4010
G.A. Casagrande et al. / Journal of Organometallic Chemistry 691 (2006) 4006–4011
This asymmetry is evident in the apparent irregular con-
tour of the chain, which, despite this, shows in the middle
of the Te(1)–Te(1)#1 dimers inversion centres which,
respectively, enclose the two neighbored dimers, achieving
vicinal sequences of 12-atom rings.
Attempts to study the dissociation of the title complexes
in solution by means of multinuclear NMR spectra were
limited by the fact that the crystals of 1 and 2 are soluble
only in coordinating solvents like dimethylsulfoxide
(DMSO). Another limiting factor represents the occurrence
of dynamic equilibrium in solution due to the exchange
between ligand and solvent molecules, predominantly with
1
13
125
DMSO. To minimize this effect H, C, and Te NMR
studies were conducted in solutions of acetone-d6 and
DMSO-d in a 9:1 proportion, respectively. Complex 1
6
25
Fig. 3. Asymmetric unit of [RTeI
Secondary interactions and bonds as dashed lines.
3 6 4
(l-I)Te(tu)R] {R = p-PhO(C H )}.
1
gives a Te NMR broad signal at 933.5 ppm, 2 generates
1
13
a wide peak localized in 894.6 ppm. The H and C NMR
1
signals of compounds 1 and 2 are: H NMR 1: 8.93 (broad,
mixed valence complex salt [p-PhO(C H )Te(tu)][p-
2N–H), 8.25 (d, 4C–Harom.), 6.81 (d, 4C–Harom.), 3.90 (s,
6
4
PhO(C H )TeI ] (2) which corresponds to the real (molecu-
4H CH etu), 3.82 ppm (s, 6H CH –O–); 2: 8.5 (broad,
6
4
4
2
3
1
3
lar) atomic aggregation of the compound would be
RTeI (l-I)Te(tu)R] {R = p-PhO(C H )}. This spell way
4H N–H), 6.8–7.5 ppm (multiplet, 18Harom.). C NMR
1: 176.3 (C@S), 160.89 (C4), 143.95 (C2 and C6), 115.3
(C3 and C5), 108.6 (s, weak, C –Te), 55.56 (CH –O–),
[
3
6
4
does not exclude the dimerization tendency of the [RTeI4]
1
3
moieties, where the reciprocal Teꢂ ꢂ ꢂI secondary bonds mea-
46.3 ppm (2CH etu); 2: 171.0 (C@S), whole aromatic sig-
nals 158.6, 157.9, 156.8, 144.3, 140.3, 130.9, 130.7, 130.6,
124.7, 124.0, 120.6, 120.2, 119.4, 119.3, 118.8 ppm,
2
˚
sure 3.8422(5) A {Te(1)ꢂ ꢂ ꢂI(4)#1}, somewhat longer than
the equivalent distances observed in compound
1
˚
{
Te(1)ꢂ ꢂ ꢂI(2)#1 = 3.7800(4) A}.
In both compounds the tectonic character of the RTeI4
moieties is remarkably strong. The Iꢂ ꢂ ꢂI (secondary) dis-
112.07 ppm (s, weak, C –Te).
1
4. Supplementary material
2
4 2
ꢀ
tances of the dimers ½p-CH OðC H ÞTeI ꢁ
in 1 is
3
6
4
˚
3
.6660(6) A {I(3)ꢂ ꢂ ꢂI(3)#1}. In compound 2 the supramo-
Crystallographic data for the structural analyses have
been deposited with the Cambridge Crystallographic Data
Centre CCDC nos. CSD 609607 and 609608 for com-
lecular tectonic assembling of the type [RTeI (l-I)-
3
Te(tu)R] {R = p-PhO(C H )} is achieved through double,
n
6
4
asymmetric Iꢂ ꢂ ꢂI secondary interactions (see Fig. 4):
I(3)#1ꢂ ꢂ ꢂI(5)#1 = 3.637(2), I(1)ꢂ ꢂ ꢂI(7)#1 = 4.0595(5),
I(3)ꢂ ꢂ ꢂI(5) = 3.6367(5) and I(1)#1ꢂ ꢂ ꢂI(7)#2 = 4.0595(5) A.
˚
Fig. 4. Supramolecular lattice of [RTeI
3 n 6 4 6 4 4
(l-I)Te(tu)R] {R = p-PhO(C H )}; for clarity only the [p-PhO(C H )TeI ] dimers are represented. Secondary
interactions in dashed lines. Symmetry transformations used to generate equivalent atoms: #1 ꢀx + 1, ꢀy, ꢀz + 1; #2 ꢀx, 1 ꢀ y, 1 ꢀ z.