title: Manganese coordination chemistry of bis(imino)phenoxide derived [2 + 2] Schiff-base macrocyclic ligands.
abstract: The [2 + 2] Schiff-base macrocycles [2,2'-(CH2CH2)(C6H4N[double bond, length as m-dash]CH)2-2,6-(4-RC6H2OH)]2 ((R)H2), upon reaction with MnCl2 (two equivalents) afforded the bimetallic complex [Cl3Mn(μ-Cl)Mn((Me)H2)] (1) or the salt complex [Cl3Mn(NCMe)][MnCl((tBu)H2)] (2). Under similar conditions, use of the related [2 + 2] oxy-bridged macrocycle [2,2'-O(C6H4N[double bond, length as m-dash]CH)2-4-RC6H2OH] (II(R)H2), afforded the bimetallic complexes [(MnCl)2II(R)] (R = Me 3, tBu 4), whilst the macrocycle derived from 1,2-diaminobenzene and 5,5'-di-tert-butyl-2,2'-dihydroxy-3,3'-methylenedibenzaldehyde (H4) afforded the complex [(MnCl)2(III)]·2MeCN (5·2MeCN). For comparative studies, the salt complexes [2,6-(ArNHCH)2-4-MeC6H2O][MnCl3(NCMe)] (Ar = 2,4-Me2C6H3, 6) and {[(2-ArN[double bond, length as m-dash]CH),6-(ArNHCH)-4-Me-C6H2O]MnCl}2[MnCl4]7·8CH2Cl2 (Ar = 4-MeC6H4, ·8CH2Cl2) were prepared. The crystal structures of 1 - 7 are reported (synchrotron radiation was necessary for complexes 1, 3 and 5). Complexes 1 - 7 (not 5) were screened for their potential to act as pre-catalysts for the ring opening polymerization (ROP) of ε-caprolactone; 3, 4 and 6, 7 were inactive, whilst 1 and 2 exhibited only poor activity with low conversion (<15%) at temperatures above 60 °C.
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China. C.Redshaw@hull.ac.uk.
authors.forename: Wenxue
authors.initials: W
authors.lastname: Yang
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China. C.Redshaw@hull.ac.uk.
authors.forename: Ke-Qing
authors.initials: KQ
authors.lastname: Zhao
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China. C.Redshaw@hull.ac.uk.
authors.forename: Bi-Qin
authors.initials: BQ
authors.lastname: Wang
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China. C.Redshaw@hull.ac.uk and Department of Chemistry, The University of Hull, Cottingham Rd, Hull, HU6 7RX, UK.
authors.forename: Carl
authors.initials: C
authors.lastname: Redshaw
authors.affiliation: Chemistry Department, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK.
authors.forename: Mark R J
authors.initials: MR
authors.lastname: Elsegood
authors.affiliation: Department of Applied Chemistry, Saga University, Saga, 840-8502, Japan.
authors.forename: Jiang-Lin
authors.initials: JL
authors.lastname: Zhao
authors.affiliation: Department of Applied Chemistry, Saga University, Saga, 840-8502, Japan.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Yamato