Copper(II) complexes containing N′-aromatic group substituted N,N′,N-bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)amines: Synthesis, structures, polymerization of methyl methacrylate and ring opening polymerization of rac-lactide

Diverse coordination geometry of cobalt (II), zinc (II), and cadmium (II) complexes comprising N,N‐bis(1H‐pyrazol‐1‐yl)methyl)amines derivatives: Synthesis, structures, and ring opening polymerization of rac‐lactide

“…[50,52,69,70] The M-N pyrazole , M-Cl, and M-Br bond lengths of these distorted tetrahedral complexes are in the ranges of 2.006(2)-2.252(3), 2.207( 9)-2.256(1), and 2.533( 6)-2.557(6) Å, respectively, and agree well with the accepted values. [50,52,69,70] . They were slightly affected by the amine substituents.…”

“…[48] In our recently published work, late-transition-metal complexes based on N,N-bis(1H-pyrazolyl-1-methyl) aniline derivatives were confirmed to exhibit promising activities and stereoselectivities. [49,50] Based on the importance of bis(1H-pyrazolyl-1-methyl)aniline derivatives and taking into consideration of work reported by our group and others, we herein explored the complexation of N,N-bis(1H-pyrazolyl-1-methyl)aniline derivatives with various N-aromatic-amine substituents to Zn (II), Co (II), and Cd (II) metals and their catalytic capabilities toward ROP of rac-LA.…”

Synthesis, structures, and catalytic efficiency in ring opening polymerization of rac-lactide with tridentate vs. bidentate cobalt(ii), zinc(ii), and cadmium(ii) complexes containing N-substituted N,N-bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)amine ligands

“…bonds appeared at the expected wavenumbers, based on literature data. 50,51,66 Additionally, the C-O bond stretching appeared in the 1110-1230 cm À1 wavenumber range, in the case of [L B MX 2 ] (M ¼ Zn(II) or Co(II), with X ¼ Cl; M ¼ Cd(II), with X ¼ Br). The absorption bands assigned to the stretching of the (C]N) pyrazole bond shied to higher wavenumbers in the FTIR spectra of [L n MX 2 ] complexes with respect to the corresponding (free) ligands, which suggests the possibility of a back-donation and the involvement of the nitrogen atoms of pyrazolyl or/and amine moieties in metal bonding.…”

“…3,5-Dimethyl-1 H -pyrazolyl-1-methanol was prepared as reported previously. 52 Notably, the ligands employed in the current study, L A 53 and L B , 54 and complex [L A CdBr 2 ] 51 were synthesized according to previously reported methods. It is important to note that safety protocol should be followed using cadmium bromide salt (CdBr 2 ·4H 2 O) for synthesis of Cd-complexes as they are highly toxic and mishandling can cause skin and respiratory irritation.…”

“…49 The catalytic capabilities of these complexes and the stereoselectivity they afforded were promising, and the relevant reactions yielded PLAs of moderate-to-high molecular weight. 50,51 In the present contribution, we intended to study the catalytic properties of N-substituted N,N-bis((3,5-dimethyl-1Hpyrazol-1-yl)methyl)amine-based Zn(II), Co(II), and Cd(II) complexes in the ROP of rac-LA.…”