Bimetallic nickel complexes of macrocyclic tetraiminodiphenols and their ethylene polymerization

Dinickel Bisphenoxyiminato Complexes for the Polymerization of Ethylene and α-Olefins

“…7,11,17–24 With systems a and b , ethylene polymerization activities are similar to mononuclear controls, but enhanced comonomer incorporation and activity occur in the copolymerization of ethylene with functionalized norbornene derivatives. 19,20 When activated with MAO, system e produces polymer with higher M w than some previously reported mononuclear systems. 21 Complex f (R = Ph) shows increased ethylene polymerization activity compared to a mononuclear system studied under the same conditions and produces polymers with higher M w , but broader molecular weight distributions.…”

“…The measured or proposed Ni–Ni distance varies from 3.1 Å ( h ) to between 7.5–8.5 Å ( c , d , e , and f ). 11,18,19,21–24 Analysis of the solid-state structures highlights the challenge in orienting the metal centers such that they would react cooperatively with substrates. For some of the reported systems the metals are found in geometries that make intramolecular cooperativity unlikely.…”

10,21-Dimethyl-2,7,13,18-tetraphenyl-3,6,14,17-tetraazatricyclo[17.3.1.18,12]tetracosa-1(23),2,6,8(24),9,11,13,17,19,21-decaene-23,24-diol cyclohexane 0.33-solvate

“…For information on phenol-based Schiff base ligands, complexes and their applications, see: Vigato et al (2007); Fenton et al (2010); Avaji et al (2009);Na et al (2006); Dutta et al (2004); Mandal et al (1989); Gupta et al (2002Gupta et al ( , 2010 Table 1 Hydrogen-bond geometry (Å , ). Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.…”

“…Schiff bases have played an important role in the development of coordination chemistry related to catalysis and enzymatic reactions, magnetism and supramolecular architectures (Vigato et al, 2007;Fenton et al, 2010;Avaji et al, 2009;Na et al, 2006;Dutta et al, 2004;Mandal et al, 1989). Very recently we have reported a dinuclear copper (II) complex with a neutral tetraiminodiphenol macrocycle with a C2 lateral chain (Gupta et al, 2010).…”

Development of heterogeneous catalyst by ionically bonding macrocyclic Zr–Zr complex to montmorillonite clay for depolymerization of polypropylene

“…Macrocyclic complexes can be formed when a dialdehyde is reacted with diamines and some of the complexes utilized in the chemical reactions are presented in Table 1 [27][28][29][30][31][32][33][34][35][36][37][38]. In preparing various metal complexes, the size of the cavities for complexion are adjusted by selecting the ligands and the phenol group in the bridging ligand divides the over all cavity into two parts.…”