The triangulo Re
3
9+
cluster
[Re
3
(µ-Cl)
3
X
9
]
3-
(X = Cl 1a or Br 1b) in concentrated aqueous
hydrohalogenic acid solutions underwent a facile one-electron reduction
by various reducing agents (VCl
2
·4H
2
O,
Sn–SnCl
2
or Hg) to give the air-sensitive
Re
3
8+
anion
[Re
3
(µ-Cl)
3
X
9-n
(H
2
O)
n
]
(4-n)
-
(X = Cl 2a or Br 2b), where n may
be 1; the diamagnetism and EPR silence of this compound indicate that it
may exist as a dimer with a direct or indirect rhenium–rhenium
bond linking two Re
3
8+
trimetal cores. Oxidation
of 2 by molecular oxygen in 6 mol dm
-3
HX
(X = Cl or Br) solutions yielded 1 quantitatively, whereas
in the absence of acid and in aprotic solvents oxo-derivatives are
formed; from 2b the hexanuclear anion
[Re
3
(µ-Cl)
3
Br
6
(H
2
O)(µ-O)}
2
]
2-
3b was
obtained whose structural characterization, as its
[PPh
4
]
+
salt 3c, shows that two µ-O
ligands bridge two oxidized Re
3
10+
units. The
structure of the Re
3
9+
cluster
[Co(en)
3
][Re
3
(µ-Cl)
3
Br
8
(H
2
O)]Br has been also determined by X-ray
diffraction. The redox couple
xRe
3
9+
–(Re
3
8
)
x
, where x = 1 or 2,
derived upon mixing 6 mol dm
-3
HX (X = Cl
or Br) solutions of 1 with an excess of mercury, catalyses efficiently
the reduction of molecular oxygen to water.
三聚氰胺 Re₃[Re₃(µ-Cl)₃X₉]³⁻(X = Cl 1a 或 Br 1b)在浓缩的
水相氢卤酸溶液中通过各种还原剂(
VCl₂·4H₂O、Sn–SnCl₂或Hg)发生了简单的一电子还原,生成了对空气敏感的 Re₃⁸⁺ 陰离子 [Re₃(µ-Cl)₃X₉-n(H₂O)ₙ]⁴⁻(X = Cl 2a 或 Br 2b),其中 n 可能为 1;该化合物的抗磁性和 EPR 静默表明它可能存在为一个二聚体,其中两个 Re₃⁸⁺ 三
金属核心通过直接或间接的
铼-
铼键链接。通过分子氧对 2 的氧化在 6 mol dm⁻³ HX(X = Cl 或 Br)溶液中定量生成 1,而在缺乏酸和极性溶剂的情况下形成氧衍
生物;从 2b 得到的六核阴离子 [Re₃(µ-Cl)₃Br₆(H₂O)(µ-O)}₂]²⁻ 3b 的结构表征,其相应的 [PPh₄]⁺ 盐 3c 显示两个 µ-O
配体桥接两个氧化的 Re₃¹⁰⁺ 单元。Re₃⁹⁺ 簇 [Co(en)₃][Re₃(µ-Cl)₃Br₈(H₂O)]Br 的结构也通过 X 射线衍射确定。红氧化还原对 xRe₃⁹⁺ –(Re₃⁸)x,其中 x = 1 或 2,由将 6 mol dm⁻³ HX(X = Cl 或 Br)溶液中的 1 与过量的
汞混合得到,有效催化分子氧还原为
水。