Os. Jung et al., Structures and related properties of AgX bearing 3,3 '-thiobispyridine (X-= NO3-, BF4-, ClO4-, and PF6-), INORG CHEM, 40(9), 2001, pp. 2105-2110
Infinite molecular helices [Ag(3,3 ' -Py2S)]X (3,3 ' -Py2S = 3,3 ' -thiobis
pyridine; X- = BF4-, ClO4-, and PF6-) have been rationally constructed or i
nduced. Crystallographic characterization (X- = BF4-, monoclinic P2(1)/n, a
= 8.946(3) Angstrom, b = 14.130(2) Angstrom, c 10.124(2) Angstrom, beta =
107.83(2)degrees, V = 1218.3(5) Angstrom (3), Z = 4, R = 0.0351; X- = ClO4-
, monoclinic P2(1)/n, a = S.884(1) Angstrom, b = 14.305(3) Angstrom, c = 10
.110(1) Angstrom, beta = 106.78(1)degrees, V= 1230.1(3) Angstrom (3), Z = 4
, R = 0.0417; X- = PF6-, monoclinic P2(1)/c, a = 10.959(2) Angstrom, b = 9.
808(2) Angstrom, c = 14.065(3) Angstrom, beta = 112.03(2)degrees, V = 1401.
4(5) Angstrom (3), Z = 4, R = 0.0442) reveals that the skeletal structure i
s an oblong cylindrical cationic helix consisting of alternating Ag(I) and
3,3 ' -Py2S species and that its counteranions are pinched in two columns i
nside each helix. The formation of the helical coordination polymer appears
to be primarily associated with a suitable combination of the skewed confo
rmer of 3,3 ' -Py2S and the potential linear geometry of the N-Ag(I)-N bond
. However, the framework of the nitrate analogue [Ag(3,3 ' -Py2S)NO3] (mono
clinic P2(1)/c, a = 8.177(2) Angstrom, b = 10.291(1) Angstrom, c 14.771(2)
Angstrom, beta = 102.19(1)degrees V = 1214.9(4) Angstrom (3), Z = 4, R = 0.
0300) is a two-dimensional network consisting of an 18-membered ring unit,
where each 3,3 ' -Py2S acts as a N,N ' ,S- tridentate ligand connecting thr
ee tetrahedral silver(Ij ions with the monodentate nitrate weakly bonded to
the silver (Ag . . .O = 2.65(1) Angstrom) rather than acting as a countera
nion. The anion exchange of [Ag(3,3 ' -Py2S)-NO3] with BF4-, ClO4-, or PF6-
has been accomplished in aqueous media. The two-dimensional networks are e
asily converted into the helices via the anion exchange, but the reverse an
ion exchange proceeds slightly. Thermal analyses indicate a relationship be
tween the thermal stabilities and the structural properties.