Oxidation Reactions of Dithiocarbamate Complexes of Ruthenium(II)

The reaction of
Ru(Et2dtc)2(DMSO)2
(Et2dtc =
N,N-diethyldithiocarbamate; DMSO = dimethyl
sulfoxide) with
t-BuNC gave
trans-Ru(Et2dtc)2(CN-t-Bu)2,
1. Complex 1 crystallizes in the monoclinic
space group P21/n with
a = 9.753(2) Å, b = 11.583(2) Å,
c = 12.974(2) Å, and β = 91.8(2)° for
Z = 2. The crystal structure of 1
shows
the trans disposition of the two isocyanides; the mean Ru−S and
Ru−C distances are 2.409 and 1.977(2) Å,
respectively. Treatment of
[Ru(diene)Cl2]n with
Na(Et2dtc) afforded
Ru(Et2dtc)2(diene) (diene =
bicyclo[2.2.1]hepta-2,5-diene (NBD), 2, 1,5-cyclooctadiene (COD),
3). Complex 2 crystallizes in the triclinic
space group P1̄
with a = 7.316(1) Å, b = 10.346(1)
Å, c = 15.123(2) Å, α = 103.69(2)°, β
= 93.54(2)°, and γ = 100.61(2)°
for Z = 2. The mean Ru−S and Ru−C distances in 2
are 2.416 and 2.137 Å, respectively. The reaction of
cis-Ru(Et2dtc)2(CO)2
with iodine gave the 2:1 molecular iodine complex
cis-Ru(Et2dtc)2(CO)2·1/2I2
4, which
crystallizes in the monoclinic space group
P21/c with a =
7.347(2), b = 22.227(2) Å, c =
12.891(2) Å, and β
=95.98 (2)° for Z = 4. The mean Ru−S and Ru−C
and the I−I distances in complex 4 are 2.427, 1.903,
and
2.745(1) Å, respectively. Treatment of
Ru(Et2dtc)2(DMSO)2
with I2 gave the linear Ru(II)−Ru(III)−Ru(III)
trimer
[Ru3(Et2dtc)6(DMSO)2](I3)2,
5, which crystallizes in the triclinic space group
P1̄ with a = 14.125(3) Å,
b =
20.829(6) Å, c = 13.658(3) Å, α =
97.57(2)°, β = 110.01(2)°, and γ =
71.25(2)° for Z = 2. The structure
of
complex 6 can be viewed as consisting of a
{Ru2III(Et2dtc)4}2+
core and a
{RuII(Et2dtc)2(DMSO)2}
moiety, which
are linked together via the two dithiocarbamate sulfurs of the latter.
While the two Ru(III) centers are connected
by a Ru−Ru single bond (Ru−Ru = 2.826(2) Å), there is no
direct interaction between the Ru(III) and
Ru(II)
centers. Oxidation of
Ru(Et2dtc)2L2 (L =
PPh3, t-BuNC) by I2 gave the
respective
[Ru(Et2dtc)2L2]+
cations.
The reaction of
cis-Ru(Et2dtc)2(PPh3)2
with excess tosyl azide gave the diamagnetic Ru(IV) tetrazene
complex
Ru(Et2dtc)2(Ts2N4),
7. Complex 7 crystallizes in the triclinic
space group P1̄ with a = 10.380(1)
Å, b = 11.322(1) Å, c = 15.310(1) Å, α = 106.84(2)°,
β = 106.87(2)°, and γ = 92.63(2)° for
Z = 2. The Ru−S and
Ru−Nα
distances in 7 are 2.385 and 1.98 Å, respectively. The
formal potentials of the Ru dithiocarbamate complexes
were determined by cyclic voltammetry.