No abstract

Cl (R ) Cy, 11; t-Bu, 12) and (Ph 3 PNH)AlMe 3 (13), respectively. The dimeric species [Me 2 Al(µ-NPt-Bu 3 )] 2 (14) [AlCl 2 (µ-NPt-Bu 3 )] 2 (15) were derived from reactions of (t-Bu 3 PNH) and AlMe 3 and t-Bu 3 PNLi and MeAlCl 2 , respectively. Reaction of the bisphosphinimine salt LiCH(PPh 2 (NSiMe 3 )) 2 (16) with aluminum, gallium, and indium halides yielded [CH(PPh 2 (NSiMe 3 )) 2 ]MCl 2 (M ) Al, 17; Ga, 18; In, 19) while the analogous species [CH(PPh 2 (NSiMe 3 )) 2 ]AlMe 2 (20) was prepared via reaction of 16 with Me 2 AlCl. The compounds [CH(PPh 2 (NSiMe 3 )) 2 ]MR 2 (M ) Al, Bz, 21; M ) Ga, R ) Me, 22; Bz, 23; M ) In, R ) Me, 24; Bz, 25) were readily prepared by treatment of 17-19 with the appropriate alkylating reagents. The borane B(C 6 F 5 ) 3 reacts stoichiometrically with the adducts 8-10 to give the products [(R 3 PNSiMe 3 )AlMe 2 ][MeB(C 6 F 5 ) 3 ] (R ) i-Pr, 26; Ph, 27; Cy, 28) while treatment of 27 with PMe 3 affords clean conversion to the salt [(Ph 3 PNSiMe 3 ) 2 AlMe(PMe 3 )]-[(MeB(C 6 F 5 ) 3 )] (29). Similarly, species [Me 2 Al(µ-NPt-Bu 3 ) 2 AlMe][MeB(C 6 F 5 ) 3 ] ( 30) and [Me 2 -Al(µ-NPt-Bu 3 ) 2 AlMe(PMe 3 )][MeB(C 6 F 5 ) 3 ] (31) were obtained from 14. Attempts to generate the related ionic derivatives from 20-25 yielded unstable mixtures of products. Under mild conditions these group 13 ionic species did not effect the polymerization of ethylene.

The preparation of a silyl−phosphinimide of the form (R3PN)SiMe3 (R = Me (1), i-Pr (2), Ph (3), t-Bu (4)) was achieved by the conventional literature methodology of oxidation of phosphine by N3SiMe3. The analogous species (t-Bu3PN)MMe3 (M = Ge (5), Sn (6)) were derived via a stoichiometric reaction of the salt Li[NP-t-Bu3] with Me3MCl. Similarly, the species (t-Bu3PN)2MMe2 (M = Si (7), Ge (8), Sn (9)), (i-Pr3PN)SnMe3 (10), (i-Pr3PN)2SnMe2 (11), and (t-Bu3PN)2SnMeCl (12) were prepared. Subsequent reactions of 12 afforded (t-Bu3PN)3SnMe (13) and (t-Bu3PN)2Sn(Ot-Bu)Me (14). In analogous metathesis reactions R3PNSnPh3 (R = t-Bu (15), i-Pr (16)), (t-Bu3PN)2SnPh2 (17), and (t-Bu3PN)2Sn(t-Bu)2 (18) were also prepared. Reaction of i-Pr3PNH and ClSnMe3 gave (i-Pr3PNH)SnMe3Cl (19), whereas 6 was obtained from the reaction of t-Bu3PNH with Me3SnCl. The reaction of 1 with B(C6F5)3 resulted in the formation of Me3PN(SiMe3)B(C6F5)3 (20), whereas the phosphinimines 2 and 3 react with B(C6F5)3 in a 2:1 ratio to give [R3PNSiMe2(N(PR3)SiMe3)][MeB(C6F5)3] (R = i-Pr (21), Ph (22)). In contrast, reaction of 4 and 6 with B(C6F5)3 afforded [((μ-t-Bu3PN)MMe2)2][MeB(C6F5)3]2 (M = Si (23), Sn (24)). The analogous reaction of 7 and 9 with B(C6F5)3 gave products formulated as [((t-Bu3PN)2MMe)2][MeB(C6F5)3]2 (M = Si (25), Sn (26)) and [((i-Pr3PN)2SnMe)2][MeB(C6F5)3]2 (27). Complexes 7−9, 17, 19, 20, and 24 were characterized crystallographically. The implications of this chemistry with regard to the steric demands of phosphinimide ligands are considered.

Addition of acids of the form HX (X = Cl, BF4, CF3SO3, CF3CO2) to complexes [PtPh2(NN)] (NN = bu2bpy = 4,4'-di-tert-butyl-2,2'-bipyridine) and [PtPh(NCN)] (NCN = 2,6-C6H3(CH2NMe2)2) at –78 °C gave the corresponding phenyl(hydrido)platinum(IV) complexes [PtX(H)Ph2(NN)] and [PtX(H)Ph(NCN)], which decomposed by reductive elimination of benzene at about –20 °C to give the platinum(II) complexes [PtXPh(NN)] and [PtX(NCN)]. Further addition of HCl to [PtClPh(NN)] at low temperature gave [PtHCl2Ph(NN)], which decomposed above –10 °C, to give benzene and [PtCl2(NN)]. The reaction of DBF4 in the presence of excess CD3OD with [PtPh2(NN)] led to formation of C6H5D and C6H4D2 but with [PtPh(NCN)] no multiple deuterium incorporation was observed in the product benzene. The mechanisms of these reactions are discussed. Key words: platinum, phenyl, benzene, protonolysis.

1,2-disubstituted cyclopentadienyl diimine anions are examples of extended π-systems that bind metals through the nitrogen atoms. Reaction of Cp2Mg with benzonitrile gives the product (1,2-C5H3(C(Ph)NH)2)CpMg(NCPh) (1) in 98% yield. In an analogous manner, the related complexes (1,2-C5H3(C(Ph)NH)2)CpMg(OEt2) (2) and ((4-Me3SiC5H2)(1,2-(C(Ph)NH)2)(Me3SiC5H4)Mg(OEt2) (3) were prepared in situ. Demetalation of these complexes 1−3 yields the corresponding free diimine ligands of formulation H[(1,2-C5H3(C(Ph)NH)2)] (4) and H[4-Me3SiC5H2-1,2-(C(Ph)NH)2] (5). Hydrolysis of compound 4 leads to the fulvene derivative 1-(C(OH)Ph)-2-(OC(Ph))C5H3 (6). The zirconium complexes (C5H3-1,2-(C(Ph)NH)2)ZrCl3(THF) (7) and (C5H3-1,2-(C(Ph)NH)2)3ZrCl (8) were isolated from reactions of 4 with ZrCl4(THF)2. X-ray crystallographic studies of 1, 7, and 8 are reported. Evidence suggests that these new 1,2-disubstituted cyclopentadienyl diimine anions impart some charge delocalization, thus offering a new approach to electrophilic metal centers. This view is supported by EHMO calculations.