Martin Alexander Zuideveld

A remarkable inversion of structure–activity dependence on imido N-substituents with varying co-ligand topology and the synthesis of a new borate-free zwitterionic polymerisation catalyst

Ethylene polymerisation productivities of tris(pyrazolyl)methane-supported catalysts [Ti(NR){HC(Me2pz)3}Cl2] show a dramatically different dependence on the imido R-group compared to those of their TACN analogues, attributed to differences in fac-N3 donor topology; when treated with AliBu3, the zwitterionic tris(pyrazolyl)methide compound [Ti(N-2-C6H4tBu){C(Me2pz)3}Cl(THF)] also acts as a highly active, single site catalyst (TACN = 1,4,7-trimethyltriazacyclononane).

Palladium(II) complexes containing symmetrical diphosphine ligands based on ferrocene. Sterically enforced palladiumiron bonds

Abstract Methylpalladium chloride, cationic methyl- and acylpalladium triflate complexes were synthesised containing bis(dialkyl) and bis(diphenyl)phosphine ferrocene ligands. Trans -coordinated cationic methylpalladium complexes containing 1,1′-bis(di- tert -butylphosphino)ferrocene, form a palladiumiron bond. The less bulky 1,1′-bis(di- iso -propylphosphino)ferrocene ligand coordinates in a cis fashion in methylpalladium chloride complexes. A palladiumiron bond was indicated in the cationic acylpalladium complexes of both alkylphosphine ligands. 1,1′-Bis(diphenylphosphino)ferrocene does not form a palladiumiron bond in the monocationic acyl- and methylpalladium complexes. The complexes were characterised by 1 H-, 31 P-, 13 C-NMR spectroscopy, elemental analysis, and UV–vis spectroscopy.

The coordination behaviour of large natural bite angle diphosphine ligands towards methyl and 4-cyanophenylpalladium(II) complexes

The structures of neutral and ionic 4-cyanophenylpalladium(II) and methylpalladium(II) complexes containing bidentate phosphine ligands were investigated in solution and in the solid state. Diphosphine ligands with a xanthene and a ferrocene backbone were used. New bis(dialkylphosphino) substituted Xantphos ligands were synthesised. 1H NMR and 31P NMR spectroscopy, conductivity measurements, UV-Vis spectroscopy, and X-ray crystallography were used to elucidate the structures of the complexes. Subtle changes of the phosphine ligands govern the coordination mode of the ligand. A variety of bidentate cis-, and trans-coordination and terdentate P–O–P, P–S–P and P–Fe–P coordination modes of the ligands were observed.