The α-diimine ligand ArNC(Me)C(Me)NAr (Ar = 2,6-C6H3-iPr2) reacts with Pd(OAc)2 in the presence of HBF4·Et2O, or [Pd(MeCN)4](BF4)2 in the absence of acid, to give ethylene polymerization catalysts. The reactions of a related β-diimine ligand with [Pd(MeCN)4](BF4)2 and (1,2-dimethoxyethane)NiBr2, and the polymerization activity of catalysts derived from it, are discussed.

1423actual dissociation (AD2 -AD + D) in which the leaving molecule carries away the excess energy. SummaryThe emission properties of jet-cooled adducts between ethers and some aromatic hydrocarbons may be accounted for by assuming an excited state that is a superposition of a van der Waals locally excited (LE) state and a charge-transfer (CT) state. The direct optical transition from the ground state to the C T state is forbidden by either symmetry or Franck-Condon considerations. Thus, the excitation spectrum is dominated by the LE state, and emission from the CT state has a longer decay time. The C T character of the excited state is more prominent in anthracene and its derivatives than in perylene. This is particularly so when a hydrogen atom is bound to a C-9 or C-IO carbon. It is therefore proposed that this atom may serve as a bridge in transmitting the charge from the oxygen lone pair orbital of the ether. Geometric factors appear to be decisive in determining the interaction as shown by the fact that tetrahydrofuran, in which the oxygen atom is constrained to be away from the 9-or 10-position, does not show exciplex-type emission with anthracene. Abstract:The reaction between W(C-t-Bu)(dme)CI, and ArNH(TMS) (Ar = 2,6-C,H3-i-Pr2) yields W(C-t-Bu)(NHAr)(dme)CI,.

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