Syntheses, structures and spectroscopy of new heteroselenometalates
[PPh 4] 2[MoSe 4] and [PPh 4] 2[WSe 4] react with two equivalents of AuCN in CH 3CN to afford [PPh 4] 2[(NC)Au(μ-Se) 2-Mo(μ-Se) 2Au(CN)] · CH 3CN (bd1) and [PPh 4] 2[(NC)Au(μ-Se) 2Au(CN)] · CH 3CN (bd2), respectively. Compounds 1 and 2 are isostructural. Compound 1 crystallizes in the triclinic spac...
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Published in | Inorganica Chimica Acta Vol. 240; no. 1; pp. 239 - 249 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
01.12.1995
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Subjects | |
Online Access | Get full text |
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Summary: | [PPh
4]
2[MoSe
4] and [PPh
4]
2[WSe
4] react with two equivalents of AuCN in CH
3CN to afford [PPh
4]
2[(NC)Au(μ-Se)
2-Mo(μ-Se)
2Au(CN)] · CH
3CN (bd1) and [PPh
4]
2[(NC)Au(μ-Se)
2Au(CN)] · CH
3CN (bd2), respectively. Compounds
1 and
2 are isostructural. Compound
1 crystallizes in the triclinic space group
P
1
with two formula units in a cell dimensions
a=13.181(4),
b=14.239(4), c=14.684(4)
A
̊
, α=73.00(3), β=73.66(2), γ=79.06(2)°
at 113 K. Full anisotropic refinement of the structure of
1 on
F
2 led to a value of
R
1=0.0562 for those 9075 data having
F
o
2 . 2
σ(
F
o
2). The [(NC)Au(μ-Se)
2Mo(μ-Se)
2Au(CN)]
2− anion of
1 comprises two AuCN fragments ligating the opposite edges of a tetrahedral [MoSe
4]
2− moiety. Compounds
1 and
2 exhibit an IR band at 2250 cm
−1 that may be assigned to a CN stretching mode of the CH
3CH solvate; such a solvate molecule was found in the crystal structure of
1. The
77Se NMR spectra show a resonance at 1104 ppm for
1 and 832 ppm for
2. Addition of excess PME
2Ph to the same solutions that produce
1 and
2 results in the formation of [PPh
4][(Me
2PhP)Au(μ-Se)
2MoSe
2] (
3) and [PPh
4][(Me
2PhP)Au(μ-Se)
2WSe
2] (
4), respectively. Compounds
3 and
4 are not isostructural. Compound
3 crystallizes in the monoclinic space gorup
Cc with four formula units in a cell of dimensions
a=21.912(4), b=9.809(2), c=15.959(3)
A
̊
, β=100.79(3)
at 113 K. Full anisotropic refinement of the structure of
1 on
F
2 led to a value of
R
1=0.0481 for those 6851 data having
F
o
2 > 2
σ(
F
o
2). Compound
4 crystallizes in the triclinic space group
P
1
with two formula units in a cell of dimensions
a=11.315(2), b=13.053(3), c=14.173(3)
A
̊
, α=103.59(3), β=103.55(3), γ=114.75(3)δ
at 113 K. Full anisotropic refinement of the structure of
4 on
F
2 led to a value of
R
1=0.0414 for those 7825 data having
F
o
2 > 2
σ(
F
o
2). The [(Me
2]PhP)Au(μ-Se)
2MoSe
2]
− anion of
3 and the [(Me
2PhP)Au(μ-Se)
2WSe
2]
− anion of
4 comprise an [(Me
2PhP)Au]
+ fragment ligated across an edge of a tetrahedral (MSe
4]
2− moiety. [PPh
4]
2[MoSe
4] and [PPh
4]
2[WSe
4] react with one equivalent of AuCN in CH
3CH to afford [PPh
4]
2[(NC)Au(μ-Se)
2MoSe
2] (
5) and [PPh
4]
2[(NC)Au(μ-Se)
2WSe
2] (
6), respectively. Compounds
5 and
6 are isostructural. Compounds
5 crystallizes in the monoclinic space group
C2/
c with four formula units in a cell of dimensions
a=11.234(15), b=20.329(28), c=20.046(28)
A
̊
, β=91.81(5)°
at 113 K. Full anisotropic refinement of the structure of
5 on
F
2 led to a value of
R
1=0.0457 for those 4003 data having
F
o
2 > 2
σ(
F
o
2). The [(NC)Au(μ-Se)
2MoSe
2]
2− anion of
5, which has a crystallographically imposed twofold axis, comprises an AuCN fragment ligated across an edge of a tetrahedral [MoSe
4]
2− moiety. The reaction of [PPh
4]
2(NC)Cu(μ-Se)
2MoSe
2] with one equivalent of AuCN in CH
3CN produces a precipitate that is then redissolved through reaction with an excess of PMe
2Ph to afford [PPh
4][(Me
2PhP)
2Cu(μ-Se)
2MoSe
2] (
7). Compound
7 crystallizes in the monoclonic space group
P1
1/
c with four formula units in a cell of dimensions
a=9.975(1), b=30.391(7), c=14.541(6)
A
̊
, β=109.66(3)
at 113 K. Full anisotropic refinement of the structure of
7 on
F
2 led to a value of
R
1=0.0305 for those 5205 data having
F
o
2 > 2
σ(
F
o
2). The [(Me
2PhP)
2Cu(μ-Se)
2MoSe
2]
− anion of
7 comprises an [(Me
2PhP)
2Cu]
+ fragment ligated across an edge of the [MoSe
4]
2− moiety to provide a tetrahedral geometry about the Cu atom. The NMR, IR and UV-Vis spectroscopic data for these compounds are consistent with their solid-state structures. |
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ISSN: | 0020-1693 1873-3255 |
DOI: | 10.1016/0020-1693(95)04651-8 |