19.202(3)
91.996(3)
100.047(4)
96.313(4)
1959.7(5)
1
0.40 × 0.22 × 0.10
0.40 × 0.28 × 0.10
10.431(2)
8.2168(8)
28.455(6)
25.414(5)
16.2964(14)
17.6858(19)
92.84(3)
98.383(4)
7534(3)
12
2368.2(4)
4
1418.6(4)
4
T (K)
D
193
2.10
193
1.751
193
1.952
193
1.829
193
2.911
calc (g cm-3
)
λ(Mo KR) (Å)
0.71070
62.97
55.0
0.71070
42.53
50.6
19710
7142 (Rint ) 0.039)
6339 [I > 2.00σ(I)]
266
0.0398
0.0748
0.71070
65.00
50.7
0.71070
68.66
55.0
0.71070
153.17
55.0
µ (cm-1
)
2θmax (deg)
total reflns
unique reflns
no. of obsvns
no. of param
Ra
6751
71820
24638
7843
2960 (Rint ) 0.049)
2756 [I > 2.00σ(I)]
173
0.0632
0.1694
1.422
1.451
-1.476
27159 (Rint ) 0.105)
18233 [I > 2.00σ(I)]
1381
0.0949
0.2229
1.088
2.903
-2.635
2715 (Rint ) 0.036)
2484 [I > 2.00σ(I)]
133
0.0324
0.0787
1.135
0.782
-0.942
1634 (Rint ) 0.032)
2517 [I > 2.00σ(I)]
131
0.0238
0.0434
0.759
0.963
-0.992
wRb
GOFc
1.108
0.942
-0.965
∆Fmax (e Å-3
)
)
∆Fmin (e Å-3
6
7
8
9
10
mol formula
fw
C72H104F12Hg7I8N8P2S8
4295.50
C18H26Hg2I4N2S2
1243.31
C20H26Cl2Hg2N4S4
922.81
C36H52Cl10Hg3N4S4
1625.3
C
162H234Cl11F6Hg6N18PS18
4749.39
cryst syst
space group
size (mm3)
a (Å)
b (Å)
c (Å)
orthorhombic
Pmmn
orthornombic
Pmn21
monoclinic
P21/m
monoclinic
P21/c
0.24 × 0.20 × 0.08
13.9906(19)
16.2749(18)
11.5464(12)
trigonal
R3h
0.26 × 0.20 × 0.13
0.25 × 0.20 × 0.17
0.27 × 0.24 × 0.15
0.47 × 0.30 × 0.20
16.504(3)
16.791(3)
6.3897(9)
20.8335(11)
28.009(5)
11.859(2)
10.850(2)
9.0570(18)
27.699(4)
7.5773(11)
42.762(3)
R (deg)
â (deg)
γ (deg)
V (Å3)
Z
93.234(4)
103.053(3)
120
16073.5(16)
3
5482.1(17)
2
1650.0(6)
2
1339.0(3)
2
2561.1(5)
2
T (K)
D
193
2.602
193
2.503
193
2.289
193
2.108
193
1.472
calc (g cm-3
)
λ(Mo KR) (Å)
0.71070
122.75
50.6
0.71070
131.69
50.6
0.71070
119.81
50.6
0.71070
96.86
50.0
0.71070
46.53
55.0
µ (cm-1
)
2θmax (deg)
total reflns
unique reflns
no. of obsvns
no.of param
Ra
44808
15360
13109
24920
60779
5180 (Rint ) 0.082)
4422 [I > 2.00σ(I)]
302
0.1236
0.3133
1.237
1.942
-1.953
1659 (Rint ) 0.068)
2737 [I > 2.00σ(I)]
135
0.0734
0.1771
1.115
1.554
-1.972
2513 (Rint ) 0.040)
2338 [I > 2.00σ(I)]
155
0.0256
0.0508
1.124
0.812
-1.196
4666 (Rint ) 0.063)
4047 [I > 2.00σ(I)]
561
0.0352
0.0911
1.016
1.066
-1.098
8187 (Rint ) 0.040)
7519 [I > 2.00σ(I)]
343
0.0654
0.1961
1.219
1.291
-1.350
wRb
GOFc
∆Fmax (e Å-3
)
)
∆Fmin (e Å-3
2
2
2
2
2
a R ) ∑||Fo| - |Fc|/∑|Fo|. b wR ) {∑w(Fo - Fc )2/∑w(Fo )2}1/2
.
c GOF ) {∑[w((Fo - Fc )2)/(n - p)]}1/2, where n ) number of reflections and p )
total number of parameters refined.
maps, the largest electron-density peaks in 1 (1.451 e/Å3), in 3
(2.903 e/Å3), in 6 (1.942 e/Å3), in 7 (1.554 e/Å3), in 9 (1.066 e/Å3),
and in 10 (1.291 e/Å3) were located 1.064(2) Å from atom Hg1 in
1, 0.764(1) Å from atom Hg5 in 3, 1.051(2) Å from atom Hg2 in
6, 1.084(2) Å from atom Hg1 in 7, 1.016(3) Å from atom Hg1 in
9, and 0.313(3) Å from atom Cl3 in 10, respectively. A summary
of the key crystallographic information for 1-10 is given in Table
1.
in a colorless solution, which was heated to 70 °C and stirred
for 0.5 h. A standard workup afforded colorless plates of 1
in an almost quantitative yield (Scheme 1). During the
reaction, a strong smell of acetic acid was evolved out of
the solution because TabHPF6 has stronger acidity than acetic
acid, and thus the liberation of acetic acid may be the driving
force for this reaction.10
Given the linear geometry of the dication of 1 discussed
later in this paper, we anticipated that compound 1 might
serve as a useful precursor for the preparation of new Hg/
Tab complexes with two options. One option is that the Hg
Results and Discussion
Synthesis. Treatment of a methanol solution of Hg(OAc)2
with an acetonitrile solution of 2 equiv of TabHPF6 resulted
Inorganic Chemistry, Vol. 45, No. 6, 2006 2571

Chen et al.
Scheme 1
Chart 1
with equimolar HgI2 (Scheme 1). It produced a yellow solid,
which was dissolved in a hot DMF/H2O (3:2, v/v) solution
containing KNO3. A standard workup afforded yellowish
block crystals of 6 in 78.0% yield. On the other hand, when
a solution of 1 was combined with a solution consisting of
HgI2 and Bu4NI in a 1:1:2 molar ratio, an ionic compound
7 was isolated in 83.0% yield. In the case of 1/HgCl2/KSCN
(1:1:2), another ionic compound 8 was obtained in 94.0%
yield.
atom may further complete its coordination sphere by the
addition of one or two Tab ligands or other donor ligands
such as halides and pseudohalides. Therefore, the linear HgS2
geometry (type I) in 1 may be converted to a T-shaped (type
II), trigonal-planar (type III), seesaw-shaped (type IV), or
tetrahedral (type V) coordination geometry (Chart 1).
In this context, we carried out the reactions of 1 with Tab
in a 1:1 molar ratio (Scheme 1). Intriguingly, it did not form
the expected three-coordinated monomer species [Hg-
(Tab)3]2+ but produced a four-coordinated dimeric compound
2‚2MeCN in a relatively high yield of 90.0%. This compound
was the only product isolated in a crystalline form regardless
of the 1/Tab molar ratios. However, a 1:1 or 1:2 reaction
mixture of 1 and KSCN gave rise to the corresponding 1:1
and 1:2 products 3 and 4 in high yields, respectively. If the
molar ratio of 1/KSCN was over 1:2, only 4 was isolated in
a high yield. In addition, compound 4 could be formed in a
quantitative yield when compound 3 was treated with one
or more equiv of KSCN. In the case of 1 and Bu4NI in a 1:2
molar ratio, we did not isolate the expected 1:2 compound
[Hg(Tab)2I2] but an unexpected neutral compound 5 in 95.0%
yield. Intriguingly, one Tab of 1 was lost during the reaction.
The formation of 5 may be attributed to its low solubility in
MeCN. A mixture of 1/Bu4NI in molar ratios between 2:1
and 1:4 only produced 5.
Intriguingly, when compound 1 reacted with HAuCl4, it
only produced an unexpected disulfide compound 9 (Scheme
1). The result may be due to the fact that the thiol-to-disulfide
conversion could also be completed via oxygen in the
presence of certain metal ions.14,15 In our case, the formation
of the Tab-Tab dication in 9 may be due to the protonation
and dissociation of Tab from 1 in the presence of HAuCl4
and the subsequent oxidation of TabH+ via Au3+ and/or
oxygen in open air. We also carried out the reaction of 1
with a mixture of HAuCl4 and excessive Tab (1:1:4) in
MeOH/MeCN. This reaction produced no mercury disulfide
compound but a binuclear complex 10 in high yield along
with two products, [Au(Tab)2](PF6) and [Tab-Tab](PF6)2.
Both [Au(Tab)2](PF6) and [Tab-Tab](PF6)2 were confirmed
by elemental analysis, IR spectra, and X-ray fluorescence
analysis. The formation of these two compounds may be
attributed to the fact that Tab may reduce Au3+ in HAuCl4
into Au+, forming the [Tab-Tab]2+ species. The resulting
Au+ may further react with excess Tab to afford this Au/
Tab complex [Au(Tab)2](PF6).
(14) (a) Yiannos, C. N.; Karaninos, J. V. J. Org. Chem. 1963, 28, 3246-
3248. (b) Ottersen, B.; Warner, L. G.; Seff, K. Acta Crystallogr. 1973,
B29, 2954-2958.
(15) (a) Yamamoto, T.; Sekine, Y. Can. J. Chem. 1984, 39, 1544-1547.
(b) Chowdhury, S.; Samuel, P. M.; Das, I.; Roy, S. J. Chem. Soc.,
Chem. Commun. 1994, 17, 1993-1994.
The other option is that compound 1 may further combine
other Hg atoms or other metal atoms to form polynuclear
complexes via the bridging ability of the S atoms of its two
Tab ligands. In this respect, we first ran the reactions of 1
2572 Inorganic Chemistry, Vol. 45, No. 6, 2006

Family of Mercury(II) Zwitterionic Thiolate Complexes
Figure 1. Perspective view of the structure of 1 with 50% thermal
ellipsoids. All H atoms were omitted for clarity. Selected bond lengths (Å)
and angles (deg): Hg1-S1 2.331(3), S1-Hg1-S1A 180.00(14).
Figure 2. Perspective view of the [Hg2(Tab)6]4+ tetracation of 2 with 50%
thermal ellipsoids. All H atoms were omitted for clarity.
Crystal Structure of 1. Compound 1 crystallizes in the
triclinic space group P1h, and the asymmetric unit of 1
Table 2. Selected Bond Distances (Å) and Angles (deg) for 2 and 10
Complex 2
-
contains half of the [Hg(Tab)2]2+ dication and one PF6
Hg1-S1
Hg1-S3
2.4138(14)
2.7323(13)
Hg1-S2
Hg1-S3A
2.4346(14)
2.6467(13)
anion. A perspective view of 1 is shown in Figure 1. In the
[Hg(Tab)2]2+ dication, the Hg atom, lying at the crystal-
lographic center of symmetry, is strongly coordinated by two
S atoms of the two Tab moieties, forming a linear HgS2
coordination geometry (type I) with two C6H4NMe3 groups
oriented at opposite directions. Such a structure closely
resembles those of mercury complexes containing zwitteri-
onic thiolate ligands such as [Hg{SCH(CH2CH2)2NHMe2}2]-
(ClO4)2,11a [Hg{S(CH2)3NMe3}2](PF6)2,11b [Hg{S(CH2)2-
NH3}2]Cl2,11e and its silver analogue [Ag(Tab)2](PF6).10b The
mean Hg1-S bond length and the S1-Hg1-S1A angle in
1 are 2.331(3) Å and 180.00(14)°, respectively, while the
corresponding ones found in other two-coordinated mercury
thiolate compounds are 2.330(1) Å and 176.96(2)° for [Hg-
{SCH(CH2CH2)2NHMe2}2](ClO4)2, 2.340(1) Å and 178.9-
(3)° for [Hg{S(CH2)3NMe3}2](PF6)2, 2.336(9) Å and 168.53-
(3)° for [Hg{S(CH2)2NH3}2]Cl2, 2.339(2) Å and 180.0(5)°
for [Hg(SCH2COOH)2],5f and 2.34(3) Å and 174.7(1)° for
[Hg(SBz)2]n (Bz ) benzyl), respectively.5e
The [Hg(Tab)2]2+ dications are parallel to each other, and
the Hg‚‚‚Hg separation between two neighboring cations is
6.165 Å. Interestingly, the PF6- anions are located between
the two dications, and thus the two F atoms from two
neighboring PF6- anions have weak interactions with the Hg1
atom [Hg1‚‚‚F2) (or F2A) separation ) 2.992(1) Å].
Furthermore, two H-bonding interactions between F2 and
the methyl group with C8 (x + 1, y - 1, z) and between F4
and the methyl group with C8 (-x + 1, -y + 1, -z + 1)
led to the formation of a two-dimensional network extended
along the ac plane (see the Supporting Information).
S1-Hg1-S2
S2-Hg1-S3
S2-Hg1-S3A
133.93(5)
104.26(5)
93.37(4)
S1-Hg1-S3
S1-Hg1-S3A
S3-Hg1-S3A
96.69(4)
125.45(5)
94.94(4)
Complex 10
Hg1-S1
Hg1-S3
2.441(12)
2.787(12)
Hg1-S2
Hg1-S3A
2.421(13)
2.602(12)
S1-Hg1-S2
S2-Hg1-S3
S2-Hg1-S3A
132.0(5)
104.8(4)
113.9(4)
S1-Hg1-S3
S1-Hg1-S3A
S3-Hg1-S3A
97.8(4)
104.7(4)
96.5(3)
compared in Table 2. The structure of the [Hg2(Tab)6]4+
tetracation of 2 or 10 is similar to those reported in [Et4N]2-
[Hg2(SMe)6],6b [Me4N]2[Hg2(SPh)6],4a and [(DME)3Ln-
(SC6F5)2]2[Hg2(SC6F5)6] (Ln ) La, Ce, Pr, Nd, Sm, Gd).16a
The tetracation of 2 or 10 consists of an asymmetrical Hg2S2
rhomb, with Hg1-µ-S3/Hg1-µ-S3A bond lengths being
2.7323(13)/2.6467(13) Å (2) and 2.787(12)/2.602(12) Å (10).
An inversion center lies on the midpoint of the Hg1‚‚‚Hg1A
line in 2 or 10. The Hg1‚‚‚Hg1A contact is 3.637(2) Å (2)
or 3.592(2) Å (10), which excludes any metal-metal
interaction. Each Hg atom is coordinated by four S atoms
from two terminal and two bridging Tab ligands, forming a
strongly distorted tetrahedral coordination geometry (type
V) with the S-Hg-S angles in the ranges of 93.37(4)-
133.93(5)° (2) and 96.5(3)-132.0(5)° (10). The mean
terminal and bridging Hg1-S bond lengths [2.4242(14) Å
vs 2.6895(13) Å (2); 2.4310(13) Å vs 2.6945(12) Å (10)]
are comparable to those containing tetrahedrally coordinated
HgII such as [Et4N]2[Hg2(SMe)6] [2.456(2) vs 2.668(2) Å]
and [Me4N]2[Hg2(SPh)6] [2.437(2) vs 2.686(2) Å].
Crystal Structures of 2‚2MeCN and 10. Compound 2
crystallizes in the triclinic space group P1h, and the asym-
metric unit of 2 consists of half of the [Hg2(Tab)6]4+
The tetracations in the crystals of 2 or 10 are parallel to
each other. The Hg‚‚‚Hg separations between two cations
are ca. 8.252 Å in 2 and ca. 8.826 Å in 10. The associated
[PF6]- anions in 2 are surrounded by the paralleled tetraca-
tions. In 2, three H-bonding interactions between S1 and the
phenyl group with C6 (-x + 2, -y + 1, -z), between S1
and the phenyl group with C23 (x - 1, y, z), and between
-
tetracation, two PF6 anions, and one solvent MeCN
molecule. Compound 10 crystallizes in the trigonal space
group R3h, and the asymmetric unit contains half of the [Hg2-
(Tab)6]4+ tetracation, one-sixth of the PF6- anion, one-third
of Cl-, two halves of Cl-, and three one-sixths of Cl-.
Because the tetracations in 2 and 10 are structurally similar,
only a perspective view of the tetracation of 2 is depicted in
Figure 2 and their important bond lengths and angles are
(16) (a) Banerjee, S.; Emge, T. J.; Brennan, J. G. Inorg. Chem. 2004, 43,
6307-6312. (b) Marchivie, M.; Guionneau, P.; Le´tard, J. F.; Chasseau,
D.; Howard, J. A. K. J. Phys. Chem. Solids 2004, 65, 17-23.
Inorganic Chemistry, Vol. 45, No. 6, 2006 2573

Chen et al.
Table 3. Selected Bond Distances (Å) and Angles (deg) for 3
Hg1-S1
Hg1-S2
Hg1-S3
Hg2-S4
Hg2-S5
Hg2-S6
Hg3-S7
Hg3-S8
Hg3-S9
2.340(7)
2.336(7)
2.801(8)
2.318(8)
2.352(7)
2.797(8)
2.368(6)
2.352(7)
2.823(8)
Hg4-S10
Hg4-S11
Hg4-S12
Hg5-S13
Hg5-S14
Hg5-S15
Hg6-S16
Hg6-S17
Hg6-S18
2.341(7)
2.367(7)
2.811(8)
2.330(7)
2.321(9)
2.809(8)
2.398(9)
2.291(10)
2.837(7)
S2-Hg1-S1
S2-Hg1-S3
S1-Hg1-S3
S4-Hg2-S5
S4-Hg2-S6
S5-Hg2-S6
S8-Hg3-S7
S8-Hg3-S9
S7-Hg3-S9
172.7(3)
95.5(3)
91.8(2)
171.7(3)
97.0(3)
90.5(2)
173.8(2)
98.6(2)
87.5(2)
S10-Hg4-S11
S10-Hg4-S12
S11-Hg4-S12
S14-Hg5-S13
S14-Hg5-S15
S13-Hg5-S15
S17-Hg6-S16
S17-Hg6-S18
S16-Hg6-S18
173.0(2)
97.1(2)
89.6(2)
173.9(3)
83.9(3)
101.1(2)
173.8(3)
104.5(3)
81.4(2)
weakly by one S atom from SCN- and strongly by two S
atoms from two Tab ligands, forming an uncommon T-
shaped coordination geometry (type II) with the (Tab)S-
Hg-S(Tab) angle in the range of 171.7(3)-173.9(3)°. Such
a T-shaped structure was observed in [(Ph3P)4Pt2(µ3-S)2-
HgPh][BPh4].17 Apparently, the Hg-S(Tab) bond lengths are
significantly shorter than those of the Hg-S(SCN) bonds.
The mean Hg-S(Tab) bond length [2.342(1) Å] is close to
that of 1 [2.331(3) Å]. The average Hg-S(SCN) bond length
[2.813(3) Å] is 0.242 Å longer than the average terminal
Hg-S(SCN) bond length in {[La(SCN)[(NMe2)3PO]5](µ-
SCN)[Hg(SCN)2Cl]} [2.571(2) Å].18 Interestingly, each
cation in 3 is further interconnected in an up-and-down way
via long Hg‚‚‚S secondary coordination (3.6148-3.9237 Å),
forming a one-dimensional zigzag chain extended along the
c axis (Figure 5). There are no evident H-bonding interactions
Figure 3. Stacking of 10 along the c axis, which highlights a [PF6]- anion
acting as an anionic template.
-
between the cations and associated PF6 anions.
Compound 4 crystallizes in the orthorhombic space group
Pccn, and the asymmetric unit contains half of the [Hg(Tab)2-
(SCN)2] molecule. A perspective view of 4 is shown in
Figure 6, while its important bond lengths and angles are
given in Table 4. The central Hg1 atom, lying at a
crystallographic inversion center, is strongly coordinated by
two S atoms of the two Tab ligands and loosely coordinated
by two S atoms of the two SCN- anions, forming a unique
seesaw-shaped coordination geometry (type IV).19 The mean
Hg-S(Tab) bond length is 2.3715(11) Å, which is somewhat
longer than those observed in 1 and 3 but shorter than those
containing four-coordinated Hg complexes such as two
polymorphic compounds [Hg(SPy)2(SCN)2] [2.4790(1) and
2.480(1) Å; SPy ) pyridinium-2-thiolato].20 The mean Hg-
S(SCN) bond length is 2.9281(12) Å, which is longer than
those of 3 [2.813(3) Å] and Hg(SPy)2(SCN)2 [2.635(1) and
Figure 4. Perspective view of one of the six [Hg(Tab)2(SCN)]+ cations
of 3 with 50% thermal ellipsoids. All H atoms were omitted for clarity.
the N4 from the MeCN molecule and the methyl group with
C9 (-x + 2, -y + 1, -z) led to the formation of a one-
dimensional chain extended along the b axis (see the
Supporting Information). The S‚‚‚H-C contacts are 2.66 and
2.82 Å, which are comparable to those reported in [Fe(PM-
BiA)2(NCS)2] [2.77-2.81 Å; PM ) N-2′-pyridylmethylene
and BiA ) 4-(aminobiphenyl)].16b Looking down the c axis,
it appears that [PF6]- in 10 is acting as an anionic template,
with six symmetry-related quaternary ammonium ions ar-
ranged around the ion forming a ball-like structure (Figure
3). Looking down the 3-fold axis, a stunning two-dimensional
sheet is apparent. Chloride ions appear to be sandwiched
between these sheets with complicated H-bonding interac-
tions (see the Supporting Information).
(17) Fong, S. W. A.; Yap, W. T.; Vittal, J. J.; Hor, T. S. A.; Henderson,
W.; Oliver, A. G.; Rickard, C. E. F. J. Chem. Soc., Dalton Trans.
2001, 13, 1986-2002.
Crystal Structures of 3-5. Compound 3 crystallizes in
the monoclinic space group P21, and the asymmetric unit
comprises six crystallographically independent [Hg(Tab)2-
(SCN)]+ cations and six PF6- anions. Because the six cations
are structurally very similar, a perspective view of only one
of them is shown in Figure 4 and the pertinent bond lengths
and angles of the six cations are compared in Table 3. Each
Hg atom in these [Hg(Tab)2(SCN)]+ cations is coordinated
(18) Amirkhanov, V. M.; Kapshuk, A. A.; Kramarenko, F. G.; Skopenko,
V. V. Zh. Neorg. Khim. 1994, 39, 1155-1158.
(19) (a) Liao, J. H.; Marking, G. M.; Hsu, K. F.; Matsushita, Y.; Ewbank,
M. D.; Borwick, R.; Cunningham, P.; Rosker, M. J.; Kanatzidis, M.
G. J. Am. Chem. Soc. 2003, 125, 9484-9493. (b) Korczynski, A. Rocz.
Chem. 1966, 40, 547-505.
(20) Popovic´, Z.; Matkovic´-Cˇalogovic´, D.; Hasic´, J.; Vikic´-Topic´, D. Inorg.
Chim. Acta 1999, 285, 208-216.
2574 Inorganic Chemistry, Vol. 45, No. 6, 2006

Family of Mercury(II) Zwitterionic Thiolate Complexes
Figure 5. One-dimensional zigzag chain (extended along the c axis) formed via weak Hg‚‚‚S secondary interactions in 3.
Figure 6. Molecular structure of 4 with 50% thermal ellipsoids. All H
atoms were omitted for clarity.
Table 4. Selected Bond Distances (Å) and Angles (deg) for 4 and 5
Complex 4
Hg1-S1
2.3715(11)
Hg1-S2
2.9281(12)
S1-Hg1-S2
S1-Hg1-S2A
90.31(4)
99.32(4)
S1-Hg1-S1A
S2-Hg1-S2A
163.64(6)
107.94(5)
Complex 5
Hg1-S1
Hg1-I2
2.432(2)
2.7316(7)
Hg1-I1
2.7718(7)
130.67(5)
Figure 7. Two-dimensional network along the ac plane formed via
H-bonding interactions in 4.
S1-Hg1-I1
I2-Hg1-I1
115.46(5)
113.23(2)
S1-Hg1-I2
2.596(1) Å]. The S(Tab)-Hg-S(Tab) angle of 163.64(6)°
is smaller than those of 1 (180.00°) and 3 [173.15(2)°] but
significantly larger than the S(SPy)-Hg-S(SPy) angle in
the two polymorphic compounds Hg(SPy)2(SCN)2 [116.74-
(5) and 122.03(4)°]. The S(SCN)-Hg-S(SCN) angle is
107.94(5)°, which is close to that observed in [Hg(SPy)2-
(SCN)2] [100.27(2)°] and much smaller than that in [Hg-
(tu)2(SCN)2] [171.61(2)°; tu ) thiourea].19b
In the crystal of 4, the S2 atom from the SCN- ion
interacts with the methyl group with C8 [x - 1, -y + 3/2, z
- /2] to afford intermolecular H bonds, thereby forming a
Figure 8. One-dimensional chain (extended along the c axis) formed via
Hg‚‚‚S and Hg‚‚‚I secondary interactions in 5.
1
two-dimensional H-bonded network structure along the ac
plane (Figure 7).
Compound 5 crystallizes in the monoclinic space group
Cc, and the asymmetric unit of 5 contains one discrete [Hg-
(Tab)I2] molecule. A perspective view of 5 is shown in
Figure 8, and the selected bond lengths and angles are listed
in Table 4. The Hg1 atom in 5 is coordinated by one S from
a Tab ligand and two I atoms, forming a typical trigonal-
planar geometry (type III). The Hg1-S1 bond length of
2.432(2) Å is comparable to the theoretically calculated value
Inorganic Chemistry, Vol. 45, No. 6, 2006 2575

Chen et al.
Table 5. Selected Bond Distances (Å) and Angles (deg) for 6-8
Complex 6
Hg1-S1
Hg3-I1
Hg4-I3
Hg5-I4
2.334(6)
2.733(3)
2.667(3)
2.557(2)
Hg2-S2
Hg3-I2
Hg4-I2
2.322(6)
2.923(3)
2.970(3)
S1A-Hg1-S1
I1A-Hg3-I1
I1-Hg3-I2A
I1-Hg3-I2
171.2(3)
S2A-Hg2-S2
I1A-Hg3-I2A
I1A-Hg3-I2
I2A-Hg3-I2
I3A-Hg4-I2
I3A-Hg4-I2A
I2-Hg4-I2A
Hg3-I2-Hg4
170.3(3)
122.09(14)
108.28(4)
108.28(4)
136.20(17)
104.29(5)
104.29(5)
174.62(17)
108.28(4)
108.28(4)
99.22(12)
104.29(5)
104.29(5)
97.14(12)
81.82(8)
I3A-Hg4-I3
I3-Hg4-I2
I3-Hg4-I2A
I4-Hg5-I4A
Complex 7
Hg1-S1
Hg2-I1
Hg2-I2
2.383(7)
2.762(3)
2.894(3)
Hg1-I2
Hg2-I3
3.223(3)
2.7622(19)
S1-Hg1-S1A
S1A-Hg1-I2
I1-Hg2-I3A
I1-Hg2-I2
167.4(5)
S1-Hg1-I2
I1-Hg2-I3
I3-Hg2-I3A
I3-Hg2-I2
Hg2-I2-Hg1
94.27(18)
111.34(6)
116.65(9)
103.15(6)
138.54(10)
94.27(17)
111.34(6)
110.46(9)
103.15(6)
Figure 9. One-dimensional scolopendra-like structure (extended along the
c axis) formed by Hg‚‚‚I secondary interactions among [Hg(Tab)2]2+
[Hg2I6]2-, and HgI2 in 6.
,
I3A-Hg2-I2
Complex 8
Hg1-S1
Hg2-Cl1
Hg2-S2
2.3219(14)
2.5312(17)
2.5144(13)
Hg1-N2
2.970(5)
2.4603(17)
for the sum of the covalent radii of trigonal Hg and S atoms
[2.43(1) Å]21 but longer than those in 1, 3, and 4. The mean
Hg-I bond length is 2.7517(7) Å, which is longer than the
average Hg-I bond length in [Hg(C4H8N2S)I2] [2.6958(2)
Å; C4H8N2S ) 3,4,5,6-tetrahydropyrimidinium-2-thiolato-
S′].21 It should be noted that the [Hg(Tab)I2] molecules in
the crystal of 5 are held together by long secondary Hg1‚‚
‚S1B [3.126(2) Å] and Hg1‚‚‚I1A [3.617(3) Å] interactions
to give a one-dimensional chain structure extended along
the c axis. Furthermore, two H-bonding interactions between
I2 and the methyl group with C8 (x - 1, y, z) and C8 (x -
Hg2-Cl2
S1-Hg1-S1A
S1A-Hg1-N2
S2-Hg2-S2A
S2-Hg2-Cl1
180.000(1)
73.20(10)
108.95(6)
107.99(5)
S1-Hg1-N2
Cl2-Hg2-S2
Cl2-Hg2-Cl1
106.80(10)
113.56(4)
104.43(6)
parallel to each other, and the Hg‚‚‚Hg separation between
two cations is ca. 5.893 Å. Interestingly, compound 6
contains a slightly bent HgI2 [I4-Hg5-I4A ) 174.62(17)°]
molecule. Such a deviation of the I-Hg-I angle to 180°
may also be ascribed to the weak interactions between its I
atoms and the neighboring Hg atoms of the dications. The
terminal Hg-I bond length in the HgI2 molecule is 2.557-
(2) Å, which is comparable to that observed in HgI2 vapor
[2.554 (3) Å]22 but shorter than those found in [N(C2H5)4]2-
[Hg2I6]‚HgI2 [2.574(1) Å]23 and in the 1:1 complex between
18-crown-6 and HgI2 [2.622(1) Å].24 The structure of the
dimeric [Hg2I6]2- anion in 6 is an edge-shared bitetrahedron
and very similar to those found previously.23,25 The bridging
I atoms are not equidistant from the bonded Hg atoms [2.923-
(3) Å and 2.970(3) Å], which is different from that observed
in [N(C2H5)4]2[Hg2I6]‚HgI2 [2.934(3) Å]. The four Hg-I
terminal distances [average 2.700(3) Å] are comparable to
those in [N(C2H5)4]2[Hg2I6]‚HgI2 [2.6895(2) Å]. The Hg-
3
1
1/2, -y + /2, z + /2] between chains lead to the formation
of a two-dimensional H-bonded network extended along the
ac plane (see the Supporting Information).
Crystal Structures of 6-8. An X-ray analysis revealed
that 6 crystallizes in the orthorhombic space group Pmmn,
and the asymmetric unit is composed of two halves of the
[Hg(Tab)2]2+ dications, one-quarter of the HgI2 molecule,
one-quarter of the [Hg2I6]2- dianion, two one-quarters of the
-
-
PF6 anions, and two halves of the NO3 anions. A
perspective views of the [Hg(Tab)2]2+ dications and the
[Hg2I6]2- dianions coupled with the neutral HgI2 molecule
in 6 is depicted in Figure 9. Selected bond lengths and angles
for 6 are listed in Table 5. As shown in Figure 9, all Hg
atoms in 6 are lying on the same crystallographic bc plane.
In the structure of each of the dications of 6, Hg1 or Hg2 is
coordinated by the terminal Tab ligands, forming a slightly
bent linear HgS2 coordination geometry (type I) with S1-
Hg1-S1A angles of 171.2(3)° or S2-Hg2-S2A angles of
170.3(3)°. The deviation of the S-Hg-S angles to 180° may
be due to the weak secondary interactions between Hg1 and
I4B from the HgI2 molecule and between Hg2 and I2 from
the [Hg2I6]2- dianion. The two Hg-S bond lengths for Hg1
or Hg2 are comparable to those of 1. These dications are
(22) Spiridonov, R. P.; Gershikov, A. G.; Butayev, B. S. J. Mol. Struct.
1979, 52, 53-62.
(23) Fa´bry, J.; Maximov, B. A. Acta Crystallogr. 1991, C47, 51-53.
(24) Pears, D. A.; Fraser Stoddart, J.; Crosby, J.; Allwood, B. L.; Williams,
D. J. Acta Crystallogr. 1986, C42, 51-53.
(25) (a) Pears, D. A.; Fraser Stoddart, J.; Crosby, J.; Allwood, B. L.;
Williams, D. J. Acta Crystallogr. 1986, C42, 804-806. (b) Shibaeva,
R. P.; Kaminskij, V. F. Kristallografiya 1984, 29, 606-609. (c)
Zacharie, B.; Wuest, J. D.; Olivier, M. J.; Beauchamps, A. L. Acta
Crystallogr. 1985, C41, 369-371. (d) Bogdanova, O. A.; Gristenko,
V. V.; Dyachenko, O. A.; Zhilyaeva, E. I.; Kobayashi, A.; Kobayashi,
H.; Lyubovskaya, R. N.; Lyubovskaya, R. B.; Shilov, G. V. Chem.
Lett. 1997, 675-676.
(21) Matkovic´-Cˇalogovic´, D.; Popovic´, Z.; Pavlovic´, G.; Soldin, Zˇ.; Giester,
G. Acta Crystallogr. 2001, C57, 409-411.
2576 Inorganic Chemistry, Vol. 45, No. 6, 2006

Family of Mercury(II) Zwitterionic Thiolate Complexes
Hg2-I bond lengths vary from 2.762(3) to 2.894(3) Å and
the I-Hg2-I angles range from 103.15(6) to 116.65(6)°.
Thus, the Hg2 atom adopts a distorted tetrahedral coordina-
tion geometry. The [Hg(Tab)2]2+ dications and [HgI4]2-
dianions are linked together by the secondary interactions
between Hg1 and I2 [3.223(2) Å] and between Hg1 and I1A
[3.7294(6) Å], forming a one-dimensional chain structure
extended along the c axis.
Figure 10. One-dimensional wavelike chain (extended along the c axis)
Compound 8 crystallizes in the monoclinic space group
P21/m, and the asymmetric unit consists of half of the [Hg-
(Tab)2]2+ dication and half of the [Hg(SCN)2Cl2]2- dianion.
The structures of both dications and dianions of 8 are shown
in Figure 13, and the selected bond lengths and angles are
listed in Table 5. The Hg1 atom lies at an inversion center,
while the Hg2, Cl1, and Cl2 atoms are located on the same
crystallographic plane. The structure of the dication of 8
retains almost the same structure of 1, judging from their
Hg-S bond lengths and S-Hg-S angles. In the structure
of the [Hg(SCN)2Cl2]2- dianion, the Hg2 atom also adopts
a slightly distorted HgS2Cl2 tetrahedral geometry. The Hg-
S(SCN) bond length [2.5144(13) Å] is significantly shorter
than the corresponding ones in 3 [2.813(3) Å] and 4 [2.9281-
(12) Å] but comparable to that in {[C10H8S8][C10H8S8][HgCl2-
(SCN)]}n28 {2.515(2) Å; C10H8S8 ) bis[bis(ethylenedithio)-
tetrathiafulvalene]}. The mean Hg-Cl bond length of
2.496(17) Å is slightly longer than that in {[C10H8S8]-
[C10H8S8][HgCl2(SCN)]}n [2.414(17) Å]. In addition, the
secondary interactions between Hg1 in the dication and N2
(or N2B) of the SCN- group in the dianions result in a one-
dimensional zigzag chain extended along the b axis. The Hg‚
‚‚N bond length is 2.970(1) Å, is shorter than the sum of
the van der Waals radii of N (1.55 Å)29 and Hg (1.73 Å),30
but is longer than that in {[C10H8S8][C10H8S8][HgCl2(SCN)]}n
[2.773(2) Å] and comparable to that in {[C10D8S8]2-
[C10H8D8]2[Hg2Cl2(SCN)4]}n {3.035(2) Å; C10H8D8 ) tet-
rakis[octadeuteriobis(ethylenedithio)tetrathiafulvalene]}.31
-
formed by Hg‚‚‚O secondary interactions between [Hg(Tab)2]2+ and NO3
in 6.
µ-I-Hg angle is 81.82(8)°, which is comparable to that in
[N(C2H5)4]2[Hg2I6]‚HgI2 [83.81(4)°].
The secondary and H-bonding interactions in 6 are rather
complicated. The [Hg2I6]2- dianions and the bent HgI2
molecules are interconnected via weak I1‚‚‚Hg5A [3.5284-
(5) Å] and Hg5‚‚‚I3 [3.9567(5) Å] interactions, forming a
one-dimensional {[Hg2I6‚HgI2]2-}n chain structure extended
along the c axis. Along the {[Hg2I6‚HgI2]2-}n chain back-
bone, the HgI2 molecules and the [Hg2I6]2- anions alterna-
tively coordinate to the Hg atoms of the [Hg(Tab)2]2+
dications via Hg1‚‚‚I4B [3.8210(6) Å] and Hg2‚‚‚I2 [4.0858-
(7) Å] interactions. These weak interactions make it a one-
dimensional scolopendra-like structure extended along the
c axis (Figure 9). Furthermore, each NO3- anion is arranged
between the two dications and acts as a rare tridentate ligand
to Hg1 and Hg2 atoms with relatively long Hg‚‚‚O contacts,
forming a one-dimensional wavelike chain structure extended
along the c axis (Figure 10).26 The mean Hg‚‚‚O separation
is 2.987(5) Å, which are somewhat shorter than the sum of
the van der Waals radii of Hg (1.73 Å) and O (1.4 Å).27
In the crystal of 6, the S atoms of the Tab ligands interact
with the H atoms of the phenyl groups of Tab to afford
intermolecular H bonds [C15‚‚‚S1 (-x, -y + 1, -z); C6‚
‚‚S2 (-x, -y + 1, -z)]. In addition, the two F atoms of
PF6- interact with the H atoms of the methyl groups of Tab
[C9‚‚‚F6 (x - 1, y, z)] to give a one-dimensional double-
chain structure extended along the a axis (Figure 11). The I
atoms in the above {[Hg2I6‚HgI2]2-}n chain further bind to
the Hg atoms of the [Hg(Tab)2]2+ dication in the double chain
via Hg1‚‚‚I4B and Hg2‚‚‚I2 interactions, thereby forming a
three-dimensional network (see the Supporting Information).
Compound 7 crystallizes in the orthorhombic space group
Pmn21, and the asymmetric unit contains half of the [Hg-
(Tab)2]2+ dication and half of the [HgI4]2- dianion. The
structures of both dications and dianions of 7 are depicted
in Figure 12, and the selected bond lengths and angles are
listed in Table 5. The Hg1, Hg2, I1, and I2 atoms lie on the
same crystallographic plane. Being similar to that in the
dications of 6, the Hg1 atom in the dication of 7 also adopts
a bent linear HgS2 coordination geometry with the S1-Hg1-
S1A angle of 167.4(5)°. The Hg1-S bond lengths are normal
relative to those in 1 and 6. In the anion of [HgI4]2-, the
Crystal Structure of 9. Compound 9 crystallizes in the
monoclinic space group P21/c, and the asymmetric unit
contains a discrete Tab-Tab dication and half of the
[Hg3Cl10]4- tetraanion. A perspective view of 9 is shown in
Figure 14, and the selected bond lengths and angles are listed
in Table 6. In this tetraanion, there is a crystallographic
inversion center lying at Hg2. The linear structure of the
[Hg3Cl10]4- tetraanion contains two Hg2Cl2 rhombs that are
almost located on the same plane. The two terminal Hg1
and Hg3 atoms are coordinated by two terminal and two
bridging Cl atoms, forming a tetrahedral geometry, while
the central Hg2 atom is octahedrally coordinated by two
terminal and four bridging Cl atoms. The terminal Hg-Cl
bond lengths vary from 2.3046(16) to 2.5393(15) Å, while
(28) Konovalikhin, S. V.; Shilov, G. V.; Dyachenko, O. A.; Aldoshina,
M. Z.; Lyubovskaya, R. N.; Lyubovskii, R. B. IzV. Akad. Nauk SSSR,
Ser. Khim. 1992, 2323-2331.
(29) Bondi, A. J. Phys. Chem. 1964, 68, 441-451.
(26) Mu¨ller, J.; Polonius, F. A.; Roitzsch, M. Inorg. Chim. Acta 2005, 358,
(30) Canty, A. J.; Deacon, G. B. Inorg. Chim. Acta 1980, 45, 225-230.
(31) Dyachenko, O. A.; Konovalikhin, S. V.; Shilov, G. V.; Lyubovskaya,
R. N.; Aldoshina, M. Z.; Lyubovskii, R. B. IzV. Akad. Nauk SSSR,
Ser. Khim. 1995, 905-909.
1225-1230.
(27) Zamora, F.; Sabat, M.; Lippert, B. Inorg. Chim. Acta 1998, 267, 87-
91.
Inorganic Chemistry, Vol. 45, No. 6, 2006 2577

Chen et al.
Figure 11. One-dimensional double-chain (extended along the a axis) formed via H-bonding interactions in 6.
were consistent with their chemical formulas. The charac-
teristic P-F stretching vibrations of PF6- at ca. 830 and ca.
555 cm-1 were observed in the IR spectra of 1-3, 6, and
10.10 The peak at 1350 cm-1 in 6 indicated the presence of
-
the NO3 anion.35 The peaks at 2079 and 2080 cm-1 in 3
and 4 indicated the vibrations of the terminal SCN-, while
the peak at 2114 cm-1 in 8 was assigned to be the stretching
vibration of the bridging SCN-.36 The peak at 481 cm-1 in
9 was assigned to be the S-S stretching vibration.34 The 1H
NMR spectra of 1-10 in DMSO-d6 at room temperature
showed a multiplet for protons of Ph groups at 7.42-7.81
ppm and a singlet related to protons of NMe3 at ca. 3.34
ppm.
Figure 12. One-dimensional zigzag chain (extended along the c axis)
formed by Hg‚‚‚I secondary interactions in 7.
the bridging Hg-Cl bond lengths range from 3.163(2) to
3.169(1) Å. These values are smaller than the sum of the
van der Waals radii of Hg2+ and Cl- (3.300 Å).32 The mean
Hg‚‚‚Hg contact [3.750(1) Å] is comparable to those of [Hg6-
Cl8(SCH2CH2NH3)8]]Cl4‚4H2O [3.776(1) and 3.797(1) Å]
and [Hg9Br15(SCH2CH2NH3)9](Cl0.8Br0.2)3 [3.605(2) and 3.750-
(1) Å].1m
As shown in Figure 15, the UV-vis spectra of 1 and 3-8
in DMF exhibited a strong and broad absorption ranging from
272 to 277 nm and a long absorption tail to ca. 400 nm. On
the other hand, the spectra of 2 and 10 showed a broad peak
at 287 nm for 2 or 284 nm for 10 and a shoulder peak at
312 nm for 2 or 314 nm for 10. Because the absorption
spectrum of the free Tab in DMF had a broad absorption
band at 320 nm, the peaks observed in the spectra of 1-8
and 10 were blue-shifted and may be due to the ligand(Tab)-
to-metal charge transfer (LMCT).1m,37a As discussed earlier
in this paper, the structures of 2-4, 6-8, and 10 roughly
keep the [Hg(Tab)2]2+ species of 1, although the related Hg
atoms possess somewhat different coordination geometries
when they bind to other donor atoms. Therefore, those peaks
On the other hand, the Tab-Tab dication has positive
charges located on the NMe3 groups. The S1-S2 bond length
and the C1-S1-S2-C10 torsion angle of 9 are 2.034(3) Å
and 81.5(3)°, respectively, which are similar to those in
[C8H22N2S2]Cl2 {2.075(5) Å and 82.39(2)°; C8H22N2S2 ) bis-
[2-(N,N-dimethylamino)ethyl]disulfide dihydrochloride}33 and
{[C10H10N2S2][Cu2Cl6][BF4]2}n [2.034(3) Å and 81.5(3)°;
C10H10N2S2 ) bis(4-pyridinium)disulfide].34 In the crystal
of 9, the H-bonding interactions are also abundant. The Cl
atoms of the cluster anions interact with the H atoms of the
methyl group or phenyl groups of the Tab-Tab to afford
complicated intermolecular H bonds, forming a three-
dimensional H-bonded structure (see the Supporting Infor-
mation).
(35) (a) Barron, P. F.; Dyason, J. C.; Healy, P. C.; Engelharelt, L. M.;
Skelton, B. W.; White, A. H. J. Chem. Soc., Dalton Trans. 1986, 9,
1965-1970. (b) Nakamoto, K. Infrared Spectra of Inorganic and
Coordination Compounds; Wiley: New York, 1963; p 92. (c) Lang,
J. P.; Kawaguchi, H.; Tatsumi, K. J. Organomet. Chem. 1998, 569,
109-119. (d) Catalan, K. J.; Zubkowski, J. D.; Perry, D. L.; Valente,
E. J.; Feliu, L. A.; Polanco, A. Polyhedron 1995, 14, 2165-2170.
(36) (a) Cingolani, A.; Di Nicola, C.; Effendy, Pettinari, C.; Skelton, B.
W.; Somers, N.; White, A. H. Inorg. Chim. Acta 2005, 358, 748-
762. (b) Thayer, J. S.; West, R. AdV. Organomet. Chem. 1967, 5, 169-
171. (c) Thayer, J. S.; Strommen, D. P. J. Organomet. Chem. 1966,
5, 383-388.
(37) (a) Schaffer, A.; Williman, K.; Willner, H. J. Inorg. Biochem. 1989,
36, 186-192. (b) Watton, S. P.; Wright, J. G.; MacDonnell, F. M.;
Bryson, J. W.; Sabat, M.; O’Halloran, T. V. J. Am. Soc. Chem. 1990,
112, 2824-2826. (c) Tamilarasan, R.; McMillin, D. R. Inorg. Chem.
1986, 25, 2037-2040.
Spectral Aspects of 1-10. Solids 1-10 are relatively
stable toward oxygen and moisture. Compounds 1-10 are
soluble in DMSO and DMF. The elemental analyses of 1-10
(32) Larock, R. C.; Burns, L. D.; Varaprath, S.; Russell, C. E.; Richardson,
J. W.; Janakiraman, J. M. N.; Jacobson, R. A. Organometallics 1987,
6, 1780-1789.
(33) Ottersen, T.; Warner, L. G.; Seff, K. Acta Crystallogr. 1973, B29,
2954-2956.
(38) (a) Beltramini, M.; Lerch, K.; Vaslk, M. Biochemistry 1984, 23, 3422-
3427. (b) Vaslk, M.; Kagi, J. H. R.; Hill, H. A. O. Biochemistry 1981,
20, 2852-2856. (c) Johnson, B. A.; Armitage, I. M. Inorg. Chem.
1987, 26, 3139-3144.
(34) Blake, A. J.; Champness, N. R.; Cooke, P. A.; Nicolson, J. E. B. Acta
Crystallogr., Sect. C. 1999, 55, 1422-1424.
2578 Inorganic Chemistry, Vol. 45, No. 6, 2006

Family of Mercury(II) Zwitterionic Thiolate Complexes
Figure 13. One-dimensional zigzag chain (extended along the b axis) formed by Hg‚‚‚N secondary interactions in 8.
Table 7. Principal Electronic Transitions in 1-10, Tab and
[Tab-Tab](PF6)2 and Other Mercury(II) Thiolate Compounds
Hg compounds
λ
max, nm
ref
[Hg6Cl8(SCH2CH2NH3)8]]Cl4‚4H2O
[Hg9Br15(SCH2CH2NH3)9](Cl0.8Br0.2
[Hg(l-Cys)4 peptide]a
[Hg(SEt)2]
273
1m
1m
)
3
268, 339 (sh)b
280
37a
37b
37b
37b
37b
228, 282 (sh)
228, 262 (sh)
235, 260 (sh)
240, 260 (sh),
290 (sh)
247, 280 (sh)
283
[Hg(Pri)2]
[Et4N][Hg(SBut)3]
Hg-MerRc
Hg-plastocynanin
37c
38a
neurospora Hg3-MTd
Hg7-MT
1
2
3
4
5
6
7
8
9
10
Tab
304
38b, 38c
this work
this work
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Figure 14. Perspective view of 9 with 50% thermal ellipsoids. All H atoms
were omitted for clarity.
272e
287,f 312 (sh)
275g
Table 6. Selected Bond Distances (Å) and Angles (deg) for 9
271h
Hg1-Cl1
Hg1-Cl2
Hg2-Cl5
2.372(2)
2.5335(15)
2.3046(16)
Hg1-Cl3
Hg1-Cl4
S1-S2
2.4891(15)
2.5393(15)
2.034(3)
273i
273j
274k
277l
Cl1-Hg1-Cl3
Cl3-Hg1-Cl2
Cl3-Hg1-Cl4
Cl5-Hg2-Cl5A
123.23(9)
101.95(5)
102.81(5)
180.0
Cl1-Hg1-Cl2
Cl1-Hg1-Cl4
Cl2-Hg1-Cl4
109.01(8)
115.70(7)
101.29(5)
273m
284,n 314(sh)
320,o 267 (sh)
271p
[Tab-Tab][PF6]2
a l-Cys ) L-cysteine. b sh ) shoulder. c MerR ) metalloregulatory
protein. d MT ) metallothionein. e 1.25 × 10-4 M in DMF. f 2.58 × 10-4
M in DMF. g 1.22 × 10-4 M in DMF. h 1.22 × 10-4 M in DMF. i 7.72 ×
10-5 M in DMF. j 2.68 × 10-5 M in DMF. k 1.44 × 10-4 M in DMF.
l 5.86 × 10-5 M in DMF. m 9.68 × 10-5 M in DMF. n 2.54 × 10-5 M in
DMF. o 1.25 × 10-4 M in DMF. p 1.52 × 10-4 M in DMF.
observed in the spectra of 2-4, 6-8, and 10 were red-shifted
relative to the peak of 1, which may be ascribed to the
different coordination environments about the Hg atoms in
these compounds. In addition, because the absorption
spectrum of [Tab-Tab](PF6)212 in DMF had a broad absorp-
tion band at 271 nm, the peak at 273 nm observed in the
spectrum of 9 in DMF probably originated from intraligand
transitions (Table 7).
Conclusion
In the work reported here, we have demonstrated a facile
route to a series of new mercury(II) zwitterionic thiolate
complexes (2-10) from a performed complex 1. Through
coordination of Tab ligands or other donor ligands such as
halides and pseudohalides, the Hg atom in the [Hg(Tab)2]2+
dication of 1 may turn its linear coordination sphere (type I)
into T-shaped (type II), trigonal-planar (type III), seesaw-
shaped (type IV), and tetrahedral (type V) coordination
geometry. Meanwhile, compound 1 may further combine
other Hg atoms to form polynuclear complexes (e.g., 6-8)
via the bridging ability of the S atoms of the two Tab ligands
or through the Hg-X (X ) I-, SCN-) contacts. The HgII
electron deficiency in mercury dithiolate complexes may be
readily remediated by binding to another donor ligand, which
may be attributed to the formation of mercury dithiolate
Figure 15. Absorption spectra of 1-10, Tab, and [Tab-Tab](PF6)2 in
DMF with a 1-mm optical length.
complexes 1-10. These results in this paper may provide
insight into the varieties of coordination spheres of the Hg
sites in metallothioneins. Furthermore, it is expected that 1
may also be a good precursor for the generation of electronic,
Inorganic Chemistry, Vol. 45, No. 6, 2006 2579

Chen et al.
magnetic, and optical materials of heterobimetallic com-
pounds such as lanthanide/mercury compounds.16 Research
is continuing in these areas.
Returned Overseas Chinese Scholars, State Education Min-
istry of China. The authors highly appreciate the useful
suggestions of the reviewers.
Supporting Information Available: Crystallographic data of
compounds 1-10 (CIF) and cell packing diagrams highlighting
Hg-X (X ) F, I, O, S, etc.) secondary and H-bonding interactions
(in PDF format). This material is available free of charge via the
Internet at http://pubs.acs.org.
Acknowledgment. This work was supported by the
NNSF of China (Grants 20271036 and 20525101), the NSF
of Jiangsu Province (Grant BK2004205), the Key Laboratory
of Structural Chemistry of FJIRSM (Grant 030066), the Key
Laboratory of Organic Synthesis of Jiangsu Province (Grant
JSK001), and the Scientific Research Foundation for the
IC051875N
2580 Inorganic Chemistry, Vol. 45, No. 6, 2006