Synthesis, Molecular Structures, and Norbornene Polymerization of Methallyl Nickel(II) Complexes of 2-(Diphenylamino)benzoate

Abstract

Reaction of 2-(diphenylamino)benzoic acid with bis(methallyl)nickel(II) results in the dinuclear complex bis(η 3 -methallyl)bis{µ- [(2-diphenylamino)benzoato-O:O′]}dinickel(II) ( 1), where the nitrogen atom does not coordinate to the nickel. Addition of B(C 6 F 5 ) 3 to 1 in benzene affords the nitrogen-coordinating complex [(2diphenylamino)benzoate tris(pentafluorophenyl)borateκ 2 N,O](η 3 -methallyl)nickel(II) (2). The structures of 1 and 2 are confirmed by X-ray crystallography. Complex 2 shows good activity for norbornene polymerization, while complex 1 is inactive.

Synthesis, characterization, and norbornene polymerization of η3-benzylnickel(II) complexes of N-heterocyclic carbenes

“…The 13 C-CPMAS spectrum of the polynorbornene produced by 8 looks like a combination of type-I and type-III as was observed on the polymer obtained with a zwitterionic nickel complex (Fig. 3) [40]. Broad signals at 30, 40, and 50 ppm, which are typical type-I signals, are overlapped with the signals at 35 and 58 ppm, which are typical type-III signals.…”

“…The molecular weights (M w ) of the polymers obtained by 5, 7, and 8 at room temperature (410, 323, and 341 Â 10 3 , respectively) are smaller than that of the polymer obtained either by Ni(acac) 2 / MAO catalyst (3.8 Â 10 6 ) [31] or by B(C 6 F 5 ) 3 -activated zwitterionic catalyst (633 Â 10 3 ) [40]. Narrow molecular distribution (MWD = 2.4-3.4) indicate the presence of a single active species in the polymerization solution.…”

Metal catalysts for the vinyl/addition polymerization of norbornene

“…The dinuclear Ni(II)-carboxylate complex Ni-155 did not show any activity towards the polymerization of norbornene, but could be transformed into the active compound Ni-156 by reaction with B(C 6 F 5 ) 3 , which showed a high activity of up to 3.6 × 10 6 g polymer /mol Ni h. The variation of reaction temperature from room temperature to 70 • C did not show an effect on the activity but on the molecular weights which declined at the same time [173].…”

Polymerization of 5-norbornene-2-methyl acetate catalyzed by air-stable cationic (η3-substituted allyl) palladium complexes of N-heterocyclic carbene

“…Although a variety of transition metal complexes of Ti and Zr [6,[16][17][18][19][20][21][22][23][24][25], Co [26][27][28][29][30][31][32], Ni [5,[33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50], and Pd [7,[9][10][11][12][13]34,40,[51][52][53][54] metals have been synthesized and tested for the olefin polymerization of norbornene, only a limited number of catalyst species have been proved to be effective for functionalized norbornenes. When functionalized norbornenes are employed, most transition metal catalyst systems become i...…”