CHAIN AND LARGE-RING POLYMERIC TRANSITION-METAL AND LANTHANIDE COMPLEXES FORMED BY N,N'-ETHYLENEBIS(PYRROLIDIN-2-ONE)

With the aim of exploring the types of polymeric structures generated by the ''extended reach'' ligand N,N'-ethylenebis(pyrrolidin-2-one) (ebpyrr), a range of complexes with Mn-II, Fe-III, Co-II, Ni-II, Cu-II, Zn-II, lanthanide ions, and Th-IV have been isolated, and five representative members have been structurally characterized by X-ray crystallography. [Co(ebpyrr)Cl-2](n) crystallizes in the monoclinic space group P2(1)/n, with a = 9.827(4) Angstrom, b = 9.369(3) Angstrom, c = 14.747(7) Angstrom, beta = 94.13(2)degrees, and V = 1354.2(9) Angstrom(3) for Z = 4. [Zn(ebpyrr)I-2](n) crystallizes in the monoclinic space group Cc, with a = 9.013(4) Angstrom, b = 15.967(6) Angstrom, c = 11.002(4) Angstrom, beta = 103.76(2)degrees, and V = 1537.9(11) Angstrom(3) for Z = 4. Both these complexes contain tetrahedrally coordinated metal ions linked by ebpyrr bridges to form chains. [Co(ebpyrr)(NO3)(2)(MeCN)](n) crystallizes in the monoclinic space group C2/c, with a = 31.53(6) Angstrom, b = 8.242(8) Angstrom, c = 14.99(2) Angstrom, beta = 115.3(1)degrees, and V = 3522(9) Angstrom(3) for Z = 8, Chains are also formed by this complex, but in this case the metal ion is octahedrally coordinated. Cd(ebpyrr)(2)(NO3)(2) . H2O crystallizes in the monoclinic space group C2/c, with a = 13.907(6) Angstrom, b = 11.927(5) Angstrom, c = 17.076(8) Angstrom, beta = 109.71(2)degrees, and V = 2666(2) Angstrom(3) for Z = 4. The cadmium atom in this mononuclear complex adopts an essentially pentagonal bipyramidal coordination geometry with two oxygen atoms, one from each of the two ebpyrr molecules, occupying the axial positions and two chelating nitrate groups and the aqua ligand forming the equatorial plane. The monomers are linked via hydrogen bonds to form sheets. [Zn(ebpyrr)(3)](ClO4)(2) . 2MeCN crystallizes in the triclinic space group P ($) over bar 1, with a = 7.533(2) Angstrom, b = 10.788(4) Angstrom, c = 13.014(4) Angstrom, alpha = 98.79(2)degrees, b = 92.32(2)degrees, gamma = 98.77(2)degrees, and V = 1030.7(6) Angstrom(3) for Z = 1. This compound also forms sheets but here the Linkages are covalent, via ebpyrr bridges, and the structure contains both 18- and 36-membered rings.