Synthesis of neutral nickel catalysts for ethylene polymerization ? the influence of ligand size on catalyst stabilityElectronic supplementary information (ESI) available: experimental protocol for (tmeda)Ni(Me)2 and compounds 3,4,7,8,9 and 10 and 1H-NMR magnetization transfer data for compound 7. See http://www.rsc.org/suppdata/cc/b3/b306701g/