Mononuclear and Polynuclear Chemistry of Rhenium (III): Its Pronounced Homophilicity.
Extensive chemical, spectrophotometric, and x-ray structural studies have shown that trivalent rhenium is strongly homophilic-that is, it tends to form bonds to other Re(111) atoms-and it forms at least three different series of [ReX(4)](n)(n-) complexes. The mononuclear, square complex, [ReBr(4)](-), adds two water molecules to give trans-[ReBr(4)(H(2)O)(2)](-). The binuclear complexes [Re(2)Cl(8)](2-) and [Re(2)Br(8)](2-) have strong Re-Re bonds, unsupported by halide bridges. The trinuclear species, [Re(3)X(12)](3-) or Re(3)X(9)L(3), contain the triangular Re(3)X(9) clusters. Use of ReCI(3) appears always to lead directly to products containing Re(3)Cl(9); this unit exists in ReCl(3) itself and does not appear to be kinetically labile. The [Re(2)X(8)](2-) ions are obtained by reduction of ReO(4)(-) in aqueous HCl or HBr. Salts of [ReBr(4)(H(2)O)(2)](-) can be obtained directly from solutions of ReBr(3) in HBr along with numerous other compounds, some containing trinuclear clusters.
Cotton
F A
FA
Curtis
N F
NF
Harris
C B
CB
Johnson
B F
BF
Lippard
S J
SJ
Mague
J T
JT
Robinson
W R
WR
Wood
J S
JS