Synthesis and characterization of the silver maleonitrilediselenolates and silver maleonitriledithiolates [K([2.2.2]-cryptand)]4[Ag4 (Se2C2(CN)2)4], [Na([2.2.2]-cryptand)]4[Ag4 (S2C2(CN)2)4]·0.33MeCN

Article abstract of DOI:10.1021/ic000868q

Reaction of AgBF₄, KNH₂, K₂Se, Se, and [2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)]₄[Ag₄ (Se₂C₂(CN)₂)₄] (1). In the unit cell of 1 there are four [K([2.2.2]-cryptand)]⁺ units and a tetrahedral Ag₄ anionic core coordinated in μ₁-Se, μ₂-Se fashion by each of four mns ligands (mns = maleonitrilediselenolate, [Se₂C₂(CN)₂]^2-). Reaction of AgNO₃, Na₂(mnt) (mnt = maleonitriledithiolate, [S₂C₂(CN)₂]^2-), and [2.2.2]-cryptand in acetonitrile yields [Na([2.2.2]-cryptand)]₄[Ag₄ (mnt)₄]·0.33MeCN (2). The Ag₄ anion of 2 is analogous to that in 1. Reaction of AgNO₃, Na₂(mnt), and [NBu₄]Br in acetonitrile yields [NBu₄]₄[Ag₄(mnt)₄] (3). The anion of 3 also comprises an Ag₄ core coordinated by four mnt ligands, but the Ag₄ core is diamond-shaped rather than tetrahedral. Reaction of [K([2.2.2]-cryptand)]₃[Ag(mns)(Se₆)] with KNH₂ and [2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)]₃[Ag(mns)₂]·2MeCN (4). The anion of 4 comprises an Ag center coordinated by two mns ligands in a tetrahedral arrangement. Reaction of AgNO₃, 2 equiv of Na₂(mnt), and [2.2.2]-cryptand in acetonitrile yields [Na([2.2.2]-cryptand)]₃[Ag(mnt)₂] (5). The anion of 5 is analogous to that of 4. Electronic absorption and infrared spectra of each complex show behavior characteristic of metal-maleonitriledichalcogenates. Crystal data (153 K): 1, P2/n, Z = 2, a = 18.362(2) A, b = 16.500(1) A, c = 19.673(2) A, β = 94.67(1)°, V = 5941(1) A³; 2, P4, Z = 4, a = 27.039(4) A, c = 15.358(3) A, V = 11229(3) A³; 3, P2₁/c, Z = 6, a = 15.689(3) A, b = 51.924(11) A, c = 17.393(4) A, β = 93.51(1)°, V = 14142(5) A³; 4, P2₁/c, Z = 4, a = 13.997(1) A, b = 21.866(2) A, c = 28.281(2) A, β = 97.72(1)°, V = 8578(1) A³; 5, P2/n, Z = 2, a = 11.547(2) A, b = 11.766(2) A, c = 27.774(6) A, β = 91.85(3)°, V = 3772(1) A³.

Full text of DOI:10.1021/ic000868q

Inorg. Chem. 2001, 40, 1809-1815
1809
Synthesis and Characterization of the Silver Maleonitrilediselenolates and Silver
Maleonitriledithiolates [K([2.2.2]-cryptand)]4[Ag4(Se2C2(CN)2)4],
[Na([2.2.2]-cryptand)]4[Ag4(S2C2(CN)2)4]·0.33MeCN, [NBu4]4[Ag4(S2C2(CN)2)4],
[K([2.2.2]-cryptand)]3[Ag(Se2C2(CN)2)2]·2MeCN, and [Na([2.2.2]-cryptand)]3[Ag(S2C2(CN)2)2]
Craig C. McLauchlan and James A. Ibers*
Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
ReceiVed August 1, 2000
Reaction of AgBF4, KNH2, K2Se, Se, and [2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)]4[Ag4(Se2C2-
(CN)2)4] (1). In the unit cell of 1 there are four [K([2.2.2]-cryptand)]+ units and a tetrahedral Ag4 anionic core
coordinated in µ1-Se, µ2-Se fashion by each of four mns ligands (mns ) maleonitrilediselenolate, [Se2C2(CN)2]2-).
Reaction of AgNO3, Na2(mnt) (mnt ) maleonitriledithiolate, [S2C2(CN)2]2-), and [2.2.2]-cryptand in acetonitrile
yields [Na([2.2.2]-cryptand)]4[Ag4(mnt)4]‚0.33MeCN (2). The Ag4 anion of 2 is analogous to that in 1. Reaction
of AgNO3, Na2(mnt), and [NBu4]Br in acetonitrile yields [NBu4]4[Ag4(mnt)4] (3). The anion of 3 also comprises
an Ag4 core coordinated by four mnt ligands, but the Ag4 core is diamond-shaped rather than tetrahedral. Reaction
of [K([2.2.2]-cryptand)]3[Ag(mns)(Se6)] with KNH2 and [2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)]3-
[Ag(mns)2]‚2MeCN (4). The anion of 4 comprises an Ag center coordinated by two mns ligands in a tetrahedral
arrangement. Reaction of AgNO3, 2 equiv of Na2(mnt), and [2.2.2]-cryptand in acetonitrile yields [Na([2.2.2]-
cryptand)]3[Ag(mnt)2] (5). The anion of 5 is analogous to that of 4. Electronic absorption and infrared spectra of
each complex show behavior characteristic of metal-maleonitriledichalcogenates. Crystal data (153 K): 1, P2/n,
Z ) 2, a ) 18.362(2) Å, b ) 16.500(1) Å, c ) 19.673(2) Å, â ) 94.67(1)°, V ) 5941(1) Å3; 2, P4h, Z ) 4, a
) 27.039(4) Å, c ) 15.358(3) Å, V ) 11229(3) Å3; 3, P21/c, Z ) 6, a ) 15.689(3) Å, b ) 51.924(11) Å, c )
17.393(4) Å, â ) 93.51(1)°, V ) 14142(5) Å3; 4, P21/c, Z ) 4, a ) 13.997(1) Å, b ) 21.866(2) Å, c ) 28.281(2)
Å, â ) 97.72(1)°, V ) 8578(1) Å3; 5, P2/n, Z ) 2, a ) 11.547(2) Å, b ) 11.766(2) Å, c ) 27.774(6) Å, â )
91.85(3)°, V ) 3772(1) Å3.
Introduction
However, Ag complexes with the dithiolate ligand maleoni-
triledithiolate () mnt ) [S2C2(CN)2]2-) are limited primarily
Tetrahedral Ag4 clusters, some with coordinating chalcogen-
containing ligands, are well-known.1,2 For example, clusters with
dithiolate ligands, such as [Ag4(S2C2H4(C6H4))3]2- 3 and
[Ag4(S2CdC(CN)2)4]4-,4 and the polyselenide species [Ag4-
2- 19
to the Ag2(mnt) salt,17,18 polymeric (Ag4(mnt)3)n
,
and
[Ag(PPh3)2][Ag(PPh3)2(mnt)].20-22 There is also a claim of
[Ag(mnt)2]2- 23 but no evidence is provided. [Ag(PR3)2]+
,
complexes with [M(mnt)2]2- species (M ) Ni,24-28 Pd,27 and
(Se4)3]2- 5 [Ag4(Se4)4]4- 5 and [Ag4(Se4)3-x(Se5)x]2- 6,7 have
, ,
Pt27) and Ag complexes with mnt derivatives, such as oxa-crown
been reported. Cation size has an important effect on which
Ag-chalcogenide species are formed.5,7 Noncluster complexes
of Ag with chalcogen-containing ligands are also common.5,8-16
(14) Akrivos, P. D.; Katsikis, H. J.; Koumoutsi, A. Coord. Chem. ReV.
1997, 167, 95-204.
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Commun. 1981, 322-324.
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(3) Henkel, G.; Betz, P.; Krebs, B. Angew. Chem., Int. Ed. Engl. 1987,
26, 145-146; Angew. Chem. 1987, 99, 145.
(16) Bonasia, P. J.; Mitchell, G. P.; Hollander, F. J.; Arnold, J. Inorg. Chem.
1994, 33, 1797-1802.
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75-96.
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Pitts, J. T. Pure Appl. Chem. 1998, 70, 839-844.
(18) Wolmersha¨user, G.; Kraft, G. Chem. Ber. 1989, 122, 385-387.
(19) Manecke, G.; Wo¨hrle, D. Makromol. Chem. 1968, 116, 36-61.
(20) Ba¨hr, G.; Schleitzer, G. Chem. Ber. 1957, 90, 438-443.
(21) Estevan, F.; Lahuerta, P.; Solana, I. Polyhedron 1985, 4, 1965-1967.
(22) Heinrich, D. D.; Fackler, J. P., Jr.; Lahuerta, P. Inorg. Chim. Acta
1986, 116, 15-19.
(5) Huang, S.-P.; Kanatzidis, M. G. Inorg. Chem. 1991, 30, 1455-1466.
(6) Cusick, J.; Scudder, M. L.; Craig, D. C.; Dance, I. G. Polyhedron
1989, 8, 1139-1141.
(7) Kanatzidis, M. G.; Huang, S.-P. Angew. Chem., Int. Ed. Engl. 1989,
28, 1513-1514.
(8) Mu¨ller, A.; Ro¨mer, M.; Bo¨gge, H.; Krickemeyer, E.; Baumann, F.-
W.; Schmitz, K. Inorg. Chim. Acta 1984, 89, L7-L8.
(9) Banda, R. M. H.; Craig, D. C.; Dance, I. G.; Scudder, M. L. Polyhedron
1989, 8, 2379-2383.
(23) Battaglia, R.; Henning, R.; Dinh-Ngoc, B.; Schlamann, W.; Kisch,
H. J. Mol. Catal. 1983, 21, 239-253.
(24) Coucouvanis, D.; Baenziger, N. C.; Johnson, S. M. Inorg. Chem. 1974,
13, 1191-1199.
(10) Mu¨ller, A.; Krickemeyer, E.; Zimmermann, M.; Ro¨mer, M.; Bo¨gge,
H.; Penk, M.; Schmitz, K. Inorg. Chim. Acta 1984, 90, L69-L71.
(11) Zhao, J.; Adcock, D.; Pennington, W. T.; Kolis, J. W. Inorg. Chem.
1990, 29, 4358-4360.
(12) Fenske, D.; Schreiner, B.; Dehnicke, K. Z. Anorg. Allg. Chem. 1993,
619, 253-260.
(13) Corrigan, J. F.; Fenske, D.; Power, W. P. Angew. Chem., Int. Ed. Engl.
1997, 36, 1176-1179.
(25) Hollander, F. J.; Ip, Y. L.; Coucouvanis, D. Inorg. Chem. 1976, 15,
2230-2234.
(26) Caffery, M. L.; Coucouvanis, D. J. Inorg. Nucl. Chem. 1975, 37,
2081-2086.
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Inorg. Chim. Acta 1995, 231, 35-43.
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Chem. Soc. Jpn. 2000, 73, 391-394.
10.1021/ic000868q CCC: $20.00 © 2001 American Chemical Society
Published on Web 03/15/2001

1810 Inorganic Chemistry, Vol. 40, No. 8, 2001
McLauchlan and Ibers
ethers ([15]-crown-O3(S2C2(CN)2))29-31 and alkylated mnt
(R2S2C2(CN)2),32 are also known. We recently reported the syn-
thesis of [K([2.2.2]-cryptand)]3[Ag(mns)(Se6)],33,34 an Ag com-
filtered; the red-orange filtrate was cooled to 4 °C and then layered
with 11 mL of diethyl ether/toluene (10:1). Yellow block-shaped
crystals of 2 were isolated after 2 days. Yield: 180.6 mg (68% based
on Ag). UV-vis (CH2Cl2) (λmax, nm (ꢀ, M-1 cm-1 )): 269 (33600),
306 (13200), 369 (35100), 380 (26200). IR (ν, CN region, cm-1): 2180.
ESI (-): 248.8 (m/z, [Ag4(S2C2(CN)2)4]4-), 425.8 (m/z, [Ag4(S2C2-
(CN)2)3]2-), 851.8 (m/z, [Ag4(S2C2(CN)2)3]-). EDS: Na:Ag:S ) 0.68:
1:1.51. Anal. Calcd for C88.67H145Ag4N16.33Na4O24S8: C, 40.90; H, 5.61;
N, 8.78. Found: C, 40.46; H, 5.64; N, 8.28. Mp 161-166 °C.
Preparation of [NBu4]4[Ag4(S2C2(CN)2)4] (3). AgNO3 (38 mg, 0.22
mmol) in 5 mL of acetonitrile was added via cannula to 43 mg (0.23
mmol) of Na2(mnt) in 5 mL of acetonitrile, and the resultant orange
solution was stirred for 16 h. Then 73.5 mg (0.23 mmol) of [NBu4]Br
in 3 mL of acetonitrile was added dropwise to the solution. The orange
solution was filtered, cooled to 4 °C, and layered with 11 mL of diethyl
ether/toluene (10:1). Yellow needles of 3 were isolated after 2 days.
Yield: 49.0 mg (45% based on Ag). Complex 3 was also prepared
with [NBu4][BF4] in place of [NBu4]Br. UV-vis (CH2Cl2) (λmax, nm
(ꢀ, M-1 cm-1 )): 268 (35400), 302 (16500), 369 (23800), 382 (23400).
IR (ν, CN region, cm-1): 2196. ESI (-): 247.8 (m/z, [Ag4(S2C2-
(CN)2)4]4-). EDS: Ag:S ) 1:1.7. Mp 176-180 °C.
Preparation of [K([2.2.2]-cryptand)]3[Ag(Se2C2(CN)2)2]‚2MeCN
(4). Acetonitrile (10 mL) was added to a flask charged with 25 mg (12
µmol) of [K([2.2.2]-cryptand)]3[Ag(mns)(Se6)], 7 mg (0.16 mmol) of
KNH2, and 50 mg (0.13 mmol) of [2.2.2]-cryptand. The color of the
solution changed from red-brown to deep orange over 20 min. After
24 h the solution was filtered and the orange filtrate was cooled to 4
°C and layered with 11 mL of diethyl ether/toluene (10:1). Red needles
of 4 were isolated after 4 days. Yield: 5 mg (22% based on Ag). UV-
vis (CH2Cl2) (λmax, nm (ꢀ, M-1 cm-1 )): 290 (16800), 333 (4700), 392
(2700) 248 (11100). IR (ν, CN region, cm-1): 2168. EDS: K:Ag:Se
) 2.9:1:3.8. Mp 206-208 °C. Limited amounts of material made bulk
analyses impractical.
Preparation of [Na([2.2.2]-cryptand)]3[Ag(S2C2(CN)2)2] (5). Ac-
etonitrile (5 mL) was added to a flask charged with 15.6 mg (0.09
mmol) of AgNO3 to give a colorless solution. In a separate flask, 41
mg (0.20 mmol) of Na2(mnt) and 5 mL of acetonitrile were combined
to yield a yellow suspension. After 1 h the Ag solution was added
dropwise to the mnt suspension to produce an orange solution. After
16 h a solution of acetonitrile (3 mL) containing 139 mg (0.37 mmol)
of [2.2.2]-cryptand was added dropwise to the Ag/mnt solution. The
solution was stirred for 2 h and then filtered. The red-orange filtrate
was cooled to 4 °C and layered with 11 mL of diethyl ether/toluene
(10:1). Yellow plate-shaped crystals of 5 were isolated after 2 days.
Yield: 72 mg (50% based on Ag). UV-vis (CH2Cl2) (λmax, nm (ꢀ,
M-1 cm-1 )): 270 (15300), 374 (11100), 395 (10700). IR (ν, CN region,
cm-1): 2171. ESI (-): 236.8 (m/z, [HAg(S2C2(CN)2)2‚CH2Cl2]2-),
246.7 (m/z, [Ag(S2C2(CN)2)]-). Mp 164-168 °C.
plex of the maleonitrilediselenolate () mns ) [Se2C2(CN)2]2-
)
ligand, the Se analogue of mnt. Here we report the synthesis
and characterization of new Ag-mns and Ag-mnt complexes
with structures unlike those of any reported mnt complexes.
Experimental Section
All processes were carried out under N2 with the use of standard
Schlenk and air-free manipulation techniques.35 Infrared spectra were
collected on a Bio-Rad Digilab FTS-60 FTIR as KBr mulls. Electronic
absorption spectra were collected on a Cary 1E UV-visible spectro-
photometer. Energy dispersive spectroscopy (EDS) was performed on
a Hitachi S-4500 field emission scanning electron microscope. Melting
point determinations were made in glass capillaries with a Mel-Temp
device. Electrospray mass spectroscopic analyses were performed on
a Micromass Quattro II triple quadrupole instrument operated in
negative ion mode with CH2Cl2 as the solvent. Se (99.9%), AgBF4
(98%), [NBu4]Br (98%), KBr (98%), AgNO3 (99+%), and [2.2.2]-
cryptand (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane)
(98%) were purchased from Aldrich Chemicals, Milwaukee, WI, and
used without further purification. K2Se was prepared by the stoichio-
metric combination of the elements in liquid ammonia. KNH2 was
prepared by reaction of KH with liquid ammonia. [K([2.2.2]-cryptand)]3-
[Ag(mns)(Se6)]34 and Na2(mnt)36 were prepared by published methods.
All solvents were dried and distilled prior to use.
Preparation of [K([2.2.2]-cryptand)]4[Ag4(Se2C2(CN)2)4] (1). Method
1. A mixture of 11 mg (0.2 mmol) of KNH2, 63 mg (0.4 mmol) of
K2Se, 158 mg (2 mmol) of Se, 340 mg (0.9 mmol) of [2.2.2]-cryptand,
and 40 mg (0.2 mmol) of AgBF4 was dissolved in 10 mL of acetonitrile.
The flask containing the resultant green solution was wrapped in foil
to keep out light. After it was stirred for 24 h, the solution was filtered
and the red-green filtrate was cooled to 4 °C and then layered with 11
mL of diethyl ether/toluene (10:1). Orange block-shaped crystals of 1
were isolated after 7 days. Yield: 51.7 mg (21% based on Ag). UV-
vis (CH2Cl2) (λmax, nm (ꢀ, M-1 cm-1 )): 287 (11000), 329 (2500), 383
(1400). IR (ν, CN region, cm-1): 2177. EDS: K:Ag:Se ) 1.1:1:2.3.
Anal. Calcd for C88H144Ag4K4N16O24Se8: C, 34.89; H, 4.79; N, 7.40.
Found: C, 33.82; H, 4.33; N, 7.09. Mp 242-246 °C.
Method 2. A mixture of 27 mg (13 µmol) of [K([2.2.2]-cryptand)]3-
[Ag(mns)(Se6)], 11 mg (56 µmol) of AgBF4, 7 mg (0.16 mmol) of
KNH2, and 50 mg (0.13 mmol) of [2.2.2]-cryptand was dissolved in
10 mL of acetonitrile. The flask containing the resultant red-brown
solution was wrapped in foil to keep out light. The solution was stirred
for 24 h and then filtered. The red-green filtrate was cooled to 4 °C
and layered with 11 mL of diethyl ether/toluene (10:1). Orange block-
shaped crystals of 1 were isolated after 2 days.
Preparation of [Na([2.2.2]-cryptand)]4[Ag4(S2C2(CN)2)4]‚0.33MeCN
(2). Acetonitrile (5 mL) was added to a flask charged with 42 mg (0.25
mmol) of AgNO3 to afford a colorless solution. In a separate flask, 47
mg (0.25 mmol) of Na2(mnt) and 5 mL of acetonitrile were combined
to yield a yellow suspension. After 1 h the Ag solution was added
dropwise to the mnt suspension to produce an orange solution. After
16 h a solution of acetonitrile (3 mL) containing 374 mg (1 mmol) of
[2.2.2]-cryptand was added dropwise to the Ag/mnt solution. The color
of the solution darkened. The solution was stirred for 2 h and then
X-ray Crystallography. A crystal of 1, 2, 3, 4, or 5 was mounted
on the end of a fiber on a goniometer head. The head was placed in
the cold stream of a Bruker-AXS SMART-1000 diffractometer equipped
with a CCD area detector and graphite-monochromated Mo KR
radiation. Data were collected at 153 K with 0.3° steps in ω for 606
frames each, with φ ) 0°, 120°, 240° for 1, 4, and 5 and æ ) 0°, 90°,
180°, 270° for 2 and 3. An additional 50 frames at æ ) 0° were
collected for 1-5 at the end of each data collection. Data were processed
with the program SAINT+.37 A face-indexed absorption correction was
applied with the use of the program XPREP of the SHELXTL-PC
suite.38 Data were further corrected for frame variations with the
program SADABS,37 which relies on redundant data. Structure solutions
were obtained by direct methods and refined on F2 with the use of
full-matrix least-squares techniques.38 Except where noted, all non-
hydrogen atoms were refined anisotropically and hydrogen atoms were
refined with a riding model.
(29) Sibert, J. W.; Lange, S. J.; Williams, D. J.; Barrett, A. G. M.; Hoffman,
B. M. Inorg. Chem. 1995, 34, 2300-2305.
(30) Drexler, H.-J.; Reinke, H.; Holdt, H.-J. Chem. Ber. 1996, 129, 807-
814.
(31) Drexler, H.-J.; Grotjahn, M.; Kleinpeter, E.; Holdt, H.-J. Inorg. Chim.
Acta 1999, 285, 305-308.
Of the two unique [K([2.2.2]-cryptand)]+ units in 1, one is well-
behaved, whereas the second shows some disorder in the flexible C2H4-
(32) Heber, R.; Hoyer, E. J. Prakt. Chem. 1976, 318, 19-25.
(33) Smith, D. M.; Albrecht-Schmitt, T. E.; Ibers, J. A. Angew. Chem.,
Int. Ed. Engl. 1998, 37, 1089-1091.
(37) SMART Version 5.054 Data Collection and SAINT-Plus Version
6.02A Data Processing Software for the SMART System; Bruker
Analytical X-Ray Instruments, Inc.: Madison, WI, 2000.
(38) Sheldrick, G. M. SHELXTL DOS/Windows/NT, version 5.10; Bruker
Analytical X-ray Instruments, Inc.: Madison, WI, 1997.
(34) McLauchlan, C. C.; Ibers, J. A. Inorg. Chem. 2000, 39, 1046-1048.
(35) Shriver, D. F.; Drezdon, M. A. Manipulation of Air SensitiVe
Compounds, 2nd ed.; Wiley: New York, 1986.
(36) Davison, A.; Holm, R. H. Inorg. Synth. 1967, 10, 8-26.

Silver Maleonitrilediselenolates and -dithiolates
Inorganic Chemistry, Vol. 40, No. 8, 2001 1811
Table 1. Crystallographic Data for [K([2.2.2]-cryptand)]4[Ag4(Se2C2(CN)2)4] (1), [Na([2.2.2]-cryptand)]4[Ag4(S2C2(CN)2)4]‚0.33MeCN (2),
[NBu4]4[Ag4(S2C2(CN)2)4] (3), [K([2.2.2]-cryptand)]3[Ag(Se2C2(CN)2)2]‚2MeCN (4), and [Na([2.2.2]-cryptand)]3[Ag(S2C2(CN)2)2] (5)a
1
2
3
4
5
formula
fw
a, Å
b, Å
c, Å
C88H144Ag4K4N16O24Se8 C88.67H145Ag4N16.33Na4O24S8 C80H144Ag4N12S8 C66H108AgK3N12O18Se4 C62H108AgN10Na3O18S4
3029.75
2603.80
27.039(4)
27.039(4)
15.358(3)
90
11229(3)
1.541
1962.03
15.689(3)
51.924(11)
17.393(4)
93.51(1)
14142(5)
1.382
1904.70
13.997(1)
21.866(2)
28.281(2)
97.72(1)
8578(1)
1.475
1586.66
11.547(2)
11.766(2)
27.774(6)
91.85(3)
3772(1)
1.397
18.362(2)
16.500(1)
19.673(1)
94.67(1)
5941(1)
â, °
V, Å3
F
calcd, g cm-3 1.694
T, K
153(2)
P2/n
2
153(2)
P4h
4
153(2)
P21/c
6
153(2)
P21/c
4
153(2)
P2/n
2
space group
Z
λ, Å
0.71073
33.10
0.076
0.143
0.71073
9.25
0.047
0.71073
10.41
0.082
0.71073
21.45
0.036
0.71073
4.67
0.081
µ, cm-1
R(F)b
2
wR(Fo )c
0.098
0.153
0.070
0.132
a Crystal data for [K([2.2.2]-cryptand)]2[Cu(Se2C2(CN)2)2]: C44H72CuK2N8O12Se4, monoclinic, P21/c, a ) 12.211(2) Å, b ) 16.086(3) Å, c )
15.158(3) Å, â ) 107.05(3)°, V ) 2847(1) Å3, T ) -120 °C, Z ) 2. b R(F) ) ∑||Fo| - |Fc||/∑|Fo|. c wR(Fo ) ) [∑w(Fo - Fc2)2/∑wFo ]1/2; w-1
2
2
4
) σ2(Fo ) + (0.03Fo )2 for Fo > 0; w-1 ) σ2(Fo ) for Fo e 0.
2
2
2
2
2
OC2H4OC2H4 arms and has been refined isotropically. As refinement
in both P2/n and Pn produced similar results, the higher symmetry
space group P2/n was used.
Compound 2 crystallizes with 0.333(4) molecules of acetonitrile in
the asymmetric unit. Atom N20 of the acetonitrile is too close to its
symmetry-generated counterpart (0.90(3) Å) for both to be present
simultaneously. No evidence of a supercell was found. Although P4h is
a noncentrosymmetric space group, the 4h axis precludes the possibility
of enantiomorphs. However, a metric of racemic cocrystallization, the
Flack parameter,39 refined to 0.41(1). Examination of the atomic
coordinates of the anions with the program MISSYM in the PLATON
suite of programs did not suggest the presence of any additional
symmetry.40,41
In 3, five of the six unique [NBu4]+ cations refined well but the
other showed some disorder of a butyl group. This was modeled
accordingly.
Compound 4 solved and refined routinely.
Compound 5 contains 1.5 crystallographically unique [Na([2.2.2]-
1
cryptand)]+ cations. The half cation with Na located at /4,0.4891,1/4
showed disorder in several C and N positions of the flexible cryptand
and was modeled accordingly. No evidence of a supercell was found.
Crystallographic details are summarized in Table 1 and in the
Supporting Information.
Figure 1. Displacement ellipsoid plot of the [Ag4(mns)4]4- anion in
[K([2.2.2]-cryptand)]4[Ag4(mns)4] (1). Here and in subsequent figures
displacement ellipsoids are drawn at the 50% probability level. The
anion has crystallographically imposed symmetry 2.
Results and Discussion
Syntheses. The reaction of AgBF4, KNH2, K2Se, Se, and
[2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)]4[Ag4-
(mns)4] (1). Compound 1 can also be formed by reaction of
[K([2.2.2]-cryptand)]3[Ag(mns)(Se6)] with AgBF4, KNH2, and
[2.2.2]-cryptand in acetonitrile. The reaction of AgNO3, Na2-
(mnt), and [2.2.2]-cryptand in acetonitrile yields [Na([2.2.2]-
cryptand)]4[Ag4(mnt)4]‚0.33MeCN (2), the anion of which is
analogous to that of 1. The reaction of AgNO3, Na2(mnt), and
[NBu4]Br in acetonitrile yields [NBu4]4[Ag4(mnt)4] (3). The
syntheses of 2 and 3 differ only in the cation added to the
reaction mixture. The reaction of [K([2.2.2]-cryptand)]3[Ag-
(mns)(Se6)] with KNH2 and [2.2.2]-cryptand in acetonitrile
yields [K([2.2.2]-cryptand)]3[Ag(mns)2]‚2MeCN (4). An analo-
gous anion is observed in complex 5, [Na([2.2.2]-cryptand)]3-
[Ag(mnt)2], obtained by reaction of AgNO3, 2 equiv of
Na2(mnt), and [2.2.2]-cryptand in acetonitrile. Unoptimized
yields range from 21% to 68%.
but idealized S4 symmetry (Figure 1). The central Ag4 core
contains Ag‚‚‚Ag distances of 3.026(1)-3.103(1) Å, which are
typical for tetrahedral clusters5-7 but are longer than Ag-Ag
bonding distances (Ag-Ag ) 2.89 Å in Ag metal).42-44 The
mns ligands in 1 have CdC and CN distances and angles typical
for the ligand.33,34,45,46 Selected distances and angles are
presented in Table 2.
(39) Flack, H. D. Acta Crystallogr., Sect. A: Found. Crystallogr. 1983,
39, 876-881.
(40) Le Page, Y. J. Appl. Crystallogr. 1987, 20, 264-269.
(41) Spek, A. L. Acta Crystallogr., Sect. A: Found. Crystallogr. 1990,
46, C34.
(42) Shannon, R. D. Acta Crystallogr., Sect. A: Cryst. Phys., Diffr., Theor.
Gen. Crystallogr. 1976, 32, 751-767.
(43) Wells, A. F. Structural Inorganic Chemistry, 5th ed.; Clarendon
Press: Oxford, 1984.
(44) Villars, P., Calvert, L. D., Eds. Pearson’s Handbook of Crystal-
lographic Data for Intermetallic Phases, 2nd ed.; ASM International:
Materials Park, OH, 1991; Vol. 1.
(45) Morgado, J.; Santos, I. C.; Duarte, M. T.; Alca´cer, L.; Almeida, M.
Chem. Commun. (Cambridge) 1996, 1837-1838.
(46) McLauchlan, C. C.; Robowski, S. D.; Ibers, J. A. Inorg. Chem. 2001,
40, 1372-1375.
Structure of [K([2.2.2]-cryptand)]4[Ag4(Se2C2(CN)2)4] (1).
The crystal structure of [K([2.2.2]-cryptand)]4[Ag4(mns)4] (1)
consists of well-separated anions and cations. The anion,
[Ag4(mns)4]4-, has crystallographically imposed C2 symmetry

1812 Inorganic Chemistry, Vol. 40, No. 8, 2001
McLauchlan and Ibers
Table 2. Averagea Bond Distances (Å) and Bond Angles (deg) in
Metal-mns Complexesb
Ag (1)c
Ag (4)c
Sbd
Agd
M-Se
Se-C
µ1-Se 2.562(1) 2.6579(4) 2.654(2) 2.567(4)
µ2-Se 2.608(1)
µ1-Se 1.880(8) 1.888(3)
µ2-Se 1.936(9)
1.87(2)
1.853(2)
CdC
1.379(11)
1.390(13)
1.159(11)
91.22(3)
1.368(4)
1.434(4)
1.131(4)
87.96(1)
1.36(2)
1.44(2)
1.14(2)
1.38(3)
1.43(3)
1.116(3)
C-CN
C-N
Se-M-Se
87.81(7) 91.4(1)
(same ligand)
M-Se-C
Se-CdC
CdC-CN
C-C-N
95.8(3)
97.11(8)
128.0(2)
118.4(2)
178.4(3)
96.7(5)
128(1)
118(2)
177(2)
97.54(8)
128(2)
114(2)
176(3)
128.0(7)
119.0(8)
176.9(10)
a Average values are unweighted arithmetic means with the largest
esd of the series as the esd. b Some bond lengths and angles for
[K([2.2.2]-cryptand)]2[Cu(mns)2]: Cu-Se, 2.3823(8); Se-C, 1.880(3);
CdC, 1.351(3); C-CN, 1.431(4); CtN, 1.149(3) Å; Se-Cu-Se,
91.93(2)°; Cu-Se-C, 100.27(8)°; C-CtN, 179.1(1)°. See Sup-
porting Information. c [Ag4(mns)4]4- (1) and [Ag(mns)2]3- (4); this
work. d [Sb(mns)2]3- and [Ag(mns)(Se6)]3-; ref 33.
In the [Ag4(mns)4]4- anion of 1 (Figure 1), each mns ligand
has a µ1-Se bond to a Ag atom and a µ2-Se bond to that same
Ag atom and to an adjacent Ag atom. For example, for one
mns ligand of 1, Se(1) is µ1 to Ag(1) whereas Se(2) is µ2
between Ag(1) and Ag(2). This unusual bridging arrangement
is also seen in one Se42- ring in [Ag4(Se4)4]4-.5 In 1, the aver-
age µ1-Se-Ag distance of 2.562(1) Å is significantly shorter
than the average µ2-Se-Ag distance of 2.608(1) Å. However,
the µ2-Se-Ag distance to the neighboring mns ligand is the
same (2.560(1) Å) and is significantly shorter than the µ2-Se-
Ag distance of 2.655(1) Å to the “attached” ligand. The
Seµ1-CCN bond is shorter than the Seµ2-CCN bond (1.880(9)
vs 1.938(9) Å), probably because the bridging Se atom possesses
less electron density. Each Ag is coordinated to three Se atoms
in a trigonal planar environment. A trigonal planar environ-
ment of chalcogens around each Ag is unusual,47,48 but is also
found in [PPh4]2[Ag4(S2C2H4(C6H4))3], which has an [Ag4S6]
core.3
Structure of [Na([2.2.2]-cryptand)]4[Ag4(S2C2(CN)2)4]‚
0.33MeCN (2). The crystal structure of [Na([2.2.2]-cryptand)]4-
[Ag4(mnt)4]‚0.33MeCN (2) consists of well-separated anions
and cations and partially occupied acetonitrile molecules. The
structural solution contains three distinct [Ag4(mnt)4]4- anionic
moieties and four unique [Na([2.2.2]-cryptand)]+ units. Two
of the anions, centered at Wyckoff positions 1a and 1c, exhibit
S4 symmetry (Figure 2), whereas the remaining anion, centered
at Wyckoff position 2g, exhibits C2 symmetry crystallographi-
cally. The anion of 2 is analogous to that of 1. As in 1, the
three central Ag4 cores contain Ag‚‚‚Ag interactions that are
longer than Ag-Ag bond distances; two Ag4 cores have
distances similar to those seen in 1 (2.9732(6)-3.1832(6) Å)
whereas the other Ag4 core has longer interactions (3.0031-
(7)-3.4320(9) Å). Each mnt ligand has a µ1-S bond to a Ag
atom and a µ2-S bond to that same Ag atom and to an adjacent
Ag atom, and these distances show the same trends as the Ag-
Se distances in 1. The mnt ligands in 2 have S-C, CdC, and
CN distances and angles typical for the ligand.21,22,49-52 Selected
distances and angles are presented in Table 3.
Figure 2. Displacement ellipsoid plot of the tetrahedral [Ag4(mnt)4]4-
anion of [Na([2.2.2]-cryptand)]4[Ag4(mnt)4]‚0.33MeCN (2). The anion
has crystallographically imposed symmetry 4h.
Structure of [NBu4]4[Ag4(S2C2(CN)2)4] (3). The crystal
structure of [NBu4]4[Ag4(mnt)4] (3) consists of planar [Ag4-
(mnt)4]4- anions and well-separated [NBu4]+ cations. The
structure contains two unique but very similar cluster units, one
with no crystallographically imposed symmetry (Figure 3) and
one with an imposed inversion center. The anion comprises an
Ag4 diamond bound by four mnt ligands. The mnt ligands have
distances and angles typical for mnt.21,22,49-52 Average bond
distances and angles for selected portions of the anion are
summarized in Table 3.
In this planar [Ag4(mnt)4]4- anion, each mnt ligand has two
distinct S atoms, as was seen in the anion of 2. Again, each
mnt ligand has a µ1-S bond to a Ag atom and a µ2-S bond to
that same Ag atom and to an adjacent Ag atom. The average
Ag‚‚‚Ag interaction is 3.0211(8) Å for adjacent Ag atoms, and
the interactions are even longer between opposing Ag atoms of
the diamond. The Ag-S distances in the anion of 3 are
significantly longer than those in the anion of 2.
Binding Modes in the Ag4 Clusters 1, 2, and 3. Both
[K([2.2.2]-cryptand)]4[Ag4(mns)4] (1) and [Na([2.2.2]-cryp-
tand)]4[Ag4(mnt)4]‚0.33MeCN (2) comprise encapsulated alkali-
metal cations and an Ag4 tetrahedron bound by four bidentate
mns or mnt ligands. [NBu4]4[Ag4(mnt)4] (3), however, comprises
[NBu4]+ cations and an Ag4 planar diamond bound by four bi-
dentate mnt ligands. For [Ag4(mns)4]4-, tetrahedral [Ag4(mnt)4]4-,
and planar [Ag4(mnt)4]4-, the bidentate ligands have one µ1-Q
(Q ) S, Se) atom bound to one Ag atom and one µ2-Q atom
bridging the same Ag atom and an adjacent Ag atom. One Se4
ring of [Ag4(Se4)4]4- 5 also bridges in this fashion. Similar
bridging is seen in [Ag(PPh3)2][Ag(PPh3)2(mnt)],21,22 with one
µ1-S atom bound to a Ag atom and a µ2-S atom bridging the
two Ag(PPh3)2 moieties. More typically, the bridging that occurs
(50) Burns, R. P.; McAuliffe, C. A. AdV. Inorg. Chem. Radiochem. 1979,
22, 303-348.
(51) Underhill, A. E.; Clemenson, P. I.; Hursthouse, M. B.; Short, R. L.;
Ashwell, G. J.; Sandy, I. M.; Carneiro, K. Synth. Met. 1987, 19, 953-
958.
(52) Plumlee, K. W.; Hoffman, B. M.; Ibers, J. A.; Soos, Z. G. J. Chem.
Phys. 1975, 63, 1926-1942.
(47) Cotton, F. A.; Wilkinson, G. AdVanced Inorganic Chemistry, 5th ed.;
John Wiley & Sons: New York, 1988.
(48) Mascal, M.; Kerdehue´, J.-L.; Blake, A. J.; Cooke, P. A.; Mortimer,
R. J.; Teat, S. J. Eur. J. Inorg. Chem. 2000, 485-490.
(49) Clemenson, P. I. Coord. Chem. ReV. 1990, 106, 171-203.

Silver Maleonitrilediselenolates and -dithiolates
Inorganic Chemistry, Vol. 40, No. 8, 2001 1813
Table 3. Averagea Bond Distances (Å) and Bond Angles (deg) in Ag-mnt Complexes
[Ag4(mnt)4]4- (2)b
[Ag4(mnt)4]4- (3)c
[Ag(mnt)2]3- (5)d
[(PPh2)4Ag2(mnt)]e
Ag-S
S-C
µ1-S 2.451(1)
µ2-S 2.467(1)
µ1-S 1.725(5)
µ2-S 1.749(5)
1.375(7)
1.438(7)
1.146(7)
µ1-S 2.485(2)
µ2-S 2.494(2)
µ1-S 1.721(6)
µ2-S 1.751(6)
1.373(8)
1.439(9)
1.149(8)
2.563(2)
µ1-S 2.568(7)
µ2-S 2.566(7)
1.740(17)
1.730(6)
CdC
1.387(8)
1.444(8)
1.132(7)
86.51(5)
1.35(2)
1.44(3)
1.13(3)
82.2(2)
C-CN
C-N
S-Ag-S
88.57(4)
87.59(6)
(same ligand)
Ag-S-C
µ1-S 98.9(2)
µ1-Sintra 96.3(2)
µ2-Sinter 102.6(2)
127.8(4)
117.4(5)
177.8(7)
µ1-S 98.7(2)
µ1-Sintra 97.0(2)
µ2-Sinter 103.7(2)
127.4(5)
118.1(5)
178.1(9)
98.8(2)
97.9(6)
S-CdC
CdC-CN
C-C-N
127.9(4)
117.3(5)
178.1(7)
121(1)
117(2)
176(2)
a Average values are unweighted arithmetic means with the largest esd of the series as the esd. b [K([2.2.2]-cryptand)]4[Ag4(mnt)4] (2), this work.
c [NBu4]4[Ag4(mnt)4] (3), this work. d [K([2.2.2]-cryptand)]3[Ag(mnt)2] (5); this work. e [(PPh2)4Ag2(mnt)]; ref 22.
Figure 4. Representation of the Ag4 core and binding dichalcogenate
ligands in (a) [Ag4(i-mnt)4]4-, ref 4; (b) [Ag4(mns)4]4- (1) and
[Ag4(mnt)4]4- (2), this work; and (c) [Ag4(mnt)4]4- (3), this work. Each
arrow represents a bridging mns or mnt ligand. The tail of each arrow
represents a µ1-chalcogen, and the head is a µ2-chalcogen.4
Figure 5. Conceptual transformation of the planar [Ag4(mnt)4]4- of 3
Figure 3. Displacement ellipsoid plot of the planar [Ag4(mnt)4]4- anion
to the tetrahedral [Ag4(mnt)4]4- of 2.
of [NBu4]4[Ag4(mnt)4] (3).
bridge across three faces of the Ag4 core.3 The [Ag4S6] species
in dichalcogenates is akin to that seen in the [Ag4(i-mnt)4]4-
-
ideally has C3 symmetry. The differences in the structures of
this dithiolate and the mns/mnt species may be attributed to
the differences in the bite angles of the ligands involved. The
o-xylene-1,2-dithiolate ligand of the [Ag4S6] species has a much
larger bite angle than either the mns or mnt ligand (112.62(4)°
vs 91.22(3)° or 88.07(6)°). Perhaps the smaller bite angle and
lower steric hindrance (CN in lieu of m-(CH2)2(C6H4)) of mns/
mnt allow a higher coordination number around the Ag4 core.
The structure of [Ag4(i-mnt)4]4-, where four i-mnt ligands fit
around the Ag4 center (bite angle ) 92.6°),54 is consistent with
this notion. However, as noted, the i-mnt units possess a different
binding mode from the mns and mnt units.
In both 2 and 3 the anions are completely surrounded by
cations, but neither forms discrete anion or cation layers. The
differences in the Ag4 core of 2 and 3 must arise from the cations
used for crystallization, as the syntheses for the two materials
are otherwise identical. Cation effects on crystallization have
been known for many years55-57 and have been noted in the
anion (i-mnt ) isomaleonitriledithiolate, [S2CdC(CN)2]2-).4
This anion also has two different S environments, with one µ1-S
atom and one µ2-S atom; however, one S atom of the i-mnt
ligand is µ1 to one Ag atom and the other S atom is µ2 between
two additional Ag atoms. In [Ag4(i-mnt)4]4-, the i-mnt bridges
across each face of the Ag4 core, whereas in 1 and 2 the ligands
bridge along four of six of the edges of the Ag4 core and in 3
the ligands bridge along all four edges of the Ag4 core. The
geometries of these complexes are sketched in Figure 4. There
the central polygon represents the Ag4 core, and each arrow
represents a bridging bidentate dichalcogenate ligand. The tail
of each arrow is a µ1-Q atom and originates from the vertex of
the Ag atom to which Q is bound. The head of each arrow is a
µ2-Q atom with the head terminus lying on the line connecting
the two atoms bridged by the µ2-Q atom.53 The cores of [Ag4-
(i-mnt)4]4-, 1, and 2 have idealized S4 symmetry whereas the
core of 3 has idealized C2 symmetry. In another dithiolate-bound
Ag4 species, [Ag4(S2C2H4(C6H4))3]2-, each S atom is µ2 and
only three ligands surround the Ag4 tetrahedron; the ligands
(54) Liu, C. W.; McNeal, C. J.; Fackler, J. P., Jr. J. Cluster Sci. 1996, 7,
385-406.
(55) Basolo, F. Coord. Chem. ReV. 1968, 3, 213-223.
(53) For a complete description of this notation, see ref 4.

1814 Inorganic Chemistry, Vol. 40, No. 8, 2001
McLauchlan and Ibers
Figure 6. Displacement ellipsoid plot of the [Ag(mns)2]3- anion of [K([2.2.2]-cryptand)]3[Ag(mns)2]‚2MeCN (4) showing selected average bond
distances and angles.
Figure 7. Displacement ellipsoid plot of the [Ag(mnt)2]3- anion of [Na([2.2.2]-cryptand)]3[Ag(mnt)2] (5) showing selected average bond distances
and angles. The anion has crystallographically imposed symmetry 2.
Ag-chalcogenide literature as well; in mixing AgNO3 with K2-
Se5 and a cation in N,N-dimethylformamide, [Ag4(Se4)3]2-
crystallizes in the presence of [NPr4]+,7 whereas the use of
anion of 5 has crystallographically imposed C2 symmetry and
is shown in Figure 7. Selected bond distances and angles are
shown in Table 3 and Figure 7.
[K(18-crown-6)]+ 58 or [PPh4]+ 6 affords [Ag4(Se4)3-x(Se5)x]2-
,
Spectroscopy. The UV-vis spectra for 1 and 4 are consistent
with those of other metal-maleonitrilediselenolates.34,46 For
such complexes the dominant transition has been attributed to
a ligand-metal charge transfer, by comparison with the
analogous mnt complexes.60 Therefore, the electronic transitions
of complexes 1 and 4 are expected to be similar, since both
metal and ligand are identical. The UV-vis spectra for 2, 3,
and 5 are very similar to one anothers2 and 3 are nearly iden-
ticalsand are consistent with those of other metal-maleoni-
triledithiolates.60
and the use of [NMe4]+ 5 or [NEt4]+ 59 instead yields polymeric
structures. In the present instance the use of [Na([2.2.2]-
cryptand)]+ affords a tetrahedral Ag4 core (2) whereas the use
of [NBu4]+ results in a planar diamond-shaped Ag4 core (3).
The conversion between the structures of the two anions may
be accomplished conceptually by folding the Ag4 diamond in
half such that one Ag corner of the diamond becomes positioned
above the plane to form a tetrahedron (Figure 5).
Structure of [K([2.2.2]-cryptand)]3[Ag(Se2C2(CN)2)2]‚
2MeCN (4). The crystal structure of [K([2.2.2]-cryptand)]3[Ag-
(mns)2]‚2MeCN (4) comprises well-separated cations and
anions. The anion of 4 contains a nominally Ag+ center
tetrahedrally coordinated by two mns ligands. The anion,
[Ag(mns)2]3-, has idealized D2d symmetry; it is shown in Figure
6. Complex 4 is isostructural with [K([2.2.2]-cryptand)]3[Sb-
(mns)2]‚2MeCN.33 The anion contains bond distances typical
for Ag-Se complexes5-7,33 and bond distances and angles
consistent with literature values for the mns ligand.33,34,45,46
Selected distances and angles are summarized in Table 2 and
in Figure 6.
Structure of [Na([2.2.2]-cryptand)]3[Ag(S2C2(CN)2)2] (5).
The anion of 5 is the mnt analogue of the [Ag(mns)2]3- anion
seen in complex 4. The tetrahedrally coordinated Ag center has
Ag-S distances ranging from 2.549(2) to 2.577(2) Å, and the
ligands have bond distances and angles typical for mnt. The
The infrared spectrum of 1 shows a νCN stretch at 2177 cm-1
,
much like the spectrum of [K([2.2.2]-cryptand)]3[Ag(mns)(Se6)]
and other metal-mns species.33,34 In contrast, 4 shows a νCN
stretch at 2168 cm-1 much like the lower energy peak of 2170
cm-1 seen in [Na([2.2.2]-cryptand)]3[Ag(mnt)2] (5) and [K([2.2.2]-
cryptand)]3[Sb(mns)2]‚2MeCN.33 Lower energy νCN stretches
in [M(mnt)2]3- complexes have been noted.61 The infrared spec-
trum of 2 shows a νCN stretch at 2180 cm-1, much like the
spectrum of [K([2.2.2]-cryptand)]4[Ag4(mns)4] (1), whereas 3
has shows a νCN stretch at 2196 cm-1 with the much higher
energy value νCN peak consistent with that for other mnt com-
plexes.61
Reactivity. Since acetonitrile is the source of CN in a variety
of mns complexes, it is likely that formation of the mns ligand
proceeds through the deprotonation of acetonitrile. Clearly base
has a role, whether it be deprotonation or not, as the preparation
of [K([2.2.2]-cryptand)]4[Ag4(mns)4] (1) only differs from that
for [K([2.2.2]-cryptand)]3[Ag(mns)(Se6)] in the quantity of base
used. Substitution of KNH2 by similar molar quantities of KOH,
Et3N, Ph3N, or Aliquat 336 () tricaprylmethylammonium
chloride ) [NCH3(C8H17)3]Cl) leads only to the formation of
[K([2.2.2]-cryptand)]3[Ag(mns)(Se6)], whereas the use of ex-
(56) Mingos, D. M. P.; Rohl, A. L. J. Chem. Soc., Dalton Trans. 1991,
3419-3425.
(57) Mingos, D. M. P.; Rohl, A. L. Inorg. Chem. 1991, 30, 3769-3771.
(58) Evans, W. J.; Meadows, J. H.; Kostka, A. G.; Closs, G. L. Organo-
metallics 1985, 4, 324-326.
(59) Kanatzidis, M. G.; Huang, S.-P. J. Am. Chem. Soc. 1989, 111, 760-
761.

Silver Maleonitrilediselenolates and -dithiolates
Inorganic Chemistry, Vol. 40, No. 8, 2001 1815
unsuccessful. It is more likely that [Ag(mns)(Se6)]3- is an
intermediate in the formation of 1; attempts to synthesize 4
directly led only to the synthesis of 1 or [K([2.2.2]-cryptand)]3-
[Ag(mns)(Se6)].
The substitution chemistry of [K([2.2.2]-cryptand)]3[Ag(mns)-
(Se6)] has also been explored. Metal chlorides can be reacted
with [K([2.2.2]-cryptand)]3[Ag(mns)(Se6)] to form other metal-
mns complexes, e.g., [Ni(mns)2]2- from NiCl2.34,46 [K([2.2.2]-
cryptand)]3[Ag(mns)(Se6)] is an effective synthon to make a
variety of metal mns complexes.
Silver-mnt analogues of 1 and 4, i.e., 2 and 5, were prepared
by direct reaction of AgNO3 with Na2(mnt). As many M-mnt
complexes are known and readily prepared by other methods,
the substitution chemistry of 2 and 5 was not explored.
Figure 8. Summary of the reactivity of the [Ag(mns)(Se6)]3- anion.
{K} is [K([2.2.2]-cryptand)].
Acknowledgment. This work was supported by the National
Science Foundation (Grant No. CHE-9819385). The Quattro II
spectrometer was provided by the National Institutes of Health
(Grant S10 RR11320).
cess of these bases affords 1. Reaction with CuCl in lieu of
AgBF4 under both sets of conditions led instead to [K([2.2.2]-
cryptand)]2[Cu(mns)2], which contains a Cu2+ center and is
isostructural with other known [K([2.2.2]-cryptand)]2[M2+
(mns)2] complexes.34,46
-
Supporting Information Available: Crystallographic data for
[K([2.2.2]-cryptand)]4[Ag4(mns)4] (1), [Na([2.2.2]-cryptand)]4[Ag4-
(mns)4]‚0.33MeCN (2), [NBu4]4[Ag4(mns)4] (3), [K([2.2.2]-cryptand)]3-
[Ag(mns)2]‚2MeCN (4), [Na([2.2.2]-cryptand)]3[Ag(mnt)2] (5), and
[K([2.2.2]-cryptand)]2[Cu(mns)2] in CIF format. This material is
available free of charge via the Internet at http://pubs.acs.org.
Some insight has been gained into the reactivity of [K([2.2.2]-
cryptand)]3[Ag(mns)(Se6)] (Figure 8). The addition of AgBF4
and [K([2.2.2]-cryptand)][NH2] to [K([2.2.2]-cryptand)]3[Ag-
(mns)(Se6)] in acetonitrile yields [K([2.2.2]-cryptand)]4[Ag4-
(mns)4] (1). However, the addition of just [K([2.2.2]-cryptand)]-
[NH2] to [K([2.2.2]-cryptand)]3[Ag(mns)(Se6)] in acetonitrile
yields [K([2.2.2]-cryptand)]3[Ag(mns)2]‚2MeCN (4). It is un-
likely that 4 is merely an intermediate in the process to form 1,
as repeated efforts to form 1 from 4 with Ag sources have been
IC000868Q
(60) Shupack, S. I.; Bilig, E.; Clark, R. J. H.; Williams, R.; Gray, H. B. J.
Am. Chem. Soc. 1964, 86, 4594-4602.
(61) Best, S. P.; Ciniawsky, S. A.; Clark, R. J. H.; McQueen, R. C. S. J.
Chem. Soc., Dalton Trans. 1993, 2267-2271.