Author:
Semenova Lioubov I.,White Allan H.
Abstract
Room-temperature single-crystal X-ray structure determinations are recorded
for (hydrated) lanthanoid(III)
nitrate/2,2′:6′,2″-terpyridine (‘tpy’) (1 :
1) complexes; all are of the form
Ln(NO3)3/tpy/H2O(1
: 1 :x),
[(tpy)Ln(O2NO)2(OH2)y](NO3)(.z
H2O), and form two series of compounds. For Ln =
La(-)Gd, the complexes are
[(tpy)Ln(O2NO)2(OH2)3](NO3),
the lanthanoid atom being ten-coordinate; crystals are triclinic,
P 1, a ≈ 11·8,
b ≈ 11·3, c ≈
8·9 Å, α ≈ 75, β 69, γ ≈ 89°,
Z = 2 f.u., conventional R
on |F| 0·045, 0·062 for
No 4513, 2710 independent
‘observed’ (I >
3σ(I)) diffractometer reflections for Ln =
La, Gd respectively. For Ln = Tb(-)Lu, a different form is found:
monoclinic, P
21/c, a
≈ 8·8, b ≈ 11·5,
c ≈ 23·8 Å, β ≈ 111°,
Z = 4, R 0·055,
0·037, 0·056 for No
2427, 3079, 1857 for Ln = Tb, Lu, Y respectively, the form of the
complex being
[(tpy)Ln(O2NO)2(OH2)2](NO3).2H2O,
with nine-coordinate lanthanoid. Crystallization of the Ln = La adduct
from methanol yields an adduct of
La(NO3)3/tpy/MeOH (1 : 1 : 2)
[(tpy)La(O2NO)3(HOMe)2]
stoichiometry with 11-coordinate lanthanum. Crystals are triclinic,
P 1, a 12·361(2),
b 12·244(3), c
7·753(2) Å, α 96·56(2), β 103·22(2),
γ 91·16(2)°, Z = 2,
R 0·037 for
No 6597.