No abstract

The synthesis, structures and thermal properties of threeComplexes 1 and 2 show the dia topology with the rare 8-and 9-fold interpenetrating modes, respectively, while 3 exhibits an interpenetrating 3-fold framework with the pcu Zn 2 (COO) 2 dimer decorated topology.Complex 2 shows the maximum number of interpenetration presently known for interpenetrating diamondoid networks of coordination networks containing mixed spacer ligands.3

We report the synthesis, crystal structure, and catalytic studies for ringopening polymerization (ROP) of group 4 metal alkoxides based on amine-BiBTP derivatives (amine-BiBTP = amine-bis(benzotriazole phenolate)). Dinuclear group 4 metal alkoxides [{(amine-BiBTP)M t (O i Pr)} 2 (μ-O)] (4−7, M t = Ti, Zr, Hf) resulted from treatment of amine-BiBTP-H 2 as the ligand precursor with 1.0 molar equiv of metal precursor (Ti(O i Pr) 4 , Zr(O i Pr) 4 ( i PrOH), or Hf(O i Pr) 4 ( i PrOH)), followed by the addition of H 2 O (0.5 equiv) in good yields. The solid-state structure of 4−7 reveals a bimetallic BiBTP-ligated metal(IV) alkoxide with an oxo ligand chelating two metal atoms, and the bonding mode of the metal-O(μ-oxo)-metal moiety assumes a linear type. Catalysis of lactide polymerization and carbon dioxide/cyclohexene oxide copolymerization of oxo-bridged bimetallic metal complexes was systematically examined. Zirconium alkoxide 6 shows an effective catalyst in the ROP of lactide with "living" and "immortal" fashions, yielding poly(lactide)s with the predicted molecular weights and narrow polydispersity indices (PDIs <1.25) as well as an isotactic-enriched predominance (P m up to 0.71). Bimetallic BiBTP-featuring Zr complex 6 was also able to couple carbon dioxide and cyclohexene oxide to give poly(cyclohexene carbonate-co-cyclohexene oxide), having a high copolymer selectivity and good carbonate-linkage contents under the optimal conditions. This is a successful example of catalysis for both processes using one well-defined zirconium(IV) alkoxide complex as a bifunctional catalyst.

The polymeric complex [CuSO4(L)(H2O)2]∞, 1, which was prepared by the reaction of a flexible ligand N,N′-di(4-pyridyl)adipoamide), L, and copper sulfate forms a 12-fold diamondoid network showing an unusual [6 + 6] mode of interpenetration. The L ligands in 1 adopt the AAA trans and GAG trans conformations which also differ in the dihedral angle between the two pyridyl rings.