Structural Systematics of Rare Earth Complexes. XIV Hydrated 1 : 1 Adducts of Lanthanoid( <i>III</i> ) Nitrates with 2,2′:6′,2&amp;Prime;-Terpyridine

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, a ˜ 75, ß 69, ? ˜ 89°, Z = 2 f.u., conventional R on | F | 0·045, 0·062 for N o 4513, 2710 independent ‘observed’ ( I &amp;gt; 3s( 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, ß ˜ 111°, Z = 4, R 0·055, 0·037, 0·056 for N o 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, a 96·56(2), ß 103·22(2), ? 91·16(2)°, Z = 2, R 0·037 for N o 6597.