Titanium and zirconium complexes with aminoiminophosphorane ligands

Qi, Changhe; Zhang, Suobo

doi:10.1002/aoc.1019

Cited by 9 publications

(6 citation statements)

References 24 publications

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“…dt, 3 J HP = 16, 3 J = 8, 6H, CH 2 CH 3 ). 13 C NMR (CDCl 3 ): δ 141.4 (d, 2 J CP = 4.0, i-C Tol (N)), 134.9 (d, 5 J CP = 2.0, i-C Tol (Me)), 130.3 (s, β-C Tol ), 125.7 (d, 3 ). UV-vis (CH 2 Cl 2 ; λ max , nm; ε, M −1 cm −1 ): 550 (1300).…”

Section: General Proceduresmentioning

confidence: 99%

“…Among transition metal complexes with κ 2 -N,N-heteroallylic ligands, the iminophosphonamides bearing a coordinated R 2 P(NR′) 2 − anion (NPN) are studied fragmentarily; there have been less than a hundred of molecular structures of NPN complexes established to date, that is in sharp contrast to more than a thousand of transition metal amidinate structures, according to the Cambridge Structural Database (CSD). The IV group metals, [1][2][3][4][5][6] chromium, 7-10 nickel [11][12][13][14][15] and copper [16][17][18][19][20][21][22] iminophosphonamides are the most studied, which is due to their catalytic application in cyclopropanation, 16,21,23 olefin oligomerization [7][8][9] and polymerization. 2,6,12,15,24,25 A few platinum metal group iminophosphonamides have been reported for palladium 24 and ruthenium 26 before 2009, when we started systematic studies of these complexes.…”

Section: Introductionmentioning

confidence: 99%

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The half-sandwich 18- and 16-electron arene ruthenium iminophosphonamide complexes

et al. 2016

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Novel half-sandwich 18ē and 16ē arene ruthenium iminophosphonamide complexes [(η-CMe)RuCl{(R'N)PR}] (3a-c) and [(η-CMe)Ru{(R'N)PR}](X) (4a-c) (a, R = Ph, R' = p-Tol; b, R = Et, R' = p-Tol; c, R = Ph, R' = Me. X = BF, PF or BAr) were synthesized. The elongated Ru-Cl bond in the 18ē complexes is shown to dissociate even in apolar solvents to form the corresponding 16ē cations, which can be readily isolated as salts with non-coordinating anions. The coordinatively unsaturated 16ē complexes are stable species due to efficient π-electron donation from the nitrogen atoms of the zwitterionic NPN-ligand. The ruthenium iminophosphonamides are moderately active in the ROMP polymerization of norbornene; the 16ē complexes 4a,b yield high molecular weight polymers (M∼ 300 × 10) with a narrow distribution M/M∼ 1.6, while the 18ē complexes 3a,b give polymers of lower molecular weight (M < 50 × 10) with a wider polydispersity index M/M∼ 2.5.

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Section: General Proceduresmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The half-sandwich 18- and 16-electron arene ruthenium iminophosphonamide complexes

et al. 2016

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“…9 In transition-metal chemistry this concept is today sometimes referred as ''post-metallocene'' chemistry. [11][12][13] In this context ligands that contain P-N units such as phosphoraneiminates (R 3 PN) À , [14][15][16][17][18] phosphinimines (R 2 PNR 0 ), [19][20][21][22][23] diphosphanylamides (R 2 PNPR 2 ) À , [24][25][26][27] and iminophosphonamides ((R 2 P(NR 0 ) 2 ) À , [28][29][30][31][32] attracted much attention in main-group and transition-metal chemistry.…”

Section: Introductionmentioning

confidence: 99%

Main-group and transition-metal complexes of bis(phosphinimino)methanides

Panda

Roesky

2009

Chem. Soc. Rev.

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Bis(phosphinimino)methanides exhibit a wide variety of coordination chemistry with almost all elements in the periodic table. This critical review deals with the chemistry and coordination behavior of bulky monoanionic {CH(PPh(2)NR)(2)}(-) bis(phosphinimino)methanide and dianionic {C(PPh(2)NR)(2)}(2-) bis(phosphinimino)methanediide (R = SiMe(3), aryl) ligands focusing on s- and p-block as well as transition metals (109 references).

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“…The complexes bearing phosphorus auxiliary ligands have the potential for catalyzing the specific polymerization of conjugated dienes, because the introduction of a “large” and “soft” phosphorus donor is anticipated to increase the steric bulk and to lower the electron density of metal center, which is favored for initiating the polymerization of nonpolar monomers. Although Ti, Zr, Ni, etc., metal complexes with NPN-type ligands have been reported and their chemistry has been studied, the corresponding rare earth metal analogues are unknown, as far as we are aware. Herein, we wish to report the first example of NPN-type rare earth metal bis(alkyl)s, which in combination with [PhNHMe 2 ][B(C 6 F 5 ) 4 ] and Al i Bu 3 act as the first non-Cp group 3 metal precursors for the 3,4-selective polymerization of isoprene.…”

Section: Introductionmentioning

confidence: 99%

New Rare Earth Metal Bis(alkyl)s Bearing an Iminophosphonamido Ligand. Synthesis and Catalysis toward Highly 3,4-Selective Polymerization of Isoprene

Tang

Dong

et al. 2008

Organometallics

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Newrareearthmetalbis(alkyl)complexes[(NPN Ph )Ln(CH 2 SiMe 3 ) 2 (THF)](NPN Ph :N(Ph)PPh 2 dNC 6 H 2 Me 3 -2,4,6; Ln ) Sc (3a), Ln ) Y (3b), Ln ) Lu (3c)) and [(NPN Py )Sc(CH 2 SiMe 3 ) 2 (THF)] (NPN Py ) N(Py)PPh 2 dNC 6 H 2 Me 3 -2,4,6) (3d)) have been prepared via protonolysis reaction between rare earth metal tris(alkyl)s and the corresponding iminophosphonamines. Complexes 3a-d are analogous monomers of THF solvate. Each metal ion coordinates to a η 2 -chelated NPN ligand and two cis-located alkyl groups, adopting tetrahedron geometry. The scandium complex [(NPN Ph )Sc(CH 2 SiMe 3 ) 2 (THF)] in combination with [PhNHMe 2 ][B(C 6 F 5 ) 4 ] and AliBu 3 forms the first non-Cp-ligated rare earth metal based catalyst system to provide extremely high activity and 3,4-selectivity for the polymerization of isoprene. The resultant high molecular weight polymer (M n ) 99 × 10 4 ) with narrow molecular weight distribution (PDI ) 1.55) has a 3,4-regularity up to 94.7% (Tp ) -40°C, toluene, 2 h, 100% yield). The complexes 3b and 3c, with a larger ionic radius, are less regioselective, and 3d, with an electron-donating pyridyl moiety, is inert. The probable initiation species and mechanistic scenario are also presented.

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Titanium and zirconium complexes with aminoiminophosphorane ligands

Cited by 9 publications

References 24 publications

The half-sandwich 18- and 16-electron arene ruthenium iminophosphonamide complexes

The half-sandwich 18- and 16-electron arene ruthenium iminophosphonamide complexes

Main-group and transition-metal complexes of bis(phosphinimino)methanides

New Rare Earth Metal Bis(alkyl)s Bearing an Iminophosphonamido Ligand. Synthesis and Catalysis toward Highly 3,4-Selective Polymerization of Isoprene

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