3.3. 1,10-Phenanthroline-2,9-Bis(hydroxymethyl)

The metal ion selectivity for M(III) (M = metal) ions exhibited by the highly preorganized ligand PDALC is investigated (PDALC = 2,9-bis(hydroxymethyl)-1,10-phenanthroline). The structures are reported of [Bi(PDALC)(H(2)O)(2)(ClO(4))(3)] x H(2)O (1), monoclinic, P2(1)/c, a = 12.8140(17), b = 19.242(3), c = 9.2917(12) A, beta = 91.763(2) degrees, V = 2289.9(5) A(3), Z = 4, R = 0.0428; [Th(PDALC)(NO(3))(4)] x 3 H(2)O (2), monoclinic, P2(1)/n, a = 7.876(3), b = 22.827(9), c = 12.324(5) A, beta = 94.651(6) degrees, V = 2208...

Metal ion complexing properties of the ligand 2,9-bis(hydroxymethyl)-1,10-phenanthroline (PDALC) are reported. For PDALC, the rigid 1,10-phenanthroline backbone leads to high levels of preorganization and enhanced selectivity for larger metal ions with an ionic radius of about 1.0 A that can fit well into the cleft of the ligand. Structures of PDALC complexes with two larger metal ions, Ca(II) and Pb(II), are reported. [Ca(PDALC) 2](ClO 4) 2 ( 1) is triclinic, Pi, a = 7.646(3), b = 13.927(4), c = 14.859(5) (A), alpha = 72...