Structural systematics of rare earth complexes. XVIII - (Hydrated) mononuclear 1 : 1 adducts of Lanthanoid(III) chlorides with 2,2 '-bipyridine

Room-temperature single-crystal X-ray structure determinations are recorded for a number of adducts of hydrated lanthanoid(III) chlorides with 2,2'-bi pyridine, 'bpy', crystallized from water/ethanol solutions, which contain m ononuclear arrays with 1 : 1 Ln/bpy stoichiometry. Extended isomorphous ser ies have been defined pertinent to the heavy end of the Ln series: crystals of LnCl(3)/bpy/H2O (1 : 1 : 6) ([(bpy)Ln(OH2)(6)]Cl-3), seemingly inclusiv e of (at least) the range Ln = Ho(-)Lu and Y, are monoclinic, P 2(1)/n, a a pproximate to 14.2, b approximate to 7.7, c approximate to 17.4 Angstrom, b eta approximate to 91 degrees, Z = 4, with an eight-coordinate LnN(2)O(6) a rray; conventional R values on \F\ were 0.043, 0.029, 0.057 for No 2435, 31 20, 1846 independent 'observed'(I > 3 sigma(I)) diffractometer reflections (Ln = Ho, Lu, Y). Crystals of LnCl(3)/bpy/H2O (1 : 1.5 : 8) ([(bpy)Ln(OH2)( 6)]Cl-3.1/2 bpy.2H(2)O), seemingly encompassing (at least) the range Ln = E r(-)Lu and Y, are triclinic, <P(1)over bar>, a approximate to 11.7, b appro ximate to 11.0, c approximate to 10.1 Angstrom, alpha approximate to 85.8, beta approximate to 74.7, gamma approximate to 79.5 degrees, Z = 2, R 0.038 , 0.033, 0.048 for N-o 3897, 4377, 3130, and contain similar [(bpy)Ln(OH2)( 6)](3+) cations as does HoCl3/bpy/H2O (1 : 2 : 7), [(bpy)Ho(OH2)(6)]Cl-3.bp y.H2O, orthorhombic, Pbca, a 18.02(2), b 20.06(2), c 15.051(9) Angstrom, Z = 8, R 0.057 for N-o 3009. By contrast, only sporadic, diverse and unrelate d forms are thus far defined among the lighter Ln: EuCl3/bpy/H2O(1 : 1 : 5) ([(bpy)Eu(OH2)(4)Cl-2]Cl.H2O), triclinic, <P(1)over bar>, a 11.506(7), b 1 1.098(5), c 6.974(8) Angstrom, alpha 77.35(7), beta 85.1(1), gamma 89.54(4) degrees, Z = 2, R 0.063 for No 4633, also contains a mononuclear [(N,N'-bid entate)Ln(unidentate)(6)] array. PrCl3/bpy/H2O(1 : 1 : 3)(x4) is a remarkab le compound, being 2[(bpy)Pr(OH2)(3)Cl-3] [(bpy)(H2O)(2)Cl2Pr(mu-Cl)(2)PrCl 2(OH2)(2)(bpy)].2H(2)O, triclinic, <P(1)over bar>, a 13.490(4), b 11.121(2) , c 10.162(1) Angstrom, alpha 96.06(1), beta 90.08(2), gamma 96.43(2)degree s, Z = 2 f.u., R 0.045 for N-o 4127, with a mononuclear species of PrCl3/bp y/H2O (1 : 1 : 3) stoichiometry and a binuclear species of 1 : 1 : 2 stoich iometry. A binuclear ethanol solvated array has been characterized for LaCl 3/bpy/EtOH (1 : 1 : 2) [(bpy)(EtOH)(2)Cl2La(mu-Cl)(2)LaCl2(HOEt)(2)(bpy)], with eight-coordinate lanthanum; this complex is triclinic, <P(1)over bar>, a 11.426(8), b 10.673(7), c 10.453(7) Angstrom, alpha 109.60(5), beta 113. 10(5), gamma 105.80(5)degrees, Z = 1 dimer, R 0.046 for N-o 2786.