Polypyridyl Large Holes In The Synthesis, Structure And Properties Of Metal Complexes

Three new polypyridine ligands of 2,2'-bipyridine-3-carbomethoxy-3'-formyl-hydrazide (bpmh), 2,2'-bipyridine-3,3'-diformylhydrazide (bpdh) and 2,2'-bipyridine-3,3 -bis(N-ferrocenylmethylene formylhydrazone) (bpbfz), and two reported polypyridine ligands of 4,5-diazafluorene-9-one (dafo) and 2,2'-bipyridine-3,3'-dicarboxylic acid (bpda) have been successfully synthesized. Using them and two commercial polypyridine ligands of 4,4'-bipyridine (bp) and 1.2-bis(4-pyridine) ethane (bpe) as ligands, eleven new complexes have been synthesized. The Crystal structures of complexes [Cu'(bp)(H2O)3]ClO4.2H2O 1, [CuICuII(bpe)2(H2O)7ClO4](ClO4)2.3.5H2O 2, [Cd"(dafo)2(tphpo)(CH3COO)]ClO4 3 (tphpo=triphenylphosphine oxide), [Con(bpdc)(H2O)2] 4 ( bpdc=2,2'-bipyridine-3,3' -dicarboxylate ), [Ni"(bpdc)(H2O)2] 5, [Cuu(bpmh)Cl2]2 6, and [CuII2(bpdpz)2 (H2O)2].3H2O 7 ( bpdpz = enolic anion of 2,2'-bipyridyl-3,3'-bis(N,N'-diisopropylidene) formylhydrazone) have been determined by x-ray diffraction.Complex 1 and 2 have been prepared using three-layer diffusion self-assembly. Complex 1 crystallizes in a hexagonal cell with space group P6(l). The complex contains 1-D infinite polymeric chains that are formed through bp bridging cuprous ions. These chains array in parallel in ab plane and alternatively stack up at three cross directions (60?for all cross angles) along c axis. This regular stacking pattern repeats per three layers. Finally, novel triprismatic tunnels with nanometer opening are formed. C1CV ions and water molecules are trapped in them. The coordination sphere around cuprous centers in complex 1 can be described as distorted trigonal bipyramidal geometry, with three oxygen atoms from water molecules forming the trigonal plane and two nitrogen atoms from two bp occupying the axial sites. Complex 2 crystallizes in a monoclinic cell with space group P2(l)/c. The complex consists of binuclear unit [CuICuII(bpe)(H2O)7ClO4]2+ where the perchlorate ion links the cuprous ion with the other cupric ion. Two bpe molecules just act as monodentate ligands coordinating to the cuprous ion at axial sites. The cuprous ion in O4Ni siteinhas a distorted octahedral geometry that is seldom observed in cuprous complexes, whereas the cupric ion in O5 site has a distorted square-pyramidal geometry with the perchlorate oxygen at the apex. Complexes 1 and 2 have complicated hydrogen-bonding networks by which they are linked into 3-D supramolecules.Complex 3 crystallizes in a monoclinic cell with space group P2(1)/N. The geometry at cadmium centers can be regarded as distorted monocapped trigonal prism geometry. Two oxygen atoms of acetate and one oxygen atom of triphenylphosphine oxide form the top trigonometry of the trigonal prism, while three nitrogen atoms from two dafo molecules construct the bigger bottom trigonometry. The last nitrogen atom of the two dafo molecules occupies the monocapped position. Interesting intra- and inter-molecular π -π stacking interaction leads to pseudo helical chains in complex 3.Complexes 4 and 5 are isomorphous and crystallize in a monoclinic cell with space group C2/c. Complexes 4 and 5 have been synthesized using hydrothermal method and determined as 1-D chain-like polymers. Complicated hydrogen network links these structural chains of complex 4 or 5 into 2-D layer supramolecules. The geometry at metal centers (CoII or NiII) can be described as a distorted octahedron, with two nitrogen atoms of one bpdc and two oxygen atoms of another forming square plane and two oxygen atoms of water molecules occupying axial sites. Bpdc acts as an excellent tetradentate bridging ligand to bichelate to metal ions, which has been rarely reported.Complexes 6 and 7 crystallize in a monoclinic cell and respectively belong to C2/c and Cc space group. Complex 6 is a dichloro-bridged butterfly-shaped dimer. The geometry at copper centers is tetragonal pyramidal, with two chlorines and two pyridine nitrogen atoms at the base and the out-of-plane bridging chlorine atom at the apex. The cis configuration of complex 6 i...