An insoluble form of methylaluminoxane, also known as solid polymethylaluminoxane (sMAO), has been synthesized by the controlled hydrolysis of trimethylaluminum (TMA) with benzoic acid, followed by thermolysis. Characterization of sMAO by multinuclear NMR spectroscopy in solution and the solid state reveals an aluminoxane structure that features "free" and bound TMA and incorporation of a benzoate residue. Total X-ray scattering (or pair distribution function, PDF) measurements on sMAO allow comparisons to be made with simulated data for DFT modeled structures of MAO. Several TMA-bound (AlOMe) n cage and nanotubular structures with n>10 are consistent with the experimental data. The measured Brunauer-Emmett-Teller (BET) surface area of sMAO ranges between 312 -606 m 2 g -1 and shows an N 2 adsorption/desorption isotherm consistent with a non-porous material. sMAO can be utilized to support metallocene pre-catalysts in slurry-phase ethylene polymerization reactions. Metallocene pre-catalyst rac-ethylenebis(1-indenyl)dichlorozirconium, rac-(EBI)ZrCl 2 was immobilized on sMAO samples, to afford solids which showed very high polymerization activities in hexane, comparable to those of the respective homogeneous catalysts formed by treatment of the pre-catalysts with MAO. rac-(EBI)ZrCl 2 immobilized on an sMAO containing an Al:O ratio of 1.2 gave the highest ethylene polymerization activity.

Nickel N-confused tetraphenylporphyrin, 1, and nickel 2-N-methyl-N-confused tetraphenylporphyrin, 1-Me, exhibit unusual sign-reversed (positive-to-negative intensities in ascending energy) MCD spectra in the Q-type band region, suggesting a rare ΔHOMO < ΔLUMO relationship between π and π* MOs in the porphyrin core. Simple and reversible deprotonation of the external NH proton in 1 dramatically changes the electronic structure of the porphyrin core into the ΔHOMO > ΔLUMO combination characteristic for the meso-(tetraaryl)porphyrins. DFT, time-dependent DFT, and semiempirical ZINDO/S calculations on 1, 1-Me, and 1(-) confirm the experimental finding and successfully explain the MCD pattern in the target compounds.

Post synthesis modification of solid polymethylaluminoxane (sMAO) with tris(pentafluorophenyl)borane or pentafluorophenol produces highly active metallocene supports "sMMAOs" for use in slurry-phase ethylene polymerization. Characterization of the sMMAOs using ICP-MS analysis, BET isotherm, SEM-EDX, diffuse FT-IR and solid state NMR spectroscopy reveals that the surface methyl groups are exchanged for C 6 F 5 and C 6 F 5 O moieties respectively, giving a material with reduced aluminum content and a lower specific surface area than sMAO. Rac-ethylenebis(1-indenyl) zirconium dichloride, {(EBI)ZrCl 2 } immobilized on B(C 6 F 5) 3 and C 6 F 5 OH modified sMAO displayed activity increases of 66 and 71% respectively for ethylene polymerization compared to the same zirconocene catalyst precursor on unmodified sMAO. In the case of B(C 6 F 5) 3 modified sMAO this enhanced polymerization activity is accompanied by excellent control of polymer particle size and morphology, and a small decrease in polymer molecular weight and polydispersities. Scheme 1. Schematic of the synthetic routes to (a) Lewis acid; (b) phenoxy modified MAO solutions; and (c) free TMA removal. A linear MAO formula is shown for simplicity.

Cobalt complexes of N-confused porphyrins and benziphthalocyanine, which both feature organometallic bonds at the macrocycle cores, catalyze the cyclopropanation of styrene with a higher trans-selectivity than the corresponding porphyrin and phthalocyanine complexes.

The first nickel complexes of two carbon-substituted phthalocyanine analogues are reported; both exhibit direct Ni-C bonding and oxygen activation chemistry is observed.