Zirconium complexes having a chiral phosphanylamide in the co-ordination sphere

Abstract

The chiral phosphanylamido ligand, (N(CHMePh)(PPh2))-, has been introduced into co-ordination chemistry. As starting material the oily amines HN(R-*CHMePh)(PPh2)(1a) and HN(S-*CHMePh)(PPh2)(1b) were used. To reconfirm their absolute structure, 1b was oxidized with H2O2 in air to obtain HN(S-*CHMePh)(P(O)Ph2)(2) as a solid compound. The solid-state structure of 2 was established by single-crystal X-ray diffraction. The lithium salts of both enantiomers Li(N(R-*CHMePh)(PPh2))(3a) and Li(N(S-*CHMePh)(PPh2))(3b) were prepared by deprotonation reaction of 1a,b. Compounds 3a,b were further reacted with zirconocen dichloride to give the chiral metallocenes [(eta5-C5H5)2Zr(Cl)(eta2-N(R-*CHMePh)(PPh2))](4a) and [(eta5-C5H5)2Zr(Cl)(eta2-N(S-*CHMePh)(PPh2))](4b). In an alternative approach to give chiral zirconium compounds, the neutral amine 1b was reacted with [(PhCH2)4Zr] to give the enantiomeric pure complex [(PhCH2)3Zr(eta2-N(S-*CHMePh)(PPh2))](5). The solid-state structures of all zirconium complexes were determined by single-crystal X-ray diffraction.

Synthesis and Structure of Potassium and Barium Complexes With Diphenylphosphinothioicamido Ligand Containing Ba-S Direct Bonds

“…20 The phosphineamine, A, can coordinate to the metal through the nitrogen atom and phosphorus atom resulting a highly strained three member metallacycle and reported by Roesky and others. [21][22][23][24][25] The phosphineamine chalcogenides, A-NPO, A-NPS, and A-NPSe, can either form a four member metallacycle if the nitrogen and chalcogen atom (O, S, Se) coordinate to the metal center, or it can form two fused three member metallacycle to stabilized the metal complexes and it is observed by us in alkali metal as well as heavier alkaline earth metal complexes. 19,20 Thus, due to the presence of adjacent three potentially donor atoms, polymetallacyclic structural motif of the metal complexes can be observed.…”

Chiral alkaline earth metal complexes with M–Se direct bond (M = Mg, Ca, Sr, Ba): syntheses, structures and ε-caprolactone polymerisation

“…-butadiene in the literature. 18 The observed Ca-Se bond distances of 3.0303(9) and 3.0794(9)Å for 4a and 3.0327 (15) and 3.0817(14)Å for 4b are slightly elongated but within the range of the reported Ca-Se distance of 2.9889 8 20,21 The considerably elongated Ca-P distance of 3.2960(13), 3.3013(11)Å in 4a and 3.295(2), 3.3069(19)Å in 4b, was greater than the sum of the covalent radii of calcium and phosphorus (3.07Å), indicating no interaction between calcium and phosphorus atoms. The P]Se distances [2.1444(10), 2.1389(10)Å for 4a and 2.1443 17, 2.1420 16 5, 2.394(5)Å for 4b to adopt the calcium atom distorted octahedron geometry.…”

“…14a 1a. P1-Se1 2.1219 (15), P1-N1 1.671(5), P1-C9 1.818(6), P1-C15 1.815(6), C1-N1 1.454(7), C1-C2 1.551(10), C1-C3 1.517(9), N1-P1-Se1 116.4(2), C9-P1-C15 106.5(3), C9-P1-Se1 111.0(2), C15-P1-Se1 112.8(2), C9-P1-N1 105.7(3), C15-P1-N1…”

Alkene Polymerization Catalysts Bearing Tridentate Phenoxyamine Ligands with sp3 C Donors

“…The solid-state molecular structure ( Figure 5) revealed a distorted tetrahedral coordination geometry about titanium. [29] Furthermore, the short Ti1ÀC7 distance (2.560(5) ) and significant bending of the phenyl ring adjacent to the titanium-bound alkene towards the metal center (aC7-C31-Ti1: 89.3 (3)8) suggest that there is h 3 -coordination of this substituent as well. This binding mode has been reported for neutral electron-deficient zirconium complexes.…”

“…This binding mode has been reported for neutral electron-deficient zirconium complexes. [29] Furthermore, the short Ti1ÀC7 distance (2.560(5) ) and significant bending of the phenyl ring adjacent to the titanium-bound alkene towards the metal center (aC7-C31-Ti1: 89.3(3)8) suggest that there is h 3 -coordination of this substituent as well. The p bonding of the benzyl s ligand, in addition to the p bonding of the supported tridentate ligand, is a result of the electron-deficient character of the titanium metal center.…”