Zirconium phosphinimide complexes of the form CpZr(NP-t-Bu 3 )Cl 2 (1) and Cp*Zr(NPR 3 )-Cl 2 (R ) i-Pr (2), t-Bu (3)) were readily prepared under ambient conditions via the reaction of [CpZrCl 3 ] n or Cp*ZrCl 3 with the appropriate trialkylphosphinimide lithium salt (R 3 PNLi). A series of derivatives were readily obtained via alkylation or arylation of the above dihalide precursors. These included CpZr(NP-t-Bu 3 )Me 2 (4), Cp*Zr(NPR 3 )Me 2 (R ) i-Pr (5), t-Bu (6)),. Reaction of 17 with the borane B(C 6 F 5 ) 3 yielded the zwitterionic and cationic complexes Cp*Zr(NP-t-Bu 3 )(CH 2 C(CH 3 )C(CH 3 )CH 2 B(C 6 F 5 ) 3 ) (18) and Cp*Zr(NP-t-Bu 3 )(THF)-(CH 2 C(CH 3 )C(CH 3 )CH 2 B(C 6 F 5 ) 3 ) (19). A number of the above compounds were screened for their potential as catalyst precursors in ethylene polymerization. In general, upon activation with methylaluminoxane, the resulting catalysts exhibit low activity. Efforts to understand the deactivation pathway for these zirconium catalysts involved investigating the interactions of catalyst precursors with activators. For example, reaction of 4 with the borane B(C 6 F 5 ) 3 leads to aryl group transfer and formation of catalytically inactive CpZr(NP-t-Bu 3 )(C 6 F 5 ) 2 (20). Interactions with MAO were modeled via reaction with AlMe 3 . The Zr clusters (Cp*Zr) 4 -(µ-Cl) 5 (Cl)(µ-CH) 2 ( 21) and (Cp*Zr) 5 (µ-Cl) 6 (µ-CH) 3 ( 22) were two of the products that were characterized from these reactions. The isolation of 21 and 22 infers that aryl for methyl exchange, ligand abstraction, and C-H bond activation may be catalyst deactivation pathways.

The reactions of [PdCl2(NCPh)2] in a 1:1 ratio with the bis(amidopyridine) ligands LL=C6H3(5-R)(1,3-CONH-3-C5H4N)2 with R=H (1a) or R=t-Bu (1b) give the corresponding neutral dipalladium(II) macrocycles trans,trans-[Pd2Cl4(mu-LL)2], 2a and 2b, which crystallize from dimethylformamide with one or two solvent molecules as macrocycle guests. The reaction of [PdCl2(NCPh)2] with LL in a 1:2 ratio gave the cationic lantern complex [Pd2(mu-LL)4]Cl4, 3c (LL=1b), and the reaction in the presence of AgO2CCF3 gave the corresponding trifluoroacetate salts [Pd2(mu-LL)4](CF3CO2)4, 3a (LL=1a) and 3b (LL=1b). These lantern complexes exhibit a remarkable host-guest chemistry, as they can encapsulate cations, anions, and water molecules by interaction of the guest with either the electrophilic NH or the nucleophilic C=O substituents of the amide groups, which can be directed toward the center of the lantern through easy conformational change. The structures of several of these host-guest complexes were determined, and it was found that the cavity size and shape vary according to the ligand conformation, with Pd...Pd separations in the range from 9.45 to 11.95 A. Supramolecular ordering of the lanterns was observed in the solid state, through either hydrogen bonding or secondary bonding to the cationic palladium(II) centers. The selective inclusion by the lantern complexes of alkali metal ions in the sequence Na+ >> K+ >> Li+ was observed by ESI-MS.

The digold(I) diacetylides [4-RC 6 H 9 (4-C 6 H 4 OCH 2 CtCAu) 2 ], which contain a cyclohexylidene hinge group 4-RC 6 H 9 with R ) H or t-Bu, react with diphosphine ligands Ph 2 PZPPh 2 to give the corresponding macrocycles orBu, the bulky tert-butyl group locks the cyclohexane ring conformation and so provides a good NMR spectroscopic probe of the structure. The organogold(I) [2]catenane complexes are chiral when R ) t-Bu, and the complex with Z ) (CH 2 ) 4 gives an equilibrium in solution between ring, double-ring, and [2]catenane. When R ) H and Z ) (CH 2 ) 3 , the variabletemperature NMR spectra give new insight into the fluxionality in the [2]catenane complex, and when R ) H and Z ) (CH 2 ) 4 , it is shown that the complex exists in solution as the ring structure, although it crystallizes as a doubly braided [2]catenane.

Reaction of the N-methylated bis(amidopyridine) ligand, LL = C6H4(1,3-CONMe-4-C5H4N)2, with the silver salts AgNO3, AgO2CCF3, AgO3SCF3, AgBF4, and AgPF6 gave the corresponding cationic disilver(I) macrocycles [Ag2(micro-LL)2]X2, 2a-e. The transannular silver...silver distance in the macrocycles varies greatly from 2.99 to 7.03 A, and these differences arise through a combination of different modes ofanion binding and from the presence or absence of silver...silver secondary bonding. In all complexes, the ligand adopts a conformation in which the methyl group and oxygen atom of the MeNCO units are mutually cis, but the overall macrocycle can exist in either boat (X = PF6 only) or chair conformation. Short transannular silver...silver distances are found in complexes 2b,c, in which the anions CF3CO2- and CF3SO3- bind above and below the macrocycle, but longer silver...silver distances are found for 2a,d,e, in which the anions are present, at least in part, inside the disilver macrocycle. Easy anion exchange occurs in solution, and studies using ESI-MS indicate that the anion binding to form [Ag2X(micro-LL)2]+ follows the sequence X = CF3CO2- > NO3- > CF3SO3-.

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