TY - JOUR
T1 - Anion-Anion Interactions Involving the [Mo 3 Se 13 ] 2− Cluster. Syntheses and Characterization of (Me 4 N) 2 Mo 3 Se 13 , K 2 Mo 3 Se 12.5 O 0.5 , and K 6 M o6 Se 27 •6H 2 O
AU - Liao, Ju Hsiou
AU - Li, Jing
AU - Kanatzidis, Mercouri G.
PY - 1995/5/1
Y1 - 1995/5/1
N2 -
The hydrothermal reaction of M0O
3
, Na
2
Se
2
and Me
4
NCl (molar ratio, 1:3:2) at 135 °C for 3 days gave dark red needles of (Me
4
N)2Mo
3
Se
13
(I); the reaction of M0O
3
and K
2
Se
2
(molar ratio of 1:2 for one month and 1:3-5 for 3 days) at 135 °C gave black needle-like crystals of K
2
Mo
3
Se
12.5
O
0
.
5
(II) and black chunky crystals of K
6
Mo
6
-Se
27
6H
2
O (III) respectively. The structures were determined by single crystal X-ray diffraction techniques. Compound I crystallizes in the trigonal space group P3
1
m (No. 157), Z = 1, a = 11.578(1) Å, c = 6.110(2) Å, V = 709.4(3) Å
3
. d
calc
= 3.42 g/cm
3
, μ = 177.99 cm
−1
Number of data measured: 992. Number of unique data: 502. Number of data having I> 3.0σ(I): 438. Number of variables = 49. R/R
w
= 6.0/7.5%. Compound II crystallizes in the monoclinic space group Cm (No. 8), Z = 2, a = 11.874(3) Å, b = 16.834(3) Å, c = 5.820(3) Å, β = 116.65(2)°, V = 1040(1) Å
3
, d
cale
= 4.45 g/cm
3
, μ = 246.64 cm
−1
. Number of data measured: 997. Number of unique data: 951. Number of data having I > 3.0σ(I): 849. Number of variables = 89. R/R
W
= 4.3/5.3%. III crystallizes in the monoclinic space group P2
1
/n (No. 14), Z = 4, a = 10.21(2) Å, b = 17.84(1) Å, c = 27.04(2) Å, ß = 98.8(1)°, V = 4868(21) Å
3
, d
Calc
= 4.15 g/cm
3
. μ = 219.98 cm
−1
. Number of data measured: 8706. Number of unique data: 7920. Number of data having I> 3.0σ(I): 3520. Number of variables = 391. The [Mo
3
Se
13
]
2−
in I and [Mo
3
Se
12.5
O
0.5
]
2−
in II are isostructural with [Mo
3
S
13
]
2−
, while III is the cocrystallization of two K
2
Mo
3
Se
13
clusters and one K
2
Se. The anions of I and II are the same except that the triply bridging Se site is partially occupied by O atoms in II. Solid state IR and UV/vis spectra are reported. The [Mo
3
Se
13
]
2−
cluster has been found to possess significant affinity for anionic species, and this has been manifested in all currently known compounds containing this trinuclear cluster. The new compounds reported in this paper also exhibit clearly defined anion-anion weakly bonding interactions. Extended Hiickel calculations were performed to explain the unusual [Mo
3
Se
13
]
2−
Se
2−
interactions in these compounds. The calculations show that the Se atoms (of the bridging Se
2
2−
), which form the points of interaction of the cluster with the anionic species, are weakly positively charged.
AB -
The hydrothermal reaction of M0O
3
, Na
2
Se
2
and Me
4
NCl (molar ratio, 1:3:2) at 135 °C for 3 days gave dark red needles of (Me
4
N)2Mo
3
Se
13
(I); the reaction of M0O
3
and K
2
Se
2
(molar ratio of 1:2 for one month and 1:3-5 for 3 days) at 135 °C gave black needle-like crystals of K
2
Mo
3
Se
12.5
O
0
.
5
(II) and black chunky crystals of K
6
Mo
6
-Se
27
6H
2
O (III) respectively. The structures were determined by single crystal X-ray diffraction techniques. Compound I crystallizes in the trigonal space group P3
1
m (No. 157), Z = 1, a = 11.578(1) Å, c = 6.110(2) Å, V = 709.4(3) Å
3
. d
calc
= 3.42 g/cm
3
, μ = 177.99 cm
−1
Number of data measured: 992. Number of unique data: 502. Number of data having I> 3.0σ(I): 438. Number of variables = 49. R/R
w
= 6.0/7.5%. Compound II crystallizes in the monoclinic space group Cm (No. 8), Z = 2, a = 11.874(3) Å, b = 16.834(3) Å, c = 5.820(3) Å, β = 116.65(2)°, V = 1040(1) Å
3
, d
cale
= 4.45 g/cm
3
, μ = 246.64 cm
−1
. Number of data measured: 997. Number of unique data: 951. Number of data having I > 3.0σ(I): 849. Number of variables = 89. R/R
W
= 4.3/5.3%. III crystallizes in the monoclinic space group P2
1
/n (No. 14), Z = 4, a = 10.21(2) Å, b = 17.84(1) Å, c = 27.04(2) Å, ß = 98.8(1)°, V = 4868(21) Å
3
, d
Calc
= 4.15 g/cm
3
. μ = 219.98 cm
−1
. Number of data measured: 8706. Number of unique data: 7920. Number of data having I> 3.0σ(I): 3520. Number of variables = 391. The [Mo
3
Se
13
]
2−
in I and [Mo
3
Se
12.5
O
0.5
]
2−
in II are isostructural with [Mo
3
S
13
]
2−
, while III is the cocrystallization of two K
2
Mo
3
Se
13
clusters and one K
2
Se. The anions of I and II are the same except that the triply bridging Se site is partially occupied by O atoms in II. Solid state IR and UV/vis spectra are reported. The [Mo
3
Se
13
]
2−
cluster has been found to possess significant affinity for anionic species, and this has been manifested in all currently known compounds containing this trinuclear cluster. The new compounds reported in this paper also exhibit clearly defined anion-anion weakly bonding interactions. Extended Hiickel calculations were performed to explain the unusual [Mo
3
Se
13
]
2−
Se
2−
interactions in these compounds. The calculations show that the Se atoms (of the bridging Se
2
2−
), which form the points of interaction of the cluster with the anionic species, are weakly positively charged.
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U2 - 10.1021/ic00114a026
DO - 10.1021/ic00114a026
M3 - Article
AN - SCOPUS:0001516571
VL - 34
SP - 2658
EP - 2670
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 10
ER -