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A series of metal compounds (M = Al, Ti, W, and Zn) containing pyrrole-imine ligands have been prepared and structurally characterized. The reactions of AlMe3 with one and three equivs of pyrrole-imine ligand [C4H3NH-(2-CH=NCH2Ph)] ( 1) generated aluminum compounds Al[C4H3N-(2-CH=NCH2Ph)]Me2 ( 2) and Al[C4H3N-(2-CH=NCH2Ph)]3 ( 3), respectively, in relatively high yield. Reacting two equivs of 1 with Ti(O iPr)4, W(NH tBu)2(=N tBu)2, or ZnMe2 afforded Ti[C4H3N-(2-CH=NCH2Ph)]2(O iPr)2 ( 4), W[C4H3N-(2-CH=NCH2Ph)]2(=N tBu)2 ( 5), and Zn[C4H3N-(2-CH=NCH2Ph)]2 ( 6), respectively. All the compounds have been characterized by 1H and 13C NMR spectroscopy. Compounds 3- 6 have also been characterized by single-crystal X-ray structural analysis. The biting angles of pyrrole-imine ligand with metals decrease and their related MNpyrrole and MNimine bond lengths increase in the order of 6, 3, 4, and 5. [ABSTRACT FROM AUTHOR]

A series of aluminum complexes incorporating substituted symmetrical and asymmetrical tridentate pyrrolyl ligands are synthesized conveniently and the treatment of the derivatives with small organic molecules are analyzed. The reaction of lithiated [C4H2NH(2-CH2NHtBu)(5-CH2NR1R2)], where for 1, R1 = R2 = Me; 2, R1 = H, R2 = tBu, with AlCl3 in diethyl ether affords Al[C4H2N(2-CH2NHtBu)(5-CH2NMe2)]Cl2 (3) and Al[C4H2N(2,5-CH2NHtBu)2]Cl2 (4), respectively, in high yields. Furthermore, subjecting 3 and 4 to reaction with one equiv. of LiNMePh in diethyl ether generates Al[C4H2N(2-CH2NHtBu)(5-CH2NMe2)][NMePh]Cl (5) and Al[C4H2N(2,5-CH2NHtBu)2][NMePh]Cl (6), respectively, while eliminating one equiv. of LiCl. The reaction between compound 4 with two equiv. of LiO-Ph-4-Me in diethyl ether yields the aluminum di-phenoxide compound Al[C4H2N(2,5-CH2NHtBu)2](O-Ph-4-Me)2 (7) whereas the combination of 3 and two equiv. of LiNHtBu, produces Al[C4H2N(2-CH2NtBu)(5-CH2NMe2)](NHtBu)(NH2tBu) (8). Additionally, the mixing of 1 and one equiv. of AlMe3 renders Al[C4H2N(2-CH2NHtBu)(5-CH2NMe2)]Me2 (9). Adding one more equiv. of AlMe3 with 9 affords {Al[C4H2N(2-CH2NHtBu)(5-CH2NMe2)AlMe3]Me2} (10), which can also be obtained by treating 1 with two equiv. of AlMe3 directly. The treatment of 9 with one equiv. of 2,6-dimethylphenol in diethyl ether gives the aluminum alkoxide derivative, Al[C4H2N(2-CH2NHtBu)(5-CH2NMe2)](O-C6H3-2,6-Me2)Me (11). Furthermore, the reaction between 9 and one equiv. of 1-ethyl-1-phenyl ketene, initiates the aluminum dimethyl complex Al{C4H2N[2-CH2CEtPh-C(=O)-NHtBu](5-CH2NMe2)}Me2 (12) with a C–N bond breakage and a C–C bond formation. All the Al-derivatives are characterized by 1H and 13C NMR spectroscopy and the molecular structures are determined by single crystal X-ray diffractometry in solid state. [ABSTRACT FROM AUTHOR]

A trinuclear, doubly azido-bridged Cu(II) complex, [Cu1.50(L)(N3)3(CH3OH)]2, (LH = [(CH3)2NCH2CH2N=CHC6H3(OH) (OMe)]), has been synthesised and fully characterised by elemental analyses, IR, UV-Vis, EPR and DFT studies. Its single crystal X-ray structure reveals that adjacent CuII ions are linked by double end-on azido-bridges; thus the full molecule is generated by the site symmetry of a crystallographic two-fold rotation axis. [ABSTRACT FROM AUTHOR]

Highlights: [•] Tungsten imido compounds. [•] Bi-dentate pyrrole-amine and pyrrole-imine. [•] Bidentate ketimine ligands. [Copyright &y& Elsevier]

Abstract: The reactions of Zn-alkyls with bidentate as well as symmetrical and asymmetrical tridentate pyrrolyl ligands, have been carried out and characterized. Reacting ZnR2 with 1 equiv of C4H3NH(2-CH2NHtBu) in diethyl ether yields [Zn{C4H3N(2-CH2NHtBu)}R] (1, R = Me; 2, R = Et) in high yield. Similarly, the reactions of 2 equiv of C4H3NH(2-CH2NH t Bu) and ZnR2 (R = Me, Et) in toluene both produce [Zn{C4H3N(2-CH2NHtBu)}2] (3). Furthermore, while subjecting 2 equiv of C4H2NH(2-CH2NHtBu)(5-CH2NMe2) with ZnMe2 in diethyl ether, affords [Zn{C4H2N(2-CH2NHtBu)(5-CH2NMe2)}2] (4) and additionally, reacting C4H2NH(2,5-CH2NHtBu)2 with ZnMe2 generates [Zn{C4H2N(2,5-CH2NHtBu)2}2] (5) in satisfactory yield. All the aforementioned compounds were characterized by 1H and 13C NMR spectrometry and the molecular structures were determined by single crystal X-ray diffractometry. Compounds 1, 3, 4 and 5 are moderate catalysts for the ring-opening polymerization of ε-caprolactone in toluene. [Copyright &y& Elsevier]

Abstract: A series of zirconium and hafnium alkoxide and amide complexes containing symmetrical tridentate pyrrolyl ligand, [C4H2NH(2,5-CH2NMe2)2] have been synthesized conveniently by treatment of 2,6-di-tert-butylphenol, tert-butanol or pyrrole in pentane and their reactivity over ring opening polymerization of ε-caprolactone have been carried out. Reactions of [C4H2NH(2,5-CH2NMe2)2] with M(NEt2)4 (M = Zr or Hf) originate [C4H2N(2,5-CH2NMe2)2]M(NEt2)3 (1, M = Zr; 2, M = Hf). Furthermore, reactions of [C4H2N(2,5-CH2NMe2)2]M(NEt2)3 with 2,6-di-tert-butylphenol, tert-butanol or pyrrole afford [C4H2N(2,5-CH2NMe2)2]M(OC6H3-2,6- t Bu2)(NEt2)2 (3, M = Zr; 4, M = Hf), [C4H2N(2,5-CH2NMe2)2]M(O t Bu)3 (5, M = Zr; 6, M = Hf) and [C4H2N(2,5-CH2NMe2)2]M(C4H4N)3 (7, M = Zr; 8, M = Hf), respectively, in satisfactory yield. All the complexes have been characterized by NMR spectra as well 3, 4 and 6 subjected to the X-ray diffraction analysis. Complexes 3–8 have been used as initiators for the ring-opening polymerization of ε-caprolactone and observed broad PDI values (1.84–2.75) representing multiple reactivity centers of these complexes. [Copyright &y& Elsevier]

Abstract: Two novel iron and vanadium compounds, [OCMeCHCMeNAr]2Fe (1) and [OCMeCHCMeNAr]2VCl (2) have been synthesized by the reaction of FeCl2 with Li[OCMeCHCMeNAr] in THF and VCl3(THF)3 with OCMeCHCMeNHAr, in toluene and triethylamine, respectively, where Ar=2,6-diisopropylphenyl. Both the complexes have been systematically characterized by elemental analysis, NMR spectroscopy and exhibit paramagnetically shifted resonances, with relative intensities as expected for the η2-ketiminate ligands. Single crystal X-ray structural analysis reveals that compound 1 adopts a distorted tetrahedral geometry consisting with a C 2 symmetry where as in 2, the geometry around the vanadium atom can be described as a trigonal bipyramid. Concerning the atom-transfer radical polymerization behavior, complex 1 and 2 shows their catalytic activity on polymerization of methyl methacrylate (MMA) in toluene. [Copyright &y& Elsevier]