The stoichiometric reactions of 5,6,7,8-tetrahydrocycloheptapyridin-9-one (cycloheptapyridin-9-one) with various anilines lead to corresponding mixtures of 9-aryliminocycloheptapyridine and the isomeric 9-arylamino-5,6,7-trihydrocycloheptapyridine derivatives; these compounds further reacted with nickel dichloride to form 9-aryliminocycloheptapyridyl nickel chlorides, respectively. The new organic compounds were analyzed by the NMR measurements, and all the organic and complex compounds were characterized by the FT-IR spectroscopy and elemental analysis. In addition, the molecular structures of representative nickel complexes and , determined by means of single-crystal X-ray diffraction, were found to be binuclear dimers with distorted square-pyramidal geometry around the nickel centers. On activation with either ethylaluminium sesquichloride (Et3Al2Cl3) or methylaluminoxane (MAO), all nickel complex pre-catalysts exhibited high activities of up to 7.80 × 10(6) g PE mol(-1) (Ni) h(-1) toward ethylene polymerization and produced highly branched polyethylenes in narrow polydispersity. The title nickel complexes showed comparable activities with 8-arylimino-5,6,7-trihydroquinolyl nickel analogues; whilst both exhibited higher activities than did the 2-iminopyridyl nickel analogues due to the enhancement of the ring-tension of cyclic-fused pyridine derivatives.

Cycloalkyl-modified 8-arylimino-5,6,7-trihydroquinolylnickel pre-catalysts highly polymerize ethylene into branched polyethylene waxes.

A series of 9-(2-cycloalkylphenylimino)-5,6,7,8-tetrahydrocycloheptapyridine derivatives (L1-L3) was synthesized, and reacted with nickel halides to form their corresponding nickel complexes (bromide: Ni1-Ni3; chloride: Ni4-Ni6). All organic compounds and nickel complexes were well characterized. The structure of a representative complex Ni1 was determined by a single crystal X-ray study, revealing a distorted trigonal bipyramidal geometry at the nickel centre. Upon activation with either modified methylaluminoxane (MMAO) or diethylaluminium chloride (Et 2 AlCl), all nickel complexes showed high activities toward ethylene polymerization. The obtained polymers were confirmed to be polyethylene waxes with low molecular weights (in the range of 1.83 to 6.78 kg mol À1 ) and narrow polydispersity (PDI:1.38-1.78); moreover, the obtained polyethylenes were highly branched ones. These polyethylene waxes have potential application as functional adducts of lubricants or pour-point depressants.

The CuCl catalyzed direct trifluoromethylation of sp(2) C-H bonds has been realized, using the Togni reagent as the CF3 source. This reaction achieves the goal of regio-selectively converting C-H into C-CF3 with ecological and readily available starting materials.

Precise synthesis of soluble star-shaped polymers has been achieved by adopting living ring-opening metathesis polymerisation (ROMP) using a molybdenum-alkylidene catalyst with sequential addition of norbornene and cross-linking agent; the method provides efficient one-pot synthesis of high molecular weight end-functionalised star-shaped polymers (M n ¼ >1.37 Â 10 5 ) with more arms (branching) with rather low PDI values (M w /M n ¼ 1.17-1.37) under the optimised conditions.

The synthesis and identification of half-titanocenes containing an aryloxide ligand supported at the chain end (surface) of soluble star-shaped polymers, by adopting sequential one-pot living ring-opening metathesis polymerizations (ROMP) of norbornene (NBE) and a cross-linking reagent using a molybdenum alkylidene catalyst, have been explored. The Ti Kedge XANES spectra (in toluene at 25 °C) indicate that the basic geometry and electronic nature of the original complex, Cp*TiMe 2 (O-i Pr 2 C 6 H 3 ) (1), were preserved in the supported catalyst on the star-shaped ROMP polymers. The supported catalyst showed high catalytic activities for ethylene polymerization, which are lower than that by 1 but higher than that by the supported catalyst at the linear ROMP polymer chain end; efficient 1-hexene incorporation in the ethylene/1-hexene copolymerization has also been demonstrated in this star-shaped supported catalyst.

An effective regioselective cyclotrimerization of terminal alkynes is achieved by the direct utilization of NiCl2·6H2O, Zn, and 2-(benzimidazolyl)-6-(1-(arylimino)ethyl)pyridine in one step under ambient temperature.

The methods for one-pot synthesis of ‘soluble’ star-shaped polymers by sequential living ring-opening metathesis polymerization (ROMP) of norbornene (NBE) and cross-linking (CL) reagent using Mo(CHCMe2Ph)(N-2,6-iPr2C6H3)(OtBu)2 have been explored. The method (called the “in and out” or core-first approach) basically consists of (i) the living ROMP of NBE (formation of arm), (ii) reaction with CL (formation of core), (iii) additional living ROMP of NBE (propagating arms from the core, formation of star), (iv) end-modification via Wittig-type cleavage of metal–carbon double bonds containing polymer chain with aldehyde. Two different approaches in the core formation step (reaction with CL mixed with/without NBE) for synthesis of the high molecular weight star-shaped ROMP polymers with more branching, unimodal molecular weight distributions have been explored in detail. The method (reacting CL with NBE in the core formation step) under highly diluted conditions afforded the high molecular weight polymers with unimodal molecular weight distributions.